RU2531076C1 - Method and device for isolation of troublesome zones when drilling wells and detecting faults in casing strings with shaped shutter with cylindrical sections - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device comprises a shaped shutter, a shoe with return valve and fishing head, an expanding head formed of several sections and containing a locking mechanism from below, a hydraulic jack of coaxially connected hollow pistons with rods and cylinders. The anchor bend is made of sections placed outside of the respective cylinder of the hydraulic jack case, a cone rigidly fixed to the case and the hydraulic jack cylinder, slips with pushers interacting with a circular piston spring-actuated upwards from the case, which is located so that may overlap longitudinal coverage of the cylinder longitudinal channels and their opening at movement downwards. Upon running in of the shutter to the well and expansion of shaped areas by development of hydraulic pressure in it distribution of cylinder areas and calibration of shaped areas is performed by movement of the expanding head under action of the flow string weight and by hydraulic jack at sections, which require additional efforts. Rigid connection of hydraulic jack rods with the pipe string and punches of the expanding head and rigid connection of the anchor bend with the case and hydraulic jack cylinder allows summing up of the axial load from the hydraulic jack cylinder and weight of the drilling stem. Preliminary protrusion of the anchor slips promotes stronger fixation of the anchor gear in the casing string.

EFFECT: improving reliability of the anchor gear and efficiency of hydraulic jack.

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Description

The invention relates to drilling and overhaul of wells, and in particular to technology and means for eliminating complication zones when drilling wells and repairing casing strings in case of leakage.

A device for repairing casing strings in a well is known (AS No. 976020, IPC ЕВВ 29/10, published in Bulletin No. 43 of 11/23/1982). This device contains a profile overlap with cylindrical ends, at the ends of which are installed upper and lower anchor assemblies in the form of cones with seals and fixing dies, forming a hydraulic chamber with a shutter, as well as gripping and gripping elements, one of which is connected to the cone of the upper anchor assembly, and the other with the cone of the lower anchor node. In this case, the gripping and gripping elements have protrusions for interacting with the profile part of the overlap. The lower end of the cone of the lower anchor assembly is equipped with a mandrel, and the upper end of the cone of the upper anchor assembly is equipped with a check valve. The shutter is lowered into the column leakage zone (or the drilling complication zone) using the installation head, the profile sections of the shutter are expanded by creating hydraulic pressure in it, and the cylindrical sections are distributed using the mandrel.

The main disadvantages of the known device are the low quality and unreliability of overlapping zones of casing leakage or complications of well drilling, especially when the overlap interval reaches several hundred meters. This is a consequence of the fact that when the profile pipes are expanded by hydraulic pressure, the overlap anchors in the casing string or in the wellbore above and below the disturbance or complication interval, and when profile and cylindrical sections are distributed, first “downward” metal flows on threaded connections, respectively, above and below, which can lead to their depressurization due to the displacement of the sections connected by a thread. Emergencies are also possible in cases of jamming of cones during flaring of a profile overlap.

Also known is a device for blocking the complication zone in a well (AS SU No. 1712581, IPC ЕВВ 29/10, 33/13, published in Bulletin No. 6 of February 15, 1992), which includes a profile pipe with cylindrical sections at the ends, on the lower of which there is a shoe with a check valve, and in the upper - an expander with rolling elements, an expanding head located above the profile pipe, consisting of several sections installed stepwise with rolling elements decreasing in diameter towards the distribution, rigidly interconnected : gripping element t, locking mechanism and drill pipe connection unit.

The main disadvantage of this device is the unreliability of isolation of the zones of complications of well drilling due to poor calibration of the inflated profile part of the overlap and poor-quality pressing of the cylindrical part of the overlap by flaring, which can lead to jamming of the bit when it is lowered after installing the profile overlap to continue drilling, to impair the tightness of the threaded joints of the overlap, and sometimes to their destruction due to reusable alternating load. Also, at shallow drilling intervals, the weight of the drill pipe string may not be enough to pass the cylindrical parts, which will lead to jamming of the tool and, as a result, to an emergency.

