CN112627729B - Method and device for a turbine-type re-entrant branch well - Google Patents

Abstract

The invention relates to a turbine type reentry method and a device for a branch well, which comprises an upper drill rod or oil pipe, a turbine section, a hydraulic anchor and a guider which are sequentially connected from top to bottom, wherein a guide hole is formed in the guider, a flexible rod penetrates through the guide hole, one end of the flexible rod is connected with a piston body, the other end of the flexible rod is connected with a guide head, the guide head can penetrate out of the guider along the guide hole, a spring is sleeved at one end of the flexible rod connected with the piston body, the piston body slides in a channel formed by the drill rod or oil pipe, an inner pipe of the turbine section and an inner cavity of the hydraulic anchor, a one-way cavity is axially formed on the top surface of the piston body, an upper pair of through holes and a lower pair of through holes are radially distributed in the one-way cavity, and the included angle of the two pairs of through holes is 90 degrees. The branch well reentry method provided by the invention is simple in operation method and rapid and efficient in identification. By using the method, the work of releasing the anchoring and guiding to other boreholes again can be finished in one time in the multilateral borehole, and the realization method is simple and reliable.

Description

Method and device for a turbine-type re-entrant branch well

technical field

The invention belongs to the field of drilling machinery and equipment in petroleum and natural gas engineering, and relates to a downhole operation method, in particular to a method and device for reentry branch wells.

Background technique

Branch well is an effective means to improve oilfield development efficiency. It is a well that sidetracks two or more branch wells from one main wellbore, reducing the number of wells, reducing development costs, and increasing single well production and oil and gas reservoirs. recovery factor. Since there are multiple branch boreholes downhole in the branch well, when various downhole tools are lowered into the bottom of the well after completion, it is necessary to use the positioning guide to re-enter the branch wellbore. If there are multiple branches in the branch well or multiple sets of tools need to be run in, it will consume a lot of energy and time to complete the loading and unloading of the steering tools, which will cause huge consumption of downhole operation costs of oil and gas wells.

Through the patent search, the following related public invention patents were found

1. The post-operation pipe string re-entry method for multi-branch wells (CN101787856A). This method utilizes the principle of the cooperation between the guide key and the guide groove, and presets the guide groove above the branch wellbore. The projection of the guide groove and the branch wellbore on the horizontal plane The included angle is the leading angle. When running into the pipe string, a guide key and a guide shoe with a certain angle are preset, and the angle between the guide key and the guide shoe projected on the horizontal plane should be equal to the guide angle. By using the combination of the guide key and the guide groove when the pipe string is run in, the curved guide shoe can be used to enter the branch wellbore, so as to guide the post-operation pipe string to enter the branch wellbore.

This method completes the re-entry operation of the multi-branch wellbore, but the guide sleeve needs to be preset in the main wellbore in the early stage of operation, and the guide angle needs to be known. Accurately measure lead angles. The operation process is cumbersome and complicated, and takes a long time.

2. A wellbore selective reentry device and method (CN104405318A), the method is completed by the cooperation of three tools: the downhole permanent positioning tool, the main wellbore reentry guide tool and the branch wellbore reentry guide tool. First run the downhole permanent positioning tool into the main wellbore at a certain angle, then run into the main wellbore re-entry guide tool, place the annular guide slope to the branch wellbore, and then run the re-entry guide into the branch wellbore The tool extends from the side port into the branch wellbore through the guidance of the annular guiding surface, so as to guide the later operation string into the branch wellbore.

This method can selectively guide the working pipe string into the main wellbore or the branch wellbore, but the positioning tool needs to be lowered and positioned in the early stage of the operation, which makes the operation cumbersome and time-consuming. In addition, after the branch borehole reentry operation is completed, there are still permanent positioning tools in the main borehole, which will bring a lot of inconvenience to other construction operations in the main borehole in the future.

3. A branch well selective reentry method and device (CN1932231A), the method is to use the pressure drop to make the selective reentry device bend at a certain angle in a certain direction, and then slowly lower and rotate the reentry string; when the bending When the lateral force makes the bending orientation of the device of the present invention consistent with the branch wellbore, the device of the present invention guides the working pipe string into the branch wellbore.

