CN115306302A - Rotary nozzle for hydraulic jet drilling of radial branch hole, system and method for drilling radial branch hole by using system - Google Patents

Abstract

The invention discloses a method and a tool for hydraulic jet drilling a radial branch hole, which comprises a casing pipe arranged vertically, wherein a cement ring is arranged outside the casing pipe, a plurality of main oil pipes arranged in series are arranged inside the casing pipe, an anchor is arranged between the main oil pipes and anchored on the inner wall of the casing pipe, a steering gear joint is arranged at the bottom of the main oil pipe, a steering gear is arranged below the steering gear joint, a continuous oil pipe is arranged in the main oil pipe, and the tail end of the lower part of the continuous oil pipe is detachably connected with a milling drilling tool assembly or a high-pressure jet assembly. The system for drilling the radial branch hole by hydraulic jet drills holes on a sleeve and a cement sheath by using a milling drilling tool assembly, then utilizes a high-pressure jet assembly to jet and crush stratum rocks, utilizes the high-pressure jet assembly to transfer thrust, finally forms a radial horizontal well hole, and is simple, convenient, safe and efficient.

Description

Rotary nozzle, system for drilling radially branched holes with hydrojet and drilling with the same Radial Branch Eyelet Method

technical field

The present invention relates to a drilling facility, more specifically, a method and tool for drilling radially branched holes with hydraulic jets.

Background technique

Radial branch holes are also called ultra-short radius branch holes, which are drilled in the direction perpendicular to the main wellbore in oil and gas reservoirs by means of high-pressure water jet injection within a turning radius of 0.3m using special devices and tools. One or more lateral lateral boreholes. The length of the radial branch hole can reach tens of meters to hundreds of meters, and the diameter of the hole is about 30-50mm. It can be used not only for the reconstruction of old wells but also for the development of new wells, which is conducive to increasing the exposed area of oil and gas layers. It is especially suitable for Stimulation of thin oil layers and low-permeability oil and gas reservoirs, as well as directional hydraulic fracturing stimulation.

At present, radial horizontal wells are drilled at home and abroad by the sidetracking method of opening windows in the casing. The drilling method of radial branch holes generally adopts self-advancing jet nozzles with holes in the front and rear directions. This nozzle uses a part of the hydraulic energy to break rocks through the forward holes, and converts the other part of the hydraulic energy through the backward nozzles. As the power to drive the jet nozzle and high-pressure hose forward, this part of the power is provided by the reverse thrust of the backward jet overcoming the reverse thrust of the forward jet and the friction between the high-pressure hose, the diverter and the well wall, usually the backward jet The energy must account for more than 50% of the hydraulic energy of the entire system to provide forward power. However, due to the limitation of the working pump conditions in China, it cannot achieve sufficient displacement and nozzle pressure drop, so it cannot provide sufficient hydraulic energy. On the one hand, it is difficult Effective rock breaking, on the other hand, cannot provide enough power to drag the high-pressure hose and jet nozzle forward, so it is easy to cause the problem that the extension length of the radial hole is too short, and the rock holes broken by the multi-hole jet nozzle are irregular and rough It not only increases the frictional resistance of the hole wall to the high-pressure hose, but also increases the difficulty of cuttings discharge, and makes the flow resistance of oil and gas in the radial branch holes larger during the production process, making it difficult to achieve the expected oil and gas reservoir development effect .

Contents of the invention

The present invention mainly solves the technical problems existing in the prior art, thereby providing a method and a tool for drilling radial branch holes by hydraulic jetting.

Above-mentioned technical problem of the present invention is mainly solved by following technical scheme:

A rotary nozzle for hydraulic jet drilling radial branch holes, characterized in that the rotary nozzle includes an upper casing and a lower casing, a rotor is arranged between the upper casing and the lower casing, and the The outer edge of the lower casing is provided with several lower casing holes, the center of the head of the rotor is provided with a through rotor shaft hole, and the head of the rotor is provided with a number of obliquely arranged rotors on the side. Side eyelets.