The closest in technical essence and the achieved result to the proposed are the method and device for isolating the zones of complication of drilling a well with a profile overlap with cylindrical sections (patent RU No. 2374424, IPC ЕВВ 29/10, published in bulletin No. 33 dated November 27, 2009) .

The device according to this patent includes a profile overlap with cylindrical sections and threaded connections mounted on the lower end of the overlap shoe with a check valve and a fishing head at the top, an expanding head, consisting of several sections mounted on top of each other in the form of punches with decreasing from section to section to the side the overlap with working maximum diameters and containing on top a connection node with a pipe string, and below - a locking mechanism with a catcher under the catch head of the shoe, and that the anchor node configured to cooperate with the bore walls or profile liner with increasing internal pressure, and arranged successively lower hydraulic jack consisting of connected coaxial hollow pistons and cylinders.

The disadvantages of this device are the unreliability and lack of efficiency of the anchor unit and the hydraulic jack, which is expressed in the following. Due to the fact that the hydraulic jack, the anchor device and the drill string, the weight of which is used when distributing the overlap, are arranged in series with respect to each other, when the hydraulic jack is operated, the force is compensated for by the weight of the drill pipe string due to the hydraulic jack force. This leads to the fact that part of the force from the hydraulic jack, equal to the weight of the pipe string, does not produce useful work when distributing the shutoff. Only when the pressure in the hydraulic jack is exceeded, corresponding to the hydraulic jack force equal to the weight of the pipe string, further distribution of the cylindrical sections of the overlap with punches, requiring a lot of effort when distributing them, begins. The anchor assembly interacting with the walls of the borehole or profile blocking device must have a significant jamming force in order to prevent the drill string from being pushed out during operation of the hydraulic jack. Therefore, the hydraulic anchor with radially extendable dies in the proposed design unsatisfactorily performs its functions of securing the drill string. When applying hydraulic pressure, the dies of the anchor, at the same time as the hydraulic jack starts to work, extend into the working position and, as a result, do not have time to fix themselves on the borehole walls. Field tests showed the unreliability of the anchor unit with radially extendable dies and the lack of efficiency of the hydraulic jack.

An object of the invention is to increase the reliability and efficiency of the device for eliminating the zones of complications of drilling wells and repairing casing strings in case of leakage due to more efficient operation of the hydraulic jack and anchor unit, which consists in summing the axial load of the hydraulic jack and the weight of the drill string, preliminary extension of the dies of the anchor and more firmly fixing the dies of the anchor device on the walls of the borehole or casing.

This problem is solved by a device for isolating zones of complication of well drilling and casing disturbances by a profile overlap with cylindrical sections, including a profile overlap with cylindrical sections and threaded joints, a shoe with a check valve and a catch head at the top at the lower end of the overlap, an expanding head consisting of several sections installed one above the other, with decreasing in diameter working surfaces towards the overlap and containing lower the locking mechanism is hermetically connected to the upper end of the overlapper, with a catch below the catch head of the shoe, an anchor assembly installed above the expanding head, made with the possibility of interaction with the walls of the well or profile shutter with increasing internal pressure, a hydraulic jack consisting of coaxially connected hollow pistons with rods and cylinders, and the connection node with the pipe string.

What is new is that the hydraulic jack rods are rigidly connected to each other and from the top to the pipe string, and from the bottom to the expansion head, respectively, through the upper and lower rigid centralizers, the pistons being spring-loaded upward from the corresponding hydraulic jack cylinder, in which longitudinal channels are made above the pistons, the anchor assembly is made in the form of sections consisting of a casing hydraulic jack located outside the corresponding cylinder, a cone expanding from top to bottom and rigidly connected to the casing and the cylinder m of a hydraulic jack, dies with pushers interacting with an annular piston spring-loaded upward from the casing, placed in the cavity between the casing and the hydraulic jack cylinder with the possibility of tightly closing the longitudinal channels of the cylinder and opening them when moving downward, the casing being made tight and communicating with the rod cavity above the annular piston above the corresponding cylinder, and the dies interact with the cone and expandable when moving downward under the action of the annular piston and pushers to -interaction with the borehole walls or profile liner, wherein the annular pistons are fitted inside the protrusions inserted into the longitudinal channels of the cylinder and adapted to interact with the piston when it is moved upward.

