CN108386154B - Well completion conversion casing head - Google Patents

Abstract

The overall structure of the device of the invention combines the advantages of the mandrel type casing head and the slip type casing head to form a well completion variable casing head, and forms more variable connection, sealing, installation and other structures aiming at a complex well completion wellhead on the basis of the structure of a coupling type casing head; for another example, the advantages of the BT sealing technology are integrated into the special-shaped variable-installation wellhead sealing flange, and sealing combination structures such as special-shaped sealing elements and the like are derived; for another example, the modified wellhead sealing flange and the deformed modified wellhead sealing flange can be applied to modified structures such as standard flanges of standard types, and non-standard double flanges, welding flanges and threaded flanges which are commonly used in the well completion process.

Description

Well completion conversion casing head

Technical Field

The invention belongs to the technical field of casing heads, and particularly relates to a well completion conversion casing head.

Background

The casing head product is a well mouth guarantee condition which must be provided in oil and gas well drilling and production operation, mainly meets the requirement that a well mouth blowout preventer group must be installed in a matched manner for preventing 'blowout' in the drilling operation, provides effective well mouth connection for the production and transportation operation, and provides a safe, efficient and convenient ground and underground effective communication mode for multiple engineering operations. After many researches and innovations in the development history of casing head products, the connection between the casing head products and a casing string entering a well cannot be separated according to the structural characteristics of the casing head products, however, along with the innovation of drilling process contents, the combination form of a wellhead device is required to be diversified, the functional requirements of later-stage well repair and production operations on the wellhead device are increased, and the functional requirements on the casing head products are increased accordingly. Slip-type casing heads and mandrel-type casing heads are mainly used in the prior art. The two types of casing heads have the following disadvantages:

(1) the slip type casing head has the advantages of complex structure, high manufacturing cost and higher selling price, and users are generally limited to the exploration well type with more casing layers;

(2) the well mouth installation of the slip type casing head can be carried out in a long time at the later stage of well cementation operation, the waiting time is long, a blowout preventer well mouth device needs to be repeatedly disassembled and installed, the operation is troublesome, and the safety risk is high;

(3) the slip type casing head is connected with a casing in a manner of cutting the casing body, and then well completion handover is calculated, an injection molding type sealing structure is adopted to be butted with the casing body, and for the injection molding type sealing structure, special tools and technical personnel are required to be equipped for field service, so that the content is more, the operation is troublesome, the later-stage replacement operation is complex, and the performance and the durability of the sealing structure are controversial;

(4) the configuration of the wellhead of the slip type casing head only meets the requirement of a flange (unique) form, so that inconvenience is caused in the later mining and transportation operation due to the fact that the connection mode needs to be replaced;

(5) the mandrel type casing head requires accurate control on the position of the mandrel hanger, the difficulty of selecting and matching the casing string entering a well by an operation party is increased, particularly the position of the last casing which is put into the well must be ensured that the hanger can be accurately seated at the design position of the flange of the casing head body, otherwise abnormal working conditions can occur, and the subsequent processing is complicated;

(6) along with the increase of the types of the directional wells and the horizontal wells, the weight loss phenomenon of a casing string in the well in cement slurry is increased, so that a hanger cannot seat and seal the design position of a casing head, a drilling user is very troublesome in the face of the phenomenon, the field maintenance and treatment process of a casing head manufacturer is complex, and the repair cost is high;

(7) the problem of excessive short section of the mandrel exists when the mandrel hanger of the mandrel type casing head is connected with the casing, thread gluing or other damage phenomena are easily caused due to different materials of the short section of the mandrel and the casing, disputes and disputes are formed due to poor identification of damage reasons, and the use and the sale of the casing head products at the later stage are directly influenced;

(8) the well completion wellhead of the mandrel hanger is also in a female thread connection mode, the processing technology of the female thread damage is very troublesome, the power and gas welding are very inconvenient, the safety and welding quality risks exist, the ground exposure height of the wellhead can be increased, the cost is increased for the ground engineering of the later oil production operation, and the first party is difficult to receive or does not receive well completion transfer at all;

(9) when a Christmas tree or other engineering operation devices are installed on a well completion wellhead in a female thread connection mode, a male thread short section needs to be additionally arranged, the Christmas tree device is in flange connection, the conversion is somewhat redundant, the thread short section excessively forms a heavy-end and light-foot shape, a lot of damage is formed on threads, particularly, the threads are accelerated to be damaged by screwing up and off for many times, and the same result as that of the (7) th and (8) th threads occurs.

The present invention is an improvement based on the above technical problems.

Disclosure of Invention

The invention aims to solve the problem of developing a novel casing head product with a rich structure, promoting the technical progress of the industry, adding two or more forms on the basis of the well head form of the well completion of the original casing head product, endowing the novel product with preventive measures, adapting to the connection with the new process of the current drilling and oil extraction operation, and improving and enhancing the functions of the product to a greater extent.

In order to solve the technical problems, the invention adopts the technical scheme that:

the well completion modified casing head comprises a production casing, a casing hanger, a body flange and a protection device; the production casing is fixedly arranged in the casing hanger, the casing hanger is seated in the body flange, and the protection device is fixedly arranged above the body flange;

the casing hanger comprises a rubber plate pressing plate, a sealing rubber plate, a slip tooth pressing cover and a hanger body which are sequentially arranged from top to bottom, wherein the rubber plate pressing plate, the sealing rubber plate and the slip tooth pressing cover penetrate through the hanger body through a pressing plate bolt, are screwed and fixed by a pressing plate bolt square section, are screwed, compacted and fixed through a pressing plate nut, and slip teeth for tightly holding the production casing are fixedly arranged below the slip tooth pressing cover;

the outer periphery of the hanger body comprises an upper cylindrical section, a conical section and a short cylindrical section which are sequentially connected from top to bottom;

the body flange is internally provided with a main drift diameter hole, an upper smooth section, a setting taper section and a middle smooth section are arranged in the main drift diameter hole from top to bottom, and the setting taper section is matched with the taper section on the hanger body to form setting.

Furthermore, the sealing rubber plate is of a circular ring structure, and the upper surface of the sealing rubber plate is an upward convex arc surface.

Further, the hanger body is provided with a plurality of spring mounting holes and spring screw holes which are vertically communicated, the spring screw holes are located in the lower portions of the spring mounting holes, compression springs are mounted in the spring mounting holes, the top ends of the compression springs are abutted to the lower surface of the slip tooth gland, spring screws are mounted in the spring screw holes, and the top ends of the spring screws are abutted to the bottom ends of the compression springs and are fixed in the spring screw holes.

Further, a plurality of hanger lock pins are annularly arranged on the upper portion of the body flange, and when the casing hanger is seated in the body flange, the hanger lock pins are abutted to the outer surface of the pressing plate nut.

Furthermore, the slips are conical structures and comprise three independent coupling slips, a guide clamping block is arranged on each coupling slip, a slip guide groove matched with the guide clamping block is correspondingly arranged in a slip gland, and the tooth surface of each slip is abutted to the periphery of the production casing.

Furthermore, a plurality of side circulation holes are annularly formed in the lower portion of the body flange, and a local plane used for being connected with the side flange is arranged on the outer side face of each side circulation hole.

Further, the production casing comprises a casing body and a casing collar fixedly arranged on the upper part of the casing body.

The invention also discloses a casing coupling hanger, wherein the slip teeth in the casing coupling hanger are coupling slip teeth, the coupling tooth surfaces of the coupling slip teeth are abutted against the periphery of a casing coupling, a plurality of jackscrews are annularly arranged on the short cylindrical section at the lower part of the casing coupling hanger, a vertically through coupling through hole and a casing hanging hole are formed in the casing coupling hanger, the casing coupling is fixedly arranged in the coupling through hole through the clasping action of the coupling slip teeth, and the casing body is locked in the casing hanging hole through the jackscrews.

Furthermore, the coupling tooth surface consists of a plurality of longitudinal tooth grooves which are annularly arranged.

The invention also discloses a casing body hanger, wherein the slip teeth in the casing body hanger are body slip teeth, the body tooth surface of the body slip teeth is abutted against the periphery of the casing body, the short cylindrical section at the lower part of the casing body hanger is provided with a locking mechanism, the casing body hanger comprises a casing hanging hole which is communicated up and down, and the casing body is fixedly arranged in the casing hanging hole through the holding effect of the body slip teeth and the locking effect of the locking mechanism.

Furthermore, the tooth surface of the body is of a single-row tooth, circumferential and multi-layer hierarchical structure.

Further, the locking mechanism is one of a push rod locking mechanism or a connecting rod locking mechanism.

The ejector rod locking mechanism is an ejector rod pin, an ejector rod threaded hole is formed in the casing body hanger, an ejector rod screw is arranged in the ejector rod threaded hole, a lock pin through hole is formed in a short cylindrical section of the lower portion of the casing body hanger, the ejector rod pin is arranged in the lock pin through hole, the ejector rod threaded hole is vertically communicated with the lock pin through hole, a 45-degree conical inclined surface is arranged at the end portion of the ejector rod pin and is in contact with a 90-degree direction axis line of the 45-degree conical inclined surface at the end portion of the ejector rod screw in a crossed mode, the ejector rod screw is adjusted to generate downward displacement, then the ejector rod pin is pushed through the conical inclined surface, and the end face of the ejector.

The connecting rod locking mechanism is a connecting rod pin, a connecting rod through hole is formed in the casing pipe body hanger, a connecting rod bolt is arranged in the connecting rod through hole, a lock pin through groove is formed in a short cylindrical section of the lower portion of the casing pipe body hanger, the connecting rod pin is arranged in the lock pin through groove, the connecting rod through hole is vertically communicated with the lock pin through groove, a rotating nut for adjustment is arranged on the upper portion of the connecting rod bolt, the rotating nut can lift or lower the connecting rod bolt in a rotating mode and is linked with the connecting rod pin in a linkage mode, the lower end of the connecting rod bolt is rotatably connected with one end of the connecting rod pin through the connecting rod pin, and the other end of the connecting rod pin can rotate relative to the.

The invention also discloses a protective cap, which is one of the protective devices and comprises a flange protective plate, a well mouth protective plate and a hanger protective plate; the flange protection plate is an annular steel plate and is connected with the body flange through a flange bolt, and a short circular tube connected with the wellhead protection plate is welded at the hollow part of the flange protection plate; the short round tube is provided with a cutting tape identification groove in a lathing manner, and the lower part of the cutting tape is provided with the hanger protection plate.

Furthermore, the middle part of the wellhead protection plate is provided with a hanging ring.

The invention also discloses a variable-assembly wellhead sealing flange which is one of the protection devices, a cone sealing cover is arranged in the variable-assembly wellhead sealing flange, and the variable-assembly wellhead sealing flange is in sealing connection with the production casing through the matching of the cone sealing cover and the cone sealing piece.

Furthermore, the cone sealing cover is of a conical cylindrical structure with a small upper part and a large lower part, a flat circular bead surface is formed at the joint of the cone sealing cover and the flange through hole, and the inner conical cylinder surface of the cone sealing cover is in contact sealing with the outer conical surface of the cone sealing element.

Furthermore, the upper top end of the cone sealing element is provided with a hood top structure, the upper surface of the hood top is abutted against the shoulder surface of the platform, and the lower surface of the hood top is abutted against the upper end surface of the production casing.

