CN111963135A - Throttling-free self-service deblocking two-layer fracturing string and fracturing method thereof - Google Patents
Throttling-free self-service deblocking two-layer fracturing string and fracturing method thereof Download PDFInfo
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- CN111963135A CN111963135A CN202010962657.1A CN202010962657A CN111963135A CN 111963135 A CN111963135 A CN 111963135A CN 202010962657 A CN202010962657 A CN 202010962657A CN 111963135 A CN111963135 A CN 111963135A
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- 238000000034 method Methods 0.000 title claims description 15
- 238000010276 construction Methods 0.000 claims abstract description 44
- 239000012530 fluid Substances 0.000 claims abstract description 7
- 238000007789 sealing Methods 0.000 claims description 22
- 230000007246 mechanism Effects 0.000 claims description 21
- 238000004519 manufacturing process Methods 0.000 claims description 18
- 239000007788 liquid Substances 0.000 claims description 14
- 230000006835 compression Effects 0.000 claims description 10
- 238000007906 compression Methods 0.000 claims description 10
- 230000000694 effects Effects 0.000 claims description 7
- 238000013461 design Methods 0.000 claims description 3
- 238000005488 sandblasting Methods 0.000 abstract description 24
- 239000004576 sand Substances 0.000 abstract description 10
- 239000010410 layer Substances 0.000 description 35
- 238000012856 packing Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 7
- 125000006850 spacer group Chemical group 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000002706 hydrostatic effect Effects 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 238000005299 abrasion Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/12—Packers; Plugs
- E21B33/128—Packers; Plugs with a member expanded radially by axial pressure
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/14—Obtaining from a multiple-zone well
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Abstract
The invention discloses a throttling-free self-service deblocking two-layer fracturing string which comprises a bell mouth, a sand-prevention hydraulic anchor, a throttling-free self-service deblocking packer and a hydraulic safety joint which are sequentially connected through an oil pipe from bottom to top, wherein the packer is set between two reservoir sections by sequentially replacing a pad fluid with the oil pipe during fracturing, balanced pressure is applied to an annular pipeline and fracturing construction is carried out on a first reservoir section, the pressure of the oil pipe is kept to maintain the setting to carry out fracturing construction on a second reservoir section, and the construction of taking out the string after the construction is finished; the fracturing string and the fracturing construction method can achieve two-layer fracturing construction under the condition that the sand blasting sliding sleeve does not need to be put in, throttling is not generated in the string, so that the overflowing rate and the overflowing speed are almost close to the full drift diameter of an oil pipe, flow limitation is effectively avoided, the requirement of large-scale fracturing construction is met, meanwhile, the safety and the sand conveying efficiency of the fracturing string are also improved, and the lifting safety of the fracturing string is effectively improved.
Description
Technical Field
The invention relates to the technical field of fracturing operation of oil and gas fields, in particular to a throttling-free self-service deblocking two-layer fracturing string and a fracturing method thereof.
Background
In recent years, along with the continuous deepening of the development of domestic oil and gas fields, the 'K344 packer + sand blasting sliding sleeve' layered fracturing technology becomes a main technology for improving the single-well yield of the oil and gas fields, the technology realizes the interlayer isolation of fracturing layer sections through the K344 packer, and the corresponding sand blasting sliding sleeve is opened through a throttling bottom valve and a pitching ball to carry out the step-by-step fracturing construction. However, for a two-layer fracturing string, the technology can only realize the fracturing from the inside of an oil pipe, the first layer of fracturing is firstly carried out through a throttling bottom valve, then a ball is thrown to open a sand blasting sliding sleeve for the second layer of fracturing, and meanwhile, a K344 packer also needs to realize the setting through throttling generated by the throttling bottom valve and a sand blasting hole of the sand blasting sliding sleeve, so that the following problems are exposed: (1) the throttling is generated by the throttling bottom valve in the fracturing string and the sand blasting holes of the sand blasting sliding sleeve, so that the friction resistance of the fracturing fluid is increased, the pumping pressure of a wellhead on the ground is increased, the construction discharge capacity, the sand adding amount and the construction scale are limited, the sand conveying efficiency is reduced, the requirement of large-scale fracturing construction cannot be met, meanwhile, the flow velocity of the fracturing fluid passing through the sand blasting holes is increased due to the throttling of the sand blasting holes of the sand blasting sliding sleeve, the abrasion of the sand blasting holes is intensified, the back-splashing generated by the high-flow-velocity fracturing fluid can also generate serious erosion damage to the sand blasting holes and the production casing, accidents such as fracturing string fracture, production casing deformation and the like can be possibly caused, and great risk is brought to subsequent shaft operation; (2) in the process of lowering the fracturing string, the K344 packer is easy to generate unnecessary advanced setting due to the fluctuation of the pressure in the well, so that the risk of friction damage to a packer rubber sleeve is caused; (3) after fracturing construction, the automatic deblocking of K344 packer expansion packing element, but the structural feature of packing element self has decided that the packing element can not retrieve completely, if meet sand blocking, then incomplete, the sand card of deblocking can appear, causes the risk of playing the tubular column difficulty or unable play tubular column.
