RU2713284C1 - Device for deepening of well bottom - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used in deepening of well bottom in process of its operation with possibility of core sampling. Proposed device comprises hollow body, plunger arranged inside said hollow body, spring, annular bead and valve. Plunger is equipped with a partition from above, and below the partition the plunger is equipped with a valve made in form of a seat and a sealing plate with a guide rod. Guide rod is tightly fitted from above in a sealed way into the plunger partition, and the plate is spring loaded upwards from the partition. From below hollow body is equipped with bottom-hole cutter, above which annular shoulder is made in hollow body. Above the annular collar in the hollow body there is an internal annular recess, in which a petal core-cutter is installed. Inside the plunger there is a receiving chamber divided by a valve into upper and lower parts. Force of compression of valve spring is less than force of compression of spring of hollow housing, wherein diameter d of valve plate is half an inner diameter D of plunger, and valve seat is made for cone, tapering from bottom to top with taper angle of 130°, wherein in transport position spring is arranged inside hollow housing and presses plunger from partition wall to hollow housing, and from below plunger interacts with annular collar of hollow housing, which limits axial movement of plunger downwards, lobes of core-cutter are forced spring-loaded radially outward by plunger in annular sample of hollow housing, and in working position, plunger has the possibility of limited axial movement upwards relative to hollow housing and release of petals of core-cutter from interaction with plunger and their radial compression inside.

EFFECT: higher reliability of the device, broader functional capabilities, higher quality of cleaning the well bottom from foreign objects, higher efficiency of the device.

1 cl, 3 dwg

Description

The invention relates to the oil industry and may find application in deepening the bottom of the well during its operation with the possibility of coring.

A device for cleaning the bottom of the well (patent RU No. 2097531, IPC ЕВВ 37/00, publ. 11/27/1997 in Bull. No. 33), comprising a housing, a partition with a central channel, a closed locking mechanism and separating the housing into an air chamber and a camera trap, and cable head. The device is equipped with a load discharged by means of an electric drive and a spring-loaded striker located above the locking mechanism. The locking mechanism is made in the form of a diaphragm, destroyed by a spring-loaded striker under the action of the load. The spring-loaded striker is configured to close the air chamber at the end of suction of the bottomhole sludge into it. The end face of the spring-loaded striker, destroying the diaphragm, is made beveled at an angle.

The disadvantages of the device are:

- firstly, the complexity of the design, due to the large number of components and parts (electric drive, locking mechanism, cable head, spring-loaded striker, etc.);

- secondly, the high cost of the device associated with the presence of an electric drive and technologically difficult to manufacture parts (locking mechanism, spring-loaded striker);

- thirdly, the low reliability of the operation, due to the fact that for the device to operate, it is necessary to dump the load using the electric drive, so there is a possibility of the device not working.

A device for cleaning the bottom of foreign objects (patent PM RU No. 158017, IPC ЕВВ 37/00, published on December 20, 2015 in Bull. No. 35), including a hollow body, a plugged plunger, inserted inside the hollow body, a spring and an annular collar. The spring is located inside the hollow body. The plugged plunger is spring-loaded upward from the hollow body. The lower end of the hollow body is equipped with serrated notches. An annular bead is made in the hollow body above the serrated notches, limiting the axial movement of the plugged plunger down. Through the annular flange in the hollow body, through grooves are made in which a petal core is installed, which forms a receiving chamber with a muffled plunger. The plugged plunger has the ability to compress the spring and axially move upward relative to the hollow body when in contact with foreign objects located at the bottom. The device provides the extraction of foreign objects from the bottom of the well with simultaneous coring in one round trip.

The disadvantages of the device are:

- low reliability of the device associated with a high probability of jamming of the petals of the rotary core punch when the core is torn;

- low quality of coring without preliminary cleaning of the bottom of the well from sludge, sand, dirt, etc.