The invention also discloses a special-shaped variable wellhead sealing flange which is one of the protection devices, a clamping section and a special-shaped sealing cover surface are manufactured on a flange through hole of the special-shaped variable wellhead sealing flange, a shoulder surface is formed between the section surfaces, the top of the production casing is positioned in the clamping section, a special-shaped sealing element is positioned in the special-shaped sealing cover surface, and the special-shaped variable wellhead sealing flange is in sealing connection with the production casing through the matching of the special-shaped sealing cover surface and the special-shaped sealing element.

Furthermore, the special-shaped sealing element comprises two special-shaped sealing rings which are arranged up and down, an isolating ring which is positioned between the two special-shaped sealing rings and an adjusting ring which is positioned on the lower surface of the lower special-shaped sealing ring, and a sealing observation hole which is communicated with the outer circular surface of the special-shaped variable-loading wellhead sealing flange is formed in the middle section of the special-shaped sealing cover surface.

Furthermore, the special-shaped sealing ring is annular, the upper part and the lower part of the special-shaped sealing ring are flat end surfaces, the outer circumference and the inner circumference are provided with slow pressing grooves, the outer circumference is contacted with the special-shaped sealing cover surface, and the inner circumference is contacted with the production sleeve.

Furthermore, the isolating ring is an upper flat end face and a lower flat end face, annular negative pressure grooves are formed in the inner circumferential face and the outer circumferential face of the middle section of the isolating ring, negative pressure small holes penetrating through the isolating ring are symmetrically formed in the ring circumferential face of each negative pressure groove, and the negative pressure small holes are communicated with the sealed observation holes.

Furthermore, the adjusting ring is of a rectangular annular structure, a plurality of adjusting threaded holes are uniformly formed in the circumference of the lower end face of the adjusting ring, adjusting screws are installed in the adjusting threaded holes, and the cap portions of the adjusting screws are abutted to the upper surface of the rubber plate pressing plate of the casing hanger.

Furthermore, the special-shaped sealing element also comprises a guide righting sleeve, when a gap exists between the production casing and the clamping section, the guide righting sleeve is positioned in the gap, and the guide righting sleeve is of a rectangular annular structure.

It should be noted that the overall structure of the device of the invention combines the advantages of the mandrel type casing head and the slip type casing head to form a coupling type casing head, and on the basis of the structure of the coupling type casing head, more structures such as connection, sealing, installation and the like aiming at a complex well completion modified well head are formed, and a plurality of connection and installation plans are pre-designed aiming at well head complexity possibly occurring on site, for example, a casing coupling hanger in the coupling type casing head is modified into a casing body hanger with stronger universality; for another example, the advantages of the BT sealing technology are integrated into the special-shaped variable-installation wellhead sealing flange, and sealing combination structures such as special-shaped sealing elements and the like are derived; for another example, the modified wellhead sealing flange and the deformed modified wellhead sealing flange can be applied to modified structures such as standard flanges of standard types, and non-standard double flanges, welding flanges and threaded flanges which are commonly used in the well completion process.

The invention takes the casing head installed in each well as a platform, develops the engineering content related to a plurality of operations in the later period of well completion as a research subject, enriches the functions of casing head products, improves the product performance of the casing head, reduces the time required by the installation link, reduces the labor intensity, the safety risk and other superior performances as design content, and gives more sharing and interchangeability to novel products to form novel products such as a casing collar meeting the requirements of hanging, connecting and sealing production of a casing, a dual-function type cone sealing element and a special-shaped sealing element of a casing body, and further expands the concept, function and form of 'well completion changing and assembly well mouth' of the casing head products, and the products and the structures have interchangeability and universality. The device can meet and adapt to the complex backgrounds of a plurality of wellheads on site, provides a pretreatment technology, and creates a well completion modified wellhead platform.

The invention not only improves the applicability, functionality and universality of the product, but also simplifies the structure, the manufacturing cost is not increased, and the invention develops the 'coupling type casing head' by showing the shaft which is formed by the material of the production casing at the well completion well head, and further forms a series of structures and products such as a 'casing coupling hanger', 'casing body hanger', 'casing sealing combination structure' and the like aiming at the conditions which appear or possibly appear at the two forms of the connection casing coupling and the casing body, and the structural products are installed and connected aiming at the well head required by the later oil production and the well drilling and repairing operation to form the 'well completion variable-installation casing head' of the invention.

The well completion conversion casing head has the following beneficial effects:

(1) the well completion wellhead is changed into a casing coupling type from a mandrel hanger thread type, the mode of hanging a casing by a mandrel hanging type casing head is changed, the casing coupling is directly hung in a main drift diameter hole of the casing head, the phenomena of thread gluing and broken thread which are easily caused by self-made threads (male/female) on the mandrel hanger are eliminated, the quality qualification rate of the well completion wellhead is improved, the cause of damage of the wellhead can be more clearly identified, and the significance and the corresponding benefit on guiding and determining identification are provided for drilling construction units and casing head manufacturers;

(2) after the abnormal wellhead background appears, the casing collar can be hung by the casing collar hanger to be changed into a casing body hung by the casing body hanger, and a sealing and connecting relation is formed between the casing body and the casing body, so that the well completion wellhead can meet the operation requirement of a later-stage oil extraction process, the handover of the well completion wellhead is smoothly realized, the time efficiency is improved, and the complex background and difficulty in well completion are relieved;

(3) the variable wellhead sealing flange can be changed into any flange structure of a BT sealing flange, a standard flange, a double flange, a welding flange, a threaded flange and the like according to the requirements of a well completion site, and forms a sealing effect with a production casing through a cone sealing element and a special-shaped sealing element;

(4) in the prior art, a blowout preventer and a cutting sleeve body need to be disassembled firstly in well completion operation, and a BT sealing flange is additionally assembled, so that the whole process is complicated; the casing head can realize the disassembly of the coupling top section before the blowout preventer is disassembled, further provides loose and safe operating environment and convenience for the disassembly of a wellhead blowout preventer and the like, reduces the cutting phenomenon of the production casing or the coupling top section, does not need to be provided with complex cutting facilities and does not need to finely process the wellhead forming degree of the cutting casing, and saves the cost and the time.

Drawings

FIG. 1 is a schematic view of an example wellhead modified by a collar-type casing head;

FIG. 2 is a schematic structural view of the casing head body flange 1 installed in FIG. 1;

FIG. 3 is a schematic view of the casing head hanger latch 11 assembly of FIG. 1;

FIG. 4A is a schematic diagram of the construction of the casing head casing collar hanger 15 assembly installed in FIG. 1, and FIG. 4B is a schematic diagram of a socket wrench 1533 used in conjunction with a pressure plate bolt;

FIG. 5 is a schematic view of the hanger body part of the casing collar hanger 15 of an embodiment;

FIG. 6 is a schematic diagram of an exemplary compression spring 1510 assembly;

FIG. 7A is a schematic view of an embodiment of a slip gland 1512, FIG. 7B is a schematic view of a slip guide channel 1531 in cross-section, and FIG. 7C is a schematic view of the slip guide channel in cross-section from the side of FIG. 7A;

FIG. 8A is a schematic view of the configuration of coupling slip teeth 1513 of casing collar hanger 15, FIG. 8B is a schematic view of the configuration of coupling tooth surface 1528, and FIG. 8C is a schematic view of the cross-section of FIG. 8A in the direction A-A;

FIG. 9 is a schematic structural view of a sealing rubber sheet 1514 in the example;

FIG. 10 is a schematic structural diagram of a rubber plate pressing plate 1515 in the embodiment;

FIG. 11 is a schematic diagram of the structure of the platen bolts 1516 according to the embodiment;

FIG. 12 is a schematic diagram of the construction of the embodiment of the hanger pin 11 and casing collar hanger 15 assembly;

fig. 13 is a schematic structural view of the wellhead protective cap 12 in the embodiment;

FIG. 14 is a schematic structural view of a surface double male nipple 501 connected with the female thread section 5 in FIG. 2;

FIG. 15 is a schematic diagram of the installation configuration of the casing collar hanger 15 assembly with production casing in an embodiment;

FIG. 16 is a schematic diagram of an embodiment of the casing collar hanger 15 in an abnormal wellhead background condition;

FIG. 17 is a schematic representation of an alternate wellhead of casing body hanger 1500 in an embodiment;

FIG. 18 is a schematic structural view of a casing body hanger 1500 of an embodiment;

FIG. 19 is a schematic diagram of the construction of the hanger body in the casing body hanger 1500 of an embodiment;

FIG. 20A is a schematic representation of the configuration of the body slips 1537 of the casing body hanger 1500 of the example embodiment, and FIG. 20B is a schematic representation of the configuration of the body flanks 1538 of the body slips 1537;

FIG. 21A is a schematic diagram illustrating the structure and principle of a pin locking mechanism of the casing hanger 1500 according to an embodiment;

fig. 21B is a schematic structural and schematic diagram of a link locking mechanism of the casing hanger 1500 according to an embodiment, wherein a link socket wrench 1550 is used with the link locking mechanism;

FIG. 22 is a schematic representation of a prior art BT sealing flange used with an embodiment of a casing body hanger 1500;

FIG. 23 is a schematic view of the structure of the cone seal 51 in the embodiment;

24A, 24B, 24C are schematic views of the sealing assembly of the cone seal 51 and the production casing in the embodiment, wherein FIG. 24A is the clamping assembly of the cone seal 51 and the casing collar 16; FIG. 24B is the retaining assembly of the cone seal 51 and the sleeve body 17; FIG. 24C is a schematic view of the mating relationship of the cone seal 51 to the modified wellhead sealing flange 30;

FIG. 24D is a schematic view of the sealing assembly of the standard flange 33 with the production casing via the cone seal 51 according to the embodiment; FIG. 24E is a schematic view of the sealing assembly of the double flange 37 with the production casing via the cone seal 51 in the embodiment; FIG. 24F is a schematic view of the sealing assembly of the welding flange 40 with the production casing via the cone seal 51 according to the embodiment; FIG. 24G is a schematic view of the sealing assembly of the threaded flange 42 with the production casing via the cone seal 51 according to the embodiment;

FIG. 25 is a schematic view of the combination of the modified wellhead sealing flange 55 with the casing collar 16 via a modified sealing member according to the embodiment;

FIG. 26 is a schematic view of the assembly structure of the special-shaped modified wellhead sealing flange 55 and the casing body 17 through a special-shaped sealing element in the embodiment;

FIG. 27 is a schematic structural diagram of a modified wellhead sealing flange 55 in an embodiment;

FIG. 28 is a schematic structural view of a profiled sealing ring 61 in an embodiment;

FIG. 29 is a schematic structural view of an embodiment of a spacer ring 64;

FIG. 30 is a schematic view of the adjusting ring 58 of the embodiment;

FIG. 31 is a schematic structural view of a guide centering sleeve 69 according to an embodiment;

fig. 32 is a schematic structural diagram of a metal seal ring 70 in an embodiment.

