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 for hydraulic jet drilling of radial branch hole, system and method for drilling radial branch hole by using system

Technical Field

The present invention relates to a drilling installation, in particular, it is a method for hydraulic jet drilling radial branch hole and its tool.

Background

Radial branch boreholes, also known as ultra-short radius branch boreholes, are horizontal branch boreholes drilled in a hydrocarbon reservoir by means of high-pressure water jet injection within a turning radius of 0.3m in a direction perpendicular to the main borehole using special devices and tools. The length of the radial branch hole can reach dozens of meters to hundreds of meters, the diameter of the well hole is about 30-50 mm, the radial branch hole can be used for modifying an old well and developing a new well, the exposed area of an oil-gas layer can be increased, and the radial branch hole is particularly suitable for increasing the yield of thin oil layers and low-permeability oil-gas reservoirs and also can be used for increasing the yield of oriented hydraulic fracturing.

At present, a radial horizontal well is drilled at home and abroad by a method of casing pipe inward opening window sidetracking. The drilling mode of the radial branch hole generally adopts a self-advancing jet nozzle with front and rear holes, the nozzle uses a part of hydraulic energy to break rock through the front hole, the other part of hydraulic energy is converted into power for driving a jet nozzle and a high-pressure hose to advance through the rear nozzle, the part of power is provided by overcoming the reverse thrust of the front jet and the friction between the high-pressure hose and a steering gear and a well wall through the reverse thrust of the rear jet, the energy of the rear jet usually occupies more than 50% of the hydraulic energy of the whole system to provide the forward power, but the domestic limitation of working pump conditions cannot achieve enough discharge capacity and nozzle pressure drop, so that enough hydraulic energy cannot be provided, on one hand, effective rock breaking is difficult, on the other hand, enough power cannot be provided to drag the high-pressure hose and the jet nozzle to advance, so that the problem of too short radial hole extension length is easily caused, and the holes of the rock broken by using the porous jet nozzle are irregular, the roughness is large, so that the friction resistance of the hole wall surface of the high-pressure hose is increased, the difficulty in discharging of debris is increased, and the expected oil and gas exploitation of the rock deposit is difficult to realize the expected oil and gas development.

Disclosure of Invention

The invention mainly solves the technical problems in the prior art, and provides a method and a tool for hydraulic jet drilling of a radial branch hole.

The technical problem of the invention is mainly solved by the following technical scheme:

the rotating nozzle is characterized by comprising an upper shell and a lower shell, wherein a rotor is arranged between the upper shell and the lower shell, a plurality of lower shell holes are formed in the circumferential direction of the outer edge of the lower shell, a through rotor shaft hole is formed in the center of the head of the rotor, and a plurality of rotor side holes which are obliquely arranged are formed in the lateral direction of the head of the rotor.

As a preferred embodiment of the invention, a thrust bearing is arranged between the upper shell and the lower shell.

As a preferred embodiment of the invention, the upper shell and the lower shell are connected through threads.

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

A system for drilling a radial branch hole by hydraulic jet is characterized by comprising a vertically arranged sleeve, a cement sheath is arranged outside the sleeve, a plurality of main oil pipes which are arranged in series are arranged inside the sleeve, an anchor is arranged between every two adjacent main oil pipes and anchored on the inner wall of the sleeve, a steering gear joint is arranged at the bottom of each main oil pipe and connected with a steering gear at the lowest part through threads,

the main oil pipe is internally provided with a continuous 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 injection assembly.

In a preferred embodiment of the present invention, the upper end of the steering gear is provided with a stepped hole.

As a preferred embodiment of the present invention, the milling drilling tool assembly sequentially comprises a milling adapter, a screw motor and a flexible shaft from top to bottom, the milling adapter is matched with the coiled tubing, the flexible shaft comprises a motor joint, a shaft hoop and a flexible shaft main body, the flexible shaft main body passes through the steering gear, and the end of the flexible shaft main body is provided with a milling drill.

As a preferred embodiment of the present invention, the high-pressure injection assembly sequentially comprises an upper high-pressure adapter, a weighted pipe, a lower high-pressure adapter, and a high-pressure hose from top to bottom, the upper high-pressure adapter is matched with the coiled tubing, the lower high-pressure adapter is matched with the high-pressure hose, and a rotary nozzle is disposed at the end of the high-pressure hose.

