CN110566159B - Oil-gas well fracturing transformation process adopting time-delay opening toe end sliding sleeve - Google Patents
Oil-gas well fracturing transformation process adopting time-delay opening toe end sliding sleeve Download PDFInfo
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- CN110566159B CN110566159B CN201910898555.5A CN201910898555A CN110566159B CN 110566159 B CN110566159 B CN 110566159B CN 201910898555 A CN201910898555 A CN 201910898555A CN 110566159 B CN110566159 B CN 110566159B
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- 230000008569 process Effects 0.000 title claims abstract description 34
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- 239000007788 liquid Substances 0.000 claims abstract description 18
- 238000005553 drilling Methods 0.000 claims abstract description 14
- 230000006872 improvement Effects 0.000 claims abstract description 5
- 230000007246 mechanism Effects 0.000 claims description 110
- 239000010720 hydraulic oil Substances 0.000 claims description 42
- 239000003921 oil Substances 0.000 claims description 24
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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
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/063—Valve or closure with destructible element, e.g. frangible disc
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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
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/12—Valve arrangements for boreholes or wells in wells operated by movement of casings or tubings
- E21B34/125—Valve arrangements for boreholes or wells in wells operated by movement of casings or tubings with time delay systems, e.g. hydraulic impedance mechanisms
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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
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/14—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools
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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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Abstract
The invention provides an oil and gas well fracturing improvement process adopting a time-delay opening toe end sliding sleeve, which comprises the following steps: arranging the delay opening toe sliding sleeve at a preset position in the shaft; starting the whole-well-barrel pressure test by using an initial pressure value, gradually increasing the pressure test pressure until reaching a peak pressure test value, delaying to open the toe end sliding sleeve for starting and delaying when the sum of the pressure test pressure and the pressure of a drilling fluid liquid column reaches a first preset pressure value, delaying to open the toe end sliding sleeve to finish delaying and realize fracturing after the whole-well-barrel pressure test is finished, wherein the first preset pressure value is smaller than the sum of the peak pressure test pressure value and the pressure of the drilling fluid liquid column and is larger than the initial pressure value. The invention can be used for realizing the first-stage fracturing transformation of an oil-gas well (such as a shale gas well), has simple structure and convenient operation, and can effectively solve the technical problems of harsh error range of the opening pressure of the toe end sliding sleeve, uncontrollable opening time, low opening success rate and the like in the prior art.
Description
Technical Field
The invention relates to the technical field of downhole operation in the oil and gas industry, in particular to a method for realizing first-stage fracturing reformation of an oil and gas well (such as a shale gas well) by using a time-delay opening toe end sliding sleeve.
Background
At present, the first-stage fracturing modification mode of a shale gas well has two modes: one is coiled tubing transfer perforation; the other is a toe end sliding sleeve. The continuous oil pipe transmission perforation mode is mature and reliable in technology, but low in construction timeliness and limited in putting in an ultra-long horizontal well; the toe end sliding sleeve mode is directly suppressed and opened, the construction timeliness is high, and the toe end sliding sleeve mode is not limited by the length of a horizontal section. Compared with a continuous oil pipe transmission perforation mode, the toe end sliding sleeve has the advantages of high operation timeliness, low cost, small risk, unlimited operation depth and the like, but because the toe end sliding sleeve technology is immature, the opening success rate is low, and the shale gas first-section fracturing channel still takes the continuous oil pipe transmission perforation as a main part at present.
Because the shale gas reservoir permeability is extremely low, the shale gas yield is closely related to the drilling quantity and the fracturing scale, with the continuous progress of the drilling technology, a horizontal well with an ultra-long horizontal section (more than 2500 meters) is a development trend for efficiently developing shale gas, and the continuous oil pipe transmission perforation mode cannot meet the requirement of the first section fracturing perforation of a deep and ultra-long horizontal well. The inventor considers through research and analysis that the opening success rate of the existing toe end sliding sleeve technology is low, and the main reason is that the following technical defects exist:
1. before fracturing construction of shale gas wells in China, full-well pressure testing is needed to test the sealing property of a shaft, for example, the pressure testing pressure (equivalent to pump pressure) is sometimes as high as 90 MPa; however, for a commonly used ground high-pressure manifold, the pressure-bearing grade is 15000psi, and the maximum pressure limit during construction is not allowed to exceed 100 MPa; therefore, for such situations, the opening pump pressure of the existing toe end sliding sleeve can only be in the range of 90-100 MPa, the opening pressure of the corresponding toe end sliding sleeve needs to be in the range of (90+ P) to (100+ P) MPa, and the allowable opening pressure error range is strict, wherein P is the pressure generated by the drilling fluid column;
2. in the whole well bore pressure testing process, the pressure testing pressure can gradually rise from the condition that the pressure value is 60MPa to a peak pressure value (for example, 90MPa), the opening pressure of the existing toe end sliding sleeve is generally required to be higher than the sum of the peak pressure value and the pressure of a drilling fluid column (for example, 120MPa), and the requirement on the toe end sliding sleeve is overhigh;
3. most of the existing toe end sliding sleeves are opened in a rupture disc rupture mode, the mode is instantaneous opening, and the toe end sliding sleeves are low in opening success rate and uncontrollable in opening time due to the fact that cement slurry has large influence on opening pressure after being solidified.