In the figure:

1. the device comprises a body flange, 2, an upper smooth section, 3, a setting taper section, 4, a middle smooth section, 5, a female thread section, 6, a main through hole, 7, a side circulation hole, 8, a side flange, 9, a side hole bolt, 10, a side hole steel ring groove/steel ring, 11, a hanger lock pin, 12, a protective cap, 13, a flange bolt, 14, a flange steel ring groove/steel ring, 15, a sleeve collar hanger, 16, a sleeve collar, 17, a sleeve body, 18, a production sleeve through hole, 19, a wire planting hole, 20, a bolt hole and 21, a lifting ring;

1101. a lock pin thread section 1102, a lock pin smooth section 1103, a lock pin sleeve 1104, a lock pin sealing member 1105, a lock pin square section 1106, a lock pin sleeve external thread 1107, a lock pin sleeve internal thread 1108, a lock pin hole 1109, a lock pin hole internal thread;

301. a conical section, 302, an annular groove, 303, a rubber ring, 304, a soft metal ring;

401. an upper cylindrical section;

501. surface layer double male short sections, 502, short section male threads, 503, surface layer through holes;

901. a side hole bolt hole;

1201. flange protection plate, 1202 wellhead protection plate, 1203 hanger protection plate, 1204 casing collar through hole, 1205 bolt hole, 1206 cutting belt, 1207 short round pipe;

1501. short cylindrical section 1502, jackscrew, 1503, jackscrew through hole, 1504, jackscrew threaded hole, 1505, casing hanger hole, 1506, inner conical surface, 1507, inner shoulder surface, 1508, spring mounting hole, 1509, spring screw hole, 1510, compression spring, 1511, spring screw, 1512, slip gland, 1513, collar slips, 1514, seal plate, 1515, plate clamp, 1516, clamp bolt, 1517, clamp nut, 1518, feed through hole, 1519, clamp bolt tapped hole, 1520, cylindrical shoulder section, 1521, coarse thread, 1522, seal plate outer cylindrical surface, 1523, clamp bolt through hole, 1524, coupling through hole, 1535, seal plate upper end surface, 1526, seal plate lower end surface, 1527, guide dog, 1528, coupling tooth surface, 1529, cone, 1530, press plate, arc surface, 1531, tooth guide groove, 1532, slip ring riser rope, 1533, 1524, and bolt hole, 1535. fine thread, 1536 soft metal pad;

1500. the sleeve comprises a sleeve body hanger, 1537. a body slip tooth, 1538. a body tooth surface, 1539. a body through hole, 1540. a push rod operation hole, 1541a. a push rod threaded hole, 1541b. a connecting rod through hole, 1542. a push rod screw, 1543. a push rod pin, 1544. a connecting rod bolt, 1545. a connecting rod pin, 1546. a connecting rod shaft pin/hole, 1547a. a locking pin through hole, 1547b. a locking pin through groove, 1548. a rubber plug, 1549. a sealing flat gasket, 1550. a connecting rod sleeve wrench;

30. a wellhead sealing flange is changed and installed, 31 is a cone sealing cover, and 32 is a flange through hole;

33. standard flange, 34 gasket ring groove, 35 flange wire/hole, 36 protection plate;

37. double flanges, 38. cone lead-in surface, 39. flange, 40. welding flange, 41. welding section surface, 42. screw flange, 43. collar screw section;

44, a BT sealing flange, 45., a BT sealing cavity, 46, a BT sealing groove/ring, 47, an injection hole, 48, an injection joint, 49, an observation hole and 50, a pressure gauge interface/plug for BT sealing detection;

51. a cone sealing element, 52, a cone outer circular surface, 53, a sleeving coupling through hole, 54, a hood top;

55. the special-shaped variable-mounting wellhead sealing flange comprises a special-shaped variable-mounting wellhead sealing flange body 56, a sealing observation hole 57, a special-shaped sealing cover 58, an adjusting ring 59, a clamping section 60, a special-shaped sealing cover body 61, a special-shaped sealing ring 62, a pressure relief groove 63, a special-shaped sealing through hole 64, an isolating ring 65, a negative pressure groove 66, a negative pressure small hole 67, an adjusting threaded hole 68, an adjusting screw 68, a guiding and centering sleeve 69, a metal sealing ring 70, a front face deformation groove 71, a flat end face 72, a side face deformation groove 73 and a pressure gauge interface/plug 74 for special-shaped sealing detection.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In some embodiments, the body flange is as shown in fig. 1 and 2, the main through hole 6 is arranged in the middle of the body flange 1 and is used for drilling operation to pass drilling tools and tools, well completion operation to run in production casing 17, hang casing collar hanger 15 and other elements; the middle section of the body flange 1 is provided with (3 or 4) locking pin holes 1108 which are radial and communicated with the main through hole 6; the lock pin hole 1108 is connected with the outer circumferential surface of the body flange 1 to form a section of lock pin hole internal thread 1109, the central lines of the lock pin holes 1108 are mutually at a 120-degree or 90-degree central angle and are vertical to and pass through the central line of the main through hole 6; a hanger lock pin 11 assembling mechanism is arranged in the lock pin hole 1108 and used for fixing the sleeve pipe coupling hanger 15 to prevent the sleeve from loosening; the main drift diameter hole 6 is provided with an upper smooth section 2, a setting taper section 3, a middle smooth section 4 and a female thread section 5 from top to bottom; the upper smooth section 2 and the setting taper section 3 are respectively connected with the corresponding positions of the upper cylindrical section 401 and the conical section 301 of the hanger body; the lower female thread section 5 is matched with the short section male thread 501 to form thread sealing.

2 side circulation holes 7 which are radially and symmetrically distributed and penetrate through the lower part of the body flange 1 are formed in the smooth section 4 in the main drift diameter hole 6 and are used for realizing multiple operations of an annular space; the outside of the side circulation hole 7 is provided with a local plane, and the outer circumference of the plane is uniformly provided with (6) filament-planting holes 19 which can be connected with accessory elements such as a side flange 8 and the like.

As shown in fig. 2, an upper end face of the body flange 1 is provided with an annular flange steel ring groove/steel ring 14 for sealing and matching with other wellhead equipment (mainly a blowout preventer), and a plurality of bolt holes 20 which penetrate through the body flange 1 and are parallel to the central line of the main drift diameter hole 6 are evenly distributed on the outer circumference of the steel ring groove 14 for fastening other matched wellhead equipment.

In some embodiments, a schematic view of an assembled structure of a hanger pin is shown in fig. 3; the hanger lock pin 11 comprises a lock pin shaft, a lock pin sleeve 1103 and a lock pin sealing member 1104, wherein the lock pin sleeve 1103 and the lock pin sealing member 1104 are positioned on the periphery of the lock pin shaft, the lock pin shaft comprises a lock pin square section 1105, a lock pin thread section 1101 and a lock pin smooth section 1102 which are sequentially connected, the lock pin sleeve is in threaded connection with the lock pin thread section through lock pin internal threads, the lock pin smooth section 1102 is in contact with a lock pin hole 1108 and the inner circumferential surface of the lock pin sealing member 1104, and the outer circumferential surface of the lock pin sealing member 1104 is in contact with the lock pin hole 1108 and; the lock pin thread section 1101 is in contact with the lock pin sleeve internal thread 1107 to realize thread adjustment and locking; the locking pin sleeve external thread 1106 is in contact with the locking pin hole internal thread 1109, the locking pin sleeve external thread 1106 is formed by rotating the locking pin sleeve 1103 to extrude the locking pin sealing member 1104, and the locking pin hole 1108 is sealed with the annular space of the locking pin smooth section 1102; meanwhile, the position between the lock pin sleeve 1103 and the body flange 1 is locked, further, the displacement between the lock pin thread section 1101 and the lock pin sleeve internal thread 1107 is formed by rotating the lock pin square section 1105, and the front end of the lock pin smooth section 1102 is inserted into the main through-diameter hole 6.

In some embodiments, a casing collar hanger assembly is schematically illustrated in fig. 4A, 4B. In the figure, the casing collar hanger 15 comprises a hanger body, a jackscrew 1502, a compression spring 1510, a spring screw 1511, a slip-tooth gland 1512, coupling slip-teeth 1513, a sealing rubber plate 1514, a rubber plate press plate 1515, a press plate bolt 1516, a press plate nut 1517, a bail rope 1532, and a sleeve wrench 1533; the upper portion of the socket wrench 1533 is provided with a groove for clamping the square section 1534 of the pressing plate bolt 1516, and the lower portion is provided with a groove for clamping the pressing plate nut 1517. (1532, 1533 belongs to the product equipped with accessory components).

In some embodiments, a schematic structural view of the hanger body is shown in fig. 5; wherein, the outer circumference of the hanger body is provided with an upper cylindrical section 401, a conical section 301 and a short cylindrical section 1501 from top to bottom; the conical section 301 is provided with a soft metal ring 304 (or not) and an annular groove 302, and a rubber ring 303 is arranged in the groove and used for forming 'conical plug type' pressing, holding, fitting and sealing with the setting conical section 3 on the body flange 1; the middle part of the hanger body is provided with an inner conical surface 1506, an inner shoulder surface 1507 and a sleeve hanging hole 1505 from top to bottom; the inner conical surface 1506 is in contact with a slip tooth cone arc surface 1529 to realize the principle and function of 'cone surface sliding and wedge-shaped reducing clamping'; a soft metal pad 1536 is mounted on the inner shoulder surface 1507 and used for realizing rigid sealing after extrusion deformation with the flat shoulder surface at the lower end of the casing coupling 16; the middle section of the short cylindrical section 1501 is provided with 3 sets of jackscrew through holes 1503 and jackscrew 1502 locking mechanisms which are mutually 120-degree central angles, the jackscrew 1502 and the jackscrew threaded hole 1504 are in threaded fit and penetrate through the casing suspension hole 1505, the central lines of the jackscrew through holes 1503 and the two holes of the casing suspension hole 1505 are vertical and have an intersection point, the front end of the jackscrew is a plane, the rear end of the jackscrew is of an inner hexagonal structure, and the jackscrew 1502 can be pushed to displace by rotating the inner hexagonal end, so that the position locking with the casing body 17 is realized.

In some embodiments, the assembly structure of the hanger body to mount the compression spring is schematically shown in fig. 6, wherein the circumference of the upper end face of the hanger body is provided with 3 spring mounting holes 1508 and a spring screw hole 1509 which are mutually at 120 ° central angles and parallel to the central line of the casing hanging hole 1505, the spring screw hole 1509 is arranged below the spring mounting hole 1508, a compression spring 1510 is mounted in each spring mounting hole 1508, a spring screw 1511 is mounted in each spring screw hole, the spring screw 1511 is in contact with one end of the compression spring 1510 and fixed in the spring mounting hole 1508, the spring screw 1511 is relatively stable with the compression spring 1510 and the spring screw hole 1509, the other end of the compression spring 1510 is higher than the upper end face of the casing collar hanger 15 and keeps free contact with the lower end face of the slip gland 1512 to achieve a floating supporting effect, and further centralize, floating up and float the suspended coupling slip 1513, Supporting; the circumference of the upper end face of the casing coupling hanger 15 is further provided with (6 or 8) pressing plate bolt wire planting holes 1519 with 60-degree or 45-degree central angles, the pressing plate bolt wire planting holes 1519 are used for installing pressing plate bolts 1516, the spring installation holes 1508 are arranged between adjacent hole distances of the pressing plate bolt wire planting holes 1519, the pressing plate bolt wire planting holes 1519 and the spring installation holes 1508 do not form intersection points, and intersection points at the same position can be avoided by adopting methods such as different central angles or distributed circles.

In some embodiments, the slip gland is schematically configured as shown in FIGS. 7A, 7B, and 7C; the slip insert gland 1512 is annular, and the circumference of the ring body is provided with (6 or 8) pressure plate bolt holes 1530 which form 60-degree or 45-degree central angles with each other and are used for penetrating through pressure plate bolts 1516; the middle of the connecting hoop through hole 1524 is provided for penetrating through the casing connecting hoop 16 and the casing body 17; the upper end face is a plane, the lower end face is provided with 3 dovetail (wide upper part and narrow lower part) slip tooth guide grooves 1531 with a central angle of 120 degrees, the slip tooth guide grooves 1531 penetrate through a ring body of the slip tooth gland 1512, and the central line is vertical and passes through the central line of the coupling through hole 1524.