Disclosure of Invention
The invention aims to provide a throttling-free self-service deblocking two-layer fracturing string, which solves the problem that the conventional 'K344 packer + sand blasting sliding sleeve' two-layer fracturing string can only realize the separate-layer fracturing from the interior of an oil pipe; the K344 packer needs to be set through throttling generated by a throttling bottom valve and a sand blasting hole of a sand blasting sliding sleeve, cannot meet the requirement of large-scale fracturing construction, and can possibly cause accidents such as fracturing pipe column fracture, production casing deformation and the like due to the throttling of the sand blasting hole of the sand blasting sliding sleeve; in the process of lowering the fracturing string, the K344 packer is easy to generate unnecessary advanced setting; and after the fracturing construction is finished, the K344 packer is not completely unpacked and is stuck by sand, so that the pipe string is difficult to pull up or cannot be pulled out.
The invention also aims to provide a fracturing method implemented by adopting the throttling-free self-service deblocking two-layer fracturing string.
Therefore, the technical scheme of the invention is as follows:
a throttling-free self-service deblocking two-layer fracturing string comprises a bell mouth, a first oil pipe, a sand-prevention hydraulic anchor, a throttling-free self-service deblocking packer, a second oil pipe, a hydraulic safety joint and a third oil pipe which are sequentially connected from bottom to top; the length of the first oil pipe and the length of the second oil pipe are matched with the distance between the first reservoir section and the second reservoir section, the bell mouth is located above the first reservoir section, the sand-prevention hydraulic anchor and the non-throttling self-service deblocking packer are located between the first reservoir section and the second reservoir section, and the hydraulic safety joint is located above the second reservoir section.
A fracturing method implemented by adopting the throttling-free self-service deblocking two-layer fracturing string comprises the following steps:
s1, running the throttling-free self-service deblocking two-layer fracturing string into a production casing to a target position, enabling the setting position of the throttling-free self-service deblocking packer to be located between two fracturing layer sections, and avoiding a casing coupling;
s2, opening a casing valve, and closing the casing valve after the front liquid is replaced in a third oil pipe at the top end of the pipe column; wherein the dosage of the pad fluid is consistent with the inner volume of the oil pipe, and the discharge capacity is less than or equal to 0.5m3/min；
S3, pressurizing the third oil pipe, sealing an annular space between the oil pipe and the production casing pipe, and enabling the choke-free self-service unsealing packer to complete primary sealing; continuously increasing the liquid pressure in the oil pipe to ensure that the sealing rubber cylinder of the packer achieves the best compression effect and the setting of the packer is finished; meanwhile, a deblocking mechanism of the non-throttling self-deblocking packer is contacted with liquid in the well and begins to dissolve;
s4, applying balance pressure to an annular space between the oil pipe and the production casing, and performing fracturing construction on a first reservoir section, namely a bottommost reservoir section, through the bell mouth;
s5, after fracturing construction of the first reservoir section is finished, keeping proper hydraulic pressure in the oil pipe to ensure that the non-throttling self-service unsealing packer maintains normal setting, and simultaneously performing fracturing construction on the second reservoir section through an annular space between the oil pipe and the production casing pipe according to fracturing construction design requirements;
s6, after fracturing construction of the two-layer reservoir stratum section is finished, reducing liquid pressure in the oil pipe, enabling the rubber sleeve of the non-throttling self-service deblocking packer to be deblocked quickly under the self resilience force of the rubber sleeve and the self-service deblocking force of the spring, or obtaining deblocking after a deblocking mechanism is dissolved, and taking out the non-throttling self-service deblocking two-layer fracturing pipe column.