Disclosure of Invention
The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, it is an object of the present invention to provide a method of performing fracture modification of an oil or gas well (e.g., shale gas well) using a time-delayed opening toe sleeve.
For another example, another object of the present invention is to effectively solve one or more of the technical problems of the prior art, such as a harsh opening pressure error range of the toe end sliding sleeve, an uncontrollable opening time, or a low opening success rate.
In order to achieve the aim, the invention provides an oil and gas well fracturing modification process adopting a time-delay opening toe end sliding sleeve, which comprises the following steps: arranging the delay opening toe sliding sleeve at a preset position in the shaft; starting a full-well-barrel pressure test at an initial pressure value, gradually increasing the pressure test pressure until a peak pressure test value is reached, when the sum of the pressure test pressure and the pressure of a drilling fluid liquid column reaches a first preset pressure value, delaying to open a toe end sliding sleeve for starting and delaying, delaying to open a toe end sliding sleeve for completing delaying and realizing fracturing after the full-well-barrel pressure test is finished, wherein the first preset pressure value is smaller than the sum of the peak pressure test pressure value and the pressure of the drilling fluid liquid column and is larger than the initial pressure value, the delaying to open the toe end sliding sleeve comprises an opening mechanism, a delaying mechanism, an adjusting mechanism, a fracturing port, a coaxially arranged shell, a movable piston and an inner sleeve, and the inner sleeve is provided with an upper end fixedly connected with the lower end of the movable piston; the shell is sleeved outside the movable piston and the inner sleeve, and a first cavity and a second cavity which are communicated with the movable piston and/or the inner sleeve along the direction parallel to the shaft are formed between the shell and the movable piston and/or the inner sleeve; the adjusting mechanism comprises an overflow valve body, an overflow valve core, a spring and a first adjusting piece, wherein a first through hole and a second through hole are arranged in the overflow valve body, the first through hole and the second through hole are communicated with each other, the diameter of the second through hole is larger than that of the first through hole, the overflow valve core is arranged in the second through hole and is provided with one end for plugging the first through hole and the other end connected with the spring, the spring is compressible, and the spring is connected with the overflow valve body through the first adjusting piece; the delay mechanism comprises a flow-limiting valve body, a flow-limiting valve core, a damping rod and a second adjusting piece, wherein a first through hole and a second through hole are arranged in the flow-limiting valve body, the first through hole and the second through hole are communicated with each other, the diameter of the second through hole is larger than that of the first through hole, the flow-limiting valve core is arranged in the second through hole and provided with one end for plugging the first through hole and the other end connected with the flow-limiting valve body through the second adjusting piece, and the damping rod is arranged in the first through hole; the time delay mechanism and the adjusting mechanism are arranged in the first cavity and are relatively fixed with the movable piston and/or the inner sleeve, the first through hole is communicated with the second through hole, the time delay mechanism and the adjusting mechanism divide the first cavity into a working cavity communicated with the first through hole and a time delay cavity communicated with the second through hole, the working cavity is in sealing fit with an overflow valve body of the adjusting mechanism, the working cavity is communicated with the second cavity and is filled with hydraulic oil, the time delay cavity is a cavity, and the second cavity, the overflow valve body of the adjusting mechanism and a flow limiting valve body of the time delay mechanism can form a gap through which the hydraulic oil flows; the opening mechanism is arranged on the movable piston and can be opened when the wellbore liquid reaches the first preset pressure value, so that the wellbore liquid applies force to the movable piston towards the second cavity; the fracturing port is arranged at the position where the shell is matched with the movable piston, and the distance between the fracturing port and the upper end face of the movable piston is equal to or slightly larger than the distance between the end face of the flow-limiting valve body close to the delay cavity and the end face of the second cavity close to the working cavity. For example, the first predetermined pressure value can be selected within the range of 60-120 MPa.
In an exemplary embodiment of the present invention, the toe end slip used in the oil and gas well fracture modification process may further comprise a lower joint connected with the lower end of the housing.
In an exemplary embodiment of the present invention, the toe end sliding sleeve used in the oil and gas well fracturing modification process may further include a first shear connector, wherein the first shear connector fixedly connects the movable piston or the inner sleeve with the housing, and is capable of breaking and releasing the movable piston when the pressure applied to the movable piston reaches a second predetermined pressure value, so that the movable piston directly or indirectly drives the adjusting mechanism to move along the shaft toward the second cavity. The number of first shear connectors may be one or more. In addition, the toe end sliding sleeve can further comprise a second shearing connecting piece, the second shearing connecting piece fixedly connects the movable piston or the inner sleeve with the shell and can break when the pressure borne by the piston reaches a third preset pressure value, and the third preset pressure value is smaller than the second preset pressure value. For example, the toe sleeve may include a plurality of second shear connectors.