As a preferred embodiment of the present invention, a thrust bearing is provided between the upper casing and the lower casing.

As a preferred embodiment of the present invention, the upper casing and the lower casing are connected by threads.

As a preferred embodiment of the present invention, the number of holes on the rotor side is an even number.

A system for hydraulic jet drilling radial branch holes, characterized in that the system for hydraulic jet drilling radial branch holes includes a vertically arranged casing, and the outside of the casing is provided with a cement sheath. The interior of the casing is provided with several main oil pipes arranged in series, and an anchor is arranged between adjacent main oil pipes, and the anchor is anchored on the inner wall of the casing, and the main oil pipe The bottom of the steering gear is provided with a steering gear joint, and the steering gear joint is connected with the lowermost steering gear through threads.

The main oil pipe is provided with a coiled oil pipe, and the lower end of the coiled oil pipe is detachably connected with a milling drill assembly or a high-pressure injection assembly.

As a preferred embodiment of the present invention, the upper end of the diverter is provided with a stepped hole.

As a preferred embodiment of the present invention, the milling and drilling tool assembly includes a milling adapter, a screw motor and a flexible shaft in sequence from top to bottom, and the milling adapter and the coiled tubing Matching, the flexible shaft includes a motor joint, a shaft collar and a flexible shaft main body, the flexible shaft main body passes through the steering gear, and a milling bit is provided at the end of the flexible shaft main body .

As a preferred embodiment of the present invention, the high-pressure injection assembly includes an upper high-pressure adapter, a weighted pipe, a lower high-pressure adapter and a high-pressure hose from top to bottom, and the upper high-pressure adapter and the The coiled tubing mentioned above is matched, the lower high-pressure adapter is matched with the high-pressure hose, and a rotating nozzle is arranged at the end of the high-pressure hose.

A method of drilling radial branch holes using the aforementioned hydraulic jet drilling system for radial branch holes, comprising the steps of:

Step S1. Connect the steering gear to the main tubing through the steering gear joint, and run the entire working string into the well through the main tubing. After reaching the predetermined depth and setting the orientation, the anchor anchors the casing;

Step S2, using the milling adapter to connect the milling drill assembly and the coiled tubing, lowering the milling bit, the flexible shaft and the screw motor into the main tubing through the coiled tubing, so that the milling bit is in contact with the inner wall of the casing 3;

Step S3: Use the surface high-pressure pump to pump high-pressure fluid into the coiled tubing to make the screw motor work, thereby driving the flexible shaft and the milling bit to rotate, and drilling a hole on the casing and cement ring until the shaft collar on the flexible shaft Stuck at the stepped hole at the upper end of the steering gear, the milling and milling process is over, then the screw motor, flexible shaft and milling bit are lifted out of the well bottom through the coiled tubing, and the milling drill assembly is disassembled from the coiled tubing;

Step S4. Use the upper high-pressure adapter to connect the high-pressure jet assembly and the coiled tubing, lower the high-pressure hose and the rotary nozzle into the well, press the hose to transmit the axial pressure, and push the rotary nozzle to advance while breaking the formation rock through the water jet, and finally A radially branched wellbore is formed.

As a preferred embodiment of the present invention, the steering gear is fixedly connected to the steering gear joint through several first bolts, and the steering gear is provided with several second bolts for fixing the steering gear.

The method and tool for hydraulic jet drilling radial branch holes of the present invention have the following advantages: the anchor and diverter are lowered into the cased well for positioning and fixing by using a smaller-sized tubing, and the screw motor is used to transmit the torque through the flexible shaft to the On the milling bit at the top, a hole is drilled on the casing and the cement sheath, and then the tool string composed of the rotating nozzle, the high-pressure hose and the weighted pipe is lowered into the well through the coiled tubing, the coiled tubing is lowered, and the coiled tubing and the weighted pipe are lowered into the well. Part of the gravity of the pipe pushes the high-pressure hose forward, and the rotating jet at the front end breaks the rock and drills a radial wellbore with a certain diameter and length. Among them, the rotating nozzle does not produce a backward jet. On the one hand, it can use all the hydraulic energy to break the rock; The dynamic force can make the radial horizontal wellbore extend longer.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the connection structure sectional view of the system of hydraulic jet drilling radial branch hole of the present invention;