Compared with the prior art, the throttling-free self-service deblocking two-layer fracturing string and the fracturing method thereof have the beneficial effects that:
(1) the throttling-free self-service deblocking two-layer fracturing string has the advantages that based on the characteristic that the setting of a throttling-free self-service deblocking packer is only related to the pressure in the string and is not related to the pressure difference between the inside and the outside of the string, the two-layer fracturing construction can be completed without a sand blasting sliding sleeve; after fracturing of the first reservoir stratum section is completed, as long as proper hydraulic pressure is continuously kept in the pipe column to ensure normal setting of the packer, fracturing construction of the second reservoir stratum section can be carried out through an annular space between the oil pipe and the production casing pipe without a sand blasting sliding sleeve;
(2) the throttling-free self-service deblocking two-layer fracturing string does not generate throttling, so that the over-flow and the over-flow speed are almost close to the full drift diameter of a 2-7/8' oil pipe, further, the flow limitation is effectively avoided, the requirement of large-scale fracturing construction is met, and meanwhile, the safety and the sand conveying efficiency of the fracturing string are also improved;
(3) the throttling-free self-service deblocking two-layer fracturing string adopts a throttling-free self-service deblocking packer to carry out setting, so that excessive movement of a power piston caused by excessive pressure difference in the string is avoided, and fatigue fracture of a rubber cylinder caused by excessive compression of the rubber cylinder is prevented, and the sealing effect is influenced; meanwhile, compared with the expansion rubber cylinder, the rubber cylinder bears large pressure difference and has stable setting effect;
(4) when the throttling-free self-service deblocking two-layer fracturing string is adopted to perform fracturing construction, in the process of setting the fracturing string, due to the setting of the pre-tightening force of the spring of the throttling-free self-service deblocking packer, the influence of the pressure of a hydrostatic column in a well can be balanced, the packer can be prevented from being mistakenly set in midway of the well, and the safety of setting the string is improved;
(5) after fracturing construction, quick deblocking under the resilience force of self and the self-service deblocking power double action of spring of this no-throttle self-service deblocking packer packing element in the two-layer fracturing string of unblock, or treat that deblocking mechanism obtains the deblocking after dissolving, plays out the two-layer fracturing string of the self-service deblocking of no-throttle, has improved the security that the fracturing string played out.
Drawings
FIG. 1 is a schematic structural diagram of a choke-free self-service deblocking two-layer fracturing string according to the present invention;
FIG. 2 is a schematic structural diagram of an initial state of a choke-free self-service unsetting packer for a choke-free self-service unsetting two-layer fracturing string according to the present invention;
fig. 3 is a schematic structural diagram of a setting state of the choke-free self-service unsetting packer for the choke-free self-service unsetting two-layer fracturing string.
Detailed Description
The invention will be further described with reference to the following figures and specific examples, which are not intended to limit the invention in any way. In the description of the present invention, it is to be understood that the terms "central," "lateral," "upper," "lower," "front," "rear," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the purpose of convenience and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and 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.
In the description of the invention, the term "initial state" refers to the non-working state of the non-throttling self-service unsetting packer; wherein, the horn mouth, the sand control hydraulic anchor, the hydraulic safety joint, the oil pipe and the production casing pipe that adopt in this no throttle self-service deblocking two-layer fracturing tubular column all adopt the product of selling on the market.