In an exemplary embodiment of the invention, the time delay mechanism in the toe end sliding sleeve used in the oil and gas well fracturing modification process may have more than two damping rods, which may be disposed in series within the first through-hole.
In an exemplary embodiment of the invention, the opening mechanism in the toe end sliding sleeve used in the hydrocarbon well fracturing improvement process may include a hydraulic cylinder, a control shear pin, a control piston, and a sealing plug, wherein the sealing plug has a piston cavity cooperating with the control piston, and an outer wall sealingly connected with the movable piston, the hydraulic cylinder is formed between the movable piston and the housing and is capable of being in fluid communication with the wellbore through the piston cavity, the control shear pin secures the control piston in the piston cavity to block the communication of the hydraulic cylinder with the wellbore fluid, the control shear pin is capable of breaking when the wellbore fluid reaches the first predetermined pressure value, and releases the control piston to allow the wellbore fluid to enter the hydraulic cylinder.
Drawings
FIG. 1 shows a schematic structural view of a time-delayed opening toe sleeve used in an exemplary embodiment of the oil and gas well fracture modification process of the present invention;
FIG. 2 is an enlarged partial schematic view of the adjustment mechanism and time delay mechanism of FIG. 1;
fig. 3 shows a partially enlarged schematic view of the opening mechanism of fig. 1.
The reference numerals are explained below:
1. the hydraulic oil-pressure control device comprises a shell, 2, a movable piston, 3, a piston shear pin, 4, a limiting shear pin, 5, an opening mechanism, 6, a delay mechanism, 7, an adjusting mechanism, 8, an inner sleeve, 9, a hydraulic oil ring, 10, a lower joint, 11, a fracturing port, 12, a control shear pin, 13, a control piston, 14, a sealing plug, 15, a delay cavity, 16, a flow-limiting adjusting screw, 17, a flow-limiting valve core, 18, a flow-limiting valve body, 19, a damping rod, 20, a spring adjusting screw, 21, a spring, 22, an overflow valve core, 23, an overflow valve body, 24, a hydraulic oil cavity, 25 and a failure step surface.
Detailed Description
Hereinafter, the improved process for fracturing a hydrocarbon well using a time delay opening toe end sleeve of the present invention will be described in detail with reference to exemplary embodiments. It should be noted that "first", "second", "third", "fourth", etc. are merely for convenience of description and for convenience of distinction, and are not to be construed as indicating or implying relative importance. "upper," "lower," "inner," and "outer" are merely used for convenience of description and to constitute relative orientations or positional relationships, and do not indicate or imply that the referenced components must have that particular orientation or position.
In one exemplary embodiment of the present invention, a hydrocarbon well fracture modification process employing a time-delayed opening toe sleeve may be achieved by:
arranging the delay opening toe sliding sleeve at a preset position in the shaft;
starting the whole-well-barrel pressure test by taking the initial value of the pressure test pressure, gradually increasing the pressure test pressure until the peak pressure test pressure value is reached, delaying to open the toe-end sliding sleeve for starting and delaying when the sum of the pressure test pressure and the pressure of a drilling fluid liquid column reaches a first preset pressure value, delaying to open the toe-end sliding sleeve to finish delaying and realize fracturing after the whole-well-barrel pressure test is finished, wherein the first preset pressure value is smaller than the sum of the peak pressure test pressure value and the pressure of the drilling fluid liquid column and is larger than the initial value. Here, the drilling fluid column pressure is related to the predetermined location. For example, the first predetermined pressure value can be selected in the range of 60 to 120 MPa. For another example, the first predetermined pressure value may be 65 to 80 MPa. For those of ordinary skill in the art, the term "pressure" in part herein corresponds to pressure.
In an exemplary embodiment of the invention, a time delay opening toe end sliding sleeve used in the oil and gas well fracturing modification process can comprise a shell, a movable piston and an inner sleeve which are coaxially arranged, as well as an opening mechanism, a time delay mechanism, an adjusting mechanism, a first shearing connecting piece and a fracturing port.
Specifically, the upper end of the inner sleeve is fixedly connected with the lower end of the movable piston. The shell is sleeved outside the movable piston and the inner sleeve, and a first cavity and a second cavity which are communicated with the movable piston and/or the inner sleeve along the direction parallel to the shaft are formed between the shell and the movable piston and/or the inner sleeve. It is also said that the housing may form a first chamber and a second chamber communicating with the movable piston and the inner sleeve in a direction parallel to the axis, for example, the first chamber is formed between the housing and a lower portion of the movable piston, and the second chamber is formed between the housing and upper and middle portions of the inner sleeve. However, the present invention is not limited thereto, and for example, the first and second cavities may be formed between the housing and the inner sleeve, or between the housing and the movable piston.
