RU2441140C2 - Device for hanger lowering and cementing of casing liner in well - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: proposed device comprises assembly for disconnection of casing liner connected with guide funnel of hydraulically driven anchor-parker assembly housing hollow rod with radial holes. Note here that said hollow rod and anchor-parker assembly case for annular chamber. Note also that anchor and parker assemblies are integrated and made up of shaped tube with sealed bottom. Plunger is fitted on shear pins in top section of said annular chamber to overlap channel of communication between said annular chamber and shaped tube inner space when pins are sheared by hydraulic pressure. Mind that hollow rod top end is pivoted while suspended cementing plug locking assembly is fitted on rod opposite end. Said anchor-parker assembly bottom section is connected with casing liner branch pipe engaged with liner.

EFFECT: higher reliability, ruled out sticking in curved well, simplified design, lower costs.

5 dwg

Description

The invention relates to the field of fastening of oil and gas wells, and in particular to devices for lowering, suspension and cementing secret columns, including shanks.

A known method of installing the liner casing in the well (RF patent No. 1813171, IPC ЕВВ 43/10, op. 04.30.1993, bull. No. 16), providing the descent of the liner into the well, installing its upper part in the lower end of the previous casing and flushing well, in which, before the liner is lowered into the well, a profile pipe is installed in its upper part of the casing, the diameter of the circumscribed circle of which is equal to the outer diameter of its cylindrical connecting ends, and after the liner is lowered and the well is flushed, ytochnoe pressure in the cavity of the shank and the pipe to straighten the profile is pressed firmly against the walls of its casing.

The disadvantage is that this method involves the descent and installation of the liner in the casing without cementing, and if cementing the liner is necessary, the method does not provide high-quality work due to the impossibility of using separation cement plugs. Another disadvantage of this method is the need for additional work on flaring profile pipes using a flare tool.

A device for hanging and sealing a countersunk casing (RF patent No. 2279536, IPC ЕВВ 33/14, op. 10.07.2006, bull. No. 19), comprising a housing with radial holes, a hydraulic chamber with an annular piston-pusher with rigid mounted on it centralizer lights. Anchoring and packing of the device is carried out by creating an in-tube overpressure (after receiving the “stop” pressure), which is transmitted through radial holes to the cavity of the chamber and leads to the longitudinal movement of the annular piston. The latter, in turn, pushes and compresses the sealing element (packer) and through it a movable conical sleeve, which opens the anchor dies and anchors the device.

The disadvantages of the device are: 1) the force is transmitted to the conical sleeve of the anchor dies through a plastic (rubber) sealing element, which can collapse during compression, which will lead to failure of the anchor and packer assemblies, 2) insufficient clearance between the device body and the production casing, which is significantly limits the radial dimensions of the device and makes it impossible to create a workable device for the specified sizes of the shank and production casing.

The closest technical solution taken as a prototype is a device for installing and sealing a casing liner in a well (RF patent No. 2171366, IPC ЕВВ 43/10, IPC ЕВВ 33/14, op. 27.07.2001), containing a housing and associated with a transport column, a disconnector, a packer and an anchor are placed in the upper part of the shank, the device has a nozzle with radial openings and a throttle-shutoff valve under these openings to shut off this valve with an internal section of the nozzle at a given flow rate with specified rheology physical properties. At the same time, the pipe is connected to the body, forms an annular cavity with a liner in its upper part, hydraulically connected with the pipe cavity through its radial holes, and with the armature, packer and disconnector drive units and has the ability to be removed from the well with the body and the transport column.

The disadvantages of this device include the fact that 1) this method involves lowering and installing the liner in the casing without cementing, and if cementing the liner is necessary, the method does not provide high-quality work due to the impossibility of using separation cement plugs, 2) a relatively small area contact of the anchor assembly (dies) with the string, which does not provide a proper degree of good adhesion of the dies to the production string, which, in turn, can negatively reflect during the suspension of the shank, 3) a relatively small area of the sealing elements of the packer, which, with low strength properties, does not guarantee a good overlap of the annular space, 4) there is a high probability of jamming of the mating (rubbing) surfaces of the device, which in case of failure of one of them can lead to failure in the operation of the entire device.

