CN111535746B - Cage type connecting device suitable for fishbone branch well sand prevention or well wall support and using method thereof - Google Patents

Abstract

The invention discloses a cage type connecting device suitable for fishbone branch well sand prevention or well wall support and a using method thereof. The cage attachment is configured as follows: the over-drill head suspension arm is fixed on the suspension ring; two side surfaces of the lower end of the drill bit passing suspension arm are respectively provided with a rod body; the top end face of the suspension joint is provided with a plurality of grooves I, two inner walls of each groove I are respectively provided with a blind hole I and a blind hole II, the inner diameters of the blind holes I and the blind holes II are slightly larger than the outer diameter of the rod body, and the depth of the blind holes II is larger than that of the blind holes I; a spring is fixed in the blind hole II; the connection between the over-drill suspension arm and the suspension joint is realized through the matching of the rod body with the blind hole I and the blind hole II; when the spring is compressed, the rod body can be pulled out of the blind hole I; the lower part of the suspension joint is connected with a pipe easy to drill. All components of the cage type connecting device are made of drilling-prone materials, on the premise that the strength meets the requirement of safely suspending the sand control pipe column, the screen pipe can be conveniently released after being put in place, and a PDC drill bit is used for quickly drilling through and crushing to continuously drill.

Description

Cage type connecting device suitable for fishbone branch well sand prevention or well wall support and using method thereof

Technical Field

The invention relates to a cage type connecting device suitable for fishbone branch well sand prevention or well wall support and a using method thereof, and belongs to the technical field of well drilling and completion.

Background

The fishbone branch well is a technology for drilling a plurality of fishbone branch well bores in a reservoir section by utilizing one main well bore, can effectively improve the connectivity between an oil-gas well and the reservoir, enlarges the oil drainage area of a single well, and is an effective means for increasing the productivity of the single well.

Sand production is a problem that must be solved in the development process of oil and gas wells, and once mishandled, the oil and gas wells are forced to reduce production slightly, and the oil and gas wells are scrapped seriously. The currently adopted sand control method is to construct a layer of mechanical or chemical sand blocking barrier in a shaft, sand particles are blocked outside the barrier after a sand-containing fluid in a reservoir passes through the sand blocking barrier, and only oil, gas, water and fine solid-phase particles can enter the shaft through the barrier. The chemical sand control mode is not used in large scale at present due to the complexity, reliability, durability and the like of the process. Mechanical sand control remains the current primary means of sand control. The mechanical sand control needs to put a screen pipe in a shaft, and a gravel layer needs to be filled in the space between the screen pipe and a well hole ring of a part of wells so as to realize a better sand control effect.

When a reservoir section of the fishbone branch well is drilled, a 'forward' strategy is generally adopted, after the first branch drilling is completed, a 'suspended sidetrack' technology is adopted to drill a second branch on the inner side of the open hole, the subsequent branch well drilling is completed by the same method, and the finally completed well is the main well. And completing each borehole in an open hole mode. Limited by technology and economy, for fishbone spur branch well that needs the sand control, except that the main tributary well can adopt traditional mechanical sand control mode, all the other branch well bores all are difficult to go into the sand control tubular column now. Therefore, the sand-containing fluid of the branch well hole can only realize sand filtration through the sand blocking barrier of the main branch well hole, and the risk of blockage of the sand blocking barrier of the main branch well hole is increased. For unconsolidated reservoirs, mechanically unsupported lateral wellbores may also collapse after a period of production, resulting in a loss of lateral productivity.

Therefore, it is very necessary to research a tool which is simple and convenient to operate and can realize sand prevention and mechanical support for each well of the fishbone branch well.

Disclosure of Invention

The invention aims to provide a cage type connecting device suitable for preventing sand of a fishbone branch well, which is simple and convenient to operate and can quickly realize sand prevention and mechanical support of each well hole of the fishbone branch well.

The cage type connecting device provided by the invention comprises a suspension ring, a plurality of over-drill hanging arms, a suspension joint and an easily-drilled pipe;

the drill bit passing suspension arm is fixed on the suspension ring; the suspension ring is seated on the upper shoulder of the drill bit body;

two side surfaces of the lower end of the drill bit passing suspension arm are respectively provided with a rod body;

a plurality of grooves I are formed in the top end face of the suspension joint, a blind hole I and a blind hole II are respectively formed in two inner walls of each groove I, the inner diameters of the blind holes I and the blind holes II are slightly larger than the outer diameter of the rod body, and the depth of each blind hole II is larger than that of the blind hole I; a spring is fixed in the blind hole II;

the connection, namely the hinging, between the over-drill boom and the suspension joint is realized through the matching of the rod body with the blind hole I and the blind hole II, and the hinging can be assembled and disassembled on site; when the spring is compressed, the rod body can be pulled out of the blind hole I;

the lower part of the suspension joint is connected with the easy-to-drill pipe; the lower part of the easy drilling pipe is connected with a sieve pipe/a perforated pipe.