Figure 1 and figure 2 shows the upper part of the device, including the hydraulic jack and the anchor node.

Figure 3 shows the expansion head.

Figure 4 - the lower part of the device, including the overlap with the locking mechanism of the expanding head, shoe with check valve and fishing head.

A device for isolating drilling complication zones (for example, caverns, shedding rocks, water showings, etc. - not shown in Fig.) Wells (not shown) and casing disturbances (for example, corrosion and mechanical disturbances - not shown) includes a profile overlap 1 (see FIG. 4) with cylindrical sections 2 and threaded connections 3 in these sections for tight connection to each other, mounted on the lower end of the overlap 1 shoe 4 with a check valve 5 and a fishing head 6 at the top, expanding head 7 (see FIG. .3), consisting consisting of several sections 7 ', 7' ', 7' '', mounted one above the other, with decreasing working surfaces 8 in diameter towards the profile overlap 1 (see Fig. 4) and containing a locking mechanism 9 from below, hermetically connected to the upper end of the overlap 1, with the catcher 10 below under the fishing head 6 of the shoe 4.

The device comprises a hydraulic jack 11 (see FIG. 1 and FIG. 2), consisting of coaxially connected hollow pistons 12 with rods 13 and cylinders 14. Moreover, the rods 13 of the hydraulic jack 11 are rigidly connected to each other and from above through the connection unit 15 (see FIG. .1) with a string of pipes 16, and from the bottom with an expanding head 7 (see figure 3), respectively, through the upper and lower centralizers 17 (see figure 1 and figure 2). In this case, the pistons 12 are spring-loaded upward from the corresponding cylinder 14 of the hydraulic jack 11 by the springs 18. On the outer surface of the cylinders 14 above the pistons 12 there are longitudinal channels 19.

The device also contains an anchor assembly 20 (see FIG. 1 and FIG. 2) mounted above the expansion head 7 (see FIG. 3), consisting of a hydraulic jack located outside the corresponding cylinder 14 (see FIG. 1 and FIG. 2) 11 of the casing 21, the cone 22, expanding from top to bottom and rigidly connected with the casing 21 and the cylinder 14 of the hydraulic jack 11, dies 23 with pushers 24 interacting with the annular piston 25 spring-loaded upward from the casing 21, located in the cavity between the casing 21 and the cylinder 14 of the hydraulic jack 11 with the possibility of tight overlap of the longitudinal channels 19 cylinder 14 and their opening when moving downward, and the casing 21 is made above the annular piston 25 sealed and communicating with the cavity 26 of the rod 13 through holes 27 above the corresponding cylinder 14, and the dies 23 interact with the cone 22 and can expand when moving down under the action annular piston 25 and pushers 24 before interacting with the walls of the well, casing or profile block 1 (see figure 4). In this case, the annular pistons 25 inside have protrusions 28 inserted into the longitudinal channels 19 of the cylinder 14 and configured to interact with the piston 25 as it moves up.

Seals 29, 30, 31, 32, 33, 34 serve to ensure tightness and prevent leaks in the device. Technical structural elements for which the authors do not claim are not indicated or are indicated conditionally.

The device operates as follows.

