CN116411868A - Small-well drilling-free plug cementing device, plug and well cementing construction method thereof - Google Patents

Abstract

The invention relates to a cementing device and a rubber plug without drilling a small borehole and a cementing construction method thereof, comprising a well-leaving part, wherein a cementing outer cylinder is provided with a cement injection hole, and a casing packer is provided with an annular packing liquid inlet hole and a liquid inlet valve; the drilling-free plug mechanism is provided with a hydraulic control central tube, a pawl cylinder, a closing head and a closing head connecting cylinder, and the lower end of the hydraulic control central tube is at least connected with a primary hydraulic cylinder; the closing head, the closing head connecting cylinder and the pawl cylinder after connection are positioned between the hydraulic control central pipe and the well leaving part, and the closing head and the expansion closing cylinder are positioned between the closing head connecting cylinder and the cement injection hole of the fixed outer cylinder; the lower part of the hydraulic cylinder is in threaded connection with the central tail pipe plug through the central tail pipe and is connected with the outside of the central tail pipe and the central tail pipe plug through the centralizing cylinder connector and the centralizing cylinder. The invention solves the problem that the prior drilling-plug-free well cementation device is not applicable when the drilling-plug-free well cementation is carried out in small-size well bores such as side drilling wells, and the like, and meets the requirements of the old well of the oil field on the well digging and the synergy.

Description

Small-well drilling-free plug cementing device, plug and well cementing construction method thereof

Technical Field

The invention relates to the field of oil and gas well oil extraction engineering in the petroleum industry, in particular to a small-bore drilling-free plug cementing device, a rubber plug and a well cementation construction method thereof.

Background

In the field of petroleum and natural gas exploration and development, well cementation is an important operation in the well drilling and completion process, and as the oil field is developed gradually, the underground stratum situation becomes more and more complex, so that great difficulty and challenges are brought to the well cementation operation, the selective well cementation can effectively improve the well cementation quality, adapt to the well completion process with different yield increasing purposes, and reduce the risk of the well drilling and completion operation.

The currently common stage cementing process, namely the selective cementing process, has two types, namely a stage collar cementing process requiring drilling plug and a plug-free cementing process:

1. after cementing, the well bore is penetrated by the opening sleeve, the blind plate, the rubber plug and the cement plug with a certain length which are left in the well, and risks of falling objects, deviation of drilling, casing leakage and the like exist in the drilling process, so that the later construction and the service life of the oil and gas well are directly influenced.

2. The drilling-free cementing process has the advantages that compared with the prior graded hooping cementing process, the drilling-free cementing process is reduced, the completion time is shortened, and meanwhile, the probability of underground accidents is reduced.

With the continuous development of oil fields, old well sidetrack drilling is one of the important means for treating low-yield low-efficiency wells and digging residual oil, but the existing drilling-free plug device cannot be applied to small well bores due to structural arrangement reasons, such as:

202011035585.2 a salvage type drilling-free cementing completion device comprises a well-leaving part, a salvage component, a soluble upper sealing sleeve and a soluble lower sealing sleeve; the well-leaving part comprises a body, a limiting part, a sliding part, a sealing part, an expansion assembly and a triggering part, wherein the sliding part is slidably arranged on the inner side of the body, the fishing assembly is fixed on the inner side of the upper part of the body through the limiting part, the fishing assembly is fixed on the inner side of the sliding part, the soluble upper sealing sleeve is fixed on the inner side of the sliding part and is positioned between the fishing assembly and the sliding part, the body, the sliding part, the soluble upper sealing sleeve and the fishing assembly are provided with circulating holes, the circulating holes are oppositely arranged, the sealing part is sleeved on the outer side of the body, and the upper part of the sealing part is sleeved on the position of the circulating holes and seals the circulating holes; the inner side of the lower part of the body is fixedly provided with the soluble lower sealing sleeve, the outer side of the lower part of the salvage component is fixedly connected with the inner side of the soluble lower sealing sleeve, the body and the soluble lower sealing sleeve are provided with overflow holes, the overflow holes are oppositely arranged, the lower part of the salvage component is provided with an overflow channel communicated with the overflow holes, an overflow gap communicated with the overflow holes is arranged between the lower part of the sealing component and the body, and the overflow gap is communicated with the inside of the expansion component; the trigger piece is fixed on the inner side of the fishing assembly and seals the through-flow channel. The salvaging type drilling-free cementing well completion device can ensure the existing half-way well cementation well completion mode of coal bed gas and improve the well cementation quality; meanwhile, the fishing assembly can be fished out of the shaft by the special tool after construction is finished, so that drilling and plugging are avoided, construction cost is reduced, well construction period is shortened, the recyclable inner core is fished out of the shaft by the special tool after construction is finished, the next operation procedure can be entered, and the recyclable inner core is repaired and then is assembled with the tool continuously, so that the purposes of reducing cost and enhancing efficiency are achieved; and a special soluble material technology is adopted, namely, a soluble upper sealing sleeve and a soluble lower sealing sleeve are added into the tool, so that the tool is ensured to be in good condition before entering a well, after construction is finished, the soluble material reacts with the plug pressing liquid and is dissolved, the effect that the inner diameter of the tool is completely consistent with the inner diameter of a sleeve is achieved, the later operation pipe column and the tool entering are not affected completely, and the requirement of high-efficiency development of coal bed gas is completely met.