In the cage type connecting device, the suspension rings are chain type suspension rings and are formed by a plurality of circular arc-shaped chain sheets, and the adjacent chain sheets are connected through shaft type bolts, so that the shaft type bolts at one part are installed on site, and the rest parts are preassembled, which is convenient for site operation.

In the cage type connecting device, the number of the chain pieces is equal to that of the over-drill hanging arms;

when the PDC cutter is installed, the drill bit passing suspension arm penetrates through a flow channel between PDC cutter wings;

one of the over-bit boom is suspended from one of the chain links.

In the cage type connecting device, each chain piece is provided with a groove II, each groove III is arranged on the upper part of the drill bit suspension arm, and the suspension ring is connected with the drill bit suspension arm through the matching of the groove II and the groove III.

In the cage connecting device, the rod body is a cylinder.

When the drill bit passing suspension arm is arranged on the suspension joint, the rod body on one side is arranged in the blind hole II on the inner side wall of the groove I and pressed to the bottom, then the rod body on the other side is arranged in the blind hole I on the inner measuring arm of the groove I, and the drill bit passing suspension arm cannot be separated from the groove of the suspension joint under the action of the spring.

The method for preventing sand or supporting the wall of the fishbone branch well by using the cage type connecting device comprises the following steps:

1) drilling the branch A to a target depth and then reaming to circularly pull out the drill;

2) connecting a sieve tube or a perforated tube with the easy-to-drill tube, connecting the other end of the easy-to-drill tube with the suspension joint, and connecting the suspension joint with the over-drill boom; connecting a drill assembly and placing a PDC drill bit at a suitable height directly above the suspension joint, and adjusting the angle of the PDC drill bit to fit the over-drill boom; rotating the drill bit passing suspension arm to the flow channel between the blades of the PDC drill bit along the hinged joint of the drill bit passing suspension arm and the suspension joint until the upper part of the drill bit passing suspension arm is contacted with a drill bit handle of the PDC drill bit, and at the moment, the drill bit passing suspension arm is positioned in an external circle of the drill bit and does not influence the downward placement of a pipe column in a shaft;

3) matching the suspension ring with the through-drill hanging arm, winding the suspension ring outside the drill handle in a surrounding manner, and then closing the suspension ring in a loop; when the drilling tool assembly is continuously connected with an upper drilling string, the suspension ring is seated on a shoulder above the drill bit body, and the over-drill-bit suspension arm is suspended on the suspension ring, so that the aim of using the drilling tool assembly to carry a screen pipe/a perforated pipe into a well is fulfilled;

4) lowering the sieve tube or the perforated pipe to the branch A, and slowly lifting the drill string to record the hanging weight after the sieve tube or the perforated pipe is in place; then slowly rotating the drill string, under the pushing of a blade of the PDC drill bit, enabling the drill bit passing suspension arm to move relative to the suspension joint and extrude the spring, and enabling the rod body on the other side of the drill bit passing suspension arm to be separated from the blind hole I, so that the PDC drill bit and the lowered sieve tube or the lowered perforated pipe are separated from each other; detecting the lifting hanging weight to confirm whether the hands are successfully released;

5) lifting the drill string for a certain distance, and starting sidetrack drilling of the branch B; the suspension loop, the over-bit boom, the suspension sub and part of the easy-to-drill pipe are crushed under the erosion of the drill bit and drilling fluid, leaving only part of the easy-to-drill pipe and the screen pipe or the perforated pipe in branch a; after the branch B is drilled to the target depth, tripping to the wellhead, and running the sieve tube or the perforated pipe according to the method of the steps 2) -4) to perform sidetracking;

6) continuing sidetracking and branching and setting the screen pipe or the perforated pipe according to the method of the steps 1) to 5);

7) and after the main well bore is drilled, completing the lower part of the main well bore by adopting a conventional mode.