Fig. 2 is a working schematic diagram of the system of hydraulic jet drilling radial branch holes in Fig. 1, at this time, the milling and milling drill assembly enters a predetermined position;

Fig. 3 is the working diagram of the system of hydraulic jet drilling radial branch holes in Fig. 2, at this moment, the milling bit has drilled through casing and cement sheath;

Fig. 4 is a working schematic diagram of the system of hydraulic jet drilling radial branch holes in Fig. 1, at this moment, the high-pressure jet assembly enters a predetermined position, and the high-pressure water jet jet drilling forms a radial borehole;

Fig. 5 is a structural schematic diagram of the flexible shaft of the system of hydraulic jet drilling radial branch holes in Fig. 4;

Fig. 6 is a structural sectional view of the rotary nozzle in Fig. 4;

Fig. 7 is the sectional view of the rotor of the rotary nozzle in Fig. 6;

Fig. 8 is a sectional view of the rotor of the rotary nozzle in Fig. 7 along the plane BB.

Detailed ways

The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

As shown in Figure 1, the system of the hydraulic jet drilling radial branch hole comprises a vertically arranged casing 3, the outside of the casing 3 is provided with a cement sheath 4, and the inside of the casing 3 is provided with several serially arranged The main oil pipe 1 is provided with an anchor 2 between adjacent main oil pipes 1, and the anchor 2 is anchored on the inner wall of the casing 3, and the bottom of the casing 3 is provided with a diverter joint 5, the diverter The joint 5 is connected with the lowermost main oil pipe 1 , a steering gear 8 is arranged below the steering gear joint 5 , and the steering gear 8 is fixedly connected with the steering gear joint 5 .

A coiled oil pipe 11 is arranged inside the main oil pipe 1, and a lower end of the coiled oil pipe 11 is detachably connected with a milling drill assembly S1 or a high-pressure injection assembly S2. In different stages of construction, users choose to use different components.

As shown in FIG. 2 , the milling and drilling tool assembly S1 includes a milling adapter 12 , a screw motor 13 and a flexible shaft 15 sequentially from top to bottom. The milling adapter 12 is matched with the coiled tubing 11 . As shown in Figure 5, the flexible shaft 15 includes a motor joint 14, a shaft collar 16 and a flexible shaft main body 17, the flexible shaft main body 17 passes through the diverter 8, and the end of the flexible shaft main body 17 is provided with a grinder Milling drill bit 18.

As shown in Figures 4 and 6, the high-pressure injection assembly S2 includes an upper high-pressure adapter 21, a weighted pipe 22, a lower high-pressure adapter 23, and a high-pressure hose 24 from top to bottom. Matched with the coiled tubing 11 , the lower high-pressure adapter 23 is matched with the high-pressure hose 24 , and a rotating nozzle 25 is arranged at the end of the high-pressure hose 24 .

As shown in FIG. 7 and FIG. 8 , the rotating nozzle 25 includes an upper casing 29 and a lower casing 32 , and a rotor 30 and a thrust bearing 31 are arranged between the upper casing 29 and the lower casing 32 . The upper casing 29 and the lower casing 32 clamp the rotor 30 and the thrust bearing 31 through threaded connection, wherein the thrust bearing 31 plays the role of reducing the rotational friction of the rotor. In addition, the rotary nozzle 25 is connected to the high-pressure hose 24 through the thread connection between the joint 28 and the upper casing 29 .

The outer edge of the lower casing 32 is provided with several lower casing holes 33, so that the broken cuttings can be discharged from the annular space between the nozzle 25 and the wellbore 27 in time, and the top of the lower casing 32 can be a jet The spray provides a certain spray distance to improve the rock breaking efficiency.