The method is easy to implement and does not need to preset a guide device, simplifies the construction process, and can guide the operation pipe string into the branch wellbore to complete the subsequent construction operation. But there are the following disadvantages: (1) The time when the re-entry device enters the branch wellbore cannot be judged, and the lower pipe string is prone to twisting when the upper pipe string is rotated; (2) The re-entry device guides the re-entry pipe string to enter the branch After the wellbore, the reentry device is still in the branch wellbore and at the front end of the wellbore, which brings stability to other construction operations in the branch wellbore. If repeated operations are to be performed, the reentry device needs to be lifted several times.

Contents of the invention

The purpose of the present invention is to overcome the disadvantages of the prior art, and provide a method and device for re-entering a branch well, the operation method is simple, and the identification is fast and efficient. Using this method, the work of unanchoring and guiding to other wellbores can be completed in the next trip of the pipe string in the multi-branch wellbore, and the realization method is simple and reliable.

The technical scheme that the present invention solves technical problem adopts is:

A device for re-entering branch wells, including upper drill pipes or oil pipes, turbine joints, hydraulic anchors, and guides that are sequentially connected from top to bottom. Guide holes are formed in the guides, and flexible rods are installed in the guide holes. Flexible One end of the rod is connected to the piston body, and the other end of the flexible rod is connected to the guide head. The guide head can pass through the guide along the guide hole, and a spring is placed on the end of the flexible rod connected to the piston body. The oil pipe, the inner tube of the turbine section and the inner cavity of the hydraulic anchor slide in the channel, and a one-way cavity is axially formed on the top surface of the piston body, and two pairs of upper and lower through holes are distributed radially inside the one-way cavity, and the upper through hole It is used to start the turbine, and the lower through hole is used for hydraulic anchoring and pressure relief, and the angle between the two pairs of through holes is 90°.

Moreover, the turbine section includes a stator group and a rotor group, and the stator group includes a turbine outer tube, a stator, and the stator is fixed on the inner wall of the turbine outer tube, and the described rotor group includes a turbine inner tube and a rotor, and the rotor is fixed on the turbine tube. The outer wall of the inner tube, the rotor meshes with the stator, the lower part of the inner tube of the turbine is provided with a liquid inlet tank and the liquid inlet hole, the liquid can flow into the turbine section through the liquid inlet tank and the liquid inlet hole, and the upper part of the turbine outer tube is provided with a liquid outlet hole, the liquid It can flow out of the turbine section through the outlet hole.

Moreover, the stator group also includes an outer tube end cover, one end of the turbine outer tube is threadedly connected to the outer tube end cover, and the other end is threaded to the drill pipe or the oil pipe.

Moreover, the rotor set further includes an inner tube end cover, one end of the inner tube end cover is threadedly connected to the turbine inner tube, and the other end of the inner tube end cover is threadedly connected to the hydraulic anchor.

Moreover, the stator group and the rotor group are connected through upper and lower limit bearings.

And, described device usage method is:

(1) When the re-entry device is lowered into the target position, pump liquid into the pipe string to push the piston down;

(2) When the seeker touches the casing, continue to pump liquid, so that the pressure in the pipe continues to rise, and the liquid continues to push the piston down and compress the spring;

(3) When the piston goes down until the upper through hole communicates with the liquid inlet groove of the turbine inner pipe, the liquid in the piston cavity flows from the liquid inlet groove through the liquid inlet hole into the turbine section, the pressure in the upper pipe drops, the piston stops descending, and flows into the pipe string. The liquid is continuously pumped inside to keep the fluid pressure in the string in balance with the spring reaction force on the piston, and the position of the piston remains unchanged;

(4) When the liquid is continuously pumped into the pipe string, the liquid flows into the gap between the stator and the rotor of the turbine section through the pipe string, the piston cavity, the upper through hole, the liquid inlet groove of the turbine inner pipe, and the liquid inlet hole of the turbine inner pipe, and the liquid pushes the rotor Rotate, and then flow out from the outlet hole of the turbine outer pipe, and flow to the ground through the annular space of the wellbore and the pipe string;

(5) When the liquid flow pushes the rotor to rotate, the inner tube of the turbine drives the piston and the inner guider and seeker of the lower tube string to rotate together. Under the action of rotation, at the same time, the lifting column;

(6) When the seeker enters the branch wellbore, the pressure in the pipe is greater than the reaction force of the piston, and the piston continues to move downward, resulting in the dislocation of the upper through hole and the liquid inlet tank, the liquid in the pipe string stops entering the turbine section, the turbine section stops working, and the rotor and The inner tube of the turbine stops rotating;

(7) The pressure in the pipe continues to push the piston down until the lower through hole is connected to the hydraulic anchor flow channel, and the hydraulic anchor is hydraulically anchored;

(8) Continue to pump the pressure, push the piston down, and continue to open the bypass port to release the pressure.