The technical result of the claimed device is to increase the reliability of the device by eliminating identified shortcomings in the prototype and simplifying the design.

This result is achieved by the fact that the device for suspension and cementing the liner string in the well, including a liner suspension separation unit, consisting of a disconnecting sub with locking thread for drill pipes and connected to the guide funnel of the anchor-packer unit having a hydraulic drive and in the internal cavity of which a hollow rod with radial openings is installed, which forms an annular cavity with the housing of the anchor-packer assembly, according to the invention, in that the nickname is equipped with a left connecting (trapezoidal) thread for connection with the guide funnel, while the anchor and packer units are combined and consist of a profile pipe that is installed between the upper and lower end sub, and the lower part of the annular cavity of the device is sealed with sealing cuffs, and in its upper of the part, a plunger is installed, fixed by shear elements and blocking the communication channel between the hydro chamber connected to the internal cavity of the hollow rod, and the internal space m of the profile pipe, while the fastening of the upper end of the hollow rod is pivotally movable by installing the upper suspension sleeve with a hemispherical surface in the mating surface of the disconnecting sub, and at the opposite end of the hollow rod the suspension cementing tube fixation unit is installed, including the lower sleeve mounted on it with shear screws suspended cementing plug, and the fixing unit of the plug is included in the inner cavity of the shank pipe, which is from the upper side us connected to a lower end subs, and with the bottom - with a shank.

The device consists of three functionally separate nodes (see figure 1):

1) the unit for disconnecting the device from the drill pipe (the upper part of the device is (node I));

2) combined anchor-packer unit with a hydraulic actuator (middle part of the device (unit II));

3) the fixation unit of the suspended cementing plug (lower part of the device (unit III)).

A longitudinal section of the device in the initial position with the designations of the elements shown in figure 1, where;

1 - disconnecting sub; 2 - a suspended coupling of a hollow rod with a hemispherical surface; 3 - guide funnel; 4 - left connecting thread; 5 - a hole of a hydro chamber; 6 - cavity of the hydrochamber; 7 - a plunger; 8 - shear elements; 9 - upper terminal sub; 10 - the cavity of the device; 11 - technological hole; 12 - profile pipe; 13 - in-tube space; 14 - hollow stock; 15 - lower end sub; 16 - sealing cuffs; 17 - the lower coupling of the hollow rod; 18 - shear screws; 19 - suspended cementing plug; 20 - shank pipe.

The shank suspension separation unit is located in the upper part of the device (see Fig. 1, unit 1) and consists of a disconnection sub 1 with a locking thread for drill pipes and a left connecting thread 4 for connection to a guiding funnel 3. The disconnecting sub 1 has an internal hemispherical groove for installation with an insignificant (up to 0.5 mm) clearance of the hollow rod suspension coupling with a hemispherical surface 2 (also having a reciprocal hemispherical surface), which provides articulated and movable mounting the upper end of the hollow rod 14. The hinged (pendulum) method of suspension of the hollow rod 14 allows the lower and upper ends of the hollow rod 14 to be radially moved (deflected) relative to the middle part of the hollow plunger 7 and relieves bending and other stresses in the body of the hollow rod, which also affect working elements of the hydraulic system when moving the plunger 7 in the process. And to prevent possible spells of rubbing pairs of the device (hollow stem-plunger; plunger - the inner surface of the upper end sub, etc.). In similar devices (for example, in the prototype PChZZ device), a threaded ("rigid") connection of the hollow rod to the disconnecting sub is provided, which, apparently, is the reason for its frequent failures.

To ensure the tightness of the threaded joints and the cavity of the hydraulic chamber, the device parts are equipped with sealing elements - rubber rings (not indicated).