In some embodiments, the coupling slip elements are configured as shown in FIGS. 8A, 8B, and 8C; the coupling slip teeth 1513 are cone-shaped and cut into 1/3 circular arc structures, the upper ends of the guide clamping blocks 1527 are provided with 'dovetails' (the upper part is wide and the lower part is narrow), the guide clamping blocks 1527 are matched with 'dovetails' slip tooth guide grooves 1531 to realize guide, centering and suspension connection, the outer circle is a cone arc surface 1529, the inner circle is a coupling tooth surface 1528, the coupling slip teeth 1513 are respectively suspended on the three 'dovetails' slip tooth guide grooves 1531 to form a cylindrical coupling through hole 1524 for penetrating through the casing coupling 16; the coupling tooth surface 1528 contacts and grips the casing coupling 16; mutual support and fixation among the coupling slip teeth 1513, the slip tooth gland 1512, the pressure plate bolt 1516 and the hanger body are realized in matching series connection, and further fixation between the casing coupling 16 and the casing head body flange 1 is realized to prevent loosening and buckling rotation;

the coupling slip teeth 1513 are replaceable, and slip teeth adapted to the casing coupling 16 or casing body 17 may be replaced.

In some embodiments, a schematic diagram of the sealing rubber plate structure is shown in fig. 9, and as a preferred embodiment of this embodiment, the sealing rubber plate 1514 is in a circular ring shape, and the ring body is provided with (6 or 8) pressing plate bolt through holes 1523 which are mutually at 60 ° or 45 ° central angles, and the pressing plate bolt through holes correspond to the positions of the pressing plate bolt threading holes 1519 and are used for penetrating through the pressing plate bolts 1516; the sealing rubber plate 1514 has a certain thickness, a coupling through hole 1524 is formed in the center and is in contact with a casing coupling 16, the lower end face 1526 is a plane, and the upper end face 1525 is designed to be an upwards-convex circular arc face; the design has the advantages that: when the rubber part is extruded, the middle part has the processes of deformation and expansion before the edge part, different distribution states can be formed on the internal structure of the material for the extension of the whole rubber part, the contact area of the rubber part at the middle part is large, the bearing pressure is large, the rubber storage quantity is large, the deformation is large, the arc surface 1525 firstly contacts the rubber plate pressing plate 1515 and bears the pressure, the sealing is realized before the edge part is formed, the whole rubber is extruded to expand towards the edge, the bearing pressure of the rubber part body at the edge part is lagged and smaller, the deformation is less, and the original characteristics of the rubber part material can be better maintained; the discovery and utilization of this deformation characteristic is based on a study of the structure and materials of the present embodiment, a sublimation of the entire body deformation process and the resulting sealing principle that fills the inner and outer edges and gaps; the deformation and pressure-bearing characteristics of a deformation material (rubber body) are substantially utilized, the deformation probability that more gaps can be filled in all contact surfaces of the outer cylindrical surface 1522 of the sealing rubber plate and the coupling through hole 1524 is created for the sealing rubber plate 1514, the stress environment of the rubber body is improved, and the sealing pressure-bearing capacity and the service life of the rubber body are enhanced; the friction force formed by the rubber part and the whole contact plane in the deformation process is reduced structurally, the edge rubber part does not bear pressure in advance, the encircling sealing between the main drift diameter hole 6 and the casing collar 16 can be better realized, and the integral cone plug type pressing, holding, fitting and sealing is further formed with the casing collar hanger 15; the deformation and filling principle has the same sealing effect on all bolt through holes.

In some embodiments, the structure of the plywood platen is schematically shown in fig. 10; the structure of the rubber plate pressing plate 1515 is almost the same as that of the sealing rubber plate 1514, and the difference is that the rubber plate pressing plate 1515 is made of a steel plate, the upper end surface and the lower end surface are both planes, and the upper end surface 1525 of the sealing rubber plate is a circular arc surface; the pressing force generated by the pressing plate nut 1517 is uniformly distributed in a plane by the rubber plate pressing plate 1515, so that the pressing of the binding surface and the expansion extrusion to the periphery and the gap filling and sealing of the whole rubber part are realized.

In some embodiments, a schematic view of the platen bolts is shown in fig. 11; one end of the pressure plate bolt 1516 is provided with a fine thread 1535 which is matched with the pressure plate bolt wire-cutting hole 1519 of the casing collar hanger 15; the middle section is provided with a cylindrical shoulder section 1520, the outer diameter of the cylindrical shoulder section 1520 is larger than the diameters of the fine thread 1535 and the pressure plate bolt hole 1530, a flat shoulder surface is formed, and the flat shoulder surface is used for pressing the slip gland 1512; the other end is provided with a coarse thread 1521 which is matched with a standard component pressing plate nut 1517 and is used for pressing a rubber plate pressing plate 1515 and a sealing rubber plate 1514 to form sealing; a square section 1534 is formed at the upper part of the coarse thread 1521 and used for rotating a pressure plate bolt 1516, and a clamping and extruding structure is formed by screwing the fine thread 1535 and the platform shoulder surface of the cylindrical shoulder section 1520 to generate clamping force, so that clamping and extruding of the slip thread gland 1512 and the suspended coupling slip thread 1513 are realized, and the principle and the function of 'cone surface sliding and wedge-shaped reducing and clamping' are formed; the symmetry plane of the square section 1534 is provided with a threading hole 1518 for threading each bolt to prevent the loosening of the buckle and installing the lifting ring rope 1532.

In some embodiments, during the deformation expansion of the stripper rubber 1514, the fine external threads 1535 of the (6 or 8) stripper bolts 1516 engage the stripper plate threading holes 1519 and the platform shoulder surface of the intermediate cylindrical shoulder section 1520 presses against the upper surface of the slip gland 1512 to form a secure, press-fit connection; on the basis, each pressure plate bolt 1516 cylindrical shoulder section 1520 penetrates through the pressure plate bolt through holes 1523 of the sealing rubber plate 1514 and the rubber plate pressure plate 1515 to keep contact, and the installation sequence is the sealing rubber plate 1514, the rubber plate pressure plate 1515 and the pressure plate nut 1517; the pressing plate nut 1517 is matched with the external thread 1521 with the thick teeth of the pressing plate bolt 1516, a clamping and extruding structure is formed by pressing through threads, and the rubber plate pressing plate 1515 extrudes the sealing rubber plate 1514 to form the sealing environment and the pressing and holding sealing effect.

In well completion and well head installation, the pressure plate bolts 1516 are firstly tightened on the upper end face of the slip insert gland 1512 with force to realize the compression of the flat shoulder of the cylindrical shoulder section 1520 to the slip insert gland 1512, the extrusion of the slip insert gland 1512 to the coupling slip inserts 1513 is further transmitted, the principle and the function of 'cone surface sliding and wedge reducing clamping' are further realized through the cone cambered surface 1529 of the coupling slip inserts 1513 and the inner cone section 1506 of the casing coupling hanger 15, the casing coupling 16 is further fixed, and the balance and the flatness of the stress of the slip insert gland 1512 and the consistent height and the stress of the outcrop heads of the pressure plate bolts 1516 are confirmed; then, in the process of installing the sealing rubber plate, other sealing materials (oil, grease, paste and the like) with sealing property can be filled; when the components are correctly installed and do not have non-conformity, a sleeve spanner 1533 can be used for exerting a large force on the pressing plate nut 1517, the rubber plate pressing plate 1515 and the sealing rubber plate 1514 are further subjected to high-pressure strong extrusion to generate expansion deformation of the rubber part, the surrounding surface sealing between the main through hole 6 and the casing coupling 16 is further realized, and the whole cone plug type pressing, jointing and sealing on the conical section surface 301 is formed by the sleeve coupling hanger 15 and the connecting piece.

In some embodiments, the working principle diagram of the hanger pin and casing collar hanger assembly is as shown in fig. 12, the integral casing collar hanger 15 formed by serially connecting the pressure plate bolts 1516 is first sleeved on the casing body 17 and part of the casing collar 16, and then the casing collar hanger 15 is fed into the casing collar 16 to carry the casing collar hanger 15 into the casing head main bore 6 through the landing joint or the landing parameters (the landing joint is a casing of the same type connected to the upper part of the casing collar 16), so as to realize the "conical plug type" pressing fit sealing with the setting taper section 3. In order to prevent the interlocking casing coupling 16 from being loosened when the top section is detached, the casing coupling hanger 15 needs to be fixed, the square section 1105 of the lock pin is rotated to generate relative displacement between the matching threads 1101 and 1107, the smooth section 1102 of the lock pin is pushed to extend out of the lock pin hole 1108 and be inserted into the 6-section length of the main through hole to form a cross-shaped staggered overlapping fork with the square section 1534 of the press plate bolt 1516 or the press plate nut 1517, the casing coupling hanger 15 is limited to rotate by the hanger lock pin 11, the relative displacement between the casing body 17 and the surface casing is further limited, and the loosening prevention is realized; when the hanger lock pins 11 cannot rotate to the right position, the front ends of the smooth lock pin sections 1102 and the pressure plate bolts 1516 form intersection points, and the intersection points belong to a 'top dead' state, the phenomenon can be met only by one of the hanger lock pins 11, and the other hanger lock pins 11 are structurally designed to be in a central angle distribution mode.

In some embodiments, the protective cap 12 is shaped like a "straw cap" as shown in fig. 13, and includes a lifting ring 21, a flange protection plate 1201, a wellhead protection plate 1202, a hanger protection plate 1203, a casing collar through hole 1204, a bolt hole 1205, a cutting strip 1206; the hoisting ring is a gravity center point and a hoisting point of the casing head product; the flange protection plate 1201 is an annular steel plate, 4 or more flange bolt holes 1205 are uniformly distributed on the circumference of the flange protection plate and used for being connected with the body flange 1, and a short circular tube 1207 is welded at the hollow part; a cutting belt 1206 marking groove is formed in the short circular pipe 1207 in an upper turning mode and used for indicating a cutting position when a wellhead is opened in the later period, a wellhead protection plate 1202 is welded to the top end of the short circular pipe 1207, a hanger protection plate 1203 is welded to the lower section of the inner wall cutting belt 1206 at a proper position to protect all components of the casing collar hanger 15, and a casing collar through hole 1204 is formed in the center of the hanger protection plate 1203 and used for inserting a casing collar 16; during well completion, the flange bolt 13 penetrates through the bolt hole 1205 and the bolt hole 20, so that the protective cap 12 is connected with the body flange 1, and the integral wellhead consisting of the plane of the casing head body flange 1, the steel ring groove 14, the casing collar hanger 15 and the casing collar 16 is protected.