Example 1
As shown in fig. 1, the choke-free self-service deblocking two-layer fracturing string comprises a bell mouth a, a first oil pipe B, a sand-prevention hydraulic anchor C, a choke-free self-service deblocking packer D, a second oil pipe B, a hydraulic safety joint E and a third oil pipe B which are sequentially connected from bottom to top; wherein,
the lengths of the first oil pipe and the second oil pipe are adapted to the distance between the first reservoir section and the second reservoir section, so that the bell mouth is positioned above the first reservoir section, the sand-prevention hydraulic anchor and the non-throttling self-service deblocking packer are positioned between the first reservoir section and the second reservoir section, and the hydraulic safety joint is positioned above the second reservoir section; the first oil pipe, the second oil pipe and the third oil pipe are all 2-7/8' oil pipes;
as shown in fig. 2 and 3, the choke-free self-service unsetting packer comprises an upper joint 1, an upper central pipe 2, a sealing mechanism 3, a spring central pipe 4, a spring self-service unsetting mechanism 5, a lower central pipe 6, a setting-soluble unsetting mechanism 7 and a lower joint 8;
wherein, the fixed connection of 1 below of top connection is gone up center tube 2, 2 outer wall covers of going up center tube are equipped with sealing mechanism 3, go up 2 below fixed connection spring center tubes 4 of center tube, the self-service deblocking mechanism 5 of spring is installed to the outer wall of spring center tube 4, sealing mechanism 3 below supports and presses on the top terminal surface that spring center tube 4 and the self-service deblocking mechanism 5 of spring form jointly, spring center tube 4 below fixed connection lower center tube 6 and constitute a spring groove, seat-soluble deblocking mechanism 7 is installed to 6 outer walls of lower center tube, seat-soluble deblocking mechanism 7 top and the self-service deblocking mechanism 5 below fixed connection of spring, lower center tube 6 below fixed connection lower extreme 8 internal threads, seat-soluble deblocking mechanism 7 below fixed connection lower extreme 8 external threads, lower center tube 6 inner wall is opened there is the biography pressure hole, the mid portion is provided with spacing step.
Sealing mechanism 3 includes packing element 31 and spacer ring 32, and packing element 31 top and the contact of top connection 1 below terminal surface, spacer ring 32 and packing element 31 below contact, and spacer ring 32 below supports to press on the top terminal surface that forms jointly of spring center tube 4 and the self-service deblocking mechanism 5 of spring.
The spring self-service unsealing mechanism 5 comprises a connecting sleeve 51, a spring 52 and a pressing ring 53, the spring 52 and the pressing ring 53 are arranged in a spring groove formed by fixedly connecting the spring central tube 4 and the lower central tube 6 from top to bottom, the connecting sleeve 51 is arranged outside the spring central tube 4 and is pressed against the end face below the spacer ring 32 from the top, and the connecting sleeve is fixedly connected with the setting-soluble mechanism 7 from the bottom.
The setting-soluble unsealing mechanism 7 comprises a power piston 71, a soluble plunger 74, a protective sleeve 76, an anti-rotation pin 79 and a plurality of O-shaped sealing rings;
wherein, the power piston 71 is sleeved on the outer wall of the lower central tube 6, the upper part of the power piston 71 is fixedly connected with the connecting sleeve 51, the upper inner wall of the power piston 71 is sealed with the upper boss of the lower central tube 6 through the first O-shaped sealing ring 72, the lower boss of the power piston 71 is sealed with the lower outer wall of the lower central tube 6 through the fourth O-shaped sealing ring 77, the lower outer wall of the power piston 71 is provided with the soluble plunger 74, the sealing surface of the lowermost part of the power piston 71 and the outer wall of the lower joint 8 is sealed through the fifth O-shaped sealing ring 78, the lower outer wall of the power piston 71 is provided with the protective sleeve 76 and is sealed through the second O-shaped sealing ring 73, the lower part of the protective sleeve 76 is fixedly connected with the external thread of the lower joint 8 and is circumferentially fixed through the anti-rotation pin 79, the soluble plungers 74 are circumferentially and symmetrically distributed, and have 2 in total and are arranged in the plunger holes of the power piston 71, the upper part of the soluble plunger 74 is fixedly connected with the inner thread of the plunger hole of the power piston 71 through an outer thread, the power piston 71, the lower joint 8 and the lower central tube 6 form a power cavity, the power piston 71 and the lower central tube 6 form an air cavity, and the cross sections of two ends of the external movable part of the power piston 71 are equal.