Moreover, the direction of the liquid reaction force borne by the stator is the fastening direction of the threaded connection between the outer tube of the turbine and the upper pipe string.

Advantage and positive effect of the present invention are:

1. Compared with CN101787856A, the present invention does not require positioning and prefabricating the device before installing the device of the present invention. In the present invention, the pipe string is directly lowered into the device of the present invention. During the guiding process, the positioning of the guider is directly completed. After the guider is anchored, the seeker head is taken out to complete the guiding operation. The whole process only needs to run in and out of the pipe string once. Finish. It saves the operation process and saves time.

2. Compared with CN104405318A, the present invention does not need a permanent positioning tool. After the piloting operation is finished, the anchoring of the guider can be released, and the re-entry piloting operation of the next lateral wellbore can be continued. No downhole device material consumption, cost saving, and simple operation.

3. Compared with CN1932231A, the present invention does not need to place the guide head at the front end of the re-entry string, and the re-entry guide method is more reasonable, safe and reliable. The present invention uses the turbine joint to identify and judge the state of the seeker, which not only protects the safety of the reentry pipe string, but also identifies whether the seeker enters the branch wellbore. In the method of the present invention, the guider and the seeker are lowered into the main wellbore together, and the guider aligns with the branch wellbore and at the same time accurately anchors the position of the guider. After taking out the seeker, various tools can be lowered into the reentry string according to the construction operation requirements, without being restricted by the front seeker.

4. Compared with the prior art represented by CN101787856A, CN104405318A and CN1932231A, the present invention can perform re-entry guidance in radial branch wells and ultra-short radius branch wells. Due to the small branch boreholes of radial branch wells and ultra-short radius branch wells, the above-mentioned technologies use curved guide shoes or prefabricated curved seekers, which cannot enter smoothly, and large-sized or complex tools cannot successfully fulfill the requirements in small-diameter wells Operation. The method provided by the present invention can utilize coiled tubing (the tool is a common tool for radial horizontal well drilling and completion, with a diameter of about 1 inch to 2 inches) to complete reentry in radial branch wells and ultra-short-radius branch wells of small-diameter wells Guiding operation, the method is simple and reliable.

Description of drawings

Fig. 1 is the structural diagram of this device;

Fig. 2 is the structural diagram of turbine section;

Fig. 3 a is the structural diagram of the turbine outer tube;

Figure 3b is a cross-sectional view along the A-A direction of Figure 3a;

Fig. 4a is the structural diagram of the inner tube of the turbine;

Figure 4b is a cross-sectional view along the B-B direction of Figure 4a;

Fig. 5 is the working state schematic diagram (initial) of this method device;

Fig. 6 is the working state schematic diagram of this method device (pressurization, piston advances, and seeker presses against well wall);

Fig. 7 is the working state schematic diagram of this method device (continuing downward spring compression opens turbine);

Fig. 8 is the schematic diagram of the working state of the method device (rotating the lifting string);

Fig. 9 is a schematic diagram of the working state of the method device (the addressing is successful, the piston descends and the turbine is closed);

Fig. 10 is the schematic diagram of the working state of the method device (continue to descend and open the hydraulic anchor device to anchor);

Fig. 11 is a schematic diagram of the working state of the method device (continue to descend and open the bypass system for pressure relief);

Fig. 12 is a schematic diagram of the working state of the device of this method (coiled tubing fishing).

Detailed ways

The present invention will be described in further detail below through specific examples. The following examples are only descriptive, not restrictive, and cannot limit the protection scope of the present invention with this.

