Multistage self-lifting integrated high-temperature-resistant pipe outer packer, drilling system and application

Abstract

The application discloses a multistage self-lifting integrated high-temperature-resistant external pipe packer, a drilling system and application, and the packer can comprise a central pipe, a power assembly, a pressure-bearing sealing assembly and a multistage self-lifting centralizing assembly which are sequentially arranged outside the central pipe; wherein the power assembly is used for providing power for the pressure-bearing sealing assembly and the multistage self-lifting centralizing assembly; the pressure-bearing sealing assembly is used for setting and sealing a target well; the multistage self-lifting centralizing assembly is used for centralizing the packer; and the starting thrust of the pressure-bearing sealing assembly is greater than that of the multistage self-lifting centralizing assembly. The packer can not only play a role of sealing the stratum, but also can centralize the pipe string, thereby improving the sealing effect of the external pipe packer. Further, the multistage self-lifting integrated high-temperature-resistant external pipe packer can realize multiple centralization and multiple sealing, so that sufficient centralization and sealing of the tool pipe string are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of segmented completion and segmented steam injection of heavy oil thermal recovery wells, and particularly relates to a multistage self-lifting integrated high-temperature-resistant pipe outer packer, a drilling system and application. BACKGROUND

[0002] The current some oil fields mainly using heavy oil resources, the annual heavy oil production is about 70% of the total production of the oilfield. Because of the significant differences in the oil product of heavy oil in each oilfield, the application of the recovery technology is also inconsistent. With the gradual development of this oil field, the number of horizontal wells is increasing year by year, and the number of horizontal wells requiring steam injection is also rapidly increasing. For the horizontal well of steam injection, the following problems exist. At present, the completion method of horizontal well is mostly through screen pipe completion. During steam injection, the general steam injection method is used. Affected by the heterogeneity of the oil layer and the surrounding injection and production conditions, it is easy to cause local steam breakthrough and uneven development of horizontal section reserves. The screen pipe completion method makes the oil well unable to use subsequent special production measures such as segmented water plugging, segmented steam injection and channeling sealing, thereby reducing the recovery efficiency of the horizontal well section. Segmented steam injection technology and segmented completion are inseparable. Since the horizontal well is mostly completed by screen pipe, the old well directly enters the segmented steam injection string without implementing segmented completion. Since the completion string lacks high-temperature-resistant pipe outer packer for separation, the downhole packer cannot avoid layer section channeling and interference outside the screen pipe. Therefore, the injection amount of each section allocated according to the well temperature test curve cannot truly meet the design requirements, which inevitably reduces the application effect.

[0003] Therefore, the development of horizontal well segmented completion and segmented steam injection technology requires that new wells start from completion and from the root, use segmented completion with segmented steam injection, and solve the problem of uneven development of horizontal well section reserves. The old well separately adopts the segmented steam injection technology, reasonably allocates the steam injection amount of each section of the horizontal well, and as much as possible considers various influencing factors to more scientifically and reasonably allocate the steam injection amount of each section. It has important guiding significance for solving the problems of uneven development of reserves, channeling and interference between layers, optimizing the development method, reasonably developing oil and gas reservoirs, and improving the oilfield recovery efficiency.

[0004] At present, the tool for implementing the segmented completion at home and abroad is mainly the external casing packer. The external casing packer is common, and there are compression type and thermal expansion type. The functions of various packers are different, but the effects are the same. The high-temperature-resistant external casing packer is one of the core tools for the segmented completion and segmented steam injection technology of the horizontal well. The packer adopts a heat-sensitive compression type setting structure design. In the steam injection process, the inflation agent in the packer is inflated by heat, pushes the liquid cylinder to drive the compression seal of the pressure cap, the seal is extruded and then expands outward, and finally seals the annular space between the casing and the open hole wall. The casing thermal force centralizer is one of the main tools for the segmented completion and segmented steam injection technology of the horizontal well. Due to the gravity effect of the horizontal well completion string during the completion process, the whole string is in the lower part of the open hole. If there is no centralizer and only the high-temperature-resistant external casing packer is used, it is impossible to lift the whole horizontal well string and seal the open hole section. At the same time, it is beneficial to the smooth setting of the high-temperature-resistant external casing packer and improves the sealing effect of the high-temperature-resistant external casing packer. SUMMARY

[0005] In order to reduce the overall length of the tool to pass through the wellbore with large dogleg, the embodiment of the present application provides a multi-stage self-lifting integrated high-temperature-resistant external casing packer, a drilling system and an application.

[0006] In the first aspect, the embodiment of the present application provides a multi-stage self-lifting integrated high-temperature-resistant external casing packer, which can include: a central pipe, a power assembly, a pressure sealing assembly, and a multi-stage self-lifting centralizing assembly which are sequentially sleeved outside the central pipe.