The center of the head of the rotor 30 has a through rotor shaft hole 34 , and the head of the rotor 30 has a plurality of obliquely arranged rotor side holes 35 on the side. These rotor side holes 35 form a certain angle with the axis of the rotor 30, and the number can be two, four or six, etc., and the side jets generated by them have two functions. One is that the lateral jet impacts the rock, and the other is that the reverse thrust along the tangential direction can provide the rotational torque of the rotor, so that the tangential jet can rotate, which can improve the efficiency of rock breaking, reduce the roughness of the broken wellbore 27, and make the It is more rounded, reduces the resistance of cuttings discharged from the wellbore, and effectively reduces the resistance of oil and gas flowing in the wellbore 27 in the later stage, thereby improving the development effect.

The working method of the system for drilling radial branch holes of the hydraulic jet is described below, including steps:

Step S1, connect the steering gear 8 with the main tubing 1 through the steering gear joint 5, connect the anchor 2 through the main tubing 1 at the upper part of the steering gear 8 at 3-10 m, and run the whole working string into the well through the main tubing 1 , after reaching the predetermined depth and setting the orientation, it is anchored on the casing 3 through the anchor 2, wherein the steering gear 8 is fixedly connected with the steering gear joint 5 through a number of first bolts 7, and the steering gear 8 is provided with several The second bolt 10 used to fix the steering gear 8;

Step S2, use the milling adapter 12 to connect the milling drill assembly S1 and the coiled tubing 11, install the milling bit 18 on the front end of the flexible shaft 15, the screw motor 13 drives the milling bit 18 through the flexible shaft 15, and the screw motor 13 passes through the The milling adapter 12 is connected to the coiled tubing 11, and then, the milling bit 18, the flexible shaft 15 and the screw motor 13 are lowered into the main tubing 1 through the coiled tubing 11, so that the milling bit 18 is in contact with the inner wall of the casing 3;

Step S3, using a surface high-pressure pump to pump high-pressure fluid into the coiled tubing 11 to make the screw motor 13 work, thereby driving the flexible shaft 15 and the milling bit 18 to rotate, and drilling a tunnel 20 on the casing 3 and the cement sheath 4, Until the collar 16 on the flexible shaft 15 is stuck at the stepped hole 6 at the upper end of the diverter 8, the process of milling and opening the window is completed, and then the screw motor 13, the flexible shaft 15 and the milling bit 18 are pulled out of the well bottom through the coiled tubing 11 , dismounting the milling drill assembly S1 from the coiled tubing 11;

Step S4, use the upper high-pressure adapter 21 to connect the high-pressure injection assembly S2 and the coiled tubing 11, and use the weighted pipe 22 to lower the high-pressure hose 24 and the rotating nozzle 25 into the well, wherein the high-pressure hose 24 has a relatively high bending rigidity , its outer diameter is slightly smaller than the inner diameter of the main oil pipe 1, under the constraints of the main oil pipe 1, the high-pressure hose 24 can transmit axial pressure, push the rotary nozzle 25 to advance while breaking the formation rock 19 through the water jet 26, and pass through the ground Control the hanging weight and lowering speed of the coiled tubing 11 to control the axial pressure on the high-pressure hose 24, so that the rotating nozzle 25 and the high-pressure hose 24 advance at a predetermined speed, and finally form a radial branch hole 27.

This hydrojet drilling system for radially branched holes has the following advantages:

1. The hydraulic jet drilling radial branch hole system directly connects the weighted tube through the coiled tubing, and pushes the lower high-pressure hose and jet drill bit forward under the constraints of the external small-sized tubing. Firstly, a hole of a certain size is drilled on the casing and the cement sheath by milling the drill bit, and then the high-pressure hose and the rotating nozzle are lowered to spray and break the formation rock, and part of the gravity of the coiled tubing and the weighted pipe pushes the high-pressure hose and the rotating nozzle Advance, eventually forming a radial horizontal wellbore. The method is characterized by simplicity, safety and efficiency.