A device for re-entry into a branch well, comprising an upper drill pipe or tubing 1, a turbine section 27, a hydraulic anchor 13, a guide 14, and a lower centralizer 17, which are sequentially connected from top to bottom. A centralizer 22 is installed outside the turbine section, and an arc-shaped guide hole 16 is formed in the guide. A flexible rod 18 is installed in the guide hole. One end of the flexible rod is connected to the piston body 21, and the other end of the flexible rod is connected to the guide. Head 15. The guide head can pass through the guide along the guide hole. A spring 20 is installed at one end of the flexible rod connected to the piston body, and the piston body slides in the channel formed by the drill pipe or oil pipe, the inner tube of the turbine section, the inner cavity of the upper centralizer, and the inner cavity of the hydraulic anchor. A one-way cavity 24 is axially formed on the top surface of the piston body, and two pairs of through holes, upper and lower, are distributed radially inside the one-way cavity, the upper through hole 25 is used to start the turbine, and the lower through hole is used for hydraulic anchoring and anchoring. For pressure relief, in order to prevent the lower through hole from communicating with the turbine first during the downward process, the angle between the two pairs of through holes is designed to be 90°.

The turbine section includes a stator group and a rotor group, and the stator group includes a turbine outer tube 2, a stator 4, an outer tube end cover 11, a sealing ring 10, and a stator stop ring 7, wherein one end of the turbine outer tube is connected to the drill pipe Or the oil pipe is connected through threads, and the other end is connected with the end cap of the outer pipe through threads, the stator is fixed on the inner wall of the outer pipe, and the sealing ring plays the functions of sealing and position limiting. The rotor group includes a turbine inner tube 6, a rotor 5, and a rotor stop ring 8. The rotor is fixed on the outer wall of the inner tube, and the rotor meshes with the stator. One end of the turbine inner tube is threadedly connected to the inner tube end cover 12, and the inner tube The end cap is connected with the hydraulic anchor through thread engagement. The stator group and the rotor group are connected through upper and lower limit bearings 3 and 9, and the upper and lower limit bearings are used to transmit axial force and realize relative movement in the circumferential direction. A liquid outlet hole 26 is arranged on the upper part of the turbine outer pipe, through which liquid can flow out of the turbine section. A liquid inlet groove and a liquid inlet hole 23 are arranged at the lower part of the inner tube of the turbine, and liquid can flow into the turbine section through the liquid inlet groove and the liquid inlet hole.

A method for re-entering a lateral well, taking a radial horizontal well as an example, includes the following steps:

(1) When the re-entry device is lowered to the target position, pump liquid into the pipe string to push the piston down.

(2) When the seeker touches the casing, continue to pump the liquid, so that the pressure in the tube continues to rise. The fluid continues to push the piston down and compress the spring.

(3) When the piston goes down until the upper through hole communicates with the liquid inlet groove of the turbine inner tube (the direction of the liquid inlet groove and the lower through hole will not communicate at an angle of 90°), the liquid in the piston cavity passes from the liquid inlet groove to the liquid inlet hole, When it flows into the turbine section (between the turbine inner tube and the turbine outer tube), the pressure in the upper tube drops, and the piston stops descending. Continuously pump liquid into the pipe string to keep the fluid pressure in the pipe string and the spring reaction force on the piston in balance, and the position of the piston remains unchanged.

(4) When the liquid is continuously pumped into the pipe string, the liquid flows into the gap between the stator and the rotor of the turbine section through the pipe string, the piston cavity, the upper through hole, the liquid inlet groove of the turbine inner pipe, and the liquid inlet hole of the turbine inner pipe, and the liquid pushes the rotor Rotate, and then flow out from the outlet hole of the turbine outer pipe, and flow to the ground through the annular space of the wellbore and the pipe string.

(5) When the liquid flow drives the rotor to rotate, the inner tube of the turbine drives the piston and the inner guider and guide head of the lower pipe string to rotate together. (At this time, the upper pipe string and the turbine outer pipe do not rotate, and only the lower pipe string of the turbine section rotates under the action of the liquid. At the same time, the lifting pipe string. Considering the reaction force of the fluid to the stator, in order to avoid the turbine outer pipe and the upper When the pipe string is tripped, the direction of the liquid reaction force borne by the stator should be the fastening direction of the threaded connection between the turbine outer pipe and the upper pipe string.)

(6) When the seeker enters the branch wellbore, the pressure in the pipe is greater than the reaction force of the piston, and the piston continues to descend, resulting in the dislocation of the upper through hole and the liquid inlet tank. The liquid in the string stops entering the turbine section, and the turbine section stops working (the rotor and the inner tube of the turbine stop rotating).

(7) The pressure in the pipe continues to push the piston down until the lower through hole communicates with the hydraulic anchor channel 19, and the hydraulic anchor is hydraulically anchored.

(8) Continue to pump the injection pressure again, push the piston down, and continue to open the bypass port 28 to release the pressure.