[0007] The power assembly is used to provide power for the pressure sealing assembly and the multi-stage self-lifting centralizing assembly; the pressure sealing assembly is used to set the target well; and the multi-stage self-lifting centralizing assembly is used to centralize the packer.

[0008] The starting thrust of the pressure sealing assembly is greater than that of the multi-stage self-lifting centralizing assembly.

[0009] Optionally, the power assembly can include a liquid cylinder sleeve, a piston, a first retainer, a locking ring, a second retainer, and a shear pin.

[0010] The liquid cylinder sleeve pre-stores a chemical mixed liquid; the piston is located between the central pipe and the liquid cylinder sleeve; and the first retainer, the locking ring, and the second retainer are located between the piston and the liquid cylinder sleeve.

[0011] The first retainer is fixed to the inside of the liquid cylinder sleeve, and the first retainer and the locking ring abut to limit the locking ring. The first retainer and the locking ring are used to limit the stroke of the piston. The shear pin penetrates the liquid cylinder sleeve and the second retainer to be fixed on the piston.

[0012] The piston is adjacent to a blocking ring of the pressure-bearing sealing assembly at one end close to the pressure-bearing sealing assembly.

[0013] Optionally, a first barb is arranged on the piston, and a second barb matching the first barb is arranged on the locking ring.

[0014] Optionally, the power assembly further comprises an anti-rotation pin for fixing the liquid cylinder jacket on the central pipe away from one end of the pressure-bearing sealing assembly and / or the multi-stage self-lifting centralizing assembly.

[0015] Optionally, the power assembly further comprises a plurality of fluorine rubber sealing rings.

[0016] Part of the fluorine rubber sealing rings are located between the central pipe and the liquid cylinder jacket, and part of the fluorine rubber sealing rings are located between the liquid cylinder jacket and the piston.

[0017] Optionally, the pressure-bearing sealing assembly comprises a blocking ring, a rubber sleeve, and rubber sleeve shoulder located on both sides of the rubber sleeve.

[0018] One end of the blocking ring is adjacent to the piston and the second blocking ring of the power assembly, and the other end of the blocking ring abuts against the rubber sleeve shoulder on one side of the rubber sleeve.

[0019] After the shear pin of the power assembly is sheared, the second blocking ring of the power assembly pushes the pressure-bearing sealing assembly through the piston to compress the rubber sleeve to achieve setting.

[0020] Optionally, the cross section of the blocking ring is L-shaped, and the L-shaped blocking ring and the central pipe form an annular groove, and part of the piston is located in the annular groove.

[0021] Optionally, the outer side of the piston is provided with external threads, the blocking ring is provided with internal threads, and the piston and the blocking ring are threadedly connected.

[0022] Optionally, the pressure-bearing sealing assembly further comprises a spacer ring located between the rubber sleeve shoulder and the multi-stage self-lifting centralizing assembly.

[0023] Optionally, the multi-stage self-lifting centralizing assembly comprises a first-stage centralizing block and a second-stage centralizing block.

[0024] The outer surface of the second-stage centralizing block is provided with a first-stage wedge-shaped sliding groove, and one end of the first-stage centralizing block is located in and can slide in the first-stage wedge-shaped sliding groove.

[0025] The center pipe is provided with a second wedge-shaped sliding groove, and one end of the second centralizing block is located in the second wedge-shaped sliding groove and can slide in the second wedge-shaped sliding groove.

[0026] Optionally, the multi-stage self-lifting centralizing assembly can further include: a third centralizing block; the outer surface of the third centralizing block is provided with a second wedge-shaped sliding groove, and one end of the second centralizing block is located in the second wedge-shaped sliding groove and can slide in the second wedge-shaped sliding groove.

[0027] The center pipe is provided with a third wedge-shaped sliding groove, and one end of the third centralizing block is located in the third wedge-shaped sliding groove and can slide in the third wedge-shaped sliding groove.

[0028] Optionally, the above packer can further include: a connection between the center pipe two end collars and / or joints, and the collars and / or joints are used to connect the packer with the casing.

[0029] In the second aspect, the embodiments of the present application provide a drilling system, which can include: a casing / screen pipe and at least one multi-stage self-lifting integrated high-temperature pipe external packer as described in the first aspect.

[0030] The casing / screen pipe is connected with the collars and / or joints of the multi-stage self-lifting integrated high-temperature pipe external packer, and the multi-stage self-lifting integrated high-temperature pipe external packer is used to set the annular space between the casing / screen pipe and the open hole wall.

[0031] In the third aspect, the embodiments of the present application provide an application of the multi-stage self-lifting integrated high-temperature pipe external packer as described in the first aspect in a drilling system.