The adjustment mechanism may include a spill valve body, a spill valve cartridge, a spring, and a first adjustment member. The overflow valve comprises an overflow valve body, an overflow valve core and a first regulating piece, wherein a first through hole and a second through hole which are communicated with each other are formed in the overflow valve body, the diameter of the second through hole is larger than that of the first through hole, the overflow valve core is arranged in the second through hole and provided with one end for plugging the first through hole and the other end connected with a spring, and the spring is connected with the overflow valve body through the first regulating piece. The first adjusting member may be an adjusting screw, but the present invention is not limited thereto, and other members capable of connecting the other end of the relief valve spool to the relief valve body may be used. When one end of the overflow valve core, which is used for plugging the first through hole, is pushed by hydraulic oil with gradually increased pressure, the spring contracts, the plugging of the first through hole is released by the end of the overflow valve core, and the hydraulic oil can flow through the first through hole and the second through hole of the overflow valve body.
The time delay mechanism may include a flow-limiting valve body, a flow-limiting valve spool, a damping rod, and a second adjustment member. The flow limiting valve is internally provided with a first through hole and a second through hole which are communicated with each other, and the diameter of the second through hole is larger than that of the first through hole. The flow-limiting valve core is arranged in the second through hole and is provided with one end for plugging the first through hole and the other end connected with the flow-limiting valve body through the second adjusting piece. The second adjusting piece can drive the flow limiting valve core to remove the blockage of the first through hole under the condition that one end of the flow limiting valve core is subjected to hydraulic oil pressure, so that hydraulic oil flows through the first through hole and the second through hole, wherein the first through hole is provided with a damping rod. The second adjusting member may be an adjusting screw, but the invention is not limited thereto, and other members capable of connecting the other end of the flow restriction valve core to the flow restriction valve body and driving the flow restriction valve core due to the pressure of the flow restriction valve core are also possible. The damping rod is arranged in the first through hole and can play a certain degree of blocking effect on hydraulic oil entering the first through hole. Specifically, the damping rod and the first through hole can be in clearance fit, for example, the clearance between the damping rod and the first through hole can be 1-10 μm, so that when hydraulic oil enters the time delay mechanism, the hydraulic oil is firstly throttled through an annular clearance formed by the damping rod and the first through hole. For example, the damping rod may be a rod body made of metal or ceramic. Further, the time delay mechanism may further have a plurality of damping rods, and the plurality of damping rods may be disposed in series in the first through hole.
The time delay mechanism and the adjusting mechanism are arranged in the first cavity, are relatively fixed with the movable piston and/or the inner sleeve, and divide the first cavity into a working cavity communicated with the first through hole and a time delay cavity communicated with the second through hole. The time delay mechanism and the adjusting mechanism can be in end face contact fit or have a certain interval, as long as the first through hole is communicated with the second through hole. The working chamber is in sealing fit with the overflow valve body of the adjusting mechanism, the working chamber is communicated with the second cavity, and the working chamber and the second cavity are both filled with hydraulic oil. The time delay cavity is a cavity which is not filled with hydraulic oil. The second cavity, the overflow valve body of the adjusting mechanism and the flow-limiting valve body of the delay mechanism can form a gap through which the hydraulic oil flows. For example, the aperture of the second cavity may be larger than the aperture of the working cavity. When the adjusting mechanism and the delay mechanism are driven by the shell and/or the inner sleeve connected with the adjusting mechanism to move towards the second cavity, hydraulic oil in the working cavity and the second cavity is compressed and can only enter the delay cavity after sequentially passing through the first through hole and the second through hole of the adjusting mechanism and the first through hole and the second through hole of the delay mechanism; when the adjusting mechanism and the delay mechanism are brought into the second cavity by the shell and/or the inner sleeve connected with the adjusting mechanism and the delay mechanism, hydraulic oil in the second cavity directly enters the working cavity and the delay cavity through the gap, namely, the adjusting mechanism and the delay mechanism are invalid at the moment. For example, the time delay mechanism can be fixedly arranged at the lower part of the movable piston, the adjusting mechanism can be fixedly arranged at the upper part of the inner sleeve, and the first through hole of the time delay mechanism is communicated with the second through hole of the adjusting mechanism. However, the present invention is not limited thereto, and for example, the delay mechanism and the adjustment mechanism may be provided together on the inner sleeve or the movable piston.
The opening mechanism is arranged on the movable piston and can be opened when the wellbore liquid reaches a first preset pressure value, so that the wellbore liquid applies force to the movable piston towards the second cavity. Here, the first predetermined pressure value may be determined according to the well depth, the cementing construction pressure, and the drilling fluid medium (mud), etc. For example, the first predetermined pressure may be greater than a starting value (or minimum value) of the full wellbore test pressure and less than a peak value of the test pressure. For example, the first predetermined pressure value can be selected in the range of 60 to 120 MPa. For example, the opening mechanism may include a hydraulic cylinder, a control shear pin, a control piston, and a sealing plug. Wherein, the sealing plug is provided with a piston cavity matched with the control piston and an outer wall hermetically connected with the movable piston; the hydraulic cylinder is formed between the movable piston and the housing and is capable of being in fluid communication with the wellbore through the piston cavity; the control shear pin fixes the control piston in the piston cavity to block the communication between the hydraulic cylinder and the shaft liquid; the control shear pin is capable of breaking when the wellbore fluid reaches the first predetermined pressure value and releasing the control piston to allow the wellbore fluid to enter the hydraulic cylinder such that the wellbore fluid applies a force to the movable piston towards the second chamber. However, the opening mechanism of the present invention is not limited thereto, and other members capable of opening when the wellbore fluid reaches the first predetermined pressure value, so that the wellbore fluid applies a force to the movable piston towards the second chamber, are also possible.