In the method, in order to reduce the blockage of the drilling fluid to the sieve tube in the running process of the branch well sieve tube, a blind guide shoe is required to be assembled at the lower end part of the sieve tube, so that the filterability flow of the drilling fluid inside and outside the sieve tube in the running process of the sieve tube is reduced as much as possible. As in the case of perforated pipes, this problem does not have to be taken into account specifically. In addition, before tripping the drill bit to the target depth, the drilling fluid in the branch well bore needs to be replaced by clean drilling fluid so as to reduce the blockage of the sand control barrier of the well bore relative to the main well bore during flowback production.

By utilizing the cage type connecting device, the purposes of putting the branch pipe column into the well and continuously drilling the branch pipe column in one drilling are realized, and the field operation time is saved to the maximum extent while the sand prevention/well wall support of each branch well is realized.

After the cage type connecting device and the drill bit are assembled, the maximum outer diameter is smaller than the outer diameter of the drill bit, and smooth lowering to the target depth can be guaranteed. All components of the cage type connecting device are made of drilling-prone materials, on the premise that the strength meets the requirement of safely suspending the sand control pipe column, the screen pipe can be conveniently released after being put in place, and a PDC drill bit is used for quickly drilling through and crushing to continuously drill.

Drawings

Figure 1 is a schematic diagram of the overall construction of the cage assembly of the present invention.

Fig. 2 is a schematic view of a chain suspension ring in the cage connecting device of the present invention.

FIG. 3 is a schematic representation of the construction of the over-the-bit boom of the cage attachment of the present invention.

Fig. 4 is a cross-sectional view taken along line a-a of fig. 1.

Figure 5 is a schematic diagram of the construction of the suspension fittings of the cage assembly of the present invention.

Fig. 6 is a cross-sectional view taken along line B-B of fig. 1.

Figure 7 is a schematic of the screen/perforated pipe run in branch a with a drilling string.

Figure 8 is a schematic of the screen/perforated pipe run in branch B with a drill string.

FIG. 9 is a schematic view of the screen/perforated pipe run into the main wellbore using a drilling string.

The respective symbols in the figure are as follows:

1, a chain type suspension ring; 2 passing through a drill bit suspension arm; 3 hanging the joint; 4, drilling a pipe easily; 5PDC drill bits; 6 sieve tube/perforated pipe; 7, the drill bit is circumscribed with a circle; 8, a groove I; 9, a spring; 10 blind guide shoes; 11, a groove II; 12, a groove III; 13 a cylinder; 14, blind holes I; 15 blind holes II.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.

The following description will be made by taking a scheme of incorporating 5-blade PDC as an example.

As shown in fig. 1, the cage type connection device provided by the present invention comprises 1 chain suspension ring 1, several over-bit booms 2, 1 suspension joint 3 and a section of easy-to-drill pipe 4.

As shown in fig. 2, the chain suspension ring 1 is composed of 5 circular arc-shaped chain pieces, and the number of the chain pieces is consistent with the number of blades of the PDC drill bit used in cooperation. The chain sheets are connected into a closed loop through shaft type bolts and are seated on the shoulder of the drill bit body. In order to facilitate field operation, the shaft type bolt at one position is installed on site, and the other parts are preassembled. And each chain piece is provided with a groove II 11 for hanging the over-drill suspension arm 2.

As shown in fig. 3, the over-drill boom 2 is an elongated bar structure with a trapezoidal main cross-section and passes through the flow channel between the PDC blades when installed. The upper part of the over-drill head suspension arm 2 is provided with a groove III 12, and the groove III 12 is suspended on a groove II 11 on the chain type suspension ring 1. A cylinder 13 is provided on each side of the lower part of the over-drill boom 2.

As shown in figure 5, the suspension joint 3 is a hollow joint, a plurality of grooves I8 are annularly and uniformly distributed on the top end surface, a blind hole is respectively arranged on the inner walls of two sides of each groove I8, and as shown in figure 6, the hole diameters of the blind holes I14 and the blind holes II 15 are slightly larger than the outer diameter of the lower side cylinder 13 of the over-drill suspension arm 2. In a top view, the depth of the right blind hole II 15 is larger than that of the left blind hole I14, and a spring 9 is arranged in the blind hole II 15. When the over-drill boom 2 is installed on the suspension joint 3, the cylinder 13 on the right side is installed in the blind hole II 15 on the right side of the groove I8 and pressed to the bottom, then the cylinder 13 on the left side is installed in the blind hole I14 on the left side of the groove I8, and under the action of the spring 9, the over-drill boom 2 cannot be separated from the groove I8 of the suspension joint 3.