Although the shape and function of the protective cap are not important, the protective cap has the following advantages as the design of the embodiment is preferable: the completion riveting and welding solidification can be carried out on the connected flange bolts 13, and wellhead accidents and breakage phenomena caused by the fact that the flange bolts can be detached randomly under the condition that the field cannot be monitored are prevented; the information which is necessary to be kept in the well completion can be kept outside and inside the protective cap for a long time by adopting the modes of stamping steel characters, welding characters and pasting identification plates, the phenomena of field fire and welding traces which are not directly generated by important elements related to the body flange 1 and the shaft are eliminated, and the original material characteristics of the wellhead component are kept; for other operation forms adopting external threads to be connected with the casing coupling 16 in the later period, the wellhead can be opened only by cutting the upper part of the cutting belt 1206 without removing the protective cap 12, the wellhead is blocked by the hanger protection plate 1203, the damage to elements such as a rubber part and the like caused by the loss of cutting waste residues and splashes is avoided, and the casing coupling hanger 15 is integrally protected; the hanger protection plate 1203 is made into a cone surface with a middle-high shape and a low periphery, so that rainwater and corrosive fluid can be prevented from permeating, the sealing performance of the hanger can be protected, and the service life of each part can be prolonged.

In some embodiments, a schematic structural view of a surface double male nipple connected with the female thread section 5 in fig. 2 is shown in fig. 14; as shown in fig. 1, 2 and 15, the lower part of the main through hole 6 is a female thread section 5, in the drilling operation, most of the shaft is reserved in a surface casing coupling female thread mode, and the surface casing coupling female thread mode are connected by a surface double male short section 501; the two ends of the surface layer double male short joint 501 are short joint male threads 502, a surface layer through hole 503 is arranged in the middle, the short joint male threads 502 are respectively connected with the female thread section 5 and the wellhead surface layer casing coupling female threads, the body flange 1 is communicated with the surface layer casing in a sealing mode, and an insertion channel of a drilling fluid circulation and drilling tool and casing body 17 is formed; the surface layer double male short piece 501 has other functions: the device can adapt to the changes of different surface layer sleeves and female threads, realizes the mutual connection and sealing in a changing system, and does not need to change the structure of the female thread section 5 of the body flange 1; further function lies in that pit shaft top layer casing coupling box screw thread damages or does not have the state of box thread to appear, and the two public nipple joints in top layer can be made suitable length, accord with the physique at will to satisfy and realize with the interconnect of pit shaft, keep casing head body flange 1 not influenced by welding environment and quality.

In some embodiments, a schematic of a casing collar hanger and casing collar, casing body mounting arrangement is shown in figure 15; the coupling suspension hole 1524 and the casing suspension hole 1505 in the sleeved casing coupling hanger 15 component are sleeved to the end of the casing coupling 16 through the male thread end of the casing body 17, and the sleeving manner is mainly flexible and diversified by slippage; in this embodiment, the proper installation lifting rope 1532 is provided, the sleeving can be completed by means of an external source condition, and when it is confirmed that the flat shoulder surface of the casing collar 16 is in complete contact with the soft metal pad 1536 of the casing collar hanger 15 without shaking, the internal hexagonal wrench can apply force to the jackscrew 1502 to realize the position locking with the casing body 17, and particularly in the operation of lifting the production casing 17 and the linked casing collar hanger 15, whether the jackscrew 1502 is locked with the casing body 17 must be confirmed, so that the casing collar hanger 15 slides down from a high place to cause damage or accidents. After confirming that the production casing 17 is reliably connected with the shaft inner casing coupling 16, the casing coupling hanger 15 is slowly lowered from a high position to a position where a drilling platform can be operated by a person, and the square sections 1534 of the pressure plate bolts 1516 are symmetrically rotated with equal force by a wrench, so that the installation of the casing coupling hanger 15 is completed.

The coupling type casing head in the above embodiment is designed under the normal working condition, namely the production casing can be lowered to a preset well depth, the casing coupling hanger under the normal working condition comprises a coupling through hole and a casing hanging hole which are vertically communicated, the casing coupling is fixedly arranged in the coupling through hole, and the casing body is fixedly arranged in the casing hanging hole. However, during completion, abnormal conditions are often encountered, i.e., production casing cannot be lowered to a predetermined well depth (as shown in fig. 16), and particularly as horizontal wells increase, such abnormal conditions sometimes occur.

Under this abnormal operating mode, need solve the mode of hanging of sleeve pipe body 17 and sleeve pipe coupling hanger 15 at first, later need solve with the body flange between the rigidity, need solve at last with setting up the annular space sealing relation between taper surface 3, the main diameter hole 6.

For this abnormal condition, the following embodiments select an adaptive well completion retrofit configuration according to each wellhead context.

In some embodiments, the invention provides a modified hanging technology and structure of a hanging casing body 17, in particular to a casing body hanger and a corresponding body type casing head thereof, and the invention is developed by mainly hanging the casing body 17 around a casing coupling hanger 15, solves the problem of the background-shaped well head in fig. 16, ensures that the well head can meet the operation requirement of the later oil extraction process, smoothly realizes the connection of the well head, improves the time efficiency, and relieves the complex background and difficulty in well completion.

In some embodiments, a casing body hanger for a body type casing head is shown in fig. 17. the casing body hanger 1500 differs from the casing collar hanger 15 described above in that it includes body slips 1537, body flanks 1538, body through holes 1539, ram locking mechanisms, and link locking mechanisms.

Briefly, when the casing collar hanger 15 encounters a wellhead background of the form of figure 16, the difficulty of handling increases and sometimes some remedy is taken in the form of damage or destruction of the wellhead. Therefore, against the background of the wellhead and the desire to form an effective wellhead with little or no damage, a casing 'body' hanger with shared and interchangeable meanings has been developed on the basis of the structure of the casing 'collar' hanger; referring to the installation process of the casing coupling hanger described in the above embodiments, the coupling slips 1513 in the assembly of the casing coupling hanger 15 is replaced by the body slips 1537, the sealing rubber plate 1514 and the rubber plate pressure plate 1515 which are suitable for the casing body 17 are further selected, and the sharing characteristics of other main body components are maintained according to the original structure installation rules, so that the clamping and hanging of any pipe body section of the casing body 17 can be realized, wherein the installation flexibility varies from person to person.

Specifically, as shown in fig. 18 and 19, 3 ejector rod operation holes 1540 and ejector rod threaded holes 1541 a/connecting rod through holes 1541b which are mutually at 120 ° central angles and are parallel to the central line of the casing hanging hole 1505 are additionally arranged on the circumference of the upper end face of the hanger body of the casing body hanger, and ejector rod screws 1542/connecting rod bolts 1544 are installed in the holes; the middle section of a short cylindrical section 1501 at the lower end of the outer circumference of the hanger body of the casing body hanger is provided with 3 locking pin through holes 1547 a/locking pin through grooves 1547b which are mutually at a central angle of 120 degrees, are vertical and intersect the central lines of the ejector rod threaded hole 1541 a/connecting rod through hole 1541b and the casing hanging hole 1505, and ejector rod pins 1543/connecting rod locking pins 1545 for locking the casing body 17 are arranged in the locking pin through holes 1547 a/locking pin through grooves 1547b.

That is, the casing body hanger in this embodiment employs the ejector pin 1543/connecting rod pin 1545 structure when fixed with the casing body, rather than the configuration of the jack 1502 in the casing collar hanger, the advantages of this design are as follows: when meeting the wellhead background shape of the form of fig. 16, the unlocking/locking operation on any pipe body section of the casing body 17 can be realized on the upper end face of the casing body hanger 1500, the difficulty that the locking mechanism of the jackscrew 1502 in the casing coupling hanger 15 is difficult to operate under special conditions is solved, and the wellhead and the production casing can be protected from being damaged and destroyed by external force. Other structures, components of the casing body hanger 1500 are identical to, shared with, the casing collar hanger 15.

In some embodiments, the body slips in the casing body hanger are as shown in fig. 20A, 20B; as shown in fig. 16, a coupling slip 1513 is assembled in the casing 'collar' hanger 15, the coupling slip 1513 is used for realizing the holding function with the outer surface of the collar, the tooth socket of the tooth surface is designed longitudinally, the structure can not realize the hanging and holding function with the casing body 17, after meeting the wellhead background shape of fig. 16, the casing collar slip 1513 must be replaced by a casing body slip 1537, the tooth socket of the tooth surface of the casing body slip 1537 is designed transversely and hierarchically, so as to realize the holding function with the smooth casing body 17 better;

the sleeve body slip 1537 and the coupling slip 1513 are substantially unchanged in structure, and have the following contents: the collar through hole 1524 varies to a casing body through hole 1539 that accommodates the casing body 17, the casing hanger hole 1505; coupling flank 1528 changes to body flank 1538, and the alveolus distribution is single row tooth, circumference, multilayer grade form. The tooth surface has the main functions of fixing and bearing the vertical axial gravity of the hanging casing body 17, adopts visual cutting technology for forming the wellhead production casing under the background shape, and realizes the functions of preventing falling and loosening. The alveolar distribution, the tooth shape and the material selection and determination in the embodiment are effective parameters and application structures obtained through multiple theoretical designs and experiments and field application, and the effect can be brought into full play by combining with actual installation skills.

In addition, the sealing rubber plate 1514 and the rubber plate pressing plate 1515 on the upper part of the sleeve are replaced, so that the surrounding sealing effect of the section surface of the pipe body formed by the sleeve body 17 is ensured, and the effective sealing with the annular space of the main through hole 6 is realized.

In some embodiments, the structure and schematic diagram of the ram locking mechanism for fixing the casing body 17 in the casing body hanger is shown in fig. 21A; wherein, the ejector pin 1543 is arranged in the lock pin through hole 1547a, the outer diameter of the contact end of the ejector pin 1543 and the sleeve body 17 is slightly smaller than the other end, and the ejector pin is of a flat end surface structure and is used for contacting when the sleeve body 17 is locked, and the slightly smaller outer diameter section is arranged in the hole section with the relatively smaller diameter of the lock pin through hole 1547a, so that the ejector pin 1543 can only be inserted in one direction from the hole in the direction of the short cylindrical section 1501 on the outer circumference of the sleeve body hanger, and the stroke and the sliding loss phenomenon of the ejector pin 1543 are further limited; the other end of the ejector pin 1543 is provided with a straight cylindrical section, the end of the straight cylindrical section is provided with a 45-degree conical inclined plane, the inclined plane and the 45-degree conical inclined plane at the end of the ejector screw 1542 are kept to be crossed along a 90-degree direction axis to form contact, the ejector screw 1542 is adjusted to generate displacement through an internal hexagonal wrench, the contact conical inclined plane can be pushed and slid, the ejector pin 1543 is further pushed and displaced towards the direction of the sleeve suspension hole 1505, and the sleeve pin is in contact locking with the sleeve body 17.

The design has the advantages that: the casing body hanger 1500 can be unlocked/locked by operating from the upper end face of the casing body hanger 1500 and the positive direction of the wellhead under the background shape of the wellhead in fig. 16, and the conical section surface 301 on the outer circumferential surface of the casing body hanger 1500 and the setting conical surface 3 on the main through hole 6 can form an integral 'conical plug type' pressing, jointing and sealing effect. The ejector rod screw 1542 is connected with the ejector rod threaded hole 1541a through standard threads to form adjusting, locking and sealing effects, a sealing flat gasket 1549 is further designed between a pressing shoulder surface of the ejector rod screw 1542, which is in contact with the flat end surface of the ejector rod threaded hole 1541a, and the pressing and sealing effects on the sealing flat gasket 1549 can be formed while the adjusting and locking functions are realized; the other end of the ejector rod screw 1542 is provided with an inner hexagonal body, and the adjustment can be realized by inserting and rotating an inner hexagonal wrench; a rubber plug 1548 for sealing is further designed in the ejector rod operation hole 1540, and the rubber plug 1548 can be placed after the casing body hanger 1500 is confirmed to be locked with the casing body 17, so as to form blind plugging.