The first shearing connecting piece can be arranged to fixedly connect the movable piston or the inner sleeve with the shell, and can break and release the movable piston when the pressure born by the movable piston reaches a second preset pressure value, so that the movable piston directly or indirectly drives the adjusting mechanism to move towards the second cavity along the shaft. The pressure experienced by the movable piston is exerted by the wellbore fluid. Here, the second predetermined pressure value may substantially correspond to the first set pressure value. The number of first shear connectors may be plural. For example, the first shear connector may be a piston shear pin. That is, the first shear connector is configured to relatively secure the movable piston and the inner sleeve within the housing, and when the pressure applied by the wellbore fluid to the movable piston reaches a second predetermined pressure value, the first shear connector fractures such that the movable piston is able to move toward the second chamber. It should be noted that in the exemplary embodiment, the provision of the first shear connection can provide a certain safety for the opening mechanism. For example, the first shear connector may function to open the toe end sleeve of the exemplary embodiment in the event that the opening mechanism fails and wellbore fluid may momentarily apply a force to the movable piston toward the second chamber.
When the movable piston moves, the movable piston inevitably drives the adjusting mechanism and the time delay mechanism to move towards the second cavity, so that the hydraulic oil in the working cavity and the second cavity is compressed, and the pressure of the hydraulic oil in the working cavity and the second cavity is continuously increased. When the pressure of the hydraulic oil in the working cavity reaches a fourth preset pressure value, the spring of the adjusting mechanism contracts and drives the overflow valve core, the first through hole is removed from being blocked, the hydraulic oil flows through the first through hole and the second through hole, then flows through the first through hole provided with the damping rod, and then flows into the delay cavity through the second through hole, so that the delay effect is achieved. And when the adjusting mechanism and the time delay mechanism enter the second cavity, the adjusting mechanism and the time delay mechanism are invalid, and the time delay is finished. For example, the fourth predetermined pressure value may be determined based on the well depth, the well medium (e.g., clean water) at the time of opening the slip, etc. The fourth preset pressure value can be selected in the range of 20-45 MPa. The delay time can be maintained until the whole well bore pressure test process is finished. For example, the delay time may be 30-90 min. However, the present invention is not limited thereto.
The fracturing port is arranged at the position where the shell is matched with the movable piston, and the distance between the fracturing port and the upper end face of the movable piston is equal to or slightly larger than the distance between the end face of the flow-limiting valve body close to the delay cavity and the end face of the second cavity close to the working cavity. When the adjustment mechanism and the delay mechanism fail, the fracturing port is opened, thereby opening the toe end sliding sleeve. The number of the press-breaking holes may be plural.
In another exemplary embodiment of the present invention, the time-delay opening toe-end sliding sleeve used in the oil and gas well fracturing modification process may further include a lower joint connected to the lower end of the housing, based on the toe-end sliding sleeve structure in the above exemplary embodiment. The time-delay opening toe-end sliding sleeve of the invention is connected with other related components or equipment by arranging the lower joint. In addition, the connecting part of the lower joint and the shell can be provided with a hydraulic oil ring so as to enable the second cavity to form a better sealing effect. However, the present invention is not limited thereto, and for example, the time-delay opening toe-end sliding sleeve may also have a better sealing effect of the second chamber by forming a barrier and a sealing member on an inner wall of the lower portion of the housing, in case that the lower joint is not included.
In yet another exemplary embodiment of the present invention, the delayed opening toe end slip cover used in the oil and gas well fracturing modification process may further include a second shear connection based on the toe end slip cover structure of the above exemplary embodiment. The second shearing connecting piece fixedly connects the movable piston or the inner sleeve with the shell and can break when the pressure borne by the piston reaches a third preset pressure value, and the third preset pressure value is smaller than the second preset pressure value. For example, the third predetermined pressure may be slightly greater than the wall scraping force of the movable piston. For example, the third predetermined pressure may be selected in the range of 2 to 10 MPa. The number of the second shear connectors may be plural. For example, the second shear connector may be a restraining shear pin. By providing a second shear connector, it is possible to facilitate the destruction of cement concretions that may form and to a certain extent to share the role of the first shear connector.
FIG. 1 shows a schematic structural view of a time-delayed opening toe sleeve used in an exemplary embodiment of the oil and gas well fracture modification process of the present invention; FIG. 2 is an enlarged partial schematic view of the adjustment mechanism and time delay mechanism of FIG. 1; fig. 3 shows a partially enlarged schematic view of the opening mechanism of fig. 1.
