CN110965966A

CN110965966A - Riser reentry whipstock

Info

Publication number: CN110965966A
Application number: CN201911122826.4A
Authority: CN
Inventors: 郭永宾; 管申; 刘智勤; 李龙; 郭浩; 朱志潜
Original assignee: China National Offshore Oil Corp CNOOC; CNOOC China Ltd Zhanjiang Branch
Current assignee: China National Offshore Oil Corp CNOOC; CNOOC China Ltd Zhanjiang Branch
Priority date: 2019-11-16
Filing date: 2019-11-16
Publication date: 2020-04-07
Anticipated expiration: 2039-11-16
Also published as: CN110965966B

Abstract

The invention relates to the technical field of underwater detection devices, and particularly discloses a riser reentry whipstock, which comprises: the device comprises an inclined plane body, a centralizing unit, a sleeve, an anchoring unit and a guiding head; the inclined plane body is fixed at a cutting opening of the casing pipe, and is straightened through the straightening unit, and is provided with a longitudinal groove and a transverse groove to conduct guiding action on the riser pipe and the drilling tool; the centering unit is provided with a centering conical plate, the inclined plane body is centered and simultaneously preliminarily fixed, and the sleeve is provided with a hollow hole, so that the requirement of cementing and sealing after the whipstock is detached can be met; the anchoring unit is arranged below the righting unit and can fix the depth and the direction of the inclined plane body; the leading-in head is positioned below the anchoring unit, and the bottom of the leading-in head is a conical head, so that the whipstock can be ensured to be smoothly put into the sleeve cut. The invention realizes the reutilization of the waste well slots, effectively solves the problem that the inner casing is not centered, and the longitudinal grooves and the transverse grooves provide the guidance for the water-resisting guide pipe and the drilling tool, thereby avoiding the risks of well finding and azimuth deviation.

Description

Riser reentry whipstock

Technical Field

The invention relates to the technical field of drilling tools, in particular to a riser reentry whipstock.

Background

In offshore production platforms for offshore oil, notches are commonly used up due to the limitations of construction cost and space, the notches are still required to develop oil reservoirs with proven reserves according to a mining plan, and in addition, abandoned well slots can be generated due to factors such as capacity depletion, engineering abandonment, mining period and the like.

At present, the method that the external hanging well slots are established is mainly adopted by increasing the notches of the offshore platform, the cost is high, meanwhile, the load of the jacket platform is increased, and part of the platform cannot continue to have the external hanging well slots; and secondly, windowing is performed on the riser, so that not only are complex procedures of recovering the inner casing and the outer casing, milling and forging milling and the like performed, but also subsequent risks of window passing and directional deviation are increased.

Therefore, a need exists for a riser pipe reentry whipstock which not only meets offshore oil abandoned well specifications, but also is simple to operate, low in cost and low in risk, reestablishes a new well by a mode of reentry of a abandoned well notch through a riser pipe, and has the advantages of improving the service efficiency of a platform and greatly reducing the mining cost.

Disclosure of Invention

The invention aims to provide a riser reentry whipstock which conforms to offshore oil abandoned well specifications without changing a platform structure, provides guidance of the riser and a drilling tool, avoids risks of well finding and azimuth deviation and enables a abandoned well slot to rebuild a new well.