In some embodiments, the structure and schematic diagram of the link locking mechanism for fixing the sleeve body 17 in the sleeve body hanger is shown in fig. 21B; the connecting rod pin 1545 is mounted in the lock pin through groove 1547b, a cam-shaped arc surface capable of rotating around the connecting rod pin 1546 is arranged at the contact end of the connecting rod pin 1545 and the sleeve body 17, the reducing and locking functions in a single rotating direction are achieved, the other end of the connecting rod pin 1544 and the connecting rod bolt 1546 are connected to form a crank-link swinging mechanism through the connecting rod pin 1546, and due to the fact that the gap between the cam surface of the connecting rod pin 1545 and the sleeve body 17 is small, the rotating radian of the cam surface is small, and the moving stroke is.

The connecting rod bolt 1544 and the connecting rod pin 1545 are connected by means of a connecting rod pin 1546 to form a 'connecting rod' locking mechanism; during the installation process, a connecting rod bolt 1544 of the 'connecting rod' locking mechanism is inserted into the ejector rod operation hole 1540 along the connecting rod through hole 1541b, and a connecting rod shaft pin 1546 is fixed in a connecting rod shaft hole 1546 of the lock pin through groove 1547b, so that the 'connecting rod' locking mechanism which can be operated by the connecting rod bolt 1544 and can adjust the swinging of the connecting rod pin 1545 is formed, and the locking effect of the cam arc surface on the sleeve body 17 is further formed; the flat end face of the connecting rod bolt 1544 is provided with a sealing flat pad 1549, the connecting rod bolt 1544 rotates a nut by means of a connecting rod socket wrench 1550, the connecting rod pin 1545 is lifted upwards, meanwhile, the sealing flat pad 1549 is pressed tightly to form a pressing and sealing effect with the bottom end face of the ejector rod operation hole 1540, a rubber plug 1548 for sealing is further designed in the ejector rod operation hole 1540, and the rubber plug 1548 can be placed after the casing pipe body hanger 1500 is confirmed to be locked with the casing pipe body 17, so that blind plugging is formed.

The embodiment of the casing body hanger aims at hanging the casing coupling 16 and the casing body 17, aims at solving the problem of difficulty appearing or possibly appearing in well completion operation, further develops a mechanism for hanging the production casing 'body' on the basis of hanging the production casing 'coupling', expands the functions and effects of an original product, enhances the sharing characteristic of a main structural component of the original product, replaces a few parts to generate new functional characteristics, and further expands the scientificity and rationality of each mechanism in the product and the operability realized by the process. A 'body suspension clamping' structure, an 'ejector rod' and a 'connecting rod' locking mechanism are developed, the 'ejector rod' locking mechanism and the 'connecting rod' locking mechanism can be selected or combined optionally, and are not limited and influenced, the operation difficulty in the original 'ejector wire' locking mechanism is solved, the processing difficulty of the wellhead background shape in the figure 16 is solved, and a casing head product of the 'body type' of the well completion assembly well head is formed.

In the above embodiment, the casing collar hanger and the casing body hanger are used for solving the hanging mode problem of the production casing relative to the wellhead under normal working conditions and abnormal working conditions, and then the sealing problem between the production casing and the variable-assembly wellhead sealing flange needs to be solved.

In the prior art, a common modified wellhead sealing flange is a BT sealing flange, and the BT sealing technology is a technology introduced abroad, as shown in fig. 22. One end of the BT sealing flange 44 is provided with a structure which can be connected with the casing head body flange 1, and connection, compaction and sealing are realized through flange bolts 13 and a flange steel ring groove/steel ring 14; the other end can be connected with standard wellhead Christmas tree equipment; the middle part is provided with a flange through hole 32, a BT sealing cover 45 is arranged in the through hole, two BT sealing grooves 46 are arranged in the cover and used for installing BT sealing rings 46, the middle part of each sealing groove is provided with injection molding holes 47 which penetrate through a variable-assembly wellhead sealing flange body and reach the outer circumferential surface and are symmetrical on a diameter line, an injection molding joint 48 is arranged on each injection molding hole 47 and is used for injecting sealing grease into the inner cavity of the BT sealing ring 46 after being connected with a high-pressure injection molding gun through a hose to form a high-pressure cavity, the BT sealing ring 46 is extruded to expand, and a sealing structure which is isolated from the inner channel and the outer channel of the sleeve body 17 is formed through the two BT sealing rings 46; an observation hole 49 which penetrates through the standard flange body and reaches the outer circumferential surface on the radius line is formed in the middle section position of the two BT sealing rings 46, a 90-degree circle center angle distribution is formed between the observation hole 49 and the axis of the injection hole 47, a pressure gauge interface/plug 50 for BT seal detection is formed at the outer end of the observation hole 49, and the sealing effect of the two BT sealing rings 46 can be detected through the observation hole 49.

The BT sealing structure is applied more in the existing casing head product, the sealing structure has small clearance relative to a connecting main body, good bearing strength and good material stress state, different pressures can be injected into the BT sealing ring according to the pressure value required to be sealed so as to achieve the pressure balance between the inside and the outside of the BT sealing ring, and the pressure can be injected in a later period according to actual conditions, but the BT sealing technology and the structure only form a connecting relation aiming at the casing body 17, have the limitation of corresponding structure size installation on the BT sealing flange 44, have fine and severe requirements on the forming degree of a connecting piece, are complex in installation operation, are provided with more auxiliary tools, are high in manufacturing difficulty, have high product price and low cost performance, and have no universal interchangeability;

the following embodiments explore a well completion modified wellhead structure with a cone seal cover and a cone seal piece used in cooperation, and the common attribute of the structure is that sealing and connection are formed aiming at a casing coupling 16 or a casing body 17, wherein multiple modified wellhead structure products take the casing coupling 16 as basic objects to form universal and interchangeable products, namely, the same product meets the casing coupling 16 and adapts to the casing body 17, so that the product quantity of the modified wellhead structure is reduced, and the application range of the casing head product is widened.

In some embodiments, a schematic of the structure of the cone seal is shown in FIG. 23; the outer circumference of the cone sealing element 51 is a cone outer circular surface 52 which is used for contacting with the cone sealing cover 31 of the variable wellhead sealing flange 30, the top end of the cone sealing element is provided with a cover cap top 54 structure, the hollow part is provided with a sleeving through hole 53 which is used for encircling and contacting with the casing coupling 16/casing body 17, and the lower opening is a flat end surface which is contacted with a rubber plate pressing plate 1515 in the casing coupling hanger 15/(body hanger 1500) assembly.

The cone sealing element 51 can adapt to wellhead backgrounds of two pipe bodies of a casing coupling 16 and a casing body 17, the shape change point is that a sleeving through hole 53 in the cone sealing element 51 structure has different diameters aiming at two sizes of the casing coupling 16 and the casing body 17, and the cone sealing element has universality with a variable wellhead sealing flange 30 and other variable wellhead structure products, so that the number of products in a variable wellhead structure can be correspondingly reduced, and the functions of universality and interchangeability of the variable wellhead structure products are improved.

In some embodiments, the cone seal cover and the cone seal are matched as shown in fig. 24A, 24B and 24C, the cone seal cover 31 is arranged in the middle of the modified wellhead seal flange 30 (which may be a standard flange 33, a double flange 37, a welding flange 40 or a threaded flange 42, and the like), the cone seal cover 31 is in the shape of an inner cone cylinder with a small upper part and a large lower part, a flat shoulder surface is formed at the joint of the cone seal cover 31 and the flange through hole 32, the inner cone cylinder surface of the cone seal cover 31 is in contact with the cone outer circular surface 52 of the cone seal 51, the modified wellhead seal flange 30 and the casing head body flange 1 are tightly connected by means of the flange bolts 13, so that the cone seal 51 mounted in the cone seal cover 31 is squeezed and expanded, the cone seal 51 generates a pressing and filling effect, and further forms a seal with the casing collar 16/casing body 17, the pressing and sealing effect is realized.

According to the principle of pressure-holding sealing, as shown in fig. 24C, the lower end face of the cone sealing element 51 contacts with a rubber plate pressure plate 1515 in the casing coupling hanger 15/(casing body hanger 1500) assembly to form a support, the body of the cone sealing cover 31 is slightly smaller than that of the cone sealing element 51, when the cone sealing cover 31 contacts with the outer circular surface 52 of the cone, the part of the conical section from the lower port of the cone sealing cover 31 is firstly formed to contact with the part of the conical section of the outer circular surface 52 of the cone, and the downward movement of the inner cavity of the cone sealing cover 31 and the extrusion filling effect on the cone sealing element 51 are formed under the fastening tension of the flange bolt 13, and the stress and deformation of the cone sealing element 51 in the above process are complex, and form not only the extrusion force expanding to the upper space of the cone sealing cover 31, but also the extrusion. When the variable wellhead sealing flange 30 and the casing head body flange 1 are fastened in place, the clearance between the cone sealing cover 31 and the matching sections of the cone sealing element 51, the casing coupling 16 and the like also forms full-closed contact, and the contact sections form high-pressure surrounding extrusion and pressing and holding sealing effects, so that the connection and the sealing between the variable wellhead sealing flange and the casing coupling 16/casing head body 17 are further realized.

The cone sealing element is developed by utilizing the deformation characteristic of a rubber material, the middle-lower section surface (large-caliber end) of the outer circular surface 52 of the cone is firstly in contact with part of the cone section surface of the cone sealing cover 31, the lower section surface of the sealing element is further pressed in the downward contact process in advance, the upper part of the cone sealing cover 31 is not in contact with the cone sealing element 51 in the forming process, a gap is formed, and the sealing element is not stressed, so that the energy is collected and energy slides upwards in the sealing element material and the whole shape under the action of the pressing force of the lower section of the sealing element, the original characteristic of the upper section material of the sealing element is more kept, and when all contact spaces in the cone sealing cover 31 are matched to design values, the cone sealing element 51 also keeps the filling and pressing sealing characteristics which accord with the pressing deformation, and better keeps the original material characteristic of the upper space of the sealing element, Physical properties, which enhance the deformation and life characteristics of the seal material.

In some embodiments, the modified wellhead sealing flange 30 is installed as shown in fig. 24A, 24B and 24C, when the modified wellhead sealing flange 30 is installed, the cone sealing element 51 is firstly sleeved on the casing coupling 16/casing body 17, the hood cap top 54 is contacted with the casing coupling/casing body section, whether the fit clearance between the relative connecting components is within the specified value is confirmed, if not, other technical treatment is additionally required, then the inner cone surface of the cone sealing hood 31 of the modified wellhead sealing flange 30 is sleeved on the cone sealing element 51 along the outer cone surface 52, and the flange bolts 13 are used for uniformly applying force in the circumferential direction, so that the flange surface is pressed and the sealing element is pressed. In order to reduce friction in the installation process, skills such as lubricating oil and the like can be selectively applied to each contact surface/place.