[0032] The beneficial effects of the above technical solutions provided in the embodiments of the present application at least include:

[0033] The embodiments of the present application provide a multi-stage self-lifting integrated high-temperature pipe external packer, a drilling system and an application. The above multi-stage self-lifting integrated high-temperature pipe external packer provided in the embodiments of the present application is lowered into a target well in a staged completion process, which can not only seal the formation, but also centralize the pipe string, thereby improving the sealing effect of the pipe external packer. Further, since the existing packer and centralizer combination tool can only perform one sealing and one centralizing operation, if the wellbore quality is poor, the one-time centralizing and sealing effect is poor, and it is difficult to achieve the purpose of sealing the formation. The multi-stage self-lifting integrated high-temperature pipe external packer solves the above problems and can perform multiple centralizing and sealing operations, thereby ensuring sufficient centralizing and sealing of the tool pipe string.

[0034] Additional features and advantages of the application will be set forth in the description that follows, and in part will be apparent from the description, or can be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0035] The technical solutions of the present application are described in further detail below with the help of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0037] Figure 1 A structural diagram of the multi-stage self-lifting integrated high-temperature-resistant external casing packer provided in the embodiment of the present application is shown in the figure.

[0038] Figure 2 A structural diagram of the multi-stage self-lifting integrated high-temperature-resistant external casing packer provided in the embodiment of the present application is shown in the figure. Figure 1 A partial enlarged structural diagram is shown in the figure.

[0039] Figure 3 A structural diagram of the primary centralizer provided in the embodiment of the present application is shown in the figure.

[0040] Figure 4 A structural diagram of the secondary centralizer provided in the embodiment of the present application is shown in the figure.

[0041] Figure 5 A schematic diagram of the multi-stage self-lifting centralizing assembly locking provided in the embodiment of the present application is shown in the figure.

[0042] Figure 6 A structural schematic diagram of the drilling system provided in the embodiment of the present application is shown in the figure.

[0043] In the figure, 1 is a multi-stage self-lifting integrated high-temperature-resistant external casing packer; 2 is a casing / screen pipe.

[0044] 11 is a central pipe; 12 is a power assembly; 13 is a pressure seal assembly; 14 is a multi-stage self-lifting centralizing assembly; 15 is a coupling; 16 is a joint.

[0045] 121 is a liquid cylinder sleeve; 122 is a piston; 123 is a first check ring; 124 is a locking ring; 125 is a second check ring; 126 is a shear pin; 127 is an anti-rotation pin; 128 is a fluorine rubber seal ring.

[0046] 131 is a check ring; 132 is a rubber cylinder; 133 is a rubber cylinder shoulder; 134 is a spacer ring.

[0047] 141 is a primary centralizer; 142 is a secondary centralizer; 143 is a primary wedge-shaped sliding groove.

[0048] 1221 - first barb; 1241 - second barb. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is to be understood that the present disclosure can be variously implemented and thus should not be limited to the embodiments set forth herein. Rather, the embodiments are provided so that the present disclosure can be more thoroughly understood and so that the scope of the present disclosure is complete and fully conveyed.

[0050] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "far", "near", "front", "back", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0051] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] At present, the thick oil completion pipe string basically adopts the combination pipe string of high-temperature-resistant external packer + casing thermal centralizer, the inventor finds that the problems of the pipe string are that the tool length is the sum of two tools, the total length after addition is too long, it is difficult to pass through in the wellbore with large dogleg angle, there is a risk of pipe string sticking, the pipe string downhole risk is great, therefore, although the combination mode of high-temperature-resistant external packer + casing thermal centralizer is good, there is a problem of safe downhole. Under the condition that wellbore quality is becoming more and more important, wellbore safety has been placed in the first place, therefore, it is necessary to develop a new type of segmented completion tool.

[0053] In view of the above problems, this invention is proposed to provide a multi-stage self-elevating integrated high-temperature resistant external packer, drilling system, and application that overcomes or at least partially solves the above problems. Based on a thorough investigation of the current status of packers and centralizers both domestically and internationally, this invention designs a multi-stage self-elevating integrated high-temperature resistant external packer. This tool combines the functions of a high-temperature resistant external packer in the original tubing string with the functions of a casing thermal centralizer, while significantly reducing the overall length of the tool, making it suitable for safe running into wells with large doglegs, and also saving costs.

[0054] To address the drawbacks of existing combined external packer and casing centralizer tools, where the combined length exceeds 7m, posing a risk of obstruction during lowering in wells with high dogleg angles, this invention provides a multi-stage, self-elevating, integrated high-temperature resistant external packer. (Refer to...) Figure 1 As shown, the multi-stage self-elevating integrated high-temperature resistant external packer 1 may include: a central pipe 11, and a power assembly 12, a pressure-bearing sealing assembly 13, and a multi-stage self-elevating centralizing assembly 14 sequentially sleeved on the outside of the central pipe 11; wherein, the power assembly 12 is used to provide power to the pressure-bearing sealing assembly 13 and the multi-stage self-elevating centralizing assembly 14; the pressure-bearing sealing assembly 13 is used to set the target well; the multi-stage self-elevating centralizing assembly 14 is used to centralize the packer 1; the starting thrust of the pressure-bearing sealing assembly 13 is greater than the starting thrust of the multi-stage self-elevating centralizing assembly 14.