2. The hydraulic jet drilling radial branch hole system uses small-sized tubing as the working string during construction. The inner diameter of the tubing is slightly larger than the outer diameter of the coiled tubing, and the coiled tubing is used as the main body to drive the diverter and anchor into the well. Then drill through the casing and cement sheath, and drill holes of a certain size and length in the oil and gas layer, increase the exposed area of the oil and gas layer, and improve the oil and gas development effect. Connect the coiled tubing to the hydraulic motor, that is, the screw motor, and drive the hydraulic motor to rotate with a certain displacement of fluid, and drive the milling bit through the flexible shaft to rotate on the casing and cement ring to drill holes that allow the jet bit and high-pressure hose to pass through; Then use the coiled tubing to connect the weighted pipe to lower the high-pressure hose and the jet drill bit, and use the energy jet of the water jet to drill the radial branch wellbore. Among them, the high-pressure hose has high bending rigidity, and under the constraint of the external small-sized tubing, it has the ability to transmit axial pressure. Part of the gravity of the coiled tubing and the weighted tube can push the high-pressure hose and the jet drill forward until the thrust It is equal to the resistance to complete the drilling of a radial hole, which can meet the development of low permeability reservoirs, heavy oil reservoirs and coalbed methane.

3. The hydraulic jet drilling radial branch hole system improves the current method of using a self-advancing jet drill bit to break rock and drive the high-pressure hose forward, and broadens the application range of hydraulic jet drilling radial branch holes, which can be applied to Drill radial horizontal holes in vertical wells, and drill small branch holes or fishbone wells in inclined wells and horizontal wells. Through the rotating nozzle, the torque generated by the reverse thrust generated by the tangential jet injection on the tangential component of the nozzle axis drives the rotor inside the nozzle to rotate, so that the jet rotates, and the broken holes can be made more regular and round. The jet can overcome the disadvantage that ordinary rotating jets cannot break the rock in the center of the hole, improve the efficiency of rock breaking, help to improve the efficiency of cuttings discharge and reduce the flow resistance of fluid in the wellbore, so as to achieve the purpose of forming regular oil and gas flow channels.

4. The hydraulic jet drilling radial branch hole system utilizes smaller-sized tubing to lower the anchor and diverter into the cased well for positioning and fixing, and uses a screw motor to transmit the torque to the milling bit at the top through a flexible shaft , drill a hole in the casing and cement sheath, and then run a tool string consisting of a rotating nozzle, a high-pressure hose, and a weighted pipe into the well through the coiled tubing. The hose advances, and the rotating jet at the front end breaks the rock, drilling a radial wellbore with a certain diameter and length. Among them, the role of the rotating nozzle can maximize the use of hydraulic energy to break rocks on the one hand, and on the other hand can make the borehole of the radial horizontal well smooth and round, improve the power of the high-pressure hose and the rotary jet drill bit, and make the diameter Extend longer to the horizontal wellbore.

It is not limited thereto, and any changes or replacements that do not go through creative efforts shall fall within the scope of protection of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope defined in the claims.

Claims (10)

