Drilling pipe column for multilateral well with high build-up rate and using method

Abstract

The invention discloses a drilling pipe column for a high-build-up-rate multilateral well and a using method.The drilling pipe column comprises an outer-layer pipe column body and an inner-layer pipe column body, the outer-layer pipe column body comprises a drill rod and a high-build-up-rate separation barrel, the high-build-up-rate separation barrel is connected to the lower portion of the drill rod, a plurality of inclined face holes are formed in the high-build-up-rate separation barrel in advance, and the inner-layer pipe column body is connected to the lower portion of the drill rod; the upper end of the inclined face hole is located in the high-build-up-rate separation barrel, the lower end of the inclined face hole penetrates through the side wall of the high-build-up-rate separation barrel, the inner-layer pipe column comprises a turbine motor, a steel wire and a drill bit, the steel wire is tripped into the inclined face hole in the drill rod, the lower end of the steel wire is connected with the drill bit, and the upper end of the steel wire is connected with the turbine motor. A slope hole, a turbine motor, a steel wire and the like are preset through the high-build-up-rate separation barrel, and simultaneous drilling operation of multiple branch well holes in one time is achieved; the single-well-shaft multi-branch well hole building operation is completed through one pipe column, the high build-up rate well building requirement is met, and the single-well multi-well hole drilling period is shortened.

Description

Technical Field

[0001] This invention relates to the field of petroleum development operation technology, and in particular to a drilling string for high build-up rate branch wells and its usage method. Background Technology

[0002] Currently, multi-branch well technology is used to improve the recovery rate of single wells in offshore oil and gas fields. Existing technologies have all been deployed in the field of multi-branch wells, each with its own characteristics. Analysis shows that this type of technology involves a variety of tools, complex operating procedures, and long cycles, leading to high costs and increased operational risks. Furthermore, only one wellbore can be drilled per run, and the build-up rate is low. This invention develops an efficient drilling method for multi-branch wells with high build-up rates, shortening the well construction cycle for single-well multi-wells and providing a new means for branch well drilling. Summary of the Invention

[0003] In order to solve all or some of the above problems, the present invention aims to provide a drilling string for high build-up rate branch wells and a method of using it.

[0004] The present invention solves its problems through the following technical solution: A drilling string for high build-up rate branch wells includes an outer string and an inner string. The outer string includes a drill pipe and a high build-up rate separator. The high build-up rate separator is connected below the drill pipe. The high build-up rate separator has several pre-set inclined holes inside. The upper end of the inclined holes is located inside the high build-up rate separator, and the lower end of the inclined holes penetrates the side wall of the high build-up rate separator. The upper end of the inclined holes is connected to an upward through hole. The drill pipe has an axial inner hole. The inner string includes a turbine motor, a wire rod, and a drill bit. The wire rod is inserted into the inclined holes through the inner hole of the drill pipe. The lower end of the wire rod is connected to the drill bit, and the upper end of the wire rod is connected to the turbine motor.

[0005] Optionally, the upper ends of each of the inclined holes are at different heights, and the upper ends of each of the inclined holes are located at different positions in the circumferential direction.

[0006] Optionally, the drill pipe and the high build-up rate separator are connected via API drill pipe threaded connection.

[0007] Optionally, the high inclination separation cylinder is a solid structure.

[0008] A method of using the aforementioned drilling string for high build-up rate branch wells includes the following steps: Tubing string assembly: The wellhead connects the drill pipe and the high build-up rate separator. A steel wire is lowered into the drill pipe into the inclined hole of the high build-up rate separator and then out through the inclined hole. The lower end of the steel wire is connected to the drill bit. After the tubing string is lowered into place, the upper end of the steel wire is connected to the turbine motor. High build-up rate branch well operation: After the tubing string is in place, start the mud pump and increase the mud pump discharge to start the turbine motor. The turbine motor drives the wireline and drill bit to drill through the casing and formation along the high build-up rate separation tube to complete the required wellbore.

[0009] In summary, the technical effects and advantages of this invention are as follows: The high build-up rate branch well drilling string of this invention, through the pre-set inclined holes in the high build-up rate separator, turbine motor, wire rope, etc., enables simultaneous drilling of multiple branch wells in one trip; the single-trip string of this invention completes the well construction operation of multiple branch wells in a single wellbore, meets the requirements of high build-up rate well construction, shortens the drilling cycle of multiple wells in a single well, reduces development costs, improves the single well recovery rate, and provides a new means for branch well drilling. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of a drilling string for high build-up rate branch wells in one embodiment of the present invention.