A riser reentry whipstock, comprising: the device comprises an inclined plane body, a righting unit, a sleeve, an anchoring unit and a guiding head, wherein one end of the sleeve is connected with the bottom of the inclined plane body, the other end of the sleeve is connected with the top of the anchoring unit, and the sleeve is provided with a hollow hole; the centralizing unit is connected to the surface of the casing, hollow holes are uniformly formed in the casing, the number of the hollow holes is more than 4, the diameter of each hollow hole is 20mm, and the bottom of the water-proof guide pipe is lifted up to this point, so that the circular cementing use is realized; the hollow hole is arranged between the righting unit and the anchoring unit; the leading-in head is connected with the bottom of the anchoring unit; the inclined plane body comprises a guide base body, a guide inclined plate and a water-resisting guide pipe, the guide base body comprises a base disc and a support, the bottom surface of the support is connected with the base disc, the base disc is of an eccentric structure and prevents a casing pipe from being not centered, and the guide inclined plate is connected with the surface of the support; a longitudinal groove, a first transverse groove and a second transverse groove are formed in the guide inclined plate, and the guide inclined plate plays a role in guiding the water-resisting guide pipe and the drilling tool; the longitudinal groove is arranged at the upper part of the guide inclined plate, and the sinking radian of the longitudinal groove is consistent with that of the section of the riser pipe; the first transverse groove is arranged below the middle part of the inclined guide plate, the depression radian of the first transverse groove is consistent with that of the section of the riser pipe, and the riser pipe is an 8-inch pipe column; the second transverse groove is arranged at the lower part of the inclined guide plate, and the concave radian of the second transverse groove is consistent with that of the section of the riser pipe; the bottom end of the riser is provided with more than 2 shearing pins, the diameter of each shearing pin is 12mm, the shearing force is set to be 13 tons, a sealing ring is arranged at the joint of the bottom of the inclined plane body and the anchoring unit, and the inside of the anchoring unit is enclosed into a closed space; the righting unit is a righting conical plate; the anchoring unit comprises an oil pipe slip, the oil pipe slip is provided with slip teeth, the outer surface of the slip teeth is provided with a limiting groove, a limiting ring is arranged in the limiting groove, the limiting ring is a steel strip with the width of 20mm and the thickness of 5mm, and the connecting mode is welding; limiting springs are arranged between the limiting ring and the oil pipe slips, and the number of the limiting springs is more than 2; the inner surface of each slip tooth is provided with saw teeth, the teeth of the saw teeth face downwards, the conical body is arranged at the upper end of the saw teeth, and the surface of the conical body is meshed with the saw teeth; the leading-in head comprises a leading-in rod and a conical plate, wherein the bottom of the leading-in rod is a conical head, and the conical plate is connected between the surface of the leading-in rod and the bottom surface of the anchoring unit.

Further, the radius of the base plate on one side of the inclined plane body close to the guide inclined plate is equal to the diameter of the riser on the outermost layer-the radius of the casing on the innermost layer; and the radius of the base plate on the other side close to the bracket is equal to the radius of the outermost riser pipe.

Furthermore, the outermost edge of the righting conical plate of the righting unit is more than 1 inch away from the casing, and the upper part of the righting conical plate is narrower than the lower part and is more flexible.

Furthermore, the number of the oil pipe slips of the anchoring unit is more than 3, each oil pipe slip is distributed with 4 rows and 12 rows of 48 slip teeth, and the slip teeth are engaged with the wall of the casing for anchoring.

Furthermore, the limiting groove is formed in the lower portion of the slip teeth, the groove width is 20mm, and the groove depth is 25 mm.

Furthermore, the number of the conical plates is more than 4, the conical plates are triangular, and the conical plates, the guide rod and the anchoring unit are connected in a welding mode.

Compared with the prior art:

1. simple structure, convenient processing, low cost and high scientific research value.

2. The method has the advantages of simple use flow and strong practicability, and avoids the risks of casing milling, orientation, window crossing, well abandoning specification and the like in the conventional method.

3. The application prospect is good, can once only cut multilayer sleeve pipe according to the sleeve pipe combination design tool of unidimensional, and high-efficient and satisfy each size sleeve pipe combination and implement riser pipe reentry operation.

4. The inclined plane body guide base body base plate is designed to be an eccentric structure, and the problem that the inner-layer casing pipe is not centered can be effectively solved.

5. The design of the longitudinal groove and the transverse secondary groove of the inclined plane body can simultaneously meet the guiding requirements of a water-resisting guide pipe and a drilling tool, and the risks of well finding and azimuth deviation are avoided.

6. The conventional drilling tool is used for connecting the waterproof guide pipe to feed, so that the operations of one-trip drilling, orientation, sitting and hanging, hand release and cementing can be realized, and the timeliness is high.

7. The hollow hole design between the centralizing unit and the anchoring unit can meet the requirement of cementing and sealing operation after the whipstock is out of hand, ensures the integrity of a abandoned well mouth and the stability of a sufficient whipstock, and in addition, the centralizing unit centralizes the conical plate to further ensure that the whipstock does not rotate, thereby ensuring the accurate position.

8. The sawtooth design of anchoring unit can carry out permanent fixed to the slant, avoids not hard up risk behind the pressure release.

9. The drilling of a well hole of a water-resisting casing is carried out through the direction of the whipstock, the position can be guaranteed, meanwhile, the requirement of the lower depth of various water-resisting guide pipes is met, and the risk of big dog-leg degree is avoided.