[0055] The multi-stage, self-elevating, integrated high-temperature resistant external packer provided in this embodiment of the invention is run into the target well during segmented well completion. It serves both to isolate the formation and to straighten the tubing string, thereby improving the sealing effect of the external packer. Furthermore, existing packer and straightener combination tools can only perform one isolation and one straightening operation. If the wellbore quality is poor, the single straightening and isolation effect is poor, making it difficult to achieve the purpose of formation isolation. This multi-stage, self-elevating, integrated high-temperature resistant external packer solves the above problems, allowing for multiple straightening and isolation operations, thus ensuring sufficient straightening and isolation of the tool string.

[0056] In an alternative embodiment, because current thermal pipe centralizers rely on thermal expansion to generate thrust, and the amount of thermal expansion agent is greatly affected by formation permeability and formation temperature, it is difficult to load an accurate amount of agent to achieve precise centralization. (Refer to...) Figure 1As shown, the power assembly 12 can include a liquid cylinder jacket 121, a piston 122, a first stop ring 123, a locking ring 124, a second stop ring 125, and a shear pin 126; wherein the liquid cylinder jacket 121 is pre-stored with a chemical mixed liquid (not shown in the figure); the piston 122 is located between the central tube 11 and the liquid cylinder jacket 121; the first stop ring 123, the locking ring 124, and the second stop ring 125 are located between the piston 122 and the liquid cylinder jacket 121; the first stop ring 123 is fixed on the inner side of the liquid cylinder jacket 121, the first stop ring 123 abuts against the locking ring 124 to limit the locking ring 124, and the first stop ring 123 and the locking ring 124 are used to limit the stroke of the piston 122; the shear pin 126 penetrates the liquid cylinder jacket 121 and the second stop ring 125 to be fixed on the piston 122; and the end of the piston 122 close to the pressure-bearing sealing assembly 13 is adjacent to the stop ring 131 of the pressure-bearing sealing assembly 13.

[0057] The power assembly in the embodiment of the present application is used as the power source of the pressure-bearing sealing assembly and the multi-stage self-lifting centralizing assembly in the packer, and the functions and movement relationships of the various components included in the power assembly are introduced as follows: the liquid cylinder jacket is filled with a chemical mixed liquid, the liquid can react chemically under high temperature conditions to generate hard substances, the volume of the liquid can be sharply increased, and then enough thrust can be generated to complete the setting of the packer and the centralizing; the function of the piston is to receive the thrust generated by the chemical reaction in the liquid cylinder jacket to act on the adjacent pressure-bearing sealing assembly and multi-stage self-lifting centralizing assembly; the first stop ring and the locking ring are used to fix the piston, the first stop ring is fixed on the inner side of the liquid cylinder jacket, so that the position of the first stop ring is fixed, the first stop ring abuts against the locking ring, and the locking ring cannot move in the opposite direction of the piston in the axial direction. In the embodiment, the piston can only move in the direction close to the pressure-bearing sealing assembly during use, and therefore the stroke is limited by the first stop ring and the locking ring.

[0058] The second stop ring and the shear pin are used to fix the piston, and the shear pin is sheared off when the thrust of the piston reaches a certain value to realize the compression of the pressure-bearing sealing assembly. It should be noted that the shear pin in the embodiment of the present application fixes the piston to avoid that the packer is set too early and safety accidents such as setting occur on the ground or during the process of lowering into the well, and only when the temperature reaches the preset temperature (220°) during the steam injection in the well, the chemical mixed liquid filled in the liquid cylinder jacket reacts chemically to shear off the shear pin to realize the setting.

[0059] The power assembly in the embodiment works as follows: when the packer is lowered to a preset position in the well, high-temperature hot steam is injected into the packer through the casing, the chemical mixed liquid pre-stored in the liquid cylinder jacket is subjected to high temperature and starts chemical reaction, the chemical reaction generates a pushing force acting on the piston, the piston pushes the second blocking ring to shear the shear pin when the pushing force reaches a certain value, so as to compress the pressure-bearing sealing assembly to realize centralizing and setting. After setting, the first blocking ring and the locking ring lock the piston to prevent the rubber cylinder of the pressure-bearing sealing assembly and the multi-stage self-lifting centralizing assembly from rebounding.

[0060] The power assembly included in the multi-stage self-lifting integrated high-temperature-resistant pipe-out packer in the embodiment can realize centralizing of the pipe string and sealing of the rubber cylinder without the influence of the thermal expansion agent, reduces the inadaptation of the formation environment and the error of human operation. Further, in view of the technical problem that the pushing force of the thermal expansion agent in the original centralizer is limited, the centralizing force is small and the centralizing effect is poor, the power assembly is provided between the pressure-bearing sealing assembly and the multi-stage self-centralizing assembly, i.e., the pushing force sources are consistent, so as to ensure that the multi-stage self-lifting centralizing assembly has sufficient power to realize centralizing of the pipe string, which fundamentally solves the problem of difficulty in centralizing the pipe string in complex formations.