[0012] The components include: 1. High build-up rate separation cylinder; 2. Inclined hole; 3. Turbine motor; 4. Steel wire; 5. Drill bit; and 6. Drill rod. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] This embodiment provides a drilling string for high build-up rate branch wells, such as... Figure 1As shown, the system includes an outer tubing string and an inner tubing string. The outer tubing string includes a drill pipe 6 and a high build-up rate separation cylinder 1. The high build-up rate separation cylinder 1 is connected below the drill pipe 6. The high build-up rate separation cylinder 1 has several pre-set inclined holes 2 inside. The upper end of each inclined hole 2 is located inside the high build-up rate separation cylinder 1, and the lower end of each inclined hole 2 penetrates through the side wall of the high build-up rate separation cylinder 1. The upper end of each inclined hole 2 is connected to an upward-facing through hole. The drill pipe 6 has an axial inner hole. The inner tubing string includes a turbine motor 3, a steel wire 4, and a drill bit 5. The steel wire 4 is inserted into the inclined hole 2 through the inner hole of the drill pipe 6. The lower end of the steel wire 4 is connected to the drill bit 5, and the upper end of the steel wire 4 is connected to the turbine motor 3. This embodiment enables the drill bit to drill at a predetermined build-up rate. The number and length of the steel wire depend on the specific operational requirements. The angle of the inclined holes is determined according to the build-up rate, and the inclined holes extend from the inside of the high build-up rate separation cylinder to the outside.

[0015] Optionally, the upper ends of each of the inclined holes 2 are at different heights, and the upper ends of each of the inclined holes 2 are located at different positions in the circumferential direction. This design facilitates the setting of wires and drill bits in different directions.

[0016] Optionally, the drill pipe 6 and the high build-up rate separation cylinder 1 are connected by API drill pipe threads. API drill pipe threads are a common existing structure.

[0017] Optionally, the high inclination separation cylinder 1 is a solid structure. The high inclination separation cylinder 1 is provided with multiple vertical holes and inclined holes 2 through which steel wires 4 can be passed.

[0018] This embodiment also provides a method for using the aforementioned drilling string for high build-up rate branch wells, including the following steps: Tubing string assembly: The wellhead connects the drill pipe 6 and the high build-up rate separation cylinder 1. The steel wire 4 is lowered into the inclined hole 2 of the high build-up rate separation cylinder 1 through the drill pipe 6 and then passes out through the inclined hole 2. The lower end of the steel wire 4 is connected to the drill bit 5. After the tubing string is lowered into place, the upper end of the steel wire 4 is connected to the turbine motor 3. High build-up rate branch well operation: After the tubing string is in place, the mud pump is started, and the pump's displacement is slowly increased until the turbine motor 3 starts. The turbine motor 3 drives the wireline 4 and drill bit 5 to drill through the casing and formation along the high build-up rate separation cylinder 1, completing the required wellbore. The turbine motor 3, mud pump, wireline 4, and drill bit 5 are commercially available products, and driving the turbine motor to rotate and move downwards via the mud pump is existing technology.

[0019] In summary, the high build-up rate branch well drilling string of the present invention, through the pre-set inclined holes in the high build-up rate separator, turbine motor, wire rope, etc., enables simultaneous drilling of multiple branch wells in one trip; the string of the present invention completes the well construction operation of multiple branch wells in a single wellbore in one trip, meets the requirements of high build-up rate well construction, shortens the drilling cycle of multiple wells in a single well, reduces development costs, improves the single well recovery rate, and provides a new means for branch well drilling.

[0020] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A drilling string for high build-up rate branch wells, characterized in that, The system includes an outer tubing string and an inner tubing string. The outer tubing string includes a drill pipe and a high build-up rate separator. The high build-up rate separator is connected below the drill pipe. The high build-up rate separator has several pre-set inclined holes inside. The upper end of the inclined holes is located inside the high build-up rate separator, and the lower end of the inclined holes penetrates the side wall of the high build-up rate separator. The upper end of the inclined holes is connected to an upward through hole. The drill pipe has an axial inner hole. The inner tubing string includes a turbine motor, a wire, and a drill bit. The wire is inserted into the inclined holes through the inner hole of the drill pipe. The lower end of the wire is connected to the drill bit, and the upper end of the wire is connected to the turbine motor.

2. The drilling string for high build-up rate branch wells according to claim 1, characterized in that, The upper ends of each of the inclined holes are at different heights, and the upper ends of each of the inclined holes are located at different positions in the circumferential direction.

3. The drilling string for high build-up rate branch wells according to claim 1, characterized in that, The drill pipe and the high build-up rate separator are connected by API drill pipe threaded connection.

4. The drilling string for high build-up rate branch wells according to claim 1, characterized in that, The high inclination separation cylinder is a solid structure.

5. A method of using the drilling string for high build-up rate branch wells as described in any one of claims 1-4, characterized in that, Includes the following steps: Tubing string assembly: The wellhead connects the drill pipe and the high build-up rate separator. A steel wire is lowered into the drill pipe into the inclined hole of the high build-up rate separator and then out through the inclined hole. The lower end of the steel wire is connected to the drill bit. After the tubing string is lowered into place, the upper end of the steel wire is connected to the turbine motor. High build-up rate branch well operation: After the tubing string is in place, start the mud pump and increase the mud pump discharge to start the turbine motor. The turbine motor drives the wireline and drill bit to drill through the casing and formation along the high build-up rate separation tube to complete the required wellbore.

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