And the following steps: 201821701635.4 the full-bore drilling-free plug cementing device comprises an upper joint, a clamping ring seat, a valve body, a clamping ring, a pushing and pressing sleeve, a pressing sleeve shear pin, a closing sleeve, an opening pin, a salvaging clamping ring seat, an opening sliding sleeve, a salvaging clamping ring, a communicating joint, a valve ball, a joint, an upper locking block, an upper shear pin, a locking block sleeve, a valve seat, an upper pressure transmitting pipe, an inner pipe, a sealing assembly, a sealing pipe, a plug-taking shear pin, a lower locking block, a pressure transmitting inner pipe and a lower pressure transmitting pipe, wherein the lower locking block is placed in a hole groove at the lower part of the sealing assembly, the sealing assembly is arranged on the inner pipe, the lower locking block is restrained from moving radially, the plug-taking shear pin connects the inner pipe and the sealing assembly into a whole, the sealing sleeve is arranged outside the sealing assembly, the upper part of the pressure transmitting inner pipe is connected with the lower part of the sealing pipe, the inner pipe and the sealing pipe are locked together by the lower locking block, the valve seat is arranged in the lower part of the joint, the upper communicating block is arranged in a slotted hole of the communicating joint, the inner end of the upper locking block clamps the valve seat, the locking block sleeve is sleeved on the communication joint, the locking block is restrained by the locking block sleeve to enable the locking block to be incapable of moving radially, the upper shear pin connects the locking block sleeve on the upper locking block, the valve ball is located on the valve seat, the communication joint is provided with an internal communication through hole, the salvage snap ring is placed in the salvage snap ring seat, the lower part of the salvage snap ring seat is connected with the upper part of the communication joint, the side wall of the upper pressure pipe is provided with a pressure transmission channel, the upper part of the sealing pipe is connected with the lower part of the upper pressure pipe, the connecting part is kept sealed, the upper part of the upper pressure pipe is connected with the lower part of the lower pressure pipe through the pressure transmission channel, the upper part of the inner pipe is connected with the lower part of the communication joint, the upper part of the pushing sleeve is inserted into the lower part of the snap ring seat, the outer diameter of the upper part of the pushing sleeve is larger than the inner diameter of the upper part of the snap ring seat, the upper outer diameter of the pushing sleeve is larger than the inner diameter of the upper part of the clamping ring seat, the pushing sleeve is milled into a strip body and can shrink to be smaller than the inner diameter of the upper part of the clamping ring seat, the pushing sleeve is provided with a middle communicating hole, the pushing sleeve is connected to the clamping ring seat by a pressing sleeve shear pin, the clamping ring is sleeved outside the clamping ring seat, the upper part of the closing sleeve is connected with the lower part of the clamping ring seat, the connecting part keeps sealing, the clamping ring is limited between the closing sleeve and the clamping ring seat and cannot axially move, the outer diameter of the upper part of the pushing sleeve is larger than the inner diameter of the lower part of the closing sleeve, the upper part of the clamping ring seat is inserted into the lower part of the upper joint, the inserting part keeps sealing, the valve body is provided with an outer communicating hole, the opening sleeve is arranged in the valve body, the opening sleeve is covered by the outer communicating hole, the group of the sealing ring is positioned above the outer communicating hole, the opening sleeve is positioned below the outer communicating hole, the opening sleeve is connected to the valve body by the opening pin, the opening pin is positioned between the two groups of the sealing rings, the upper part of the sealing sleeve is connected with the lower part of the clamping ring seat, the upper part of the sealing sleeve is positioned below the sealing sleeve is arranged below the sealing ring groove of the sealing sleeve, the sealing sleeve is arranged below the sealing sleeve. The well cementation device does not need a drilling plug, is easy to salvage, can improve the well cementation quality and the construction efficiency, has the same drift diameter as the inner diameter of a sleeve after well completion, is convenient to repair and recover oil in the later period, and can be used as a common tool.

However, the drilling-free plug device introduced by the above-mentioned patent technology has a larger size, and is only suitable for use in 7-in or 5 1/2-in wellbores, and in small-size wellbores such as sidetracking, the above-mentioned patent technology cannot be applied due to the working principle and structural arrangement of the tool, and the production requirements of the existing old well of the oil field on the basis of the diving and synergy and investment cost reduction cannot be met.

There is therefore a need to develop a small bore, plug-free cementing device that addresses the above-described issues.

Disclosure of Invention

In order to solve the problems, the invention provides a small-bore plug-free cementing device, a rubber plug and a cementing construction method thereof, which solve the problem that the plug-free cementing device cannot be used in small-size wellbores such as side drilling, and the like, and meet the production requirements of the old well of an oil field on the aspects of digging, immersing, enhancing and reducing the investment cost.

The technical scheme of the invention is as follows:

the small-bore drilling-free cementing device comprises a well-leaving part, wherein the well-leaving part is provided with an upper joint, a well cementation outer barrel, a sleeve packer and a sleeve connecting barrel, a cement injection hole is arranged in the well cementation outer barrel, an annular packing liquid inlet hole is arranged in the sleeve packer, the upper joint, the well cementation outer barrel, the sleeve packer and the sleeve connecting barrel are sequentially connected in a threaded manner from top to bottom, and a liquid inlet valve is arranged in the sleeve packer;

the drilling-free plug mechanism is provided with a hydraulic control central tube, a pawl cylinder, a closing head and a closing head connecting cylinder, wherein:

the hydraulic control central tube is characterized in that a hydraulic cylinder punching hole is formed in a body of the hydraulic control central tube, a punching sealing cylinder is arranged at the upper end of the hydraulic control central tube through a shear pin, the outer part of the middle section of the body is in threaded connection with a closing head connecting cylinder, and the lower end of the hydraulic control central tube is at least connected with a primary hydraulic cylinder;

a cement injection hole and an annular packing liquid inlet are arranged in the body of the closing head connecting cylinder, and the upper end and the lower end of the closing head connecting cylinder are respectively in threaded connection with the closing head and the hydraulic control central pipe;

the closing head is internally provided with a lock ring and a rubber sealing cylinder, and the outside of the closing head is provided with an expansion closing cylinder;

the upper part of the body of the pawl cylinder is provided with an annular packing liquid inlet hole and a hydraulic cylinder punching hole, the lower part of the body is provided with a pawl communicated with the bottom of the body, and the pawl cylinder is connected with the packing cylinder through a shear pin;

the closing head, the closing head connecting cylinder and the pawl cylinder after connection are positioned between the hydraulic control central pipe and the well leaving part, and the closing head and the expansion closing cylinder are positioned between the closing head connecting cylinder and the cement injection hole of the fixed outer cylinder; the annular packing liquid inlet hole in the pawl cylinder corresponds to the annular packing liquid inlet hole in the closing head connecting cylinder and the sleeve packer, and the hydraulic cylinder pressing hole is positioned between the packing cylinder and the body of the sleeve packer;

the limiting top cylinder and the top cylinder connector are in threaded connection with the hydraulic cylinder;

the lower part of the hydraulic cylinder is in threaded connection with the central tail pipe plug through the central tail pipe and is connected with the outside of the central tail pipe and the central tail pipe plug through the centralizing cylinder connector and the centralizing cylinder, and a hydraulic cylinder punching hole is formed in the central tail pipe.