Drawings

Fig. 1 is a schematic structural view of a riser reentry whipstock according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an exemplary ramp according to the present invention;

FIG. 3 is a front view of a swash plate according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a groove of a swash plate according to an embodiment of the present invention;

FIG. 5 is a schematic view of a base plate in an embodiment of the present invention;

FIG. 6 is a schematic view of a flat view of a guide ramp from the end of a substrate disk in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a centering unit according to an embodiment of the present invention;

FIG. 8 is a schematic structural view of an anchoring unit in an embodiment of the present invention;

FIG. 9 is a schematic view showing the internal structure of an anchor unit according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of an introducer head in an embodiment of the invention;

FIG. 11 is a top view of an introducer head in an embodiment of the invention;

in the figure, 1-a ramp; 2-a righting unit; 3-an anchoring unit; 4-a lead-in head; 5-a riser pipe; 6-a guide inclined plate; 7-a guiding matrix; 8-righting the conical plate; 9-hollowing out holes; 10-shear pins; 11-a sealing ring; 12-a cone; 13-tubing slips; 14-a stop collar; 15-a tapered plate; 16-a lead-in rod; 17-a conical head; 18-a closed space; 19-saw teeth; 20-a cannula; 21-a limit spring; 22-slips; 23-a limiting groove; 24-a scaffold; 25-a base plate; 26-longitudinal grooves; 27-a first transverse groove; 28-second transverse groove.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Referring to fig. 1, a riser reentry whipstock according to an embodiment of the present invention is schematically illustrated, and the riser reentry whipstock includes: the inclined plane body 1, the righting unit 2, the sleeve 29, the anchoring unit 3 and the leading-in head 4, wherein one end of the sleeve 29 is connected with the bottom of the inclined plane body 1, the other end of the sleeve 29 is connected with the top of the anchoring unit 3, and hollow holes 9 are uniformly formed in the sleeve 29; the centralizing unit 2 is connected to the surface of the casing 29, the number of the hollow holes 9 is more than 4, the diameter of each hollow hole 9 is 20mm, and the bottom of the water-resisting conduit 5 is lifted up to this point, so that the circular cementing use is realized; the hollow hole 9 is arranged between the righting unit 2 and the anchoring unit 3; the introduction head 4 is connected to the bottom of the anchoring unit 3.

Referring to fig. 2, 3, 4, 5 and 6, the inclined plane body 1 includes a guide base 7, a guide inclined plate 6 and a riser pipe 5, the guide base 7 includes a base plate 25 and a support 24, the bottom surface of the support 24 is connected with the base plate 25, the base plate 25 is in an eccentric structure to prevent the casing 29 from being not centered, and the guide inclined plate 6 is connected with the surface of the support 24; a longitudinal groove 26, a first transverse groove 27 and a second transverse groove 28 are arranged in the inclined guide plate 6, and are used for guiding the riser pipe 5 and the drilling tool; the longitudinal groove 26 is arranged at the upper part of the guide sloping plate 6, and the sunken radian of the longitudinal groove 26 is consistent with that of the section of the riser pipe 5; the first transverse groove 27 is arranged below the middle part of the inclined guide plate 6, the depression radian of the first transverse groove 27 is consistent with that of the section of the riser pipe 5, and the riser pipe 5 is an 8-inch pipe column; the second transverse groove 28 is arranged at the lower part of the inclined guide plate 6, and the concave radian of the second transverse groove 28 is consistent with that of the section of the riser pipe 5; the radius of the base plate 25 on one side of the inclined plane body 1 close to the guide inclined plate 6 is equal to the diameter of the outmost riser pipe 5-the radius of the innermost casing pipe 29; the radius of the base plate 25 on the other side close to the bracket 24 is equal to the radius of the outermost layer riser pipe 5;

the bottom end of the riser 5 is provided with more than 2 shearing pins 10, the diameter of each shearing pin 10 is 12mm, the shearing force is set to be 13 tons, a sealing ring 11 is arranged at the joint of the bottom of the inclined plane body 1 and the anchoring unit 3, and the inside of the anchoring unit 3 is enclosed into a closed space 18;

referring to fig. 7, the centering unit 2 is a centering conical plate 8; the distance between the outermost edge of the righting conical plate 8 of the righting unit 2 and the sleeve 29 is more than 1 inch, and the upper part of the righting conical plate 8 is narrower than the lower part, so that better toughness is generated.