[0061] In another optional embodiment, the first blocking ring and the locking ring limit the stroke of the piston, as shown in Figure 1 and Figure 2 , in specific implementation, the piston 122 is provided with a first barb 1221, and the locking ring 124 is provided with a second barb 1241 matched with the first barb 1221. The first barb and the second barb in the embodiment cooperate with each other to complete clamping and realize locking in the axial direction of the piston, so as to effectively prevent the rubber cylinder from rebounding and reduce the sealing performance of the packer.

[0062] In another optional embodiment, as shown in Figure 1 , in order to prevent the liquid cylinder jacket 121 from rotating in the process of using the packer, the power assembly 12 can further include an anti-rotation pin 127 for fixing one end of the liquid cylinder jacket 121 away from the pressure-bearing sealing assembly 13 and / or the multi-stage self-lifting centralizing assembly 14 on the central pipe 11. In the embodiment, the anti-rotation pin fixes the liquid cylinder jacket to prevent the liquid cylinder jacket from leaking or reacting due to vibration of the chemical mixed liquid pre-stored in the liquid cylinder jacket after rotating, and also avoids axial rotation of the liquid cylinder jacket to shear the shear pin.

[0063] In another optional embodiment, as shown in Figure 1As shown, in order to realize the sealing between various parts, the power assembly 12 can further include a plurality of fluorine rubber sealing rings 128, some of which are located between the central tube 11 and the liquid cylinder jacket 121, and some of which are located between the liquid cylinder jacket 121 and the piston 122.

[0064] In another alternative embodiment, referring to Figure 1 As shown, the pressure sealing assembly 13 can include a stop ring 131, a rubber sleeve 132, and rubber sleeve shoulder 133 located on both sides of the rubber sleeve 132; one end of the stop ring 131 is adjacent to the piston 122 and the second stop ring 123 of the power assembly 12, and the other end of the stop ring 131 abuts the rubber sleeve shoulder 133 on one side of the rubber sleeve 132; after the shear pin 126 of the power assembly 12 is cut, the second stop ring 125 of the power assembly 12 pushes the pressure sealing assembly 13 through the piston 122 to make the compressed rubber sleeve 132 set.

[0065] It should be noted that in the above embodiment of the present application, one end of the stop ring is adjacent to the piston and the second stop ring, wherein "adjacent" in this embodiment can be abutting each other, or can have a certain gap, or can have some parts connected, which is not limited in the present embodiment. It should be noted that the above rubber sleeve in the present embodiment is a high-temperature rubber sleeve, which is made of carbon fiber cord material, can withstand a temperature of 350℃, and can withstand a pressure of more than 25MPa. The high-temperature rubber sleeve can be lengthened or shortened according to the length of the formation to be sealed.

[0066] It should be further noted that the starting thrust of the rubber sleeve in the above embodiment during setting is greater than the starting thrust of the multi-stage self-elevating centralizing assembly, that is, in the present embodiment, the rubber sleeve is compressed to set after the previous centralizing, and before setting, all parts of the pressure sealing assembly move towards the multi-stage self-elevating centralizing assembly to realize centralizing.

[0067] The working process of the above pressure sealing assembly is as follows: the piston pushes the pressure sealing assembly to move towards the multi-stage self-elevating centralizing assembly to compress the multi-stage self-elevating centralizing assembly to centralize the packer. After the multi-stage self-elevating centralizing assembly completes the centralizing, the position of the rubber sleeve shoulder close to the multi-stage self-elevating centralizing assembly can be fixed, so that the piston continues to extrude the rubber sleeve to realize setting after the rubber sleeve is deformed.

[0068] In another alternative embodiment, referring to Figure 1 and Figure 2As shown, the cross section of the blocking ring 131 is L-shaped, and the L-shaped blocking ring 131 and the central tube 11 form an annular groove (the position where the front end of the piston 122 is located in the figure), and part of the piston 122 is located in the annular groove. In this embodiment, the L-shaped blocking ring can limit the one end of the piston in the radial direction of the packer, and can facilitate the piston to push the blocking ring to compress the rubber sleeve shoulder.

[0069] In another optional embodiment, referring to Figure 1 As shown, the outer side of the piston 122 is provided with external threads, and the blocking ring 131 is provided with internal threads, and the piston 122 and the blocking ring 131 are threadedly connected. In this embodiment, the one end of the piston is threadedly connected with the blocking ring, so that the movement stroke is consistent, and the pushing force of the piston can be effectively transmitted to achieve setting and centralizing.

[0070] In another optional embodiment, referring to Figure 1 As shown, the pressure-bearing sealing assembly 13 can further include a separation ring 134 between the rubber sleeve shoulder 133 and the multi-stage self-lifting centralizing assembly 14. In this embodiment, the separation ring facilitates the transmission of the pushing force to the multi-stage self-lifting centralizing assembly, and the rubber sleeve shoulder mainly functions to protect the rubber sleeve.