As shown in fig. 1 to 3, in an exemplary embodiment of the present invention, the delay opening toe end sliding sleeve used in the oil and gas well fracturing modification process may be composed of an inner layer and an outer layer, and may include a housing 1, a movable piston 2, a piston shear pin 3, a limit shear pin 4, an opening mechanism 5, a delay mechanism 6, an adjusting mechanism 7, an inner sleeve 8, a hydraulic oil ring 9, and a lower joint 10, wherein the housing 1 and the lower joint 10 are coaxially and hermetically connected through a thread in the outer layer, the movable piston 2 and the inner sleeve 8 are coaxially and hermetically connected through a thread in the inner layer, the housing 1 and the movable piston 2 are coaxially and hermetically matched and are fixed through the piston shear pin 3 and the limit shear pin 4, and the lower joint 10 and the inner sleeve 8 are coaxially and hermetically matched.
The housing 1 may be provided with a number of fracturing ports 11, a number of piston shear pins 3 and a number of stop shear pins 4.
The opening mechanism 5 is arranged in the middle of the movable piston 2 and comprises a control shear pin 12, a control piston 13 and a sealing plug 14. The control piston 13 and the sealing plug 14 are fixed through the control shear pin 12, and the sealing plug 14 is connected with the movable piston 2 through thread sealing.
The time delay mechanism 6 is arranged at the lower part of the movable piston 2, is in axial sealing fit with the movable piston 2, and comprises a flow-limiting adjusting screw 16, a flow-limiting valve core 17, a flow-limiting valve body 18 and a damping rod 19. The flow-limiting valve core 17 and the damping rod 19 are arranged inside the flow-limiting valve body 18 and are coaxially matched, and the flow-limiting adjusting screw 16 is coaxially matched with the flow-limiting valve body 18 through threads.
The adjusting mechanism 7 is also arranged at the lower part of the movable piston 2, is in axial sealing fit with the movable piston 2, is in contact fit with the end face of the delay mechanism 6, and comprises a spring adjusting screw 20, a spring 21, an overflow valve core 22 and an overflow valve body 23. The spring 21 and the overflow valve core 22 are arranged inside the overflow valve body 23 and are coaxially matched, and the spring adjusting screw 20 and the overflow valve body 23 are coaxially matched through threads.
In the exemplary embodiment, the inner and outer layers form two cavities, the delay cavity 15 is adjacent to the opening mechanism 5, which is equivalent to the first cavity, the hydraulic oil cavity 24 is adjacent to the lower joint 10, and the hydraulic oil cavity 24 is provided with two steps of step surfaces, wherein the step surface with the larger diameter is the failure step surface 25 of the delay mechanism 6. Through the setting of inefficacy step face, can divide into the working chamber and the second cavity body of intercommunication each other with the hydraulic pressure oil pocket. Hydraulic oil is injected into the hydraulic oil cavity 24, and a hydraulic oil ring 9 is arranged at the lower end close to the lower joint 10.
For the oil and gas well fracturing improvement process of the exemplary embodiment, the following are specific:
first, the time delay open toe slips are placed in a predetermined location in the wellbore, for example, where fracturing is desired. And then, carrying out full-wellbore pressure test in site construction operation. Specifically, the full wellbore test is started at an initial pressure value (e.g., 60MPa), and the test pressure is gradually increased until a peak test pressure value (e.g., 120MPa) is reached. In the process, when the pressure applied by the wellbore liquid to the opening mechanism of the delay opening toe end sliding sleeve reaches a first set pressure value (corresponding to a first preset pressure value, for example, 95MPa), the control shear pin 12 is sheared, the control piston 13 falls into the bottom of the sealing plug 14, namely, the opening mechanism 5 is started, and the wellbore liquid flows into a liquid cylinder formed by the movable piston 2 and the shell 1. When the pressure born by the hydraulic cylinder reaches a second set pressure value (equivalent to a third preset pressure value), the limiting shear pin 4 is sheared off. When the pressure born by the hydraulic cylinder reaches a third set pressure value (equivalent to a second preset pressure value), the piston shear pin 3 is sheared, the movable piston 2 and the inner sleeve 8 start to move rightwards, hydraulic oil in the hydraulic oil cavity 24 is squeezed, the pressure of the hydraulic oil in the hydraulic oil cavity 24 rises, and the movable piston 2 and the inner sleeve 8 are prevented from moving rightwards. When the hydraulic oil pressure rises to a fourth set pressure value (which is equivalent to a fourth preset pressure value), the compression spring 21 pushes the overflow valve core 22, the adjusting mechanism 7 is opened, the delay mechanism 6 is started, the hydraulic oil in the hydraulic oil chamber 24 slowly flows into the delay chamber 15 through the delay mechanism 6, after a certain amount of hydraulic oil in the hydraulic oil chamber 24 flows out, when the delay mechanism 6 moves to the failure step surface 25, the delay mechanism 6 fails, the hydraulic oil pressure in the hydraulic oil chamber 24 is relieved, under the action of the pressure in the shaft, the movable piston 2 and the inner sleeve 8 are pushed to move rightwards quickly, and the fracturing port 11 on the shell 1 is exposed, so that the sliding sleeve is opened, and fracturing is realized. The time required for the hydraulic oil in the hydraulic oil chamber 24 to flow out is basically the opening delay time of the present invention, and the delay time can be maintained until the pressure test process of the whole well bore is finished.