Referring to fig. 8 and 9, the anchoring unit 3 includes a tubing slip 13, the tubing slip 13 is provided with slip teeth 22, the outer surface of the slip teeth 22 is provided with a limiting groove 23, the limiting groove 23 is arranged at the lower part of the slip teeth 22, the groove width is 20mm, and the groove depth is 25 mm. A limiting ring 14 is arranged in the limiting groove 23, the limiting ring 14 is a steel plate strip with the width of 20mm and the thickness of 5mm, and the connection mode is welding; limiting springs 21 are arranged between the limiting ring 14 and the oil pipe slips 13, and the number of the limiting springs 21 is more than 2; the inner surface of the slip tooth 22 is provided with saw teeth 19, the teeth of the saw teeth 19 face downwards, the conical body 12 is arranged at the upper end of the saw teeth 19, and the surface of the conical body 12 is meshed with the saw teeth 19; the number of the oil pipe slips 13 of the anchoring unit 3 is more than 3, each oil pipe slip 13 is distributed with 4 rows and 12 rows of 48 slip teeth 22, and the slip teeth 22 are engaged with the wall of the casing 29 for anchoring.

Referring to fig. 10 and 11, the guiding head 4 includes a guiding rod 16 and a tapered plate 15, the bottom of the guiding rod 16 is a tapered head 17, the tapered plate 15 is connected between the surface of the guiding rod 16 and the bottom surface of the anchoring unit 3, the number of the tapered plates 15 is more than 4, the tapered plates 15 are triangular, and the tapered plates 15 are connected with the guiding rod 16 and the anchoring unit 3 by welding, so that better guiding is facilitated.

Integrally cutting the riser pipe 5 4m below the mud line to be combined with each layer of casing 29; before operation, the outer diameter of the riser pipe 5 and the inner diameter of the innermost casing 29 are investigated, and the riser pipe 5 with matched size is processed and then enters the whipstock again; the radius of the base disc 25 on one side close to the inclined guide plate 6 is equal to the diameter of the outermost layer riser pipe 5 to the radius of the innermost layer casing pipe 29, and the radius of the base disc 25 on the other side close to the support 24 is equal to the radius of the outermost layer riser pipe 5; the length of the recovered riser pipe 5 is accurately measured, so that the length of the drilling tool and the depth of the whipstock in the running process are accurately calculated.

The combined descending riser pipe 5 reenters the whipstock to be in place; a conventional drilling tool is used for connecting with the whipstock riser 5 and slowly descending into a cut of the submarine casing 29; determining that the whipstock is put in place according to the length of the recovered riser pipe 5 and the length of the drill tool, and otherwise, controlling the shearing force to be within sixty percent of 13 tons by using the lower pressure after multiple movements; recording the hanging weights of the drilling tool and the whipstock, namely the hanging weights of the neutral point;

recording the weight of the riser tube reentering the whipstock before combination; the top of the whipstock is combined and connected with a directional joint to measure the angular difference.

Orienting a gyroscope; a gyroscope instrument is put into the directional joint, and the direction of the whipstock is measured; and swinging the tool surface of the whipstock to a preset direction according to the angle difference.

Lifting the drilling tool to a neutral point for suspending, pressing down for 2 tons of force, and hanging a riser pipe to re-enter the whipstock;

the mud pump or the well cementing pump in the drill rod is stepped to 3000psi at every 300psi, the pressure increasing interval is 1 to 3 minutes every time, and the interval time is prolonged along with the pressure increasing; after the pressure is stabilized for 3000psi10 minutes, the drilling tool is lifted to confirm the successful setting, and the lifting force is within sixty percent of the shearing force of 13 tons.

The hands-off riser pipe reenters the whipstock; gradually pressing down the drilling tool by 13 tons according to the suspending weights of the neutral point and the point, and shearing the pin 10; lifting to observe the change of the hanging weight and confirming the success of the hand drop; the riser pipe 5 is lifted up properly, the highest height of the riser pipe does not exceed the base plate 25, the success of the hand release is confirmed, and the success of the hand release can also be confirmed through the pump-on circulation.