In the cage type connecting device, the cylindrical body 13 is matched with the blind hole I14 and the blind hole II 15 on the inner wall of the groove I8, so that the over-drill boom 2 and the suspension joint 3 are hinged, and the hinge can be disassembled and assembled on site. The number of the over-drill hanging arms 2 is consistent with the number of the PDC drill bit blades matched with the over-drill hanging arms. The lower part of the suspension joint 3 is connected with an easy-to-drill pipe 4, and the lower part of the easy-to-drill pipe 4 is connected with a sieve pipe/perforated pipe 6.

In the cage type connecting device, the lower part of the over-drill boom 2 is connected with the suspension joint 3 in a hinged mode, and the over-drill boom 2 can freely rotate around the hinged joint within a certain range. The over-drill boom 2 and the suspension joint 3 are preassembled, and do not occupy well head time.

The cage attachment of the present invention is used as follows:

and (4) drilling the branch A to the target depth and then reaming to circularly drill. In order to reduce the blockage of the drilling fluid to the sieve tube in the running process of the branch well sieve tube, the blind guide shoe 10 is required to be assembled at the lower end part of the sieve tube, so that the filterability flow of the drilling fluid inside and outside the sieve tube in the running process of the sieve tube is reduced as much as possible. As in the case of perforated pipes, this problem does not have to be taken into account specifically. In addition, before tripping the drill bit to the target depth, the drilling fluid in the branch well bore needs to be replaced by clean drilling fluid so as to reduce the blockage of the sand control barrier of the well bore relative to the main well bore during flowback production.

And assembling the sieve tube at the well mouth, sequentially putting in the sieve tube, and after assembling the suspension joint 3, placing all the over-drill suspension arms 2 in a horizontal position. Connecting the drill tool assembly and placing the PDC drill bit 5 at a suitable height directly above the suspension joint 3, and adjusting the angle of the drill bit to fit the drill bit suspension arm 2. And rotating the drill bit suspension arm 2 along the hinged joint to the flow channel between the PDC blades until the upper part of the drill bit suspension arm 2 is contacted with a drill bit handle. At this point, the over-bit boom 2 is within the bit circumcircle (as shown in fig. 4), and does not affect the lowering of the pipe string in the wellbore.

The grooves II 11 on the chain type suspension ring 1 are matched with the grooves III 12 on the drill bit suspension arm 2 one by one and wound outside the drill bit handle, and the shaft type plug pin is installed to form a closed ring. When the drilling tool assembly is continuously connected with an upper drill column, the chain type suspension ring 1 is seated on the shoulder above the drill bit body, and the over-drill suspension arm 2 is suspended on the chain type suspension ring 1, so that the aim of carrying the sieve tube/perforated pipe into the well by using the drilling tool assembly is fulfilled.

After lowering the branch a screen/perforated pipe in place, the drill string is slowly raised to record the hanging weight, as shown in fig. 7. The drill string is then slowly rotated. Under the push of the bit wing, the over-bit suspension arm 2 moves relative to the suspension joint 3 and extrudes the spring 9, and the cylinder 13 on the other side of the over-bit suspension arm 2 is separated from the blind hole I14, so that the bit and the lower sieve tube/perforated pipe are separated. And measuring the hanging weight to confirm the success of the hand drop.

The drill string is lifted a certain distance and sidetracking branch B is started. During sidetracking, the chain suspension ring 1, the over-bit boom 2, the suspension joint 3 and part of the easy-to-drill pipe 4 are crushed under the erosion of the drill bit and the drilling fluid, leaving only part of the easy-to-drill pipe 4 and the sieve pipe/perforated pipe in the branch a.

As shown in FIG. 8, after branch B is drilled to the desired depth, it is tripped out to the well head, and the screen is run in and sidetracked in the same manner as described above.

After completion of the main wellbore drilling, the lower completion of the main wellbore is completed in a conventional manner, as shown in fig. 9.

The invention realizes the purpose of drilling the branch pipe column and continuing drilling in one time, and maximally saves the field operation time while realizing the sand prevention/well wall support of each branch well.

