A method for asynchronous fracturing and periodic injection-production in horizontal wells

Abstract

The present invention discloses a method for asynchronous fracturing and periodic injection-production in horizontal wells. This injection-production method continuously installs multiple intelligent sliding sleeves that can be quickly switched on the casing of the horizontal wellbore, and cyclically implements fracturing operations, production operations, and water / gas injection energy supplementation operations on multiple combinations of asynchronous fracturing and periodic injection-production intervals in sequence until the economic and technical oil production limit of the horizontal well is reached. By supporting an intelligent sliding sleeve that can be quickly switched, this injection-production method realizes the switching between asynchronous fracturing and periodic injection-production in horizontal wells, and can greatly improve the development of unconventional oil resources such as shale oil and tight oil. This injection-production method has the advantages of being simple, practical, and highly reliable, and can realize the switching between asynchronous fracturing and periodic injection-production in horizontal wells.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas field exploration and development, and particularly relates to a method for asynchronous fracturing and periodic injection-production of horizontal wells. Background Art

[0002] Horizontal staged volume fracturing and periodic injection-production are the main means to improve the stable production capacity and economy of unconventional oil reservoirs. The current horizontal well bridge plug and water jet staged volume fracturing technology, horizontal well staged periodic injection-production technology cannot meet the requirements of reservoir classification and comprehensive economic benefit evaluation for horizontal wells in unconventional oil and gas reservoirs such as shale oil and tight oil.

[0003] CN201810247366.7 discloses a staged fracturing horizontal staged periodic injection-production double-tubing string. The technical solution provided by this invention can effectively inject water / gas into ultra-low permeability oil reservoirs / tight oil reservoirs / shale oil reservoirs, but it cannot achieve alternating operation of in-well periodic injection-production and asynchronous fracturing. Staged volume fracturing technologies such as bridge plug staged multi-cluster volume fracturing and hydraulic jet staged volume fracturing all perform synchronous sequential fracturing on horizontal wells from the toe to the heel, and cannot achieve asynchronous fracturing in the same well. The continuous tubing or tool tubing switchable sliding sleeve fracturing technology has problems such as cumbersome procedures, the use of special equipment and a large number of professional operators because it is necessary to trip the continuous tubing or tool tubing for sliding sleeve positioning and sliding sleeve switching operations. The dart-type and ball-drop type multi-stage sliding sleeve fracturing technologies are limited by the number of staged fracturing levels and cannot meet the requirements of fine cutting fracturing of long horizontal wells in unconventional oil reservoirs. None of the above switchable sliding sleeve fracturing technologies can achieve intelligent and rapid switching, do not meet the requirements of horizontal well asynchronous fracturing and periodic injection-production, and are difficult to meet the requirements of improving the stable production capacity and economic benefits of horizontal wells in unconventional reservoirs. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for asynchronous fracturing and periodic injection-production of horizontal wells to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A method for asynchronous fracturing and periodic injection-production of horizontal wells,

[0006] The injection-production method includes the following steps:

[0007] a: Continuously run a plurality of switchable intelligent sliding sleeves on the casing of the horizontal wellbore;

[0008] b: Divide the horizontal section into multiple layer combinations for asynchronous fracturing and periodic injection-production;

[0009] c: Perform fracturing operations on the first layer combination, and after the fracturing is completed, perform oil production operations on the first layer combination;

[0010] d: Perform water injection / gas injection energy supplementation operation on the first interval combination. After the energy supplementation is completed, close the sliding sleeve of the first interval combination;

[0011] e: Perform fracturing operation on the second interval combination. After the fracturing is completed, perform oil production operation on the second interval combination;

[0012] f: Perform water injection / gas injection energy supplementation operation on the second interval combination. After the energy supplementation is completed, close the sliding sleeve of the second interval combination;

[0013] g: Open the first interval combination and perform oil production operation on the first interval combination;

[0014] h: Perform water injection / gas injection energy supplementation operation on the first interval combination. After the energy supplementation is completed, close the sliding sleeve of the first interval combination;

[0015] i: Open the second interval combination and perform oil production operation on the second interval combination;

[0016] j: Repeat steps f - i until the economic and technical oil production limit of the horizontal well is reached.