A method of drilling a radial branch borehole using a system for drilling a radial branch borehole as described above, comprising the steps of:

s1, connecting a steering gear with a main oil pipe through a steering gear joint, enabling the whole working string to go into a well through the main oil pipe, and anchoring a casing pipe by an anchor after the preset depth and the orientation are determined;

s2, connecting the milling drilling tool assembly with the coiled tubing by using a milling adapter, and putting a milling drill bit, a flexible shaft and a screw motor into the main tubing through the coiled tubing so that the milling drill bit is in contact with the inner wall of the casing 3;

s3, pumping high-pressure fluid into the coiled tubing by using a ground high-pressure pump, enabling the screw motor to work, so as to drive the flexible shaft and the milling drill bit to rotate, drilling a hole channel on the casing and the cement sheath until a shaft hoop on the flexible shaft is clamped at a stepped hole at the upper end of the steering gear, finishing the milling windowing process, then taking the screw motor, the flexible shaft and the milling drill bit out of the well bottom through the coiled tubing, and detaching the milling drill bit assembly from the coiled tubing;

and S4, connecting the high-pressure injection assembly and the continuous oil pipe by using the high-pressure adapter, putting the high-pressure hose and the rotary nozzle into the well, transmitting axial pressure by using the pressure hose, pushing the rotary nozzle to break stratum rocks through water jet and move forward, and finally forming the radial branch well hole.

As a preferred embodiment of the invention, the steering gear is fixedly connected with the steering gear joint through a plurality of first bolts, and a plurality of second bolts for fixing the steering gear are arranged on the steering gear.

The method and the tool for drilling the radial branch hole by hydraulic jet have the following advantages: the method comprises the steps of utilizing an oil pipe with a smaller size to place and fix an anchor and a steering gear in a cased well, adopting a screw motor to transmit torque to a milling drill bit at the top through a flexible shaft, drilling a hole on a casing and a cement sheath, then placing a tool string consisting of a rotary nozzle, a high-pressure hose and a weighting pipe in the well through a continuous oil pipe, placing the continuous oil pipe, pushing the high-pressure hose to advance through partial gravity of the continuous oil pipe and the weighting pipe, crushing rocks through rotary jet flow at the front end, and drilling a radial well hole with a certain diameter and length. The rotary nozzle does not generate backward jet, on one hand, the rotary nozzle can break rock by using all hydraulic energy, on the other hand, the jet rotation can enable the radial horizontal well to be smooth and round, the forward power of the high-pressure hose and the rotary jet drill bit is improved, and the radial horizontal well can be extended for a longer time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a connection structure of a system for hydrajet drilling radial branch boreholes in accordance with the present invention;

FIG. 2 is a schematic diagram of the operation of the system for hydrajet drilling a radially offset borehole of FIG. 1 with the milling tool assembly in a predetermined position;

FIG. 3 is a schematic representation of the operation of the system for hydraulic jet drilling a radially branched borehole of FIG. 2, when the milling bit has drilled through the casing and the cement sheath;

FIG. 4 is a schematic diagram of the system of FIG. 1 for hydrajet drilling a radially branched borehole, with the high pressure jetting assembly in a predetermined position and the high pressure water jet drilling a radial wellbore;

FIG. 5 is a schematic diagram of the flexible shaft of the system for hydrajet drilling radially branched perforations of FIG. 4;

FIG. 6 is a sectional view of the rotary nozzle of FIG. 4;

FIG. 7 is a cross-sectional view of the rotor of the rotary nozzle of FIG. 6;

fig. 8 is a cross-sectional view of the rotor of the rotary nozzle of fig. 7 taken along plane B-B.

Detailed Description

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

As shown in figure 1, the system for hydraulic jet drilling of radial branch holes comprises a vertically arranged casing 3, a cement sheath 4 is arranged outside the casing 3, a plurality of main oil pipes 1 arranged in series are arranged inside the casing 3, an anchor 2 is arranged between the adjacent main oil pipes 1, the anchor 2 is anchored on the inner wall of the casing 3, a steering gear joint 5 is arranged at the bottom of the casing 3, the steering gear 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 continuous oil pipe 11 is arranged in the main oil pipe 1, and the lower end of the continuous oil pipe 11 is detachably connected with a milling drilling tool component S1 or a high-pressure injection component S2. At different construction stages, the user chooses to use different components.

As shown in fig. 2, the milling drill assembly S1 sequentially includes, from top to bottom, a milling adapter 12, a screw motor 13, and a flexible shaft 15, wherein the milling adapter 12 is matched with the coiled tubing 11. As shown in fig. 5, the flexible shaft 15 includes a motor joint 14, a shaft clamp 16, and a flexible shaft body 17, the flexible shaft body 17 passes through the steering gear 8, and the end of the flexible shaft body 17 is provided with a milling bit 18.