The reentrant device and method are not limited to application in radial horizontal wells, and can be used in all types of lateral wells. Because the reentry process of radial horizontal wells is the most difficult, we use the reentry process of radial horizontal wells as an example to illustrate.

What has been described above is only a preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the inventive concept, and these all belong to the scope of the present invention. protected range.

Claims (6)

1. A device for re-entering branch wells, characterized in that: it comprises upper drill pipes or oil pipes, turbine joints, hydraulic anchors, and guides that are sequentially connected from top to bottom, and guide holes are formed in the guides, and guide holes are formed in the guide holes. A flexible rod is installed inside, one end of the flexible rod is connected to the piston body, the other end of the flexible rod is connected to the guide head, the guide head can pass through the guide along the guide hole, and a spring is set at the end of the flexible rod connected to the piston body. The piston body slides in the channel composed of the drill pipe or oil pipe, the inner tube of the turbine section, and the inner cavity of the hydraulic anchor. A one-way cavity is axially formed on the top surface of the piston body. For the through holes, the upper through hole is used to start the turbine, and the lower through hole is used for hydraulic anchoring and pressure relief, and the angle between the two pairs of through holes is 90°. 2. The device according to claim 1, characterized in that: the turbine section includes a stator group and a rotor group, and the stator group includes a turbine outer tube, a stator, and the stator is fixed on the inner wall of the turbine outer tube, and the The rotor group includes the inner tube of the turbine and the rotor. The rotor is fixed on the outer wall of the inner tube of the turbine. The rotor meshes with the stator. There is a liquid inlet groove and a liquid inlet hole at the lower part of the inner turbine pipe. The liquid can flow into the turbine section through the liquid inlet groove and the liquid inlet hole. , There is a liquid outlet hole on the upper part of the turbine outer tube, and the liquid can flow out of the turbine section through the liquid outlet hole. 3. The device according to claim 2, characterized in that: the stator group also includes an outer tube end cover, one end of the turbine outer tube is threaded to the outer tube end cover, and the other end is threaded to the drill pipe or oil pipe . 4. The device according to claim 2, characterized in that: the rotor group also includes an inner tube end cover, one end of the inner tube end cover is threadedly connected to the inner tube of the turbine, and the other end of the inner tube end cover is connected to the inner tube of the turbine. Hydraulic anchors are connected by threaded engagement. 5. The device according to claim 2, characterized in that: the stator set and the rotor set are connected through upper and lower limit bearings. 6. The device according to claim 1, characterized in that: the method of use is: (1) When the re-entry device is lowered into the target position, pump liquid into the pipe string to push the piston down; (2) When the seeker touches the casing, continue to pump liquid, so that the pressure in the pipe continues to rise, and the liquid continues to push the piston down and compress the spring; (3) When the piston goes down until the upper through hole communicates with the liquid inlet groove of the turbine inner pipe, the liquid in the piston cavity flows from the liquid inlet groove through the liquid inlet hole into the turbine section, the pressure in the upper pipe drops, the piston stops descending, and flows into the pipe string. The liquid is continuously pumped inside to keep the fluid pressure in the string in balance with the spring reaction force on the piston, and the position of the piston remains unchanged; (4) When the liquid is continuously pumped into the pipe string, the liquid flows into the gap between the stator and the rotor of the turbine section through the pipe string, the piston cavity, the upper through hole, the liquid inlet groove of the turbine inner pipe, and the liquid inlet hole of the turbine inner pipe, and the liquid pushes the rotor Rotate, and then flow out from the outlet hole of the turbine outer pipe, and flow to the ground through the annular space of the wellbore and the pipe string; (5) When the liquid flow pushes the rotor to rotate, the inner tube of the turbine drives the piston and the inner guider and seeker of the lower tube string to rotate together. Under the action of rotation, at the same time, the lifting column; (6) When the seeker enters the branch wellbore, the pressure in the pipe is greater than the reaction force of the piston, and the piston continues to move downward, resulting in the dislocation of the upper through hole and the liquid inlet tank, the liquid in the pipe string stops entering the turbine section, the turbine section stops working, and the rotor and The inner tube of the turbine stops rotating; (7) The pressure in the pipe continues to push the piston down until the lower through hole is connected to the hydraulic anchor flow channel, and the hydraulic anchor is hydraulically anchored; (8) Continue to pump the pressure, push the piston down, and continue to open the bypass port to release the pressure.

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