Preferably, when the hydraulic cylinders with more than one level are installed, the hydraulic cylinders are connected through a hydraulic cylinder connecting central pipe, and the hydraulic cylinder at the lowest end is connected with a central tail pipe plug through a central tail pipe provided with a hydraulic cylinder punching hole; the number of the hydraulic cylinders connected in the small-bore plug-free cementing device is determined by the diameter of the well to be cemented; the larger the diameter of the well bore to be cemented, the fewer the number of hydraulic cylinders installed in the wellbore drilling-free cementing device.

Preferably, the hydraulic cylinder is provided with a hydraulic cylinder outer cylinder connector, a hydraulic cylinder inner cylinder connector and a hydraulic cylinder outer cylinder, a hydraulic cylinder pressing hole is arranged in the hydraulic cylinder inner cylinder connector, the hydraulic cylinder inner cylinder connector is a non-equal-diameter inner cavity and a non-equal-diameter outer circle, both ends of the non-equal-diameter inner cavity of the hydraulic cylinder inner cylinder connector are provided with internal threads, the internal threads at the upper end can be connected with a hydraulic control central pipe, and the internal threads at the lower end can be connected with a hydraulic cylinder connecting central pipe or a central tail pipe; the hydraulic cylinder pressing holes of the hydraulic cylinder inner cylinder connectors in each stage of hydraulic cylinders correspond to the gaps after the hydraulic cylinder connecting central pipes are connected, the hydraulic cylinder pressing holes in the central tail pipes correspond to the lower inner cavities of the centralizing cylinders,

preferably, the upper end of the hydraulic control central tube is closed by a cone, and a liquid flow channel in the hydraulic control central tube runs through from the lower part of the cone to the bottom end; the outside of the conical body at the top end of the hydraulic control central tube is provided with a shear pin slot, a hydraulic cylinder pressing hole is arranged in the hydraulic control central tube body below the conical body, and the hydraulic cylinder pressing hole is blocked by a pressing sealing cylinder before cementing is completed.

Preferably, the upper part of the pressing closed cylinder is in a conical shape which is in accordance with the conical shape of the upper end of the hydraulic control central tube, and at least one nail shearing hole is arranged at the upper part of the pressing closed cylinder.

Preferably, the closing head is a non-equal-diameter inner cavity and a non-equal-diameter outer circle, and a lock ring installation cavity, a rubber plug limiting table, a connecting cylinder thread section and a cement buffer cavity are arranged in the non-equal-diameter inner cavity of Guan Bitou; the lower part of the non-constant diameter outer circle of the closing head is provided with a conical transition section, and the middle lower outer circle of the closing head is sleeved with an expansion closing cylinder.

Preferably, the structure of the inner cavity of the lower part of the expansion closing cylinder is consistent with the structure of the conical transition section of the lower part of the closing head, and a cementing sealing element is arranged in the conical excircle of the lower part of the expansion closing cylinder and is positioned below a cementing injection hole of the well cementation outer cylinder; after the expansion closing cylinder is sleeved outside the closing head, a step clamping seat of the outer circle of the upper part of the expansion closing cylinder is arranged above a limit step above a cement injection hole in the well cementation outer cylinder.

Preferably, a shear pin arranged at the upper part of the pawl cylinder body can be connected with the packing cylinder, a packing cylinder limiting step is arranged in the inner cavity of the middle part of the shear pin, and a hydraulic cylinder punching hole is arranged in the body above the packing cylinder limiting step; an annular packing liquid inlet hole is formed in the middle body of the pawl cylinder, and sealing pieces are arranged on the upper side and the lower side between the annular packing liquid inlet hole and the sleeve packer; the lower body of the pawl cylinder is provided with a pawl communicated with the bottom of the body, the outer diameter of the lower part of the pawl is larger than the limit step of the pawl cylinder formed by the outer diameter of the upper part of the pawl cylinder, the pawl cylinder can be clamped between the sleeve packer and the sleeve connecting cylinder, and the lower end of the pawl cylinder is propped against by the limit propping cylinder; at least three pawls are arranged in the pawl cylinder.

Preferably, the excircle of the sealing and isolating cylinder is provided with a limiting step, a shear pin slot or a shear pin hole is arranged above the limiting step, and the limiting step on the outer wall of the sealing and isolating cylinder can be positioned above the sealing and isolating cylinder limiting step in the inner cavity of the pawl cylinder.

Preferably, the inner wall of the locking ring is provided with a locking ring button and a through shrinkage groove is arranged in the body of the locking ring.

Preferably, the rubber sealing cylinder is vulcanized on the rubber plug limiting table in the inner cavity of the closing head, and the central hole of the rubber sealing cylinder is equal to or larger than the outer diameter of the pressing closing cylinder.

Preferably, the middle part of the inner cavity of the center tail pipe plug is closed, the upper end of the inner cavity of the center tail pipe plug is provided with internal threads, and the internal threads at the upper part of the inner cavity of the center tail pipe plug can be in threaded connection with the center tail pipe; the outer diameter of the central tail pipe plug is consistent with the inner diameter of the centralizing cylinder.

A rubber plug is used for a small-bore hole drilling-free plug cementing device and comprises a rubber fin and salvaging threads, and is characterized in that the rubber plug is provided with a rubber plug center hole, a small-diameter end, a plate valve, a rubber plug horseshoe buckle and a sitting-pressing step;

the rubber fin is arranged above the sitting and pressing step, and a plate valve is arranged in a valve fixing step formed by the central hole of the rubber plug and the upper inner cavity;

a rubber plug cam buckle is arranged on the outer wall between the sitting and pressing step and the small-diameter end;

and when the rubber plug does not reach the conical body of the hydraulic control central tube of the small-bore drilling-free cementing device, the plate valve is in a closed state.