The closest in technical essence and the achieved result is a device for cleaning the bottom of the well (patent RU No. 2083805, IPC ЕВВ 37/00, publ. September 6, 1994), including a hollow body with a guide sleeve in its upper part, a rod connected through the guide sleeve into the body of the rod, a piston connected to it, a receiving valve mounted on the lower end of the body and a spring placed on the rod. The piston and rod are made in the form of a single hollow plug plugged from the lower end with an outer diameter less than the inner diameter of the housing. The upper end of the plunger is connected to the lower open end of the pipe string, and radial through holes are made in the side walls introduced into the housing of the lower part of the plunger. An annular bead is made on the outer surface outside the body of the upper part of the plunger. A spring is installed between the upper end of the housing and the annular collar of the plunger in a state of preliminary compression. The housing in its lower part above the receiving valve is detachable and inserted into the receiving valve body with the possibility of axial movement. A persistent flange is made on the outer surface of the casing, between which and a packer seal with an emphasis on the bottom, is placed between the upper end of the casing of the receiving valve.

The disadvantages of the device are:

- firstly, low reliability, since the spring placed on the plunger is located outside the housing and is not protected from external factors, therefore, when applying mechanical force from outside, for example, collapses in contact with the walls of the well or metal objects located in the well, the spring has the ability to bend, break, which brings the device out of order;

- secondly, limited functionality, since due to the packer compaction, the device does not allow to deepen the bottom of the well with the extraction of foreign objects (sludge, sand, metal) from the bottom of the well and with coring for one round trip, due to device designs of a plug plugged from below. In addition, sand, sludge, mud, and foreign objects located at the bottom of the well, such as crackers, jaws, cones, prevent core sampling for one descent of the device into the well;

- thirdly, there may be obstacles when deepening the face, since during work inside the plugged plunger sludge, sand, etc., as well as foreign objects, the size of which is limited by radial through holes with diameters of 10-15 mm made in the plugged plunger. Foreign objects that are larger than the diameter of the radial through holes, such as crackers, jaws, cones, are not able to get inside the plugged plunger through the radial through holes, which means they are not removed from the well and do not allow to deepen the bottom of the well;

- fourthly, the low efficiency of the device due to the imperfect design of the receiving valve, spring-loaded from the bottom, as well as the lack of a sealing o-ring, which does not ensure tightness when closing and leads to the sludge, sand, metal falling back to the face during the lifting of the device.

The technical tasks are to increase the reliability of the device, expand the functionality by deepening the bottom of the well at the same time as cleaning the bottom and coring in one round trip and the efficiency of the device, as well as seamless deepening of the bottom of the well.

The stated technical problems are solved by a device for deepening the bottom of the well, including a hollow body, a plunger located inside the hollow body, a spring, an annular collar and a valve.

What is new is that the plunger is equipped with a baffle at the top, and below the baffle, the plunger is equipped with a valve made in the form of a seat and a sealing plate with a guide rod, and the guide rod is hermetically inserted into the plunger baffle from above, and the plate is spring-loaded from the baffle, while the bottom of the hollow body is equipped a bottom-hole milling cutter, above which an annular bead is made in the hollow body, and above the annular bead in the hollow body, an internal annular selection is made in which the petal core body, and inside the plunger is equipped with a receiving chamber, divided by the valve into upper and lower parts, and the compression force of the valve spring is less than the compression force of the spring of the hollow body, while the diameter of the valve plate is half the diameter D of the plunger and the valve seat is made under the cone tapering from the bottom up with a taper angle of 130 °, and in the transport position the spring is placed inside the hollow body and presses the plunger from the partition to the hollow body, and from below the plunger interacts with the annular shoulder of the hollow body a mustache restricting the axial movement of the plunger downward, while the core-flap petals are forcibly spring-loaded radially outward by the plunger in the annular sample of the hollow body, and in the working position, the plunger has the ability to limit the axial upward movement relative to the hollow body and release the core-flap petals from interacting with the plunger and radially compress them inward .

In figures 1-3 schematically and sequentially in action shows the proposed device for deepening the bottom of the well.

A device for deepening the bottom of the well (Fig. 1) includes a hollow body 1, a plunger 2 mounted inside the hollow body 1. The plunger 2 has an inner diameter D, for example, equal to 100 mm

Plunger 2 on top is equipped with a partition 3, rigidly fixed with a welded joint. Below the partition 3, the plunger 2 is equipped with a valve 4 made in the form of a seat 5 and a sealing plate 6 with a guide rod 7. The guide rod 7 is hermetically sealed by means of a seal 8, inserted into the partition 3 of the plunger 2, and the plate 6 is spring loaded 9 upward from the partition 3. Plate 6 is equipped with a sealing ring 10 made of NBR rubber, which ensures its tight fit on the seat 5 of the valve 4.