In some embodiments, a schematic view of a combination of a standard flange 33 and a cone seal 51 is shown in fig. 24D, wherein the standard flange 33 is integrally formed by connecting two flange faces or flanges parallel to each other and conforming to the relevant standard model; the connecting end face of the standard flange 33 and the casing head body flange 1 is provided with a flange steel ring groove 14 and a bolt hole 20, and forms fastening, sealing and connecting to form a whole with the casing head body flange 1; the other end face of the standard flange 33 is provided with a connection scheme with the same specification and model as those of the Christmas tree bottom flange, the end face is provided with a gasket ring groove 33, and flange wire planting holes 35 are uniformly distributed on the circumference and used for connecting and sealing other equipment required by a well completion wellhead. A protection plate 36 is arranged on the connecting surface of the standard flange 33 and used for protecting the connecting surface and the structure; the hanging ring 21 is a gravity center point of the product and is used for carrying and hanging; the middle of the standard flange 33 is provided with a through flange through hole 32, the diameter of the through hole is larger than or equal to that of the production casing through hole 18, and the through flange is used for the operation in the later period of well completion through downhole tools; the flange through hole 32 is provided with a cone seal cover 31 corresponding to the flange 1 connection end of the body for forming connection and sealing with the casing collar 16 or the casing body 17.

In some embodiments, a schematic diagram of a combined structure of the double flange 37 and the cone seal 51 is shown in fig. 24E, and the structure of the double flange 37 mainly meets the requirement of connecting wellhead blowout preventer equipment which needs to be repeatedly installed in well repair, sidetrack drilling and the like in the later period of well completion. The double flange 37 is formed by connecting two flanges 39 with each other to form a whole, and compared with the standard flange 33, the structural change of the double flange is that two connecting end faces are in the form of the flanges 39 (specification and model can be identical/different, and the double flange can be made into a 'double-sided flange' form if the specification and the model are identical so as to reduce the connecting height), one end of a flange through hole 32 in the middle part is in a cone sealing cover 31 structure, and the other end of the flange through hole is provided with a cone leading-in face 38 for leading a well entering tool to pass through. The flange plate 39 and the casing head body flange 1 or the blowout preventer flange are fastened, sealed and connected into a whole through the flange bolts 13 and the flange steel ring grooves 14.

In some embodiments, the schematic diagram of the combined structure of the welding flange 40 and the cone sealing element 51 is shown in fig. 24F, and the welding flange 40 mainly meets the later-stage well-completion wellhead connection in the substandard form, meets the "nonstandard" form (special supply and special type products intentionally formed by manufacturers) of part of wellhead equipment, and has the purpose and function of forming variability through the welding flange 40, realizing butt joint with any connecting piece, meeting the requirements of inconvenient construction in field environment or on-site operation prohibition clauses, and ensuring safe construction and welding quality.

One end of the welding flange 40 is provided with a flange plate 39 which can be connected with the casing head body flange 1, and a cone sealing cover 31 structure is arranged in a middle through hole 32 on the same end surface; the other end is provided with a welding section surface 41 which can realize secondary processing and manufacturing according to the connection environment, thereby enhancing the variability and adaptability of the welding flange 40. The welded flange 40 is similar to the standard flange 33 in shape, and is different from the welded flange in that a reworkable material is reserved at one end of the flange 1 far away from the casing head body, so that diversified conditions of a well completion assembly well mouth are created; the welding flange 40 is mostly matched and matched with the modified wellhead structure of the corresponding embodiment of fig. 17 in installation and connection.

In some embodiments, the threaded flange 42 and cone seal 51 are combined as shown in FIG. 24G, and the threaded flange 42 is of the structural type primarily intended for protection or restoration of an already damaged production casing collar 16 in a wellhead-like application.

The threaded flange 42 is similar in shape to the welding flange 40 except that the end of the flange through bore 32 remote from the casing head body flange 1 is provided with a coupling thread segment 43 for producing a casing coupling 16 or other specifications and types, or is provided with a material which can be reprocessed into the form of the coupling thread segment 43.

The cone sealing element structure and the flexible application of the cone well completion transform assembly wellhead flange in the embodiment create a protection technology and a safe environment for the only connecting port of the wellhead; the recovery pretreatment scheme after the only wellhead is damaged is created, the structural type and the remedy scheme of the well completion wellhead are increased, the structural quality of the well completion wellhead is improved, and the safety and the timeliness of the well completion operation are improved.

The cone sealing element in the embodiment has the advantages of simple structure, low processing difficulty, intuitive installation, simple and convenient operation, good sealing capability, wide installation environment and easy replacement, but if the installation process is not studied, the fit clearance of each connecting piece exceeds the range, the lower part of the cone sealing element 51 is likely to bulge, the sealing effect of the cone sealing element cannot be tested relative to a BT sealing flange, and the internal state cannot be observed;

in order to solve the technical problems, the following embodiments explore a special-shaped variable wellhead sealing flange which has the same structure with or surpasses the functional characteristics of a BT sealing flange, and the special-shaped variable wellhead sealing flange is internally provided with a special-shaped sealing member structure.

In some embodiments, the configuration of the profiled modified wellhead sealing flange and profiled seal is as shown in fig. 25, 26; the special-shaped sealing element is also suitable for the casing coupling 16 and the casing body 17, and the special-shaped wellhead sealing flange 55 can be a standard flange, a double flange, a welding flange, a threaded flange and other common flanges.

FIG. 25 is a schematic view of the combination of a casing collar and a deformed modified wellhead sealing flange; the special-shaped sealing piece comprises two special-shaped sealing rings 61 arranged up and down, a spacer ring 64 positioned between the two special-shaped sealing rings 61, a guide righting sleeve 69 positioned on the upper surface of the upper special-shaped sealing ring and an adjusting ring 58 positioned on the lower surface of the lower special-shaped sealing ring; wherein, the flange through hole 32 of the center part of the deformed variant wellhead sealing flange 55 is provided with a clamping section 59 and a deformed sealing cover surface 57, the two sections and the formed shoulder surface are directly or through a deformed sealing element to be contacted with the casing coupling 16 in advance, and the flange bolt 13 and the flange steel ring groove/steel ring 14 are used for realizing the compression type connection and sealing; the special-shaped sealing element is limited by a closed space and is extruded under high pressure in the special-shaped sealing cover body 60, the special-shaped sealing ring 61 deforms and fills gaps, the inner circular surface surrounds the casing coupling 16, and the outer circular surface expands and extrudes the special-shaped sealing cover surface 57 to form high-pressure expansion and extrusion filling sealing, so that sealing and connection with the casing coupling and the end surface are realized.

FIG. 26 is a schematic view of a combined structure of a casing body and a deformed modified wellhead sealing flange; the clamping section 59 on the flange through hole 32 in the center of the special-shaped variable wellhead sealing flange 55 is in contact with the end face of the sleeve body 17 by adding the guide centering sleeve 69, the special-shaped sealing cover face 57 is in contact with the sleeve body 17 through the thickened special-shaped sealing piece, two section faces in the guide centering sleeve 69 and the special-shaped sealing cover face 57 are in early contact with the sleeve body 17 to form a closing space, the special-shaped sealing piece is limited by the closing space and is extruded by high pressure in the special-shaped sealing cover body 60, the special-shaped sealing ring 61 deforms and fills gaps, the inner circular surface surrounds the sleeve body 17, the outer circular surface expands and extrudes the special-shaped sealing cover face 57 to form high-pressure expansion and extrusion filling sealing, and sealing and connection with the sleeve body and the end face are.

In the following, the structure of the profiled modified wellhead sealing flange 55 is taken as an example, as shown in fig. 27, the structure, principle, connection relationship and assembling/using process of the profiled sealing element are further described in detail, and the principle and structure are also applicable to other profiled sealing structure flanges.

The lower end face of the special-shaped variable-loading wellhead sealing flange 55 is provided with a special-shaped sealing cover body 60, each section face of the flange through hole 32 is provided with a special-shaped sealing cover face 57 and a clamping section 59, the diameter of the clamping section 59 is smaller than that of the special-shaped sealing cover face 57 and larger than that of the flange through hole 32, and a plane shoulder structure is formed among the sections faces and used for installing structural components of a special-shaped sealing element; and a sealing observation hole 56 communicated with the outer circular surface of the special-shaped variable-loading wellhead sealing flange 55 is formed in the middle section of the special-shaped sealing cover surface 57, and a pressure gauge interface/plug 74 for special-shaped sealing detection is formed at the port of the observation hole 56 and is used for observing the sealing effect formed by the special-shaped sealing element. The principle is that no matter the annular space formed by the main through hole 6 and the production casing or the sealing effect in the through hole 18 of the production casing is checked, high-pressure medium can be injected from two isolated space directions, and the leakage condition is observed from the pressure gauge interface/plug 74 for special-shaped sealing detection, so that the sealing effect of the special-shaped sealing element is verified, and the special-shaped sealing element realizes reliable sealing in a state of no steam bubble, no pressure testing medium or zero pressure gauge value.

In some embodiments, the configuration of the profiled sealing ring is as shown in fig. 28; the special-shaped sealing ring 61 is made of rubber or a material with extrusion elastic deformation and certain strength characteristics, is annular in shape, is flat end surfaces at the upper part and the lower part, is provided with a slow-pressing groove 62 at the outer circumference and the inner circumference, contacts with the special-shaped sealing cover surface 57 at the outer circumference, contacts with the casing coupling 16/casing body 17 at the inner circumference, and is closed to form a special-shaped sealing through hole 63 which can realize encircling sealing and sliding with two casing pipes with wellhead backgrounds.

In some embodiments, the spacer ring is configured as shown in fig. 29; the isolating ring 64 is an upper flat end face and a lower flat end face, an annular negative pressure groove 65 is formed in the inner circumferential face and the outer circumferential face of the middle section, two negative pressure small holes 66 penetrating through the isolating ring 64 are symmetrically formed in the diameter line of the ring circumferential face of the negative pressure groove 65, and the inside and the outside of the negative pressure groove can be communicated. The isolation ring 64 is installed between the two special-shaped sealing rings 61 to form an assembly, and is installed in the special-shaped sealing cover 57, the installation positions of the negative pressure groove 65 and the negative pressure small hole 66 correspond to the positions of the sealing observation hole 56, and mutual communication can be formed, so that the sealing effect of observing the special-shaped sealing piece from the port of the pressure gauge interface/plug 74 for detecting the special-shaped sealing is realized.

In some embodiments, the structure of the adjustment ring is as shown in fig. 30; the adjusting ring 58 is in a rectangular circular ring shape, 6 adjusting threaded holes 67 are uniformly formed in the circumference of the end face of the adjusting ring, adjusting screws 68 are mounted in the adjusting threaded holes 67, the height of the adjusting ring 58 placed on the casing coupling hanger 15/casing body hanger 1500 assembly can be adjusted, and the adjusting ring and the special-shaped sealing cover surface 57 form supporting and extrusion displacement for the internal special-shaped sealing ring 61, so that connection and sealing with the casing coupling 16/casing body 17 are realized.

In some embodiments, the guide centralizing sleeve is configured as shown in fig. 31; the guide centralizing sleeve 69 is rectangular and circular, and the inner circular surface of the guide centralizing sleeve has the same diameter with the special-shaped sealing through hole 63 and is used for contacting the sleeve body 17; the outer circular surface is contacted with the clamping section 59, keeps consistent with a flat shoulder surface in the special-shaped sealing cover 57 and forms stable installation, is used for cutting off the casing coupling 16 and only leaves a wellhead background-shaped centralizing contact of the casing body 17, realizes that the special-shaped variable-installation wellhead sealing flange 55 has universality and can adapt to installation connection and sealing with the casing coupling 16/casing body 17.

The function of this guide righting cover: after the casing coupling 16 is cut off, a gap formed by the diameter difference between the coupling 16 and the body 17 is filled, and a closed compression space is created for the special-shaped sealing element; the centralizing special-shaped variable wellhead sealing flange 55 is connected and installed with the casing body 17 and a plurality of wellhead components in a coaxial manner; through increasing, subtracting the installation of direction righting cover, realize that special-shaped change dress well head sealing flange 55 and structure have the commonality, reduce the quantity of becoming dress well head structure product, promote the functional characteristic of becoming dress well head product, reduce the supporting cost of product.