[0071] In another optional embodiment, since the current thermal pipe centralizer relies on thermal expansion to generate a pushing force, and the charging amount of the thermal expansion agent is greatly affected by the formation permeability and the formation temperature, it is difficult to accurately charge the amount to achieve precise centralization. Referring to Figure 1 、 Figure 3 and Figure 4 As shown, the multi-stage self-lifting centralizing assembly 14 can include a first-stage centralizing block 141 and a second-stage centralizing block 142; the outer surface of the second-stage centralizing block 142 is provided with a first-stage wedge-shaped sliding groove 143, and one end of the first-stage centralizing block 141 is located in and can slide in the first-stage wedge-shaped sliding groove 143; the central tube 11 is provided with a second-stage wedge-shaped sliding groove (not shown in the figure), and one end of the second-stage centralizing block 142 is located in and can slide in the second-stage wedge-shaped sliding groove.

[0072] The multi-stage self-lifting centralizing assembly in the embodiment of the present application realizes the purpose of multi-stage centralization through the continuous stacking and lifting of the centralizing blocks. For example, the diameter of the first-stage centralizing block can be increased by 10%, the diameter of the second-stage centralizing block can be increased by 30%, and the diameter of the third-stage centralizing block can be increased by 50%. The multi-stage self-lifting centralizing assembly of the packer can fully guarantee the centralizing effect of the pipe string for a well with a very large diameter or a large-belly wellbore.

[0073] In another alternative embodiment, the multi-stage self-lifting centralizing assembly can further comprise: a third centralizing block (not shown in the figure); a second wedge-shaped sliding groove is formed on the outer surface of the third centralizing block, and one end of the second centralizing block is located in and can slide in the second wedge-shaped sliding groove; a third wedge-shaped sliding groove is formed on the central tube, and one end of the third centralizing block is located in and can slide in the third wedge-shaped sliding groove.

[0074] In a specific implementation, the first centralizing block is first stressed, and under the action of the pushing force, the first centralizing block moves along the first wedge-shaped sliding groove. As the pushing force increases, the first centralizing block gradually slides to the farthest end. At this time, due to the centralizing clamping grooves on both sides of the first centralizing block, the first centralizing block is clamped in the first wedge-shaped sliding groove, and the locking of the first centralizing block is realized. After the first centralizing block is locked, the pushing force continues to increase, which drives the second centralizing block to start moving. The second centralizing block gradually moves to the farthest end along the second wedge-shaped sliding groove. In the process of continuously increasing the pushing force, the second centralizing block moves to the farthest end. At this time, the second wedge-shaped sliding groove on both sides of the second centralizing block clamps the second centralizing block in the second wedge-shaped sliding groove, and the locking is realized. The first centralizing block and the second centralizing block are all self-lifted by continuously increasing the pushing force in the sliding process, the diameter of the tool (packer) is increased, and the centralization in the formation is realized. The length of each sliding track of the self-lifting assembly can be changed according to the required centralizing diameter. When a large centralizing diameter is required, the wedge-shaped sliding groove is adjusted to realize the enlargement of the well diameter. When facing a candy cane wellbore or a large-belly wellbore or a large-diameter wellbore, the number of centralizing blocks can also be increased to realize multi-stage superposition lifting and improve the centralizing effect.

[0075] In order to better illustrate the working process of the multi-stage self-lifting centralizing assembly in the packer, referring to Figure 5 , in the initial state, as shown in the uppermost graph in Figure 5 , at this time, the first centralizing block and the second centralizing block are in the original state position. When the first centralizing block is subjected to a pushing force, in combination with Figures 2 to 4 , the first centralizing block slides in the first wedge-shaped sliding groove until it is clamped and locked after sliding to the farthest end; similarly, as the pushing force increases, the second centralizing block slides in the second wedge-shaped sliding groove until the second centralizing block is locked to realize multi-stage self-lifting centralization.

[0076] The packer in the embodiment of the present application can realize the centralization of the pipe string in the condition of not being affected by the thermal expansion agent through two-stage or multi-stage centralizing superposition, reduces the inadaptability of the formation environment and the error of human operation, solves the problem that the thermal pipe string centralizer relies on the expansion of the thermal expansion agent to generate a pushing force, and the charge amount of the thermal expansion agent is greatly affected by the formation permeability and the formation temperature, and it is difficult to accurately charge the charge amount. The centralizing assembly has a self-lifting structure, can self-regulate the centralizing well diameter, and is more convenient to operate.

[0077] In another alternative embodiment, referring toFigure 1 As shown in the figure, the multi-stage self-lifting integrated high-temperature-resistant external pipe packer 1 can further include a connection at the center pipe two end collar 15 and / or joint 16, and the collar 15 and / or joint 16 is used to connect the packer 1 with the casing.