Preferably, the inner diameter of the small-diameter end is consistent with the outer diameter of the upper end of the hydraulic control central tube and is larger than the inner diameter of the rubber sealing cylinder, the end part of the lower end of the small-diameter end is of a flat head structure, and a rubber plug button on the outer wall between the sitting and pressing step and the small-diameter end is connected with a locking ring button in the locking ring; the sitting and pressing step is pressed and seated at the upper end of the locking ring.

A well cementation construction method of a small-bore drilling-free cementing device comprises the following steps:

A. after the drilling-free cementing device is assembled, the drilling-free cementing device is matched and connected to a preset position of a well completion string and is lowered into a well bore along with the well completion string;

B. before well cementation, firstly, pressing in a small-well drilling-free cementing device to seal an annulus between a casing and a well wall;

C. cementing well cementation;

D. after the well cementation construction is finished, closing a cementing circulation channel;

E. after a cementing circulation channel in the drilling-free cementing device is closed, a fishing operation pipe column with a special fishing tool is put in, all parts of the drilling-free plug mechanism except the well-remaining part are fished out, and the drilling-free plug large-drift-diameter well completion is realized.

The invention has the remarkable use effect that;

after the device finishes stage cementing, after the rubber plug is put into the device to be bumped, all parts except a well-reserved part in the rubber plug and the small-bore drilling-free plug cementing device can be fished out of a well bore at one time through a special fishing tool, the working principle is simple, the structure is reliable, the operation is convenient, the device can be used for well cementation and completion work of a small-diameter well bore, and the device has the following specific use effects and advantages:

(1) The small-bore drilling-free cementing device works together by utilizing the multistage hydraulic cylinder, so that the construction pressure for closing the cementing circulation channel is increased, the expansion closing cylinder can be smoothly expanded, the cementing circulation channel is plugged, and the stage cementing is realized.

(2) Because the working principle of the invention is simple, the inner diameter occupied by the expansion closing cylinder in the device is smaller, and the wall thickness requirement on the well-leaving part is not high, so that the inner diameter of the well-leaving part of the device is large. After the cementing well cementation construction is finished, the internal components of the device can be fished out by a special fishing tool at one time, so that a large-drift-diameter well completion channel is realized, and the well completion requirement of more than 4in well diameter can be met.

(3) The hydraulic cylinder in the device is operated to close the cementing circulation channel in a pressurizing mode, so that the device is reliable in closing, high in practicability, simple and convenient to operate, free of well-type restriction, and applicable to vertical wells and inclined wells and horizontal wells.

(4) The invention solves the problem that the prior drilling-free cementing device is not applicable when the drilling-free cementing device is used for cementing in small-size wellbores such as side drilling, and the like, meets the production requirements of the old well of the oil field on the aspects of digging, increasing efficiency and reducing investment, has obvious use effect and can generate obvious economic benefit.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic view of the detent cartridge of fig. 1.

Fig. 3 is a schematic view of the structure of the locking ring of fig. 1.

Fig. 4 is a schematic structural view of the rubber plug.

In the figure: the device comprises an upper joint 1, a well cementation outer cylinder 2, an expansion closing cylinder 3, a sleeve packer 4, a sleeve connecting cylinder 5, a pawl cylinder 6, a pawl 601, a pawl cylinder limiting step 602, a closing head 7, a packing cylinder 8, a closing head connecting cylinder 9, a limiting top cylinder 10, a top cylinder connector 11, a hydraulic cylinder outer cylinder connector 12, a hydraulic cylinder inner cylinder connector 13, a hydraulic cylinder outer cylinder 14, a central tail pipe plug 15, a pressing closing cylinder 16, a lock ring 17, a lock ring button 1701, a shrinkage groove 1702, a hydraulic control central tube 18, a hydraulic cylinder central tube 19, a central tail pipe 20, a centralizing cylinder 21, a centralizing cylinder connector 22, a rubber sealing cylinder 23, a rubber plug 24, salvaging threads 2401, a rubber plug central hole 2402, a plate valve 2403, a small diameter end 2404, a rubber plug button 5, a setting step 2406 and a rubber fin 2407.

Detailed Description

The drawings are for reference and illustration purposes only and are not intended to limit the scope of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Referring to fig. 1 to 3, a small-bore plug-free cementing device comprises a well-leaving part, wherein the well-leaving part is provided with an upper joint 1, a well cementation outer cylinder 2, a sleeve packer 4 and a sleeve connecting cylinder 5, a cement injection hole is arranged in the well cementation outer cylinder 2, an annular packing liquid inlet is arranged in the sleeve packer 4, the upper joint 1, the well cementation outer cylinder 2, the sleeve packer 4 and the sleeve connecting cylinder 5 are sequentially connected in a threaded manner from top to bottom, and a liquid inlet valve is arranged in the sleeve packer 4;

the drilling-free plug mechanism is provided with a hydraulic control central tube 18, a pawl cylinder 6, a closing head 7 and a closing head connecting cylinder 9, wherein:

the body of the hydraulic control central tube 18 is provided with a hydraulic cylinder punching hole, the upper end of the hydraulic control central tube 18 is provided with a punching closing cylinder 16 through a shear pin, the outer part of the middle section of the body is in threaded connection with a closing head connecting cylinder 9, and the lower end of the hydraulic control central tube 18 is at least connected with a primary hydraulic cylinder;

a cement injection hole and an annular packing liquid inlet are arranged in the body of the closing head connecting cylinder 9, and the upper end and the lower end of the closing head connecting cylinder 9 are respectively in threaded connection with the closing head 7 and the hydraulic control central tube 18;

guan Bitou 7 is provided with a lock ring 17 and a rubber sealing cylinder 23, and the outer surface of the closing head 7 is provided with an expansion closing cylinder 3;

the upper part of the body of the pawl cylinder 6 is provided with an annular packing liquid inlet hole and a hydraulic cylinder punching hole, the lower part of the body is provided with a pawl communicated with the bottom of the body, and the pawl cylinder 6 is connected with the packing cylinder 8 through shear nails;