The specific working principle of the non-throttling self-service deblocking packer is as follows:
setting: pressurizing from the inside of an oil pipe, wherein pressure acts on a power piston 71 through a pressure transfer hole on a lower central pipe 6 to push the power piston 71 to move upwards, meanwhile, a compression ring 53 is pushed to compress a spring 52, a spacer ring 32 is pushed to move upwards to compress a rubber barrel 31 through a connecting sleeve 51 fixedly connected with the power piston 71, when the pressure reaches a set pressure, an annular space between an oil pipe F and a sleeve G is sealed, at the moment, a throttling-free self-service deblocking packer completes initial sealing, the pressure of the oil pipe F is continuously improved, when the power piston 7 moves upwards to a limiting step on the lower central pipe 6, the rubber barrel 31 achieves an optimal compression effect, at the moment, the throttling-free self-service deblocking packer completes setting, and meanwhile, a soluble plunger 74 arranged in a plunger hole of the power piston 71 is exposed to be in contact with liquid in a well and begins;
and (3) deblocking process: after the oil pipe is decompressed, the spring 52 automatically moves downwards by the resilience force of the spring, the power piston 71 is pushed to move downwards through the compression ring 53, a free space is reserved for the rubber cylinder 31, and the rubber cylinder 31 moves downwards by the resilience force of the spring because the rubber cylinder 31 is not restrained by the downward pressure, so that the deblocking is completed;
if the pressure existing in the oil pipe is larger than the primary sealing pressure of the non-throttling self-service deblocking packer after the oil pipe is depressurized, although the non-throttling self-service deblocking packer is still in a setting state, after a certain time, the soluble plunger 74 is dissolved, the pressure of a power cavity and the pressure of an air cavity of the power piston 7 are balanced, the spring 52 self-automatically goes down by the resilience of the spring, the power piston 71 is pushed to go down by the compression ring 53 to leave a free space for the rubber sleeve 31, the rubber sleeve 31 goes down by the resilience of the rubber sleeve 31 due to the fact that the rubber sleeve 31 is not restrained by the downlink pressure, and the non-throttling self-service deblocking packer completes deblocking at the moment.
When the non-throttling self-service deblocking packer is used on two layers of fracturing strings in a fracturing construction process, in the process of setting the fracturing string, due to the setting of the pre-tightening force of the spring of the non-throttling self-service deblocking packer, the influence of the pressure of a hydrostatic string in a well can be balanced, the packer can be prevented from being mistakenly set in midway of the well, and the safety of setting the string is improved; during fracturing construction, the setting of the non-throttling self-service deblocking packer is only related to the pressure in the pipe column and is unrelated to the pressure difference between the inside and the outside of the pipe column, so that two-layer fracturing construction can be completed without putting in a sand blasting sliding sleeve, after fracturing of a first reservoir section is completed, as long as proper hydraulic pressure is continuously kept in the pipe column to ensure normal setting of the packer, fracturing construction of a second reservoir section can be performed through an annular space between an oil pipe and a production casing pipe without putting in the sand blasting sliding sleeve, and because a packer is not required to be set through throttling generated by a throttling bottom valve and a throttling sand blasting sliding sleeve matched with the fracturing pipe column, large-displacement and large-scale fracturing construction transformation can be realized, and the working efficiency of fracturing construction is improved; after fracturing construction is finished, the packer rubber barrel of the non-throttling self-service deblocking packer can be rapidly deblocked under the double effects of self resilience and self-service deblocking force of the spring, if high pressure exists in a well and is larger than the setting pressure of the non-throttling self-service deblocking packer, when the packer cannot be deblocked, a soluble plunger is in contact with liquid in the well, the soluble plunger is dissolved within a certain time, and the pressure of a power piston power cavity and the pressure of an air cavity are balanced. The non-throttling self-service deblocking packer does not need throttling setting, and when the packer achieves the sand passing amount of the maximum drift diameter, the drift diameter is increased, so that the flow rate of sand-containing liquid in the packer is reduced, the abrasion of components in the packer is reduced, and the service life of the packer is prolonged.