The anchor-packer unit is combined, and anchoring (fixing the suspension of the shank in the production string) and packing (overlapping the annular space between the shank and the production string) is performed by the profile pipe 12, which, in this device, performs the functions of both the anchor and the packer. The anchor-packer unit is located in the middle part of the device (Fig. 1, unit II) and consists of a profile pipe 12 with an upper 9 and a lower 15 end sub; the cavity of the device 10 is limited by the outer surface of the hollow rod 14 and the inner surface of the profile pipe 12; a plunger 7, overlapping (before the node is triggered) the communication channel of the cavity of the device 10 with the in-tube space 13 through the opening of the hydrochamber 5 and fixed from movement by shear elements 8. The lower part of the cavity of the device is sealed with sealing cuffs 16.

The fixing unit of the suspended cementing plug is similar to similar devices (prototype PChZZ, etc.) and consists of the hanging cementing plug 19 itself, fixed with shear screws 18 on the lower sleeve of the hollow rod 17. The assembly is installed inside the nozzle of the shank 20, connected from the upper side to the lower end sub 15, and the bottom is connected to the shank 23 (figure 2, node III).

Figure 2 presents the location of the suspension device of the liner in the well before cementing, and figure 3 after cementing, where: 21 - drill pipe; 22 - production casing; 23 - liner string; 24 - reservoir; 25 - “stop” -ring; 26 - check valve; 27 - shank shoe; 28 - cement mortar; 29 - a small cementing plug.

Figure 4 shows the cross-section (aa) of the profile pipe before the device is triggered (the pipe profile has the shape of a six-pointed star), where: 30 is the sealing material (silicone).

Figure 5 illustrates the cross-section (BB) after the device is triggered (the profile pipe opens and takes a circular shape) and the removable part of the device is lifted (hollow stem with plunger, lower sleeve and sealing cuffs).

The device operates as follows.

Assemble the bottom of the liner string with the installation of tooling in the sequence shown in Fig. 2 — shank shoe 27, check valve 26, “stop” ring 25, and lower the liner string 23 into the well. After the descent of the required (provided by the work plan) number of pipes of the liner string, the liner suspension device is installed (see Fig. 2). At the same time, the lower end of the device, ending with a nozzle of the liner 20, is screwed onto the upper (last) pipe of the liner string, and the upper end of the device (disconnecting sub 1) is connected to the drill pipes 21 by means of a locking thread and the descent of the liner string on the drill pipes continues to the design depths.

After lowering the liner string 23, the well is washed, a cement head (not indicated) is screwed onto the upper pipe with a small cement plug 29 installed and fixed in it (see Fig. 3), the calculated volume of cement mortar is pumped (in accordance with the work plan ) Next, a small cement plug 29 is released from the cementing head and the cement mortar is pushed “over the plug” with the estimated volume of drilling mud or process water. In the process of punching, a small cement plug 29 sits on the suspension cement plug 19 and closes its bore hole, as a result of which the hydraulic pressure in the tube space 13 rises and the shear screws 18 securing the suspension cement plug 19 are cut (see Fig. 1). Further, the small cement plug 29 and the suspended cement plug 19 move together to the landing seat of the “stop” ring 25 and block its hole, while the in-pipe pressure begins to increase, which signals the end of the cement grouting process and corresponds to the “stop” pressure (Рstop )

In order to anchor and pack the device, they continue to further pump the squeezing fluid into the drill pipes, thereby increasing the in-pipe pressure to a certain (indicated in the device passport) cut-off pressure (Cut) of the shear elements 8 that fix the plunger 7. The resulting excess hydraulic fluid pressure in the annulus 13, through the opening of the hydraulic chamber 5, is transferred to the internal cavity of the hydraulic chamber 6 and acts on the annular surface of the plunger 7, and upon reaching the value of roiskhodit shear shear elements 8, locking plug 7 (Figure 1). The plunger 7 is released and moves towards the expanded part (in diameter) of the cavity of the device 10, while opening the channel of communication with it. As a result of hydrodynamic communication in the cavity of the device 10, the pressure increases to a value corresponding to the in-line pressure, and the emergence of dynamic forces exerting pressure on the inner wall of the profile pipe 12. This pressure inflates and “straightens” the shape of the profile pipe to sizes corresponding to the inner diameter of the production string, before she takes a round shape. The estimated value of the pressing force is significant (up to 1000 KN), and provides a tight compression of the profile pipe 12 to the wall of the production string 22. The bench tests carried out confirmed the calculated values - the resistance to movement (adhesion force) of the "inflated" profile pipe placed inside the production string, amounted to 3000 KN (30 tf / m), which is quite sufficient for hanging a liner string up to 1000 m long.