[0078] The overall working process of the above-mentioned multi-stage self-lifting integrated high-temperature-resistant external pipe packer in the embodiment of the present application in the heavy oil well completion process is as follows: the packer is lowered into the preset position with the completion string → the steam injection temperature of the heavy oil well reaches above 220℃ → the chemical mixed liquid pre-stored in the liquid cylinder jacket develops to generate a thrust under the heat → the thrust pushes the pressure-bearing sealing assembly → the pressure-bearing sealing assembly pushes the righting blocks of the multi-stage self-lifting righting assembly → the first-stage righting block slides along the first-stage wedge-shaped sliding groove and is locked → the second-stage righting block slides along the second-stage wedge-shaped sliding groove and is locked → the rubber cylinder of the pressure-bearing sealing assembly is forced to set → the packer tool is set and the formation is sealed.

[0079] In a specific example, the above-mentioned multi-stage self-lifting integrated high-temperature-resistant external pipe packer is lowered into the well with the screen pipe during the casing completion process in a certain oilfield, and after being lowered, the righting and packer setting are completed during the steam injection process to achieve formation sealing.

[0080] In this example, the formation of a certain block is severely heterogeneous. In order to ensure the development effect of XX well, semi-length cementing technology is used for cementing, three-opening screen pipe completion is used for completion, and multi-stage self-lifting integrated high-temperature-resistant external pipe packer is lowered into the low physical property section of the well to realize horizontal well staged completion and improve the uniform production degree of the horizontal section, thereby creating conditions for later adjustment measures. The specific implementation of the tool is as follows:

[0081] 1) Reservoir property analysis: the target layer of XX block is Xing I group, which belongs to fan delta deposition, and the reservoir lithology is mainly sandy conglomerate and conglomerate sandstone. The oil layer interlayer is well developed, mainly composed of gray green mudstone, sandy mudstone, argillaceous sand (conglomerate) rock and gray argillaceous sand (conglomerate) rock. The heterogeneity is serious. In order to improve the uniform production degree of the horizontal section, the external packer is lowered into the position where the lithology and permeability of the horizontal section change obviously to realize staged completion. According to the permeability optimization, the number of stages is determined, and the optimal multi-stage self-lifting integrated high-temperature-resistant external pipe packer lowering position is determined.

[0082] 2) Tool assembly: the three main components of the multi-stage self-lifting integrated high-temperature-resistant external pipe packer are assembled together. After assembly, the indoor thermal expansion performance test is carried out to verify whether the tool can expand and seal at 220℃. If the test is qualified, the tool performance can meet the downhole expansion and sealing function and can be applied on site. At the same time, in order to verify the righting effect of the tool, the pressure test is carried out in the laboratory. After pressure test, if the multi-stage righting blocks can be opened smoothly, and the multi-stage righting blocks can slide smoothly, it means that the righting effect of the tool can meet the requirements.

[0083] 3) Tooling: Based on the previous permeability analysis, it was determined that two multi-stage self-elevating integrated high-temperature resistant external packers were required for this well. The completion string structure was as follows: guide shoe + Φ177.8mm slotted screen + multi-stage self-elevating integrated high-temperature resistant external packer + Φ177.8mm slotted screen + multi-stage self-elevating integrated high-temperature resistant external packer + Φ177.8mm slotted screen + Φ177.8mm adjustable duct + 244.5×177.8mm liner hanger + Φ127mm drill pipe.

[0084] 4) Steam injection process: After the tool is lowered, the wellhead steam injection device is installed. According to the formation conditions, the amount and speed of steam injection are determined. The multi-stage self-elevating integrated high-temperature resistant external packer is subjected to a high temperature of over 320°C downhole, which causes the multi-stage centralizing block to rise and lock. Then the pressure-bearing sealing rubber sleeve completes the setting and sealing, realizing formation steam injection and isolation.

[0085] Based on the same inventive concept, this invention also provides a drilling system, referring to... Figure 6 As shown, the system may include: casing 2 / screen pipe 2 and at least one of the aforementioned multi-stage self-elevating integrated high-temperature resistant external packers 1; the casing 2 / screen pipe 2 is connected to the multi-stage self-elevating integrated high-temperature resistant external packers 1 via couplings and / or joints; the multi-stage self-elevating integrated high-temperature resistant external packers 1 are used to seal the annular space between the casing 2 / screen pipe 2 and the open hole wellbore (not shown in the figure). Of course, the above system, as a complete completion tool string, may also include guide shoes, drill pipes, etc., and this embodiment of the invention does not specifically limit this.

[0086] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned multi-stage self-elevating integrated high-temperature resistant external packer in a drilling system.

[0087] The beneficial effects and specific implementations of the above-described systems and applications in the embodiments of the present invention can be referred to the relevant description of the packer in the above embodiments, and will not be repeated here.