As shown in fig. 4 and 6, the high-pressure injection assembly S2 includes, in order from top to bottom, an upper high-pressure adapter 21, a weighted pipe 22, a lower high-pressure adapter 23, and a high-pressure hose 24, the upper high-pressure adapter 21 is coupled to the coiled tubing 11, the lower high-pressure adapter 23 is coupled to the high-pressure hose 24, and a rotary nozzle 25 is disposed at a distal end of the high-pressure hose 24.

As shown in fig. 7 and 8, the rotary nozzle 25 includes an upper housing 29 and a lower housing 32, and a rotor 30 and a thrust bearing 31 are provided between the upper housing 29 and the lower housing 32. The upper housing 29 and the lower housing 32 are screwed to hold the rotor 30 and the thrust bearing 31, wherein the thrust bearing 31 serves to reduce the rotational friction of the rotor. In addition, the rotary nozzle 25 and the high-pressure hose 24 are connected by a screw between the joint 28 and the upper housing 29.

This outer fringe circumference of lower casing 32 upwards opens has a plurality of lower casing punchholes 33 for broken detritus can in time be followed the annular space between nozzle 25 and the well 27 and then discharged, and casing 32 top can provide certain distance of spouting for the efflux sprays down, improves broken rock efficiency.

The center of the head of the rotor 30 is provided with a through rotor shaft hole 34, and the side of the head of the rotor 30 is provided with a plurality of rotor side holes 35 which are obliquely arranged. These rotor side apertures 35 are angled with respect to the axis of the rotor 30, and may be two, four or six, etc., which produce two side jets that have two effects. Firstly, the rock is broken in the impact of side direction efflux, secondly the thrust along tangential direction's counterthrust can provide rotor pivoted turning torque to make the tangential efflux rotatory, can improve the efficiency of broken rock, reduce broken well 27's roughness, make it more round, reduce the resistance in detritus discharge well, effectively reduce the resistance that later stage oil gas flows in well 27, thereby improve the development effect.

The operation of the system for hydrajet drilling radially offset perforations will now be described, comprising the steps of:

step S1, a steering gear 8 is connected with a main oil pipe 1 through a steering gear joint 5, an anchor 2 is connected with the upper portion 3-10m of the steering gear 8 through the main oil pipe 1, the whole working pipe string is put into a well through the main oil pipe 1, and after the working pipe string reaches a preset depth and is positioned, the working pipe string is anchored on a casing 3 through the anchor 2, wherein the steering gear 8 is fixedly connected with the steering gear joint 5 through a plurality of first bolts 7, and a plurality of second bolts 10 used for fixing the steering gear 8 are arranged on the steering gear 8;

s2, connecting a milling drilling tool assembly S1 with the coiled tubing 11 by using a milling adapter 12, installing a milling drill bit 18 at the front end of a flexible shaft 15, driving the milling drill bit 18 by a screw motor 13 through the flexible shaft 15, connecting the screw motor 13 with the coiled tubing 11 through the milling adapter 12, and then lowering the milling drill bit 18, the flexible shaft 15 and the screw motor 13 into the main tubing 1 through the coiled tubing 11 so that the milling drill bit 18 is in contact with the inner wall of the casing 3;

s3, pumping high-pressure fluid into the continuous oil pipe 11 by using a ground high-pressure pump, enabling the screw motor 13 to work, so as to drive the flexible shaft 15 and the milling drill bit 18 to rotate, drilling a hole channel 20 on the casing 3 and the cement sheath 4 until a shaft hoop 16 on the flexible shaft 15 is clamped at the stepped hole 6 at the upper end of the steering gear 8, finishing the milling windowing process, then lifting the screw motor 13, the flexible shaft 15 and the milling drill bit 18 out of the well bottom through the continuous oil pipe 11, and detaching the milling drill bit assembly S1 from the continuous oil pipe 11;

and S4, connecting the high-pressure injection assembly S2 with the coiled tubing 11 by using the high-pressure adapter 21, and lowering the high-pressure hose 24 and the rotary nozzle 25 into the well by using the weighting pipe 22, wherein the high-pressure hose 24 has high bending rigidity, the outer diameter of the high-pressure hose is slightly smaller than the inner diameter of the main tubing 1, the high-pressure hose 24 can transmit axial pressure under the constraint of the main tubing 1, the rotary nozzle 25 is pushed to break the formation rock 19 through water jet flow 26 while advancing, and the axial pressure borne by the high-pressure hose 24 is controlled by controlling the hanging weight and the lowering speed of the coiled tubing 11 on the ground, so that the rotary nozzle 25 and the high-pressure hose 24 advance at a preset speed, and finally a radial branch well bore 27 is formed.