Example 2
A fracturing method implemented by adopting the choke-free self-service deblocking two-layer fracturing string in the embodiment 1 comprises the following specific implementation steps:
s1, assembling a throttling-free self-service deblocking two-layer fracturing string according to the condition of a reservoir in an oil and gas well, and putting a production casing F into a target position to enable the setting position of a throttling-free self-service deblocking packer D to be located between two fracturing layer sections and avoid a casing coupling;
s2, opening a casing valve, and closing the casing valve after the front liquid is replaced in the third oil pipe B at the top end of the pipe column; wherein the dosage of the pad fluid is consistent with the inner volume of the oil pipe, and the discharge capacity is less than or equal to 0.5m3/min；
S3, pressurizing the third oil pipe B, enabling pressure to act on the power piston 71 through a pressure transfer hole in the lower central pipe 6 in the non-throttling self-service unsetting packer D, pushing the power piston 71 to go upward, pushing the compression ring 53 to compress the spring 52 at the same time, pushing the spacer ring 32 to go upward through the connecting sleeve 51 fixedly connected with the power piston 71 to compress the rubber sleeve 31, enabling the non-throttling self-service unsetting packer D to complete preliminary sealing, and sealing an annular space between the oil pipe and the production casing pipe;
the liquid pressure in the third oil pipe B is continuously increased, when the power piston 71 moves upwards to the limiting step on the lower central pipe 6, the rubber barrel 31 achieves the optimal compression effect, the choke-free self-service unsetting packer D completes setting, and meanwhile, the soluble plunger 74 installed in the plunger hole of the power piston 71 is exposed to contact with liquid in the well and begins to dissolve;
in the process, the setting of the pre-tightening force of the spring of the non-throttling self-service deblocking packer can balance the influence of the pressure of a hydrostatic column in the well, avoid the mistaken setting of the packer in the midway of the well descending and improve the safety of the descending of the tubular column; meanwhile, during fracturing construction, the setting of the non-throttling self-service unsetting packer is only related to the pressure in the pipe column and is unrelated to the pressure difference between the inside and the outside of the pipe column, and the packer is not required to be set by throttling generated by a throttling bottom valve and a throttling sand blasting sliding sleeve matched with the fracturing pipe column, so that large-displacement and large-scale fracturing construction transformation can be realized, and the working efficiency of fracturing construction is improved;
s4, applying balance pressure to an annular space between the oil pipe and the production casing, and performing fracturing construction on a first reservoir section, namely a bottommost reservoir section, through the bell mouth A;
s5, after fracturing construction of the first reservoir section is finished, keeping proper hydraulic pressure in the third oil pipe B to ensure that the non-throttling self-service unsetting packer D maintains normal setting, and simultaneously performing fracturing construction on the second reservoir section through an annular space between the oil pipe and the production casing pipe according to fracturing construction design requirements;
s6, after fracturing construction of the two-layer reservoir stratum section is finished, the spring 52 of the non-throttling self-help unsetting packer D automatically moves downwards by the resilience force of the spring, the power piston 71 is pushed to move downwards through the compression ring 53, a free space is reserved for the rubber barrel 31, the rubber barrel 31 moves downwards by the resilience force of the rubber barrel 31 due to the fact that downward pressure constraint does not exist in the rubber barrel 31, and unsetting of the non-throttling self-help unsetting packer D is finished; if the pressure that exists in the oil pipe B is greater than during the pressure of just sealing of the self-service deblocking packer D of no throttle, this moment the self-service deblocking packer D of no throttle still is in the setting state, in a certain time, soluble plunger 74 dissolves, power piston 7's power chamber and air chamber pressure realize the balance, spring 52 leans on the resilience force of self to descend by oneself, it is down to promote power piston 71 through clamping ring 53, reserve free space for packing element 31, because packing element 31 does not have down pressure restraint, packing element 31 depends on the resilience force of self to descend, the self-service deblocking packer D of no throttle accomplishes the deblocking.
It is to be noted and understood that various modifications and improvements can be made to the invention described in detail above without departing from the spirit and scope of the invention as claimed in the appended claims. Accordingly, the scope of the claimed subject matter is not limited by any of the specific exemplary teachings provided.
The applicants hereby give notice that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (2)
1. A throttling-free self-service deblocking two-layer fracturing string is characterized by comprising a bell mouth, a first oil pipe, a sand-prevention hydraulic anchor, a throttling-free self-service deblocking packer, a second oil pipe, a hydraulic safety joint and a third oil pipe which are sequentially connected from bottom to top; the length of the first oil pipe and the length of the second oil pipe are matched with the distance between the first reservoir section and the second reservoir section, the bell mouth is located above the first reservoir section, the sand-prevention hydraulic anchor and the non-throttling self-service deblocking packer are located between the first reservoir section and the second reservoir section, and the hydraulic safety joint is located above the second reservoir section.