the closing head 7, the closing head connecting cylinder 9 and the pawl cylinder 6 after the connection are positioned between the hydraulic control central pipe 18 and the well leaving part, and the closing head 7 and the expansion closing cylinder 3 are positioned between the closing head connecting cylinder 9 and the cement injection hole of the fixed outer cylinder 2; the annular packing liquid inlet hole in the pawl cylinder 6 corresponds to the annular packing liquid inlet hole in the closing head connecting cylinder 9 and the sleeve packer 4, and the hydraulic cylinder pressing hole is positioned between the packing cylinder 8 and the body of the sleeve packer 4;

the limiting top cylinder 10 and the top cylinder joint 11 are in threaded connection with the hydraulic cylinder;

the lower part of the hydraulic cylinder is in threaded connection with the central tail pipe plug 15 through the central tail pipe 20 and is connected to the outside of the central tail pipe 20 and the central tail pipe plug 15 through the centralizing cylinder joint 22 and the centralizing cylinder 21, and a hydraulic cylinder punching hole is formed in the central tail pipe 20.

The drilling-free plug mechanism in the device is arranged in the well-leaving part, and can be completely lifted out of the well after cementing is finished.

On the basis of the first embodiment, the present invention also has the following embodiments:

when the hydraulic cylinders with more than one level are installed, the hydraulic cylinders are connected through a hydraulic cylinder connecting central pipe 19, and the hydraulic cylinder at the lowest end is connected with a central tail pipe plug 15 through a central tail pipe 20 provided with a hydraulic cylinder punching hole; the number of the hydraulic cylinders connected in the small-bore plug-free cementing device is determined by the diameter of the well to be cemented; the larger the diameter of the well to be cemented, the larger the stressed area of the single-stage hydraulic cylinder, and the fewer the number of hydraulic cylinders installed in the drilling-free cementing device for the small well.

The hydraulic cylinder is provided with a hydraulic cylinder outer cylinder connector 12, a hydraulic cylinder inner cylinder connector 13 and a hydraulic cylinder outer cylinder 14, a hydraulic cylinder punching hole is formed in the hydraulic cylinder inner cylinder connector 13, the hydraulic cylinder inner cylinder connector 13 is a non-equal-diameter inner cavity and a non-equal-diameter outer circle, both ends of the non-equal-diameter inner cavity of the hydraulic cylinder inner cylinder connector 13 are provided with internal threads, the internal threads at the upper end can be connected with a hydraulic control central pipe 18, and the internal threads at the lower end can be connected with a hydraulic cylinder connecting central pipe 19 or a central tail pipe 20; the hydraulic cylinder pressing holes of the hydraulic cylinder inner cylinder connector 13 in each stage of hydraulic cylinder correspond to the gap after the hydraulic cylinder connecting central tube 19 is connected, and the hydraulic cylinder pressing holes in the central tail tube 20 correspond to the lower inner cavity of the centralizing cylinder 22, so that hydraulic cylinder liquid feeding is facilitated.

The upper end of the hydraulic control central tube 18 is closed by a cone, and a liquid flow channel in the hydraulic control central tube 18 runs through from the lower part of the cone to the bottom end; the outside of the conical body at the top end of the hydraulic control central tube 18 is provided with a shear pin slot, and a hydraulic cylinder punching hole is arranged in the body of the hydraulic control central tube 18 below the conical body and is plugged by a punching sealing cylinder 16 before cementing is completed.

The upper part of the pressing closed cylinder 16 is in a conical shape which is in accordance with the conical shape of the upper end of the hydraulic control central tube 18, and at least one nail shearing hole is arranged on the upper part of the pressing closed cylinder 16. A shear pin can be installed in the shear pin hole to complete the connection between the pilot operated center tube 18 and the crimp closure cylinder 16.

The closing head 7 is a non-constant diameter inner cavity and a non-constant diameter outer circle, and a lock ring installation cavity, a rubber plug limiting table, a connecting cylinder thread section and a cement buffer cavity are arranged in the non-constant diameter inner cavity of the closing head 7; the lower part of the non-constant diameter outer circle of the closing head 7 is provided with a conical transition section, and the middle lower outer circle of the closing head 7 is sleeved with an expansion closing cylinder 3.

The structure of the inner cavity of the lower part of the expansion closing cylinder 3 is consistent with the structure of the conical transition section of the lower part of the closing head 7, and a cementing sealing element is arranged in the conical outer circle of the lower part of the expansion closing cylinder 3 and is positioned below a cementing injection hole in the well cementation outer cylinder 2; after the expansion closing cylinder 3 is sleeved outside the closing head 7, a step clamping seat of the outer circle of the upper part of the expansion closing cylinder 3 is arranged above a limit step above a cement injection hole in the well cementation outer cylinder 2.

The shear pin arranged at the upper part of the pawl cylinder 6 body can be connected with the packing cylinder 8, a packing cylinder limiting step is arranged in the inner cavity of the middle part of the shear pin, and a hydraulic cylinder punching hole is arranged in the body above the packing cylinder limiting step; an annular packing liquid inlet hole is formed in the middle body of the pawl cylinder 6, and sealing pieces are arranged on the upper side and the lower side between the annular packing liquid inlet hole and the sleeve packer 4; the lower body of the pawl cylinder 6 is provided with a pawl 601 communicated with the bottom of the body, a pawl cylinder limiting step 602 formed by the outer diameter of the lower part of the pawl 601 being larger than the outer diameter of the upper part of the pawl cylinder 601 can be clamped between the sleeve packer 4 and the sleeve connecting cylinder 5, and the lower end of the pawl cylinder 6 is propped against by a limiting propping cylinder 10; at least three pawls 601 in the pawl cylinder 6 are provided.

The excircle of the sealing and isolating cylinder 8 is provided with a limiting step, a shear pin slot or a shear pin hole is arranged above the limiting step, and the limiting step on the outer wall of the sealing and isolating cylinder 8 can be positioned above the sealing and isolating cylinder limiting step in the inner cavity of the pawl cylinder 6. When shear nails in the packing cylinder 8 are broken, after a limit step of the outer circle of the packing cylinder 8 is arranged on the limit step of the packing cylinder of the pawl cylinder 6, the packing cylinder 8 seals a hydraulic cylinder punching hole and an annular packing liquid inlet hole in the pawl cylinder 6, and cement injection and well cementation construction can be performed at the moment.