After assembling the overlap 1 (see FIG. 4) at the wellhead and attaching to the overlap 1 an expansion head 7 (see FIG. 3), a hydraulic jack 11 (see FIG. 1 and FIG. 2) and the anchor assembly 20, the device is connected through the connection node 15 (see figure 1) to the pipes 16, which carry out the descent of the device into the well. After lowering the overlap 1 (see Fig. 4) into the well on the pipe string 16 (see Fig. 1) to the interval where it is necessary to isolate the zone of the complication of drilling the well or disturbing the casing, into the profile overlap 1 (see Fig. 4) through the string of drill pipes 16 (see figure 1), the cavity 26 of the rods 13 (see figure 1 and figure 2), the expanding head 7 (see figure 3), the locking mechanism 9 (see figure 4) and catcher 10 serves overpressure. As a result of this, the check valve 5 of the shoe 4 closes, the profile sections of the overlap 1 are straightened and pressed against the walls of the well or casing. In this case, the bottom end of the catcher 10 is freed from interaction with the upper narrowing of the profile overlap 1, and when unloading the device with a pipe string 16 (see Fig. 1) under their weight, the locking mechanism 9 (see Fig. 4) disengages from the upper end overlap 1. With further unloading of the pipe string 16 (see Fig. 1) and its descent, the expanding head 7 (see Fig. 3) with its working surfaces 8 of the punches 7 ', 7' ', 7' '' sequentially drills and calibrates under the weight of all the equipment, the profile part of the overlap 1 (see figure 4).

When the cylindrical sections 2 and threaded joints 3 of the overlap 1 are turned over, when the weight of the pipe string 16 (see FIG. 1) is not enough to distribute it, excess pressure is again created in the pipe string 16. Excessive fluid pressure through the hole 27 (see figure 1 and figure 2) in the rod 13, acting on the piston 25, makes it move down along with the pushers 24, pushing the dies 23 to its operating position, i.e. before they interact with the walls of the well, casing or overlap 1 (see figure 4). At the end of the stroke of the piston 25 (see FIG. 2), when the rams 23 have advanced to the working position, the longitudinal channels 19 of the cylinder 14 open, and overpressure occurs in the hydraulic jack 11, affecting the pistons 12 (see FIG. 1 and FIG. .2), which, in turn, through rigid fastening with the rods 13 cause them to move down. The rods 13 act with this axial load, additional to the weight of the pipe string 16 (see FIG. 1), created by the hydraulic jack on the expanding head 7 (see FIG. 3), which, with its punches 7 ', 7' ', 7' '', is calibrated and calibrated cylindrical sections 2 (see figure 4) and threaded connections 3 of the overlap 1. The force generated by the hydraulic jack 11 (see figure 1 and figure 2) through the cylinder 14 of the hydraulic jack 11 and rigidly connected to the casing 21 and the cylinder 14 of the hydraulic jack 11 the cone 22 is held by the dies 23 of the anchor assembly 20 interacting with the walls of the well, casing or ne the vent 1 (see FIG. 4), and as a result, it is summed with the axial load from the weight of the pipe string 16 (see FIG. 1) on the expansion head 7 (see FIG. 3).

The piston stroke 12 (see FIG. 1 and FIG. 2) of the hydraulic jack 11 is limited by the stops 35 in the cylinders 14. To exit the liquid during operation of the hydraulic jack 11, holes 36 are provided in the cylinders 14.

After the pistons 12 with the rods 13 move down, i.e. the hydraulic jack 11 will move, the excess pressure in the pipe string 16 is released (see figure 1). As a result, excess pressure is relieved inside the casings 21 (see FIG. 1 and FIG. 2) and in the cylinders 14 of the hydraulic jack 11. At the same time, the compressed springs 18, acting on the cylinders 14, cause them to return to their original position relative to the rods 13. At the same time, the dies 23 disengage from the cone 22, and the annular pistons 25 spring-loaded upward from the casings 21 also return to their original state. The end of the stroke of the rods 13 of the hydraulic jack 11 is determined by the hydraulic weight indicator at the mouth of the verge and the movement of the pipe string 16 (see figure 1).