2. A fracturing method implemented by using the choke-free self-service deblocking two-layer fracturing string of claim 1, characterized by the steps of:
s1, putting the two-layer fracturing string without throttling self-service deblocking into a production casing to a target position, and enabling the setting position of the packer without throttling self-service deblocking to be located between two fracturing intervals;
s2, opening a casing valve, and closing the casing valve after the front liquid is replaced in a third oil pipe at the top end of the pipe column; wherein the dosage of the pad fluid is consistent with the inner volume of the oil pipe, and the discharge capacity is less than or equal to 0.5m3/min；
S3, pressurizing the third oil pipe, sealing an annular space between the oil pipe and the production casing pipe, and enabling the choke-free self-service unsealing packer to complete primary sealing; continuously increasing the liquid pressure in the oil pipe to ensure that the sealing rubber cylinder of the packer achieves the best compression effect and the setting of the packer is finished; meanwhile, a deblocking mechanism of the non-throttling self-deblocking packer is contacted with liquid in the well and begins to dissolve;
s4, applying balance pressure to an annular space between the oil pipe and the production casing, and performing fracturing construction on a first reservoir section, namely a bottommost reservoir section, through the bell mouth;
s5, after fracturing construction of the first reservoir section is finished, keeping proper hydraulic pressure in the oil pipe to ensure that the non-throttling self-service unsealing packer maintains normal setting, and simultaneously performing fracturing construction on the second reservoir section through an annular space between the oil pipe and the production casing pipe according to fracturing construction design requirements;
s6, after fracturing construction of the two-layer reservoir stratum section is finished, reducing liquid pressure in the oil pipe, enabling the rubber sleeve of the non-throttling self-service deblocking packer to be deblocked quickly under the self resilience force of the rubber sleeve and the self-service deblocking force of the spring, or obtaining deblocking after a deblocking mechanism is dissolved, and taking out the non-throttling self-service deblocking two-layer fracturing pipe column.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010962657.1A CN111963135A (en) | 2020-09-14 | 2020-09-14 | Throttling-free self-service deblocking two-layer fracturing string and fracturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010962657.1A CN111963135A (en) | 2020-09-14 | 2020-09-14 | Throttling-free self-service deblocking two-layer fracturing string and fracturing method thereof |
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| Publication Number | Publication Date |
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| CN111963135A true CN111963135A (en) | 2020-11-20 |
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| CN202010962657.1A Withdrawn CN111963135A (en) | 2020-09-14 | 2020-09-14 | Throttling-free self-service deblocking two-layer fracturing string and fracturing method thereof |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020162660A1 (en) * | 2000-12-20 | 2002-11-07 | Karol Depiak | Straddle packer systems |
| US20040163811A1 (en) * | 2003-02-19 | 2004-08-26 | Mckee L. Michael | Fracturing tool having tubing isolation system and method |
| CN1752404A (en) * | 2004-09-20 | 2006-03-29 | 西安益友石油科技有限公司 | Gas well separate layer fracturing and producing integrated well completing pipe string and technique |
| CN106481326A (en) * | 2015-09-02 | 2017-03-08 | 中国石油化工股份有限公司 | The no chock pressure difference fracturing strings of self controllable supercharging |
| CN206053921U (en) * | 2016-08-26 | 2017-03-29 | 中国石油化工股份有限公司 | A kind of self-unsealing successively sand washing layered fracturing pipe string |
| CN109538182A (en) * | 2018-11-19 | 2019-03-29 | 中国石油集团渤海钻探工程有限公司 | It is a kind of without the self-service deblocking packer of throttling |
-
2020
- 2020-09-14 CN CN202010962657.1A patent/CN111963135A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020162660A1 (en) * | 2000-12-20 | 2002-11-07 | Karol Depiak | Straddle packer systems |
| US20040163811A1 (en) * | 2003-02-19 | 2004-08-26 | Mckee L. Michael | Fracturing tool having tubing isolation system and method |
| CN1752404A (en) * | 2004-09-20 | 2006-03-29 | 西安益友石油科技有限公司 | Gas well separate layer fracturing and producing integrated well completing pipe string and technique |
| CN106481326A (en) * | 2015-09-02 | 2017-03-08 | 中国石油化工股份有限公司 | The no chock pressure difference fracturing strings of self controllable supercharging |
| CN206053921U (en) * | 2016-08-26 | 2017-03-29 | 中国石油化工股份有限公司 | A kind of self-unsealing successively sand washing layered fracturing pipe string |
| CN109538182A (en) * | 2018-11-19 | 2019-03-29 | 中国石油集团渤海钻探工程有限公司 | It is a kind of without the self-service deblocking packer of throttling |
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Application publication date: 20201120 |