The inner wall of the lock ring 17 is provided with a lock ring button 1701 and a through shrinkage groove 1702 is provided in the body of the lock ring 17. The constrictions 1702 are angled slots or straight slots.

The rubber sealing cylinder 23 is vulcanized on the rubber plug limiting table in the inner cavity of the closing head 7, and the central hole of the rubber sealing cylinder 23 is equal to or larger than the outer diameter of the pressing closing cylinder 16. When the pressing sealing cylinder 16 is dropped by the rubber plug 24, the pressing sealing cylinder 16 falls into the bottom of the annular gap between the closing head connecting cylinder 9 and the hydraulic control center tube 18, and the rubber plug 24 and the rubber sealing cylinder 23 form a seal.

The middle part of the inner cavity of the center tail pipe plug 15 is closed, the upper end of the inner cavity of the center tail pipe plug 15 is provided with an internal thread, and the internal thread at the upper part of the inner cavity of the center tail pipe plug 15 can be in threaded connection with the center tail pipe 20; the outer diameter of the center tailpipe plug 15 coincides with the inner diameter of the centralizing barrel 21.

Referring to fig. 4, a rubber plug for a slim hole drilling-free cementing device comprises a rubber fin 2407 and a fishing thread 2401, wherein the rubber plug 24 is provided with a rubber plug center hole 2402, a small diameter end 2404, a plate valve 2403, a rubber plug button 2405 and a setting step 2406;

the rubber fin 2407 is arranged above the sitting and pressing step 2406, and a plate valve 2403 is arranged in a valve fixing step formed by the central hole 2402 of the rubber plug and the inner cavity above;

a rubber plug horseshoe 2405 is arranged on the outer wall between the sitting step 2406 and the small diameter end 2404;

the plate valve 2403 is closed until the plug 24 has not reached the cone of the pilot operated center tube 18 of the slim hole plug-free cementing device. Plate valve 2403 is mainly composed of a circular plate and a torsion spring, and the circular plate is fixed on the valve fixing step through the torsion spring. Before the plate valve 2403 is not opened, the rubber plug 24 can replace cement under the action of hydraulic pressure, and after the cement reaches a preset position, the plate valve 2403 is opened to supply liquid to a hydraulic cylinder in the drilling-free plug mechanism.

The inner diameter of the small diameter end 2404 is consistent with the outer diameter of the upper end of the hydraulic control central tube 18 and is larger than the inner diameter of the rubber sealing cylinder 23, the end part of the lower end of the small diameter end 2404 is of a flat head structure, and a rubber plug cam buckle 2405 of the outer wall between the sitting and pressing step 2406 and the small diameter end 2404 is connected with a locking ring cam buckle 1701 in the locking ring 17; the seat pressing step 2406 is pressed against the upper end of the lock ring 17.

A well cementation construction method of a small-bore drilling-free cementing device comprises the following steps:

A. after the drilling-free cementing device is assembled, the drilling-free cementing device is matched and connected to a preset position of a well completion string and is lowered into a well bore along with the well completion string;

B. before well cementation, firstly, pressing in a small-well drilling-free cementing device to seal an annulus between a casing and a well wall:

liquid enters from the upper joint 1 and enters the sleeve packer 4 through the annular packing liquid inlet holes in the closing head connecting cylinder 9, the pawl cylinder 6 and the sleeve packer 8 so that the packing sleeve expands to seal the annular space between the sleeve and the well wall; as the pressure increases, the inlet valve provided in the casing packer 4 closes. The pressure continues to rise, the shear pins between the packing cylinder 8 and the pawl cylinder 6 shear, the packing cylinder 8 moves downwards, a cementing circulation channel between the closing head connecting cylinder 9 and the well cementation outer cylinder 2 is opened, and cement slurry can be injected at the moment for well cementation.

C. Cementing well cementation: the prepared cement slurry bypasses from the lower end of the closing head 7 along the upper joint 1 and the cement injection hole in the closing head connecting cylinder 9, and enters the annular space between the sleeve and the well wall from the cement injection hole of the well cementation outer cylinder 2, so that well cementation construction is completed.

D. After the well cementation construction is finished, closing a cementing circulation channel: putting the rubber plug 24 into the sleeve, and putting the small-diameter end 2404 of the rubber plug 24 into the drilling-free cementing device downwards to collide and press to a specified pressure value;

the rubber plug 24 is provided with a rubber plug center hole 2402, a plate valve 2403, a rubber fin 2407 and a sitting and pressing step 2406, and after the rubber plug 24 is thrown into the device of the invention downwards from the small diameter end 2404, liquid can be injected downwards from the inside of the sleeve to extrude the rubber plug 24 downwards. Because the plate valve 2403 is in a closed state before it has reached the cone of the pilot operated center tube 18 of the drill-free cementing device, the injected liquid can push the plug 24 down smoothly. The small diameter end 2404 first enters the closing head 7, and the rubber plug horseshoe 2405 of the rubber plug 24 is locked after being connected with the locking ring horseshoe 1701 of the locking ring 17. The plate valve 2403 in the rubber plug 24 is propped open by the cone at the upper end of the hydraulic control central tube 18, the small diameter end 2404 of the rubber plug 24 shears the shear pin on the pressing closing cylinder 16 in the process of entering the closing head 7, and the pressing closing cylinder 16 falls into the annular bottom between the closing head connecting cylinder 9 and the hydraulic control central tube 18 after moving downwards.

The liquid enters the inside of the hydraulic control center tube 18 through the gap between the rubber plug 24 and the hydraulic control center tube 18 and the hydraulic cylinder pressing holes in the hydraulic control center tube 18 and enters the hydraulic cylinders of all stages through the hydraulic cylinder pressing holes in the hydraulic cylinders of all stages. The liquid entering each stage of hydraulic cylinders finally pulls the hydraulic control central tube 18 downwards to move downwards under the action of hydraulic pressure, and drives the closing head 7 to move downwards through the closing head connecting cylinder 9 and presses the expansion closing cylinder 3 to expand outwards, so that cement injection holes on the well cementation outer cylinder 2 are expanded and sealed, and the closing of a cementing circulation channel is completed.