In some embodiments, the installation process and the sealing principle of the special-shaped sealing element are as follows, the special-shaped sealing ring 61 has installation directionality in the special-shaped sealing cover 57, and is formed into an assembly by two single products with opposite directions and correct type selection, the two single products are separated by the isolating ring 64, a sealing combination body is formed on two sections in the special-shaped sealing cover 57, the open end of the sealing combination body is supported by the adjusting ring 58 and forms a closed compression space with the special-shaped sealing cover 57, the adjusting ring 58 realizes the adjustment of the supporting position through the adjusting screw 68, and the requirement that the special-shaped variable wellhead sealing flange 55 can simultaneously generate the coordination fit clearance of a plurality of connecting pieces such as the special-shaped sealing cover 57 and the flange steel ring groove/steel ring 14 in the connection position and relationship in the installation and connection process is; the flange bolt 13 generates fastening force in the circumferential direction, high-pressure extrusion expansion of the special-shaped sealing ring 61 in the special-shaped sealing cover 57 is realized, surrounding sealing with the casing coupling 16/casing body 17 is further realized, and a rigid isolation ring 64 is arranged between the upper special-shaped sealing ring 61 and the lower special-shaped sealing ring 61, so that bidirectional supporting and extrusion effects are realized; the middle part of the special-shaped sealing cover 57 is provided with a sealing observation hole 56 communicated with the outside, the middle section of the isolating ring 64 is always kept at the interval section of the sealing observation hole 56 and is kept in an atmospheric pressure state, a sealing structure capable of bearing high internal pressure and self-sealing characteristics is designed in the opposite direction of the two special-shaped sealing rings 61, and no matter high pressure in the annular space of the main drift diameter hole 6 or in the shaft of the production casing through hole 18 can be isolated by the two separated special-shaped sealing rings 61, so that two sections of closed spaces which are not communicated with each other are formed. When any one group of the sealing elements fails, pressure and fluid are communicated to the negative pressure small hole 66 at the middle section of the isolating ring 64, so that the sealing effect of the special-shaped sealing ring 61 can be checked by observing the state of the pressure gauge interface/plug 74 for detecting the special-shaped sealing. Lubricating oil and grease can be selectively applied in the installation process of the special-shaped sealing ring 61 so as to reduce friction, and smooth installation can be realized by means of tools and skills.

In some embodiments, to satisfy a more severe environment, it is necessary to replace the colloid profiled sealing ring with a metal sealing ring structure, as shown in fig. 31; the metal sealing ring 70 is made of a material (Al/Pb/Cu/Sn /) which is easy to deform under extrusion and has strong corrosion resistance, the shape of the metal sealing ring is similar to that of the special-shaped sealing ring 61, the difference is that a front deformation groove 71 is additionally arranged on the upper end surface and is used for increasing the extrusion force on edge metal under a compressed state to generate deformation sealing firstly, the side surface deformation grooves 73 which are different from the structure of the pressure relief grooves 62 of the special-shaped sealing ring 61 are arranged on the side surfaces of the inner ring and the outer ring, and the groove body structures are all used for forming better contact deformation in order to increase the local extrusion force of. The metal sealing ring 70 has plastic denaturation and rigid sealing characteristics, so that the metal sealing ring can be successfully installed only once, has the connection effect of embedding and curing, and has strong corrosion resistance.

The special-shaped sealing element structure has good sealing principle and performance, the combination form is suitable for all products of a well head structure, the universality and the interchangeability are strong, multiple complex well head backgrounds in well completion field operation can be met, the most convenient technical processing platform is created for users, no worry is caused, but the fit clearance of each connecting piece needs to be measured and calculated finely, the adjusting value required by installation is calculated, and the ideal effect in design can be ensured. This measurement and precise computation creates a broad processing platform for the well-head background that has been developed in the field, and the field technician independently determines that many complex well-head problems can be solved.

The product structure features are all the revolution surface formed by rotating around the fixed axis, and the revolution surface has a cylindrical surface, a conical surface, a circular hole surface, a circular ring surface and a circular platform shoulder surface, and the local part has a milling plane and a drilling hole for installing and connecting other elements or observing.

The products provided in the above-described embodiments of the present invention are merely illustrative of one form or principle of construction of the present invention and are not limited to other forms of construction that rely on the present technology, principles.

While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims (16)

1. The well completion modified casing head is characterized by comprising a production casing, a casing hanger, a body flange and a protection device; the production casing is fixedly arranged in the casing hanger, the casing hanger is seated in the body flange, and the protection device is fixedly arranged above the body flange;

the casing hanger comprises a rubber plate pressing plate, a sealing rubber plate, a slip tooth pressing cover and a hanger body which are sequentially arranged from top to bottom, a pressing plate bolt sequentially penetrates through the rubber plate pressing plate, the sealing rubber plate and the slip tooth pressing cover and then extends into the hanger body, the pressing plate bolt is screwed and fixed by a pressing plate nut, and slip teeth for tightly holding the production casing are fixedly arranged below the slip tooth pressing cover;

the outer periphery of the hanger body is sequentially provided with an upper cylindrical section, a conical section and a short cylindrical section from top to bottom;

a main through hole is formed in the body flange, an upper smooth section, a setting taper section and a middle smooth section are sequentially arranged in the main through hole from top to bottom, and the setting taper section is matched with the taper section on the hanger body to form setting;

the production casing comprises a casing body and a casing coupling fixedly arranged on the upper part of the casing body;

the casing hanger is a casing body hanger, the slip teeth in the casing body hanger are body slip teeth, the body tooth surface of the body slip teeth is abutted to the periphery of the casing body, the short cylindrical section at the lower part of the casing body hanger is provided with a locking mechanism, the casing body hanger comprises a casing hanging hole which is communicated up and down, and the casing body is fixedly arranged in the casing hanging hole through the clasping effect of the body slip teeth and the locking effect of the locking mechanism;

the locking mechanism is a connecting rod locking mechanism;

the connecting rod locking mechanism is a connecting rod pin, a connecting rod through hole is formed in the casing pipe body hanger, a connecting rod bolt is arranged in the connecting rod through hole, a lock pin through groove is formed in a short cylindrical section of the lower portion of the casing pipe body hanger, the connecting rod pin is arranged in the lock pin through groove, the connecting rod through hole is vertically communicated with the lock pin through groove, a rotating nut for adjustment is arranged on the upper portion of the connecting rod bolt, the rotating nut can lift or lower the connecting rod pin through rotation, the lower end of the connecting rod bolt is rotatably connected with one end of the connecting rod pin through a connecting rod shaft pin, and the other end of the connecting rod pin can rotate relative to the lock pin through groove through the.

2. The casing head of claim 1, wherein the rubber sealing plate is a circular ring structure, and the upper surface of the rubber sealing plate is an arc surface which is convex upwards.

3. The well completion casing head according to claim 1, wherein the hanger body is provided with a plurality of vertically penetrating spring mounting holes and spring screw holes, the spring screw holes are located at the lower parts of the spring mounting holes, compression springs are mounted in the spring mounting holes, the top ends of the compression springs are abutted with the lower surfaces of the slip tooth glands, spring screws are mounted in the spring screw holes, the top ends of the spring screws are abutted with the bottom ends of the compression springs and are compressed and fixed in the spring screw holes, and the spring screws and the pressing plate bolts are arranged in a staggered mode.

4. A completion transfiguration casing head as in claim 1, wherein the body flange upper portion is circumferentially provided with hanger pins that abut the outer surface of the pressure plate nut when a casing hanger is seated within the body flange.

5. The completion casing head of claim 1 wherein said body flank is a single row, circumferential, multi-step configuration.

6. The completion casing head according to claim 1, wherein the protection device is a protection cap comprising a flange protection plate, a wellhead protection plate and a hanger protection plate; the flange protection plate is an annular steel plate and is connected with the body flange through a flange bolt, and a short circular tube connected with the wellhead protection plate is welded at the hollow part of the flange protection plate; the short round tube is provided with a cutting tape identification groove in a lathing manner, and the lower part of the cutting tape is provided with the hanger protection plate.

7. The well completion conversion casing head according to claim 1, wherein the protection device is a conversion wellhead sealing flange, a cone sealing cover is arranged in the conversion wellhead sealing flange, and the conversion wellhead sealing flange is connected with the production casing in a sealing mode through the matching of the cone sealing cover and the cone sealing piece.

8. The casing head of claim 7, wherein the cone sealing cover is a conical cylindrical structure with a small top and a large bottom, a flat shoulder surface is formed at the joint of the cone sealing cover and the flange through hole, and an inner conical cylindrical surface of the cone sealing cover is in contact sealing with an outer conical surface of the cone sealing element.

9. The completion conversion casing head of claim 8, wherein the cone seal upper tip is provided with a cap top structure, the cap top surface abutting the landing shoulder surface and the lower surface abutting the upper end surface of the production casing.

10. The well completion conversion casing head according to claim 1, wherein the protection device is a special-shaped conversion casing head sealing flange, a clamping section and a special-shaped sealing cover surface are formed on a flange through hole of the special-shaped conversion casing head sealing flange, a shoulder surface is formed between the sections, the top of the production casing is positioned in the clamping section, a special-shaped sealing element is positioned in the special-shaped sealing cover surface, and the special-shaped conversion casing head sealing flange is in sealing connection with the production casing through the matching of the special-shaped sealing cover surface and the special-shaped sealing element.

11. The well completion conversion and assembly casing head according to claim 10, wherein the special-shaped sealing element comprises two special-shaped sealing rings arranged up and down, a separation ring positioned between the two special-shaped sealing rings, and an adjusting ring positioned on the lower surface of the lower special-shaped sealing ring, and a sealing observation hole communicated with the outer circular surface of the special-shaped conversion and assembly wellhead sealing flange is formed in the middle section of the special-shaped sealing cover surface.

12. The casing head of claim 11, wherein the profiled sealing ring is circular in shape, has flat upper and lower end surfaces, and has relief grooves formed on the outer circumference and the inner circumference, the outer circumference contacting the profiled sealing surface, and the inner circumference contacting the production casing.

13. The completion casing head according to claim 11, wherein the isolation ring is an upper flat end face and a lower flat end face, the inner circumferential surface and the outer circumferential surface of the middle section are provided with annular negative pressure grooves, the circumferential surface of the negative pressure groove is symmetrically provided with negative pressure small holes penetrating through the isolation ring, and the negative pressure small holes are communicated with the sealing observation hole.

14. The completion casing head according to claim 11, wherein the adjusting ring is a rectangular ring-shaped structure, a plurality of adjusting threaded holes are uniformly formed in the circumference of the lower end face of the adjusting ring, adjusting screws are installed in the adjusting threaded holes, and the caps of the adjusting screws are abutted to the upper surface of the rubber plate pressing plate of the casing hanger.

15. The completion casing head of claim 11, wherein the profile seal further comprises a guide centralizing sleeve positioned in a gap between the production casing and the retainer segment when the gap is present, the guide centralizing sleeve having a rectangular ring-shaped configuration.

16. The casing head of claim 1, wherein the body flange has a plurality of side circulation holes circumferentially formed at a lower portion thereof, and the side circulation holes have partial flat surfaces formed at outer sides thereof for connection with the side flanges.

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