The system for drilling the radial branch hole by hydraulic jet has the following advantages:

1. the system for drilling the radial branch hole of the hydraulic jet drill directly pushes the high-pressure hose and the jet drill bit at the lower part to advance under the constraint of the external small-size oil pipe through the continuous oil pipe connected with the weighted pipe. Firstly, drilling holes with a certain size on a casing and a cement sheath by a milling drill bit, then, descending a high-pressure hose and a rotary nozzle to jet and crush stratum rocks, and pushing the high-pressure hose and the rotary nozzle to advance by partial gravity of a continuous oil pipe and a weighted pipe to finally form a radial horizontal well hole. The method is characterized by simplicity, safety and high efficiency.

2. The system for drilling the radial branch holes by hydraulic jet uses a small-sized oil pipe as a working pipe column in construction, the inner diameter of the oil pipe is slightly larger than the outer diameter of a coiled oil pipe, the coiled oil pipe is used as a feeding main body to place a steering gear and an anchor into a well, then drilling through a casing and a cement sheath is realized, a hole channel with certain size and length is drilled in an oil-gas layer, the exposed area of the oil-gas layer is increased, and the development effect of oil gas is improved. Connecting the continuous oil pipe with a hydraulic motor, namely a screw motor, driving the hydraulic motor to rotate by fluid with certain displacement, and driving a milling drill bit to rotatably drill holes allowing a jet drill bit and a high-pressure hose to pass through on a sleeve and a cement ring through a flexible shaft; then connecting a weighting pipe with a continuous oil pipe, descending a high-pressure hose and a jet drill bit, and jetting and drilling a radial branch borehole by using the energy of the water jet. The high-pressure hose has higher bending rigidity, and has the ability of transmitting axial pressure under the restraint of small-size oil pipe outside, and the high-pressure hose and the jet drill bit can be pushed to advance by the partial gravity of coiled tubing and aggravating pipe until thrust and resistance are equal to complete the drilling of a radial hole, and the development of low-permeability reservoir, heavy oil reservoir and coal bed gas can be satisfied.

3. The system for drilling the radial branch hole by hydraulic jet improves the current method for breaking rocks by adopting the self-propelled jet drill bit and driving the high-pressure hose to advance, widens the application range of drilling the radial branch hole by hydraulic jet, can be applied to drilling the radial horizontal hole in a straight well, and can also be applied to drilling a micro branch well or a fishbone well in an inclined well and a horizontal well. Through the rotary nozzle, the torque generated by the tangential component force to the axis of the nozzle through the reverse thrust generated by the tangential jet flow injection drives the rotor inside the nozzle to rotate, so that the jet flow is rotated, the broken hole can be more regular and round, the central jet flow can overcome the defect that the common rotary jet flow cannot break the central rock of the hole, the rock breaking efficiency is improved, the rock debris discharge efficiency is improved, the flow resistance of fluid in a well hole is reduced, and the purpose of forming a regular oil-gas flow channel is achieved.

4. The system for drilling the radial branch hole by hydraulic jet utilizes an oil pipe with a smaller size to place and fix an anchor and a steering gear in a cased well, adopts a screw motor to transmit torque to a milling drill bit at the top through a flexible shaft, drills a hole on a casing and a cement ring, then puts a tool string consisting of a rotary nozzle, a high-pressure hose and a weighted pipe in the well through a continuous oil pipe, lowers the continuous oil pipe, pushes the high-pressure hose to advance through partial gravity of the continuous oil pipe and the weighted pipe, and breaks rocks through the rotary jet flow at the front end to drill a radial well hole with a certain diameter and length. The rotary nozzle has the advantages that hydraulic energy can be utilized to break rocks to the maximum extent under the action of the rotary nozzle, radial horizontal well bores can be smooth and round, forward power of the high-pressure hose and the rotary jet drill bit is improved, and the radial horizontal well bores can be extended for a long time.

Without being limited thereto, any changes or substitutions that are not thought of through the inventive work should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope defined by the claims.

Claims (10)

1. The rotating nozzle (25) is characterized in that the rotating nozzle (25) comprises an upper shell (29) and a lower shell (32), a rotor (30) is arranged between the upper shell (29) and the lower shell (32), a plurality of lower shell holes (33) are formed in the periphery of the lower shell (32) in the circumferential direction, a penetrating rotor shaft hole (34) is formed in the center of the head of the rotor (30), and a plurality of obliquely arranged rotor side holes (35) are formed in the lateral direction of the head of the rotor (30).