Cementing and sealing the wellhead and the riser pipe to reenter the whipstock; lifting or lowering the bottom of the riser pipe 5 to the hollowed-out hole 9, pumping cement slurry by using a well cementation pump, and sealing; slowly lifting the drilling tool and the riser pipe 5 out of the riser pipe and re-entering the whipstock, the large-displacement drilling tool and the well cementation pipeline; the riser pipe 5 is lifted up properly, the highest height of the riser pipe does not exceed the base plate 25, the success of the hand release is confirmed, and the success of the hand release can also be confirmed through the pump-on circulation.

The riser pipe 5 is lifted out, and a drilling tool is put in to drill to the designed depth; the drilling tool is tripped out and the riser pipe 5 is lowered again to the design depth.

It should be understood that the terms "first", "second", etc. are used herein to describe various information, but the information should not be limited to these terms, which are only used to distinguish one type of information from another. For example, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information, without departing from the scope of the present invention.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A riser reentry whipstock, comprising: the device comprises an inclined plane body (1), a centralizing unit (2), a sleeve (20), an anchoring unit (3) and a guiding head (4), wherein one end of the sleeve (20) is connected with the bottom of the inclined plane body (1), the other end of the sleeve (20) is connected with the top of the anchoring unit (3), the centralizing unit (2) is connected to the surface of the sleeve (20), the sleeve (20) is provided with a hollowed hole (9), and the hollowed hole (9) is arranged between the centralizing unit (2) and the anchoring unit (3); the lead-in head (4) is connected with the bottom of the anchoring unit (3); the inclined plane body (1) comprises a guide base body (7), a guide inclined plate (6) and a water-resisting guide pipe (5), the guide base body (7) comprises a base disc (25) and a support (24), the bottom surface of the support (24) is connected with the base disc (25), the base disc (25) is of an eccentric structure, and the guide inclined plate (6) is connected with the surface of the support (24); a longitudinal groove (26), a first transverse groove (27) and a second transverse groove (28) are arranged in the guide sloping plate (6), the longitudinal groove (26) is arranged at the upper part of the guide sloping plate (6), and the sinking radian of the longitudinal groove (26) is consistent with that of the section of the water-resisting conduit (5); the first transverse groove (27) is arranged below the middle part of the inclined guide plate (6), and the depression radian of the first transverse groove (27) is consistent with that of the section of the riser pipe (5); the second transverse groove (28) is arranged at the lower part of the inclined guide plate (6), and the concave radian of the second transverse groove (28) is consistent with that of the section of the riser (5); the bottom end of the riser (5) is provided with a shearing pin (10), a sealing ring (11) is arranged at the joint of the bottom of the inclined plane body (1) and the anchoring unit (3), and the righting unit (2) is a righting conical plate (8); the anchoring unit (3) comprises an oil pipe slip (13), the oil pipe slip (13) is provided with slip teeth (22), the outer surface of the slip teeth (22) is provided with a limiting groove (23), a limiting ring (14) is arranged in the limiting groove (23), a limiting spring (21) is arranged between the limiting ring (14) and the oil pipe slip (13), the inner surface of the slip teeth (22) is provided with sawteeth (19), the teeth of the sawteeth (19) face downwards, a conical body (12) is arranged at the upper end of the sawteeth (19), and the surface of the conical body (12) is meshed with the sawteeth (19); the leading-in head (4) comprises a leading-in rod (16) and a conical plate (15), the bottom of the leading-in rod (16) is provided with a conical head (17), and the conical plate (15) is connected between the surface of the leading-in rod (16) and the bottom surface of the anchoring unit (3).

2. The riser reentry whipstock of claim 1, wherein the radius of the base plate (25) on the side of the ramp (1) adjacent to the deflector (6) is the diameter of the outermost riser (5) to the radius of the innermost casing (20); and the radius of the base plate (25) on the other side close to the bracket (24) is equal to the radius of the outermost layer riser pipe (5).

3. A riser reentry whipstock according to claim 2, wherein the outermost edge of the righting cone (8) of the righting element (2) is more than 1 inch from the casing (20), the upper portion of the righting cone (8) being narrower than the lower portion.

4. A riser reentry whipstock according to claim 3, wherein the number of tubing slips (13) of the anchoring unit (3) is more than 3.

5. The riser reentry whipstock of claim 4 wherein the retaining groove (23) is formed in a lower portion of the slip element (22).

6. The riser reentry whipstock of claim 5, wherein the number of the tapered plates (15) is 4 or more, the tapered plates (15) are triangular, and the tapered plates (15) are connected to the introducing rod (16) and the anchoring unit (3) by welding.