[0017] Furthermore, the intelligent sliding sleeve controls the opening and closing of the corresponding interval combination.

[0018] Furthermore, the intelligent sliding sleeve includes a fracturing channel module and a sliding sleeve switch module. The fracturing channel module prefabricates the fracturing of one or more fracturing holes. The fracturing channel module is connected to other oil / gas layer casings through screw threads. The fracturing channel module is a connecting nipple. The sliding sleeve switch module pre - sets one or more fracturing grooves. The sliding sleeve switch module is a cylindrical switch with intelligent or mechanical positioning function. The intelligent sliding sleeve controls whether the fracturing holes are exposed to the fracturing grooves through the movement of the sliding sleeve switch module, realizing the opening and closing of the intelligent sliding sleeve.

[0019] Furthermore, the horizontal section is divided according to the physical properties, oil - bearing properties and cementing and well - completion quality of the reservoir drilled in the horizontal section.

[0020] Furthermore, the horizontal section is divided into multiple asynchronous fracturing sections and multiple periodic injection - production interval combinations. The multiple periodic injection - production interval combinations include the first interval combination for fracturing and periodic injection - production and the second interval combination for fracturing and periodic injection - production.

[0021] Furthermore, the periodic injection - production interval combination is an interval combination. The first interval combination for fracturing and periodic injection - production is the first interval combination, and the second interval combination for fracturing and periodic injection - production is the second interval combination.

[0022] Furthermore, the implementation of water injection / gas injection energy supplementation operation is water injection or gas injection operation.

[0023] Further, the implementation of the water injection / gas energy supplementation operation is carried out when the oil production does not meet the development requirements.

[0024] Further, the economic and technical oil production limit of the horizontal well is the break-even point between the comprehensive oil production cost and the sales revenue calculated based on the daily recoverable oil volume of the horizontal well technology.

[0025] The technical effects and advantages of the present invention: The asynchronous fracturing and periodic injection-production method for horizontal wells realizes the switching between asynchronous fracturing and periodic injection-production of horizontal wells by supporting an intelligent sliding sleeve that can be quickly switched, and can greatly improve the development of unconventional oil resources such as shale oil and tight oil. This injection-production method has the advantages of simplicity, practicality, and high reliability, and can realize the switching between asynchronous fracturing and periodic injection-production of horizontal wells. Description of the Drawings

[0026] Figure 1 It is a flow chart of the injection-production method of the present invention. Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] The present invention provides a method for asynchronous fracturing and periodic injection-production of horizontal wells as Figure 1 shown.

[0029] The injection-production method includes the following steps:

[0030] a: Continuously lower a plurality of switchable intelligent sliding sleeves on the casing of the horizontal wellbore;

[0031] b: Divide the horizontal section into multiple layer combinations for asynchronous fracturing and periodic injection-production;

[0032] c: Perform a fracturing operation on the first layer combination. After the fracturing is completed, perform an oil production operation on the first layer combination;

[0033] d: Perform a water injection / gas energy supplementation operation on the first layer combination. After the energy supplementation is completed, close the sliding sleeve of the first layer combination;

[0034] e: Perform a fracturing operation on the second layer combination. After the fracturing is completed, perform an oil production operation on the second layer combination;

[0035] f: Perform a water injection / gas energy supplementation operation on the second layer combination. After the energy supplementation is completed, close the sliding sleeve of the second layer combination;

[0036] g: Open the first interval combination and perform oil production operations on the first interval combination;

[0037] h: Perform water injection / gas energy supplementation operations on the first interval combination. After the energy supplementation is completed, close the sliding sleeve of the first interval combination;

[0038] i: Open the second interval combination and perform oil production operations on the second interval combination;

[0039] j: Repeat steps f - i until the economic and technical oil production limit of the horizontal well is reached.

[0040] The intelligent sliding sleeve controls the opening and closing of the corresponding interval combination.