2. The rotating nozzle (25) for the hydrajet drilling of a radially branched hole according to claim 1, wherein a thrust bearing (31) is provided between the upper housing (29) and the lower housing (32).

3. The rotating nozzle (25) for the hydrajet drilling of a radially branched hole according to claim 1, wherein the upper casing (29) and the lower casing (32) are connected by a screw thread.

4. The rotary injector (25) for hydrojet drilling radially branched holes as claimed in claim 1, wherein said number of rotor side holes (35) is an even number.

5. The system for drilling the radial branch hole by hydraulic jet is characterized by comprising a vertically arranged casing (3), a cement ring (4) is arranged outside the casing (3), a plurality of main oil pipes (1) which are arranged in series are arranged inside the casing (3), an anchor (2) is arranged between every two adjacent main oil pipes (1), the anchor (2) is anchored on the inner wall of the casing (3), a steering gear joint (5) is arranged at the bottom of each main oil pipe (1), and the steering gear joint (5) is in threaded connection with a steering gear (8) at the lowest part. A continuous oil pipe (11) is arranged in the main oil pipe (1), and the tail end of the lower part of the continuous oil pipe (11) is detachably connected with a milling drilling tool assembly (S1) or a high-pressure injection assembly (S2).

6. The system for hydraulic jet drilling of radial branch holes according to claim 5, characterized in that the upper end of the diverter (8) is provided with a stepped hole (6).

7. The system for hydrajet drilling a radial branch bore according to claim 6,

milling drilling tool subassembly (S1) top-down contain one in proper order and mill adapter (12), a screw motor (13) and a flexible axle (15), mill adapter (12) with coiled tubing (11) cooperate, flexible axle (15) contain a motor joint (14), a hoop (16) and a flexible axle main part (17), flexible axle main part (17) pass steering gear (8), just the end of flexible axle main part (17) be equipped with one and mill drill bit (18).

8. The system for hydrajetting drilling a radially branched bore hole of claim 7,

high-pressure injection subassembly (S2) top-down contain one in proper order and go up high-pressure adapter (21), one aggravate pipe (22), high-pressure adapter (23) and a high-pressure hose (24) once, high-pressure adapter (21) with coiled tubing (11) cooperate, lower high-pressure adapter (23) with high-pressure hose (24) cooperate, the end of high-pressure hose (24) be equipped with a rotatory nozzle (25).

9. A method of drilling a radially branched borehole using the system for hydrajetting drilling a radially branched borehole as recited in claim 8, comprising the steps of:

s1, a steering gear (8) is connected with a main oil pipe (1) through a steering gear joint (5), the whole working pipe column is put into a well through the main oil pipe (1), and after the preset depth and the position are set, an anchor (2) anchors a casing (3);

s2, connecting the milling drilling tool assembly (S1) with the coiled tubing (11) by using a milling adapter (12), and lowering a milling drill bit (18), a flexible shaft (15) and a screw motor (13) into the main tubing (1) through the coiled tubing (11) so that the milling drill bit (18) is in contact with the inner wall of the casing (3);

s3, pumping high-pressure fluid into the coiled tubing (11) by using a ground high-pressure pump, enabling a screw motor (13) to work, driving a flexible shaft (15) and a milling drill bit (18) to rotate, drilling a hole channel (20) on the casing (3) and a cement ring (4) until a shaft hoop (16) on the flexible shaft (15) is clamped at a stepped hole (6) at the upper end of a steering gear (8), finishing the milling windowing process, then lifting the screw motor (13), the flexible shaft (15) and the milling drill bit (18) out of a well bottom through the coiled tubing (11), and detaching the milling drill bit assembly (S1) from the coiled tubing (11);

and S4, connecting the high-pressure injection assembly (S2) with the coiled tubing (11) by using the upper high-pressure adapter (21), putting the high-pressure hose (24) and the rotary nozzle (25) into the well, transmitting axial pressure by using the high-pressure hose (24), pushing the rotary nozzle (25) to break the stratum rock (19) through the water jet (26) and advance at the same time, and finally forming the radial branch well hole (27).

10. The method for drilling a radial branch hole by using the system for drilling a radial branch hole by hydraulic jet according to claim 9, wherein the steering gear (8) is fixedly connected with the steering gear joint (5) through a plurality of first bolts (7), and the steering gear (8) is provided with a plurality of second bolts (10) for fixing the steering gear (8).

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