E. After a cementing circulation channel in the drilling-free plug cementing device is closed, a fishing operation pipe column with a special fishing tool is put in, the special fishing tool is in threaded connection with a fishing thread 2401 at the upper part of a rubber plug 24, all parts of a drilling-free plug mechanism in the small-bore drilling-free plug cementing device except an upper joint 1, a well cementation outer cylinder 2, a sleeve packer 4 and a sleeve connecting cylinder 5 are fished out, and the drilling-free plug large-drift-diameter well completion is realized.

The invention has simple working principle and lower wall thickness requirement on the part of the well-leaving part, can meet the requirement of drilling-free cementing well cementation under the condition of small-size well diameter, and realizes the miniaturization of the outer diameter of the tool.

The embodiments described above are only exemplary embodiments, but the present invention is not limited to these embodiments, and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Although the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and concept of the present invention should be included in the scope of the present invention. Therefore, the scope of protection is not limited to the description above.

Claims (15)

1. The utility model provides a small well drilling plug-free cementing device, including a well-leaving part, the well-leaving part is equipped with an upper joint (1), a well cementation outer cylinder (2), a sleeve packer (4) and a sleeve connecting cylinder (5), a cement injection hole is arranged in the well cementation outer cylinder (2), an annular packing liquid inlet is arranged in the sleeve packer (4), the upper joint (1), the well cementation outer cylinder (2), the sleeve packer (4) and the sleeve connecting cylinder (5) are connected in turn by screw threads from top to bottom, a liquid inlet valve is arranged in the sleeve packer (4),

the drilling-free plug mechanism is provided with a hydraulic control central tube (18), a pawl cylinder (6), a closing head (7) and a closing head connecting cylinder (9), wherein:

a hydraulic cylinder punching hole is formed in the body of the hydraulic control central tube (18), a punching sealing cylinder (16) is arranged at the upper end of the hydraulic control central tube through a shear pin, the outer part of the middle section of the body is in threaded connection with a closing head connecting cylinder (9), and the lower end of the hydraulic control central tube (18) is at least connected with a primary hydraulic cylinder;

a cement injection hole and an annular sealing liquid inlet are arranged in the body of the Guan Bitou connecting cylinder (9), and the upper end and the lower end of the closing head connecting cylinder (9) are respectively in threaded connection with the closing head (7) and the hydraulic control central tube (18);

guan Bitou (7) is provided with a lock ring (17) and a rubber sealing cylinder (23), and the outer surface of the closing head (7) is provided with an expansion closing cylinder (3);

the upper part of the body of the pawl cylinder (6) is provided with an annular sealing liquid inlet hole and a hydraulic cylinder punching hole, the lower part of the body is provided with a pawl communicated with the bottom of the body, and the pawl cylinder (6) is connected with the sealing cylinder (8) through shear nails;

the closing head (7), the closing head connecting cylinder (9) and the pawl cylinder (6) after connection are positioned between the hydraulic control central pipe (18) and the well leaving part, and the closing head (7) and the expansion closing cylinder (3) are positioned between the closing head connecting cylinder (9) and a cement injection hole of the fixed outer cylinder (2); the annular packing liquid inlet hole in the pawl cylinder (6) corresponds to the annular packing liquid inlet hole in the closing head connecting cylinder (9) and the sleeve packer (4), and the hydraulic cylinder pressing hole is positioned between the packing cylinder (8) and the body of the sleeve packer (4);

the limiting top cylinder (10) and the top cylinder joint (11) are in threaded connection with the hydraulic cylinder; the lower part of the hydraulic cylinder is in threaded connection with the central tail pipe plug (15) through the central tail pipe (20) and is connected with the outside of the central tail pipe (20) and the central tail pipe plug (15) through the centralizing cylinder joint (22) and the centralizing cylinder (21), and a hydraulic cylinder punching hole is arranged in the central tail pipe (20).

2. A small well drilling-free cementing device according to claim 1, wherein when the hydraulic cylinders with more than one level are installed, the hydraulic cylinders are connected through a hydraulic cylinder connecting central pipe (19), and the hydraulic cylinder at the lowest end is connected with a central tail pipe plug (15) through a central tail pipe (20) provided with a hydraulic cylinder punching hole; the number of the hydraulic cylinders connected in the small-bore plug-free cementing device is determined by the diameter of the well to be cemented; the larger the diameter of the well bore to be cemented, the fewer the number of hydraulic cylinders installed in the wellbore drilling-free cementing device.

3. A small-bore plug-free cementing device according to claim 2, wherein the hydraulic cylinder is provided with a hydraulic cylinder outer cylinder connector (12), a hydraulic cylinder inner cylinder connector (13) and a hydraulic cylinder outer cylinder (14), a hydraulic cylinder punching hole is arranged in the hydraulic cylinder inner cylinder connector (13), the hydraulic cylinder inner cylinder connector (13) is a non-equal-diameter inner cavity and a non-equal-diameter outer cylinder, both ends of the non-equal-diameter inner cavity of the hydraulic cylinder inner cylinder connector (13) are provided with internal threads, the internal threads at the upper end of the non-equal-diameter inner cavity can be connected with a hydraulic control central pipe (18), and the internal threads at the lower end of the non-equal-diameter inner cavity can be connected with a hydraulic cylinder connecting central pipe (19) or a central tail pipe (20); the hydraulic cylinder pressing holes of the hydraulic cylinder inner cylinder connectors (13) in each stage of hydraulic cylinder are corresponding to the gaps after the hydraulic cylinder connecting central pipes (19) are connected, and the hydraulic cylinder pressing holes in the central tail pipe (20) are corresponding to the lower inner cavities of the centralizing cylinders (22).