[0041] The intelligent sliding sleeve includes a fracturing channel module and a sliding sleeve switch module. The fracturing channel module prefabricates the fracturing of one or more fracturing holes. The fracturing channel module is connected to other oil / gas layer casings through threads. The fracturing channel module is a connecting nipple. The sliding sleeve switch module pre - sets one or more fracturing grooves. The sliding sleeve switch module is a cylindrical switch with intelligent or mechanical positioning functions. The intelligent sliding sleeve controls whether the fracturing holes are exposed to the fracturing grooves through the movement of the sliding sleeve switch module, realizing the opening and closing of the intelligent sliding sleeve.

[0042] The horizontal section is divided based on the physical properties, oil - bearing properties, and cementing and completion quality of the reservoir drilled in the horizontal section.

[0043] The horizontal section is divided into multiple asynchronous fracturing sections and multiple cyclic injection - production interval combinations. Taking 13 asynchronous fracturing sections as an example, the 13 asynchronous fracturing sections are arranged in sequence from the toe to the heel of the horizontal section as sections 1, 2, 3... 11, 12, 13. The multiple cyclic injection - production interval combinations include the first interval combination for fracturing and cyclic injection - production and the second interval combination for fracturing and cyclic injection - production.

[0044] The cyclic injection - production interval combination is an interval combination. The first interval combination for fracturing and cyclic injection - production is the first interval combination, and the second interval combination for fracturing and cyclic injection - production is the second interval combination.

[0045] Taking the odd - numbered sections in the multiple asynchronous fracturing sections as an example for the first interval combination, and the even - numbered sections in the multiple asynchronous fracturing sections as an example for the second interval combination. Taking 13 asynchronous fracturing sections as an example, sections 1, 3, 5, 7, 9, 11, 13 in the 13 asynchronous fracturing sections are the first interval combination, and sections 2, 4, 6, 8, 10, 12 in the 13 asynchronous fracturing sections are the second interval combination.

[0046] The implementation of water injection / gas energy supplementation operations is water injection or gas injection operations.

[0047] The implementation of water injection / gas energy supplementation operation is carried out when the oil production does not meet the development requirements.

[0048] The economic and technical oil production limit of the horizontal well is the break-even point between the comprehensive oil production cost and the sales revenue calculated based on the daily recoverable oil volume of the horizontal well technology.

[0049] Embodiment

[0050] The asynchronous fracturing and periodic injection-production method for the horizontal well includes the following steps:

[0051] a: Continuously run in multiple intelligent sliding sleeves that can be quickly switched on the casing of the horizontal wellbore;

[0052] b: Divide the horizontal section into multiple layer combinations for asynchronous fracturing and periodic injection-production;

[0053] c: Implement a fracturing operation on the first layer combination. After the fracturing is completed, implement an oil production operation on the first layer combination;

[0054] d: Implement a water injection / gas energy supplementation operation on the first layer combination. After the energy supplementation is completed, close the sliding sleeve of the first layer combination;

[0055] e: Implement a fracturing operation on the second layer combination. After the fracturing is completed, implement an oil production operation on the second layer combination;

[0056] f: Implement a water injection / gas energy supplementation operation on the second layer combination. After the energy supplementation is completed, close the sliding sleeve of the second layer combination;

[0057] g: Open the first layer combination and implement an oil production operation on the first layer combination;

[0058] h: Implement a water injection / gas energy supplementation operation on the first layer combination. After the energy supplementation is completed, close the sliding sleeve of the first layer combination;

[0059] i: Open the second layer combination and implement an oil production operation on the second layer combination;

[0060] j: Repeat steps f to i until the economic and technical oil production limit of the horizontal well is reached.

[0061] The intelligent sliding sleeve controls the opening and closing of the corresponding layer combination.

[0062] The intelligent sliding sleeve includes a fracturing channel module and a sliding sleeve switch module. The fracturing channel module prefabricates the fracturing of one or more fracturing holes. The fracturing channel module is connected to other oil / gas layer casings through screw threads. The fracturing channel module is a connecting nipple. The sliding sleeve switch module is provided with one or more fracturing grooves. The sliding sleeve switch module is a cylindrical switch with intelligent or mechanical positioning functions. The intelligent sliding sleeve controls whether the fracturing holes are exposed to the fracturing grooves through the movement of the sliding sleeve switch module, realizing the opening and closing of the intelligent sliding sleeve.