1. A rotary nozzle (25) for hydraulic jet drilling radial branch holes, characterized in that, said rotary nozzle (25) comprises an upper casing (29) and a lower casing (32), said upper casing A rotor (30) is arranged between the housing (29) and the lower housing (32), and the outer edge of the lower housing (32) is provided with several lower housing holes (33). The center of the head of the rotor (30) has a through rotor shaft hole (34), and the head of the rotor (30) has a number of obliquely arranged rotor side holes (35) on the side. 2. The rotary nozzle (25) of the hydraulic jet drill radial branch hole according to claim 1, characterized in that, a thrust bearing is arranged between the upper casing (29) and the lower casing (32) (31). 3. The rotary nozzle (25) for drilling radially branched holes with water jet according to claim 1, characterized in that, the upper casing (29) and the lower casing (32) are connected by threads. 4. The rotary nozzle (25) for drilling radially branched holes by water jetting according to claim 1, characterized in that the number of the rotor side holes (35) is an even number. 5. A system for hydraulic jet drilling radial branch holes, characterized in that, the system for hydraulic jet drilling radial branch holes comprises a vertically arranged casing (3), and the casing (3) A cement sheath (4) is provided on the outside of the casing (3), and several main oil pipes (1) arranged in series are arranged inside the casing (3), and an anchor (2) is arranged between adjacent main oil pipes (1) , the anchor (2) is anchored on the inner wall of the casing (3), the bottom of the main oil pipe (1) is provided with a steering gear joint (5), and the steering gear joint ( 5) It is threadedly connected with the steering gear (8) at the bottom. The main oil pipe (1) is provided with a coiled oil pipe (11), and the lower end of the coiled oil pipe (11) is detachably connected with a milling drill assembly (S1) or a high-pressure injection assembly (S2). 6. The system for drilling radially branched holes by water jetting according to claim 5, characterized in that a stepped hole (6) is provided at the upper end of the diverter (8). 7. The system for drilling radial branch holes according to claim 6, characterized in that, The milling and drilling tool assembly (S1) sequentially includes a milling adapter (12), a screw motor (13) and a flexible shaft (15) from top to bottom, and the milling adapter (12) Matched with the coiled tubing (11), the flexible shaft (15) includes a motor joint (14), a collar (16) and a flexible shaft main body (17), and the flexible shaft main body ( 17) Pass through the diverter (8), and the end of the flexible shaft main body (17) is provided with a milling drill bit (18). 8. The system for drilling radial branch holes according to claim 7, characterized in that, The high-pressure injection assembly (S2) sequentially includes an upper high-pressure adapter (21), a weight pipe (22), a lower high-pressure adapter (23) and a high-pressure hose (24) from top to bottom. The upper high-pressure adapter (21) matches the coiled tubing (11), the lower high-pressure adapter (23) matches the high-pressure hose (24), and the high-pressure hose (24 ) is provided with a rotating nozzle (25) at the end. 9. A method of drilling a radially branched hole utilizing a system for drilling a radially branched hole as claimed in claim 8, comprising the steps of: Step S1. Connect the steering gear (8) to the main tubing (1) through the steering gear joint (5), and run the entire working string into the well through the main tubing (1). After reaching the predetermined depth and setting the orientation, anchor device (2) anchor sleeve (3); Step S2, using the milling adapter (12) to connect the milling drill assembly (S1) with the coiled tubing (11), and passing the milling bit (18), the flexible shaft (15) and the screw motor (13) through the coiled tubing ( 11) Go down into the main oil pipe (1), make the milling bit (18) contact with the inner wall of the casing (3); Step S3, use the surface high-pressure pump to pump high-pressure fluid into the coiled tubing (11) to make the screw motor (13) work, thereby driving the flexible shaft (15) and the milling bit (18) to rotate, and the casing (3) and A tunnel (20) is drilled on the cement sheath (4) until the shaft collar (16) on the flexible shaft (15) is stuck at the step hole (6) on the upper end of the steering gear (8), and the milling and window opening process is completed. Then, the screw motor (13), the flexible shaft (15) and the milling drill bit (18) are lifted out of the well bottom through the coiled tubing (11), and the milling drill assembly (S1) is disassembled from the coiled tubing (11); Step S4, use the upper high-pressure adapter (21) to connect the high-pressure injection assembly (S2) and the coiled tubing (11), lower the high-pressure hose (24) and the rotating nozzle (25) into the well, and the high-pressure hose (24) to transmit the shaft The pressure is applied to push the rotating nozzle (25) to advance while breaking the formation rock (19) through the water jet (26), and finally form a radially branched wellbore (27). 10. The method for drilling radial branch holes utilizing a hydraulic jet drilling system for radial branch holes according to claim 9, wherein the steering gear (8) is connected to the steering gear joint (5) through several first bolts (7) ) is fixedly connected, and the steering gear (8) is provided with some second bolts (10) for fixing the steering gear (8).

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