[0088] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A multi-stage self-elevating integrated high-temperature resistant external packer, characterized in that, include: The central tube, and the power assembly, pressure-bearing sealing assembly, and multi-stage self-elevating and uprighting assembly, which are sequentially sleeved on the outside of the central tube; The power assembly provides power to the pressure-bearing sealing assembly and the multi-stage self-elevating centralization assembly; the pressure-bearing sealing assembly is used to set the target well; and the multi-stage self-elevating centralization assembly is used to centralize the packer. The starting thrust of the pressure-bearing sealing assembly is greater than the starting thrust of the multi-stage self-elevating and uprighting assembly.

2. The packer according to claim 1, characterized in that, The powertrain includes: a cylinder sleeve, a piston, a first retaining ring, a locking ring, a second retaining ring, and a shear pin; The cylinder sleeve contains a pre-stored chemical mixture; the piston is located between the central tube and the cylinder sleeve; the first retaining ring, the locking ring, and the second retaining ring are located between the piston and the cylinder sleeve. The first retaining ring is fixed to the inner side of the cylinder outer sleeve, and the first retaining ring abuts against the locking ring to limit the locking ring. The first retaining ring and the locking ring are used to limit the stroke of the piston. The shear pin passes through the cylinder outer sleeve and the second retaining ring to fix it to the piston. The end of the piston near the pressure-bearing seal assembly is adjacent to the retaining ring of the pressure-bearing seal assembly.

3. The packer according to claim 2, characterized in that, The piston is provided with a first barb, and the locking ring is provided with a second barb that matches the first barb.

4. The packer according to claim 2, characterized in that, The powertrain also includes an anti-rotation pin, which is used to fix one end of the cylinder outer sleeve away from the pressure-bearing sealing assembly and / or the multi-stage self-elevating and centralizing assembly to the central tube.

5. The packer according to claim 2, characterized in that, The powertrain also includes: several fluororubber seals; Some of the fluororubber sealing rings are located between the central tube and the cylinder outer sleeve, while others are located between the cylinder outer sleeve and the piston.

6. The packer according to claim 1, characterized in that, The pressure-bearing sealing assembly includes: a retaining ring, a rubber sleeve, and rubber sleeve shoulders located on both sides of the rubber sleeve; One end of the retaining ring is adjacent to the piston and the second retaining ring of the powertrain, and the other end of the retaining ring abuts against the rubber sleeve shoulder on one side of the rubber sleeve; After the second retaining ring of the powertrain cuts off the shear pin of the powertrain, it pushes the pressure-bearing sealing assembly through the piston to compress the rubber sleeve and achieve a set seal.

7. The packer according to claim 6, characterized in that, The cross-section of the retaining ring is L-shaped, and an annular groove is formed between the L-shaped retaining ring and the central tube. A portion of the piston is located in the annular groove.

8. The packer according to claim 7, characterized in that, The piston has an external thread on its outer side, and the retaining ring has an internal thread. The piston and the retaining ring are threaded together.

9. The packer according to any one of claims 6 to 8, characterized in that, The pressure-bearing sealing assembly further includes a spacer ring located between the rubber sleeve shoulder and the multi-stage self-elevating and straightening assembly.

10. The packer according to claim 1, characterized in that, The multi-stage self-elevating straightening assembly includes: a primary straightening block and a secondary straightening block; The outer surface of the secondary straightening block is provided with a primary wedge-shaped groove, and one end of the primary straightening block is located in the primary wedge-shaped groove and can slide in the primary wedge-shaped groove; The central tube is provided with a secondary wedge-shaped groove, and one end of the secondary straightening block is located in the secondary wedge-shaped groove and can slide in the secondary wedge-shaped groove.

11. The packer according to claim 10, characterized in that, The multi-stage self-elevating straightening assembly further includes: a three-stage straightening block; the outer surface of the three-stage straightening block is provided with a two-stage wedge-shaped groove, one end of the two-stage straightening block is located in the two-stage wedge-shaped groove and can slide in the two-stage wedge-shaped groove; The central tube is provided with three levels of wedge-shaped grooves, and one end of the three-level straightening block is located in the three-level wedge-shaped grooves and can slide in the three-level wedge-shaped grooves.

12. The packer according to any one of claims 1-8 or 10, 11, characterized in that, Also includes: The couplings and / or joints connected to both ends of the central tube are used to connect the packer to the sleeve.

13. A drilling system, characterized in that, include: The sleeve and / or screen tube and at least one multi-stage self-elevating integrated high-temperature resistant external packer as described in any one of claims 1 to 12; The casing and / or screen are connected to the couplings and / or joints of the multi-stage self-elevating integrated high-temperature resistant external packer; the multi-stage self-elevating integrated high-temperature resistant external packer is used to seal the annular space between the casing and / or screen and the open hole wellbore.

14. The application of a multi-stage self-elevating integrated high-temperature resistant external packer as described in any one of claims 1 to 12 in a drilling system.

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