After hanging the liner 23 in the production string 22, it is disconnected from the drill pipe 21 (see figure 3). To this end, in order to relieve dynamic stresses in the left threaded connection 4 of the disconnecting sub 1, a part of the weight of the drill string (to the value of the dead weight of the drill pipe) is unloaded onto the anchored liner suspension device. Further, by right-handed rotation of the drill string by the rotor of the drilling rig, drill pipes 21 are disconnected along the left connecting thread 4 from the guide funnel 3 of the device. After disconnecting, together with the drill pipes 21 and the disconnecting sub 1, at the same time, the remaining internal (extractable) part of the device is lifted, which includes: a plunger 7, a hollow stem 14, sealing cuffs 16 and a lower sleeve of the hollow stem 17 (see figure 3) .

The outer part of the device (guide funnel 3, profile pipe 12, shank pipe 20) and technological equipment (small cement plug 29, suspended cement plug 19, “stop” ring 25, non-return valve 26, shank shoe 27 remain in the well.

The inner bore diameter of the device elements left in the borehole does not exceed the inner diameter of the liner string 23 and does not require additional work to restore the in-bore section.

Information sources

1. Tatar State Research and Design Institute of the Oil Industry. A method of installing a casing liner in a well. / Patent SU No. 1813171. // Bull. fig. No. 16, 1993.

2. Open Joint-Stock Company GAZPROM, Limited Liability Company Scientific-Research Institute of Natural Gases and Gas Technologies - VNIIGAZ. Device for suspension and sealing of a secret casing string. / RF patent No. 2279536. // Bull. fig. No. 19, 2006.

3. OAO Tyazhmash, Ryazan. Plant production / Catalog of a set of technical means for fastening wells with 89, 102, 114, 127 mm shanks / Design features, device and description of the operation of technical means included in the ПНН, ПХЦ, ПХЦМ complexes / Suspended shank suspension cemented protected ГТХЦЗ. http://www.tkpo.ryazan.ru/hvostphc/hvostphc.3.3.htm / PROTOTYPE /.

4. Terentyev SV, Dudaladov AK, Vanifatyev VI, and others. A device for installing and sealing the liner of the casing string in the well. / RF patent No. 2171366. // Publ. 07/27/2001.

Claims (1)

A device for lowering the suspension and the liner cementing column in the well, including a liner suspension separation unit, consisting of a disconnecting sub with locking thread for drill pipes and connected to the guide funnel of the anchor-packer unit having a hydraulic drive and a hollow rod with radial holes, forming an annular cavity with the housing of the anchor-packer unit, characterized in that the disconnecting sub is equipped with a left connecting (trapezoid ideal) thread for connecting to the guide funnel, while the anchor and packer units are combined and consist of a profile pipe that is installed between the upper and lower end sub, the lower part of the annular cavity of the device is sealed with sealing cuffs and a plunger fixed in its upper part is fixed shear elements and an overlapping channel of communication between the hydraulic chamber in communication with the internal cavity of the hollow rod and the internal space of the profile pipe, with the top of the end of the hollow rod is made pivotally movable by installing an upper suspension sleeve with a hemispherical surface in the mating surface of the isolation sub, and at the opposite end of the hollow rod, a fixing unit for fixing the cementing plug is installed, including a lower coupling with a cementing plug fixed to it by shear screws, moreover the tube fixation unit enters the inner cavity of the shank pipe, which is connected to the lower end adapter from the upper side And on the bottom - with a shank.

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