In conclusion, the oil-gas well fracturing improvement process adopting the delayed opening toe end sliding sleeve has the beneficial effects that:
1. the opening mechanism adopts a piston structure to replace a rupture disc structure, so that the opening mechanism has a cement paste isolating function, reduces the opening pressure error and reduces the influence of the solidified cement paste on the opening pressure of the toe end sliding sleeve;
2. the time delay mechanism can be started at the peak value lower than the pressure testing pressure, and the sliding sleeve is opened through a period of time delay process, so that the allowable error range of the opening pressure of the toe end sliding sleeve is enlarged, and the opening success rate is improved; the delay mechanism adopts two-stage throttling, the delay time is adjustable, and the use flexibility of the tool is improved;
3. the arranged adjusting mechanism can pause and delay when the pump is stopped due to equipment failure and leakage rectification of a high-pressure pipeline, well mouth equipment and the like, so that the sliding sleeve is ensured to be started in a specified time period;
4. the sliding sleeve is opened by graded shearing, so that the influence of cement slurry solidification and bonding on the opening of the sliding sleeve is reduced;
5. the arranged failure step surface of the delay mechanism can still continue to open the pressure crack when the adjusting mechanism is closed, so that the completeness of the whole functional process is ensured;
6. the invention is used for realizing the first-stage fracturing transformation of the oil-gas well, has simple structure and convenient operation, can effectively solve the technical problems of strict error range of opening pressure of the toe end sliding sleeve, uncontrollable opening time, low opening success rate and the like in the prior art, can effectively reduce the development cost of oil gas (such as shale gas) and has wide application prospect.
Although the present invention has been described above in connection with the exemplary embodiments and the accompanying drawings, it will be apparent to those of ordinary skill in the art that various modifications may be made to the above-described embodiments without departing from the spirit and scope of the claims.
Claims (10)
1. The oil and gas well fracturing improvement process adopting the delayed opening of the toe end sliding sleeve is characterized by comprising the following steps of:
arranging the delay opening toe sliding sleeve at a preset position in the shaft;
starting the whole well casing pressure test with an initial pressure value, gradually increasing the pressure test pressure until reaching a peak pressure test value, when the sum of the pressure test pressure and the pressure of a drilling fluid liquid column reaches a first preset pressure value, delaying opening of the toe end sliding sleeve for starting and delaying, and after the whole well casing pressure test is finished, delaying opening of the toe end sliding sleeve for completing delaying and realizing fracturing, wherein the first preset pressure value is smaller than the sum of the peak pressure test pressure value and the pressure of the drilling fluid liquid column and is larger than the initial pressure value,
the time-delay opening toe end sliding sleeve comprises an opening mechanism, a time-delay mechanism, an adjusting mechanism, a fracturing port, a shell, a movable piston and an inner sleeve which are coaxially arranged, wherein,
the inner sleeve is provided with an upper end part fixedly connected with the lower end part of the movable piston;
the shell is sleeved outside the movable piston and the inner sleeve, and a first cavity and a second cavity which are communicated with the movable piston and/or the inner sleeve along the direction parallel to the shaft are formed between the shell and the movable piston and/or the inner sleeve;
the adjusting mechanism comprises an overflow valve body, an overflow valve core, a spring and a first adjusting piece, wherein a first through hole and a second through hole are arranged in the overflow valve body, the first through hole and the second through hole are communicated with each other, the diameter of the second through hole is larger than that of the first through hole, the overflow valve core is arranged in the second through hole and is provided with one end for plugging the first through hole and the other end connected with the spring, the spring is compressible, and the spring is connected with the overflow valve body through the first adjusting piece;
the delay mechanism comprises a flow-limiting valve body, a flow-limiting valve core, a damping rod and a second adjusting piece, wherein a first through hole and a second through hole are arranged in the flow-limiting valve body, the first through hole and the second through hole are communicated with each other, the diameter of the second through hole is larger than that of the first through hole, the flow-limiting valve core is arranged in the second through hole and provided with one end for plugging the first through hole and the other end connected with the flow-limiting valve body through the second adjusting piece, and the damping rod is arranged in the first through hole;
the time delay mechanism and the adjusting mechanism are arranged in the first cavity and are relatively fixed with the movable piston and/or the inner sleeve, the first through hole is communicated with the second through hole, the time delay mechanism and the adjusting mechanism divide the first cavity into a working cavity communicated with the first through hole and a time delay cavity communicated with the second through hole, the working cavity is in sealing fit with an overflow valve body of the adjusting mechanism, the working cavity is communicated with the second cavity and is filled with hydraulic oil, the time delay cavity is a cavity, and the second cavity, the overflow valve body of the adjusting mechanism and a flow limiting valve body of the time delay mechanism can form a gap through which the hydraulic oil flows;
the opening mechanism is arranged on the movable piston and can be opened when the wellbore liquid reaches the first preset pressure value, so that the wellbore liquid applies force to the movable piston towards the second cavity;
the fracturing port is arranged at the position where the shell is matched with the movable piston, and the distance between the fracturing port and the upper end face of the movable piston is equal to or slightly larger than the distance between the end face of the flow-limiting valve body close to the delay cavity and the end face of the second cavity close to the working cavity.