In the event that for some reason the anchor assembly 20 is jammed, and the force of the springs 18 is not enough for the dies 23 to disengage from the cones 22, they lift the pipe string 16 (see Fig. 1) and are rigidly connected to her rods 13 (see figure 1 and figure 2) with the pistons 12 to the interaction of the pistons 12 of the hydraulic jack 11 with the protrusions 28 of the annular pistons 25. The pistons 25 are moved upward and thereby forcibly remove the dies 23 from engagement with the cones 22 of the anchor assembly 20.

Then, the pipe string 16 is again unloaded (see FIG. 1) and lowered until the expansion head 7 (see FIG. 3) has enough weight for the pipe string to grind and calibrate the blocker 1 (see FIG. 4) 16 (see figure 1). After that, excess pressure is again created in the pipe string 16, thereby actuating the anchor assembly 20 (see FIG. 1 and FIG. 2) and the hydraulic jack 11, turning and calibrating with punches 7 ′, 7 ″, 7 ″ ( see figure 3) cylindrical sections 2 and threaded connections 3 of the overlap 1 (see figure 4).

Having reached the shoe 4, the catcher 10 captures the fishing head 6 of the shoe 4, after which the punches 7 ', 7``, 7' '' (see Fig. 3) are dorn and calibrated the lower part of the overlap 1 (see Fig. 4). After that, the shoe 4, the locking mechanism 9, the expanding head 7 (see figure 3), the hydraulic jack 11 (see figure 1 and figure 2) and the anchor assembly 20 on the pipe string 16 (see figure 1) are removed from wells.

The upper and lower centralizers 17 (see FIG. 1 and FIG. 2) serve to prevent the casings 21 from engaging against the walls of the well, casing or shutoff 1 (see FIG. 4) when they return to their original position.

The number of cylinders 14 (see FIG. 1 and FIG. 2) in the hydraulic jack 11 and, accordingly, sections of the anchor assembly 20 depends on the maximum required force when turning and calibrating the overlap 1 (see FIG. 4), which is determined by the diameter and wall thickness overlap 1, and from the wellbore trajectory.

The proposed device allows to increase the reliability of the anchor device and the efficiency of the hydraulic jack when isolating the zones of complications of drilling wells and repairing casing strings in case of violation of their tightness.

Claims (1)

A device for isolating zones of complication of drilling a well with a profile overlap with cylindrical sections, including a profile overlap with cylindrical sections and threaded connections, mounted on the lower end of the overlap shoe with a check valve and a fishing head at the top, an expanding head consisting of several sections mounted on top of each other, with decreasing diameters of the working surfaces in the direction of the overlap, and containing the bottom locking mechanism, hermetically connected to the upper the end of the overlap, with a catcher below the catch head of the shoe, an anchor assembly installed above the expansion head, configured to interact with the walls of the well or the profile overlap with increasing internal pressure, a hydraulic jack consisting of coaxially connected hollow pistons with rods and cylinders, and a connection unit with a pipe string, characterized in that the hydraulic jack rods are rigidly connected to each other and above with a pipe string, and from the bottom with an expanding head, respectively, through the upper and lower stiff centralizers, the pistons being spring-loaded upwards from the corresponding cylinder of the hydraulic jack, in which longitudinal channels are made above the pistons, while the anchor assembly is made in the form of sections consisting of a casing located outside the corresponding hydraulic cylinder of the jack, expanding from top to bottom and rigidly connected to the casing and a cylinder of a hydraulic jack, dies with pushers interacting with an annular piston spring-loaded upward from the housing, located in the cavity between the housing and the hydraulic cylinder and with the possibility of tightly closing the longitudinal channels of the cylinder and opening them when moving downward, the casing being made tight above the annular piston and communicating with the rod cavity above the corresponding cylinder, and the dies interacting with the cone and expanding when moving downward under the action of the annular piston and pushers before interacting with the walls of the borehole or profile shutoff, while the annular pistons inside are equipped with protrusions inserted into the longitudinal channels of the cylinder and are made with the possibility of interaction with the piston when moving up.

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