[0063] The horizontal section is divided according to the physical properties, oil-bearing properties, and cementing and completion quality of the reservoir in the horizontal section drilling.

[0064] The horizontal section is divided into multiple asynchronous fracturing sections and multiple periodic injection-production layer combinations. Taking 13 asynchronous fracturing sections as an example, the 13 asynchronous fracturing sections are arranged in sequence from the toe to the root of the horizontal section as sections 1, 2, 3... 11, 12, 13. The multiple periodic injection-production layer combinations include the first fracturing and periodic injection-production layer combination and the second fracturing and periodic injection-production layer combination.

[0065] The periodic injection-production layer combination is a layer combination. The first fracturing and periodic injection-production layer combination is the first layer combination, and the second fracturing and periodic injection-production layer combination is the second layer combination.

[0066] Taking the odd-numbered sections in the multiple asynchronous fracturing sections as an example for the first layer combination, and taking the even-numbered sections in the multiple asynchronous fracturing sections as an example for the second layer combination. Taking 13 asynchronous fracturing sections as an example, sections 1, 3, 5, 7, 9, 11, 13 in the 13 asynchronous fracturing sections are the first layer combination, and sections 2, 4, 6, 8, 10, 12 in the 13 asynchronous fracturing sections are the second layer combination.

[0067] The implementation of water injection / gas energy supplementation operation is a water injection or gas injection operation.

[0068] The implementation of water injection / gas energy supplementation operation is carried out when the oil production does not meet the requirements of high-efficiency development.

[0069] The economic and technical oil production limit of the horizontal well is the break-even point between the comprehensive oil production cost and the sales revenue calculated based on the daily recoverable oil volume of the horizontal well technology.

[0070] Step 1: Horizontal well A is located in a certain shale oil block. After drilling, 13 quickly switchable sliding sleeves are installed in the wellbore casing.

[0071] Step 2: After cementing and completion, the horizontal well is transformed using the staged fracturing technology. To improve the stable production capacity and meet the economic benefit requirements, based on the physical properties, oil-bearing properties of the reservoir encountered in the horizontal section, and the cementing and completion quality, the horizontal section is divided into 13 asynchronous fracturing segments (arranged in sequence from the toe to the heel of the horizontal section as segments 1, 2, 3... 11, 12, 13) and 2 cyclic injection-production layer combinations (layer combinations). Among them: segments 1, 3, 5, 7, 9, 11, and 13 form the first fracturing and cyclic injection-production layer combination (the first layer combination); segments 2, 4, 6, 8, 10, and 12 form the second fracturing and cyclic injection-production layer combination (the second layer combination).

[0072] Step 3: Perform a fracturing operation on the first layer combination; after fracturing is completed, perform a cyclic (10-month) oil production operation on the first layer combination.

[0073] Step 4: Perform a cyclic water / gas injection (inject 3000 m 3 ) energy replenishment operation on the first layer combination; after the energy replenishment is completed, close the corresponding sliding sleeve.

[0074] Step 5: Perform a fracturing operation on the second layer combination; after fracturing is completed, perform a cyclic (9-month) oil production operation on the second layer combination.

[0075] Step 6: Perform a cyclic water / gas injection (inject 4000 m in 3 months 3 ) energy replenishment operation on the second layer combination; after the energy replenishment is completed, close the corresponding sliding sleeve.

[0076] Step 7: Perform an oil production operation (for 9 months) on the sliding sleeve corresponding to the first layer combination.

[0077] Step 8: Perform a cyclic water / gas injection (inject 4000 m in 3 months 3 ) energy replenishment operation on the first layer combination; after the energy replenishment is completed, close the corresponding sliding sleeve.

[0078] Step 9: Open the sliding sleeve corresponding to the second layer combination and perform a cyclic oil production operation on it (for 9 months).

[0079] Step 10: Repeat steps 6 - 9 until the economic and technical oil production limit of Well A is reached.