2. The process of claim 1, wherein the first predetermined pressure is selected within the range of 60 to 120 MPa.
3. The process of claim 1, wherein the toe end sleeve further comprises a first shear connector, wherein the first shear connector fixedly connects the movable piston or the inner sleeve to the housing and is capable of breaking and releasing the movable piston when the pressure applied to the movable piston reaches a second predetermined pressure value, such that the movable piston directly or indirectly drives the adjustment mechanism to move along the shaft toward the second chamber.
4. The process of improving oil and gas well fracturing with a time-delayed opening toe end sleeve of claim 3, wherein the toe end sleeve includes a plurality of first shear connectors.
5. The process of claim 3 wherein the toe end sleeve further comprises a second shear connector which fixedly connects the movable piston or inner sleeve to the housing and which is capable of breaking when the piston is subjected to a pressure up to a third predetermined pressure which is less than the second predetermined pressure.
6. The process of improving oil and gas well fracturing with delayed opening toe end slips of claim 5, wherein the toe end slips comprise a plurality of second shear connectors.
7. The process of claim 1 wherein the toe end sleeve delay mechanism has a plurality of damping rods disposed in series within the first bore.
8. The process of claim 1 for improving hydrocarbon well fracturing with delayed opening of a toe end sleeve, wherein the opening mechanism of the toe end sleeve comprises a hydraulic cylinder, a control shear pin, a control piston and a sealing plug, wherein the sealing plug has a piston cavity cooperating with the control piston and an outer wall sealingly connected to the movable piston, the hydraulic cylinder is formed between the movable piston and the housing and is capable of being in fluid communication with the wellbore through the piston cavity, the control shear pin secures the control piston within the piston cavity to block fluid communication from the hydraulic cylinder with the wellbore fluid, the control shear pin is capable of breaking when the wellbore fluid reaches the first predetermined pressure value and releases the control piston to allow the wellbore fluid to enter the hydraulic cylinder.
9. The process of improving hydrocarbon well fracturing with a time-delay opening toe end sleeve of claim 1, wherein said time-delay opening toe end sleeve comprises a plurality of fracturing ports.
10. The process of improving oil and gas well fracturing with delayed opening toe end slips of claim 1, wherein the toe end slips further comprise a lower joint connected to the lower end of the housing.
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| CN111691853B (en) * | 2020-07-08 | 2024-01-19 | 中国石油天然气集团有限公司 | High-pressure energy storage time-delay opening type toe end sliding sleeve and use method thereof |
| CN113914819A (en) * | 2021-09-30 | 2022-01-11 | 荆州市赛瑞能源技术有限公司 | Hydraulic sliding sleeve for fracturing |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104329073A (en) * | 2014-11-26 | 2015-02-04 | 中国石油集团西部钻探工程有限公司 | Delay-to-open sliding sleeve |
| US9816350B2 (en) * | 2014-05-05 | 2017-11-14 | Baker Hughes, A Ge Company, Llc | Delayed opening pressure actuated ported sub for subterranean use |
| CN207437005U (en) * | 2017-10-24 | 2018-06-01 | 中石化石油工程技术服务有限公司 | Band centering edge formula delayed start-up well cementation sliding sleeve |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9121247B2 (en) * | 2013-03-07 | 2015-09-01 | Geodynamics, Inc. | Method and apparatus for establishing injection into a cased bore hole using a time delay toe injection apparatus |
| US10337285B2 (en) * | 2016-12-12 | 2019-07-02 | Innovex Downhole Solutions, Inc. | Time-delayed downhole tool |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9816350B2 (en) * | 2014-05-05 | 2017-11-14 | Baker Hughes, A Ge Company, Llc | Delayed opening pressure actuated ported sub for subterranean use |
| CN104329073A (en) * | 2014-11-26 | 2015-02-04 | 中国石油集团西部钻探工程有限公司 | Delay-to-open sliding sleeve |
| CN207437005U (en) * | 2017-10-24 | 2018-06-01 | 中石化石油工程技术服务有限公司 | Band centering edge formula delayed start-up well cementation sliding sleeve |
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Address after: Chuanqing drilling company, No.3, Section 1, Fuqing Road, Chengdu, Sichuan 610051 Patentee after: CNPC Chuanqing Drilling Engineering Co.,Ltd. Patentee after: CHINA NATIONAL PETROLEUM Corp. Address before: Chuanqing drilling company, No.3, Section 1, Fuqing Road, Chengdu, Sichuan 610051 Patentee before: CNPC Chuanqing Drilling Engineering Co.,Ltd. Patentee before: China National Petroleum Corp. |