The foregoing description is only exemplary of the preferred embodiments of the application and is provided for the purpose of illustrating the general principles of the technology and the like. Meanwhile, the scope of the invention according to the present application is not limited to the technical solutions in which the above-described technical features are combined in a specific manner, and also covers other technical solutions in which the above-described technical features or their equivalent are combined arbitrarily without departing from the inventive concept described above. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims (7)

1. A cage type connecting device suitable for fishbone branch well sand prevention or well wall support comprises a suspension ring, a plurality of over-drill hanging arms, a suspension joint and an easy-to-drill pipe;

the drill bit passing suspension arm is fixed on the suspension ring;

two side surfaces of the lower end of the drill bit passing suspension arm are respectively provided with a rod body;

a plurality of grooves I are formed in the top end face of the suspension joint, a blind hole I and a blind hole II are respectively formed in two inner walls of each groove I, the inner diameters of the blind holes I and the blind holes II are slightly larger than the outer diameter of the rod body, and the depth of each blind hole II is larger than that of the blind hole I; a spring is fixed in the blind hole II;

the connection between the over-drill boom and the suspension joint is realized through the matching of the rod body, the blind hole I and the blind hole II; when the spring is compressed, the rod body can be pulled out of the blind hole I;

the lower part of the suspension joint is connected with the easy-to-drill pipe.

2. The cage attachment device of claim 1, wherein: the suspension rings are chain suspension rings and are formed by a plurality of circular arc-shaped chain sheets, and adjacent chain sheets are connected through shaft type bolts.

3. The cage attachment device of claim 2, wherein: the number of the chain pieces is equal to that of the over-drill hanging arms;

one of the over-the-bit booms is fixed to one of the links.

4. The cage attachment device of claim 3, wherein: each chain piece is provided with a groove II, the upper part of each drill bit passing suspension arm is provided with a groove III, and the suspension ring is connected with the drill bit passing suspension arm through the matching of the groove II and the groove III.

5. A cage attachment according to any of claims 1 to 4, in which: the rod body is a cylinder.

6. A method of sand control or wall support for a fishbone branch well using a cage assembly according to any of claims 1 to 5, comprising the steps of:

1) drilling the branch A to a target depth and then reaming to circularly pull out the drill;

2) connecting a sieve tube or a perforated tube with the easy-to-drill tube, connecting the other end of the easy-to-drill tube with the suspension joint, and connecting the suspension joint with the over-drill boom; connecting a drill assembly and placing a PDC drill bit at a suitable height directly above the suspension joint, and adjusting the angle of the PDC drill bit to fit the over-drill boom; rotating the drill bit passing suspension arm to the flow channel between the blades of the PDC drill bit along the hinged joint of the drill bit passing suspension arm and the suspension joint until the upper part of the drill bit passing suspension arm is contacted with a drill bit handle of the PDC drill bit, and at the moment, the drill bit passing suspension arm is positioned in an external circle of the drill bit and does not influence the downward placement of a pipe column in a shaft;

3) matching the suspension ring with the through-drill hanging arm, winding the suspension ring outside the drill handle in a surrounding manner, and then closing the suspension ring in a loop; when the drilling tool assembly is continuously connected with an upper drilling string, the suspension ring is seated on a shoulder above the drill bit body, and the over-drill-bit suspension arm is suspended on the suspension ring, so that the aim of using the drilling tool assembly to carry a screen pipe/a perforated pipe into a well is fulfilled;

4) lowering the sieve tube or the perforated pipe to the branch A, and slowly lifting the drill string to record the hanging weight after the sieve tube or the perforated pipe is in place; then slowly rotating the drill string, under the pushing of a blade of the PDC drill bit, enabling the drill bit passing suspension arm to move relative to the suspension joint and extrude the spring, and enabling the rod body on the other side of the drill bit passing suspension arm to be separated from the blind hole I, so that the PDC drill bit and the lowered sieve tube or the lowered perforated pipe are separated from each other; detecting the lifting hanging weight to confirm whether the hands are successfully released;

5) lifting the drill string for a certain distance, and starting sidetrack drilling of the branch B; the suspension loop, the over-bit boom, the suspension sub and part of the easy-to-drill pipe are crushed under the erosion of the drill bit and drilling fluid, leaving only part of the easy-to-drill pipe and the screen pipe or the perforated pipe in branch a; after the branch B is drilled to the target depth, tripping to the wellhead, and running the sieve tube or the perforated pipe according to the method of the steps 2) -4) to perform sidetracking;

6) continuing sidetracking and branching and setting the screen pipe or the perforated pipe according to the method of the steps 1) to 5);

7) and after the main well bore is drilled, completing the lower part of the main well bore by adopting a conventional mode.

7. The method of claim 6, wherein: and a blind guide shoe is assembled at the lower end of the sieve tube.

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