4. A slim hole plug-free cementing unit as claimed in claim 3, wherein the upper end of said pilot-operated central tube (18) is closed by a cone, and the flow passage in the pilot-operated central tube (18) extends from below said cone to the bottom end; the outside of the conical body at the top end of the hydraulic control central tube (18) is provided with a shear pin slot, a hydraulic cylinder pressing hole is arranged in the body of the hydraulic control central tube (18) below the conical body, and the hydraulic cylinder pressing hole is blocked by a pressing sealing cylinder (16) before cementing is completed.

5. A small well drilling-free cementing device according to claim 1, wherein the upper part of the said pressing closed cylinder 16 is a cone which is matched with the cone of the upper end of the hydraulic control central tube (18), and at least one shear hole is arranged on the upper part of the said pressing closed cylinder (16).

6. The small-bore plug-free cementing device according to claim 1, wherein the closing head (7) is a non-constant diameter inner cavity and a non-constant diameter outer circle, and a lock ring installation cavity, a rubber plug limiting table, a connecting cylinder thread section and a cement buffer cavity are arranged in the non-constant diameter inner cavity of the closing head (7); the lower part of the non-constant diameter excircle of Guan Bitou (7) is provided with a conical transition section, and the middle lower excircle of the closing head (7) is sleeved with an expansion closing cylinder (3).

7. A slim hole plug-free cementing device as claimed in claim 6, wherein the lower cavity of the expansion closing cylinder (3) has a structure conforming to the structure of the conical transition section of the lower part of the closing head (7), and a cementing sealing element is arranged in the conical outer circle of the lower part of the expansion closing cylinder (3) and is positioned below the cementing injection hole in the cementing outer cylinder (2); after the expansion closing cylinder (3) is sleeved outside the closing head (7), a step clamping seat of the outer circle of the upper part of the expansion closing cylinder (3) is arranged above a limit step above a cement injection hole in the well cementation outer cylinder (2).

8. A small well drilling-free cementing device according to claim 1, wherein the shear pin arranged at the upper part of the pawl cylinder (6) body can be connected with a packing cylinder (8), a packing cylinder limiting step is arranged in the middle inner cavity, and a hydraulic cylinder punching hole is arranged in the body above the packing cylinder limiting step; an annular packing liquid inlet hole is arranged in the middle body of the pawl cylinder (6), and sealing elements are arranged at the upper side and the lower side between the annular packing liquid inlet hole and the sleeve packer (4); the lower body of the pawl cylinder (6) is provided with a pawl (601) communicated with the bottom of the body, the outer diameter of the lower part of the pawl (601) is larger than the limit step (602) of the pawl cylinder formed by the outer diameter of the upper part of the pawl cylinder, the pawl cylinder can be clamped between the sleeve packer (4) and the sleeve connecting cylinder (5), and the lower end of the pawl cylinder (6) is propped against by the limit propping cylinder (10); at least three pawls (601) in the pawl cylinder (6) are provided.

9. The drilling-free cementing device for the slim hole is characterized in that a limiting step is arranged on the outer circle of the packing cylinder (8), a shear pin slot or a shear pin hole is arranged above the limiting step, and the limiting step on the outer wall of the packing cylinder (8) can be arranged above the packing cylinder limiting step in the inner cavity of the pawl cylinder (6).

10. A slim hole plug-free cementing unit according to claim 5, wherein the inner wall of the locking ring (17) is provided with locking ring studs (1701) and a through shrink groove (1702) is provided in the body of the locking ring (17).

11. A small well drilling-free cementing device according to claim 11, wherein the rubber sealing cylinder (23) is vulcanized on the rubber stopper limiting table in the inner cavity of the closing head (7), and the central hole of the rubber sealing cylinder (23) is equal to or larger than the outer diameter of the pressing sealing cylinder (16).

12. A small hole drilling-free cementing device according to claim 1, wherein the middle part of the inner cavity of the central tail pipe plug (15) is closed, the upper end of the inner cavity is provided with internal threads, and the internal threads at the upper part of the inner cavity of the central tail pipe plug (15) can be in threaded connection with the central tail pipe (20); the outer diameter of the central tail pipe plug (15) is consistent with the inner diameter of the centralizing cylinder (21).

13. A rubber plug for the small-bore plug-free cementing device according to any one of claims 1 to 12, comprising a rubber fin (2407) and a salvaging screw thread (2401), wherein the rubber plug (24) is provided with a rubber plug center hole (2402), a small-diameter end (2404), a plate valve (2403), a rubber plug button (2405) and a sitting and pressing step (2406);

the rubber fin (2407) is arranged above the sitting and pressing step (2406), and a plate valve (2403) is arranged in a valve fixing step formed by the central hole (2402) of the rubber plug and the upper inner cavity;

a rubber plug cam buckle (2405) is arranged on the outer wall between the sitting and pressing step (2406) and the small diameter end (2404);

the plate valve (2403) is closed when the plug (24) has not reached the cone of the pilot operated base pipe (18) of the slim hole plug free cementing device.

14. A rubber plug according to claim 13, wherein the inner diameter of the small diameter end (2404) is in accordance with the outer diameter of the upper end of the hydraulic control central tube (18) and is larger than the inner diameter of the rubber sealing cylinder (23), the lower end part of the small diameter end (2404) is in a flat head structure, and a rubber plug cam buckle (2405) of the outer wall between the sitting and pressing step (2406) and the small diameter end (2404) is connected with a locking ring cam buckle (1701) in the locking ring (17); the sitting step (2406) is pressed on the upper end of the lock ring (17).

15. A method of cementing construction for a slim hole plug-free cementing device of claim 14, comprising: the method comprises the following steps:

A. after the drilling-free cementing device is assembled, the drilling-free cementing device is matched and connected to a preset position of a well completion string and is lowered into a well bore along with the well completion string;

B. before well cementation, firstly, pressing in a small-well drilling-free cementing device to seal an annulus between a casing and a well wall;

cementing well cementation;

after the well cementation construction is finished, closing a cementing circulation channel;

E. after a cementing circulation channel in the drilling-free cementing device is closed, a fishing operation pipe column with a special fishing tool is put in, all parts of the drilling-free plug mechanism except the well-remaining part are fished out, and the drilling-free plug large-drift-diameter well completion is realized.

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