[0080] Working principle: This asynchronous fracturing and cyclic injection-production method for horizontal wells is equipped with an intelligent sliding sleeve that can be quickly switched to control the opening and closing of the fracturing and cyclic injection-production layer combinations, realizing the switching between asynchronous fracturing and cyclic injection-production of horizontal wells, effectively solving the problems of high one-time input cost, poor stable production capacity, low economic benefits in sequential synchronous fracturing of horizontal wells, and the inability of conventional injection-production methods to achieve precise water injection and injection-production synchronization, providing a new approach for the improvement of subsequent horizontal well fracturing, injection-production methods, and the enhancement of development benefits.

[0081] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for asynchronous fracturing and periodic injection-production in horizontal wells, characterized in that: It includes the following steps: a: Continuously run in multiple switchable intelligent sliding sleeves on the casing of the horizontal wellbore. The intelligent sliding sleeve includes a fracturing channel module and a sliding sleeve switch module. The intelligent sliding sleeve controls whether the fracturing perforations are exposed to the fracturing grooves through the movement of the sliding sleeve switch module, realizing the opening and closing of the intelligent sliding sleeve; b: Divide the horizontal section into multiple layer combinations for asynchronous fracturing and cyclic injection-production. Control the opening and closing of the layer combinations for fracturing and cyclic injection-production through the quickly switchable intelligent sliding sleeves, realizing the switching between asynchronous fracturing and cyclic injection-production of the horizontal well; c: Carry out fracturing operations on the first layer combination. After fracturing is completed, carry out oil production operations on the first layer combination; d: Carry out water injection / gas energy supplementation operations on the first layer combination. After the energy supplementation is completed, close the sliding sleeve of the first layer combination; e: Carry out fracturing operations on the second layer combination. After fracturing is completed, carry out oil production operations on the second layer combination; f: Carry out water injection / gas energy supplementation operations on the second layer combination. After the energy supplementation is completed, close the sliding sleeve of the second layer combination; g: Open the first layer combination and carry out oil production operations on the first layer combination; h: Carry out water injection / gas energy supplementation operations on the first layer combination. After the energy supplementation is completed, close the sliding sleeve of the first layer combination; i: Open the second layer combination and carry out oil production operations on the second layer combination; j: Repeat steps f to i until reaching the economic and technical oil production limit of the horizontal well.

2. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 1, wherein: The intelligent sliding sleeve controls the opening and closing of the corresponding layer combination.

3. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 2, wherein: The fracturing channel module prefabricates the fracturing of one or more fracturing perforations. The fracturing channel module is connected to other oil / gas layer casings through threads. The fracturing channel module is a connecting nipple. The sliding sleeve switch module pre-sets one or more fracturing grooves. The sliding sleeve switch module is a cylindrical switch with intelligent or mechanical positioning functions.

4. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 1, wherein: The division of the horizontal section is based on the physical properties, oil-bearing properties and cementing and completion quality of the reservoir drilled in the horizontal section.

5. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 1, wherein: The horizontal section is divided into multiple asynchronous fracturing sections and multiple cyclic injection-production layer combinations. The multiple cyclic injection-production layer combinations include the first layer combination for fracturing and cyclic injection-production and the second layer combination for fracturing and cyclic injection-production.

6. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 5, wherein: The cyclic injection-production layer combination is a layer combination. The first layer combination for fracturing and cyclic injection-production is the first layer combination, and the second layer combination for fracturing and cyclic injection-production is the second layer combination.

7. A method for asynchronous fracturing and cyclic injection-production of a horizontal well according to claim 1, wherein: The implementation of water injection / gas energy supplementation operations is water injection or gas injection operations.

8. A method for asynchronous fracturing and periodic injection-production in horizontal wells according to claim 1, characterized in that: The implementation of the water / gas injection energy supplementation operation is carried out when the oil production does not meet the development requirements.

9. A method for asynchronous fracturing and periodic injection-production in horizontal wells according to claim 1, characterized in that: The economic and technical oil production limit of the horizontal well is the break-even point between the comprehensive oil production cost and the sales revenue measured based on the daily recoverable oil volume of the horizontal well technology.

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