O-rings 8 and 10 made of NBR rubber have a high resistance to swelling with respect to benzene, are oil resistant and wear resistant to oils and fats. The material of the rubber rings 8 and 10 is NBR, Perbunan.NBR (Nitrile Butadiene Rubber) rubber - nitrile butadiene rubber is produced according to GOST 18829-73.

From the bottom, the hollow body 1 is equipped with a bottom-hole mill by means of a threaded connection 11. Above the bottom-hole ring cutter 11, an annular bead 12 is made in the hollow body 1. Any known design of the bottom-hole ring mill, for example, manufactured by Drilling Reserve LLC (Russian Federation, is used) , Republic of Bashkortostan, Ufa). Above the annular flange 12 in the hollow body 1, an internal annular sampling 13 is made, in which the petal core cutter 14 is installed. As the petal core cutter 14, a petal core cutter of any well-known manufacturer, for example, the oil and gas supply department (Russian Federation, Ekaterinburg) is used.

Inside, the plunger is equipped with a receiving chamber divided by the valve 4 into the upper 15 and lower 16 parts, and the compression force of the spring 9 of the valve 4 is less than the compression force of the spring 17 of the hollow body 1. The diameter d of the plate 6 of the valve 4 is two times less than the internal diameter D of the plunger.

The inner diameter of the plunger 2 is D = 100 mm.

Then the diameter of the plate 6 of the valve 4 is equal to d = 100 mm / 2 = 50 mm.

The seat 5 of the valve 4 is made under the cone 18, tapering from bottom to top with a taper angle of 130 °.

In the transport position, the spring 17 is placed inside the hollow body 1 and presses the plunger 2 on top from the partition 3 to the hollow body 1, and from below the plunger 2 interacts with the annular collar 12 of the hollow body 1, restricting the axial movement of the plunger 2 downward, while the petals 19 of the core core 14 spring-loaded radially outward by the plunger 2 in the inner annular sample 13 of the hollow body 1 with the possibility of compression and capture of the core with axial movement of the plunger 2 up. In the working position, the plunger 2 has the possibility of limited axial movement upward relative to the hollow body 1 and the release of the petals 19 of the core core 14 from interaction with the plunger 2 and their radial compression inward.

The device operates as follows.

The device, as shown in figure 1, at the wellhead is attached to the lower end of the drill pipe string 20 and lowered into the well. 8 m before reaching the bottom of the well, the descent of the drill string is stopped.

At the wellhead, the injection line of the pumping unit is mounted to the annular space of the well (not shown in Fig. 1-3).

As a pumping unit, any pump used in flushing wells is used, for example, the cementing unit ЦА-320 manufactured by the Ural plant of special equipment (Russian Federation, Chelyabinsk).

Then turn on the pump unit and cause circulation, backwash, i.e. injection of a process fluid, for example, wastewater with a density of 1100 kg / m ³ into the annular space (not shown in Figs. 1–3) and the outlet of the process fluid through the drill pipe string 20 (Fig. 1). Next, the drill pipe string 20 descends with fluid circulation at a speed of 0.1 m / s.

As the drill pipe string is lowered, the injection pressure increases, which visually affects the pressure gauge of the pump unit, and valve 4 opens (Fig. 2). For example, at a pressure of 5.0 MPa, the plate 6 and the guide rod 7 rise, compressing the spring 9. As a result, the sludge, sand, metal, i.e. Foreign objects freely enter the seat 5 of the valve 4, an annular gap formed between the inner diameter D = 100 mm of the plunger 2 and the plate 6 of the valve 4 with a diameter of d = 50 mm in the upper part 15 of the receiving chamber.

As they descend, they reach the bottom of the well, as evidenced by the unloading of the drill string 20 to the bottom of the well, i.e. there is a sharp decrease in weight by the weight of the drill pipe string, for example 200 kN, which is visually displayed on the weight indicator. After this, the circulation of the process fluid by reverse flushing is stopped, so the pressure in the upper part 15 of the receiving chamber decreases, and due to the return force of the spring 9, the plate 6 and the guide rod 7 are lowered, the plate 6 with the sealing ring 10 seals tightly on the valve seat 5 of the valve 4 (Fig. 3). As a result, valve 4 closes.

At the wellhead, the discharge line of the pumping unit is dismantled from the annular space of the well.

Then, a hydraulic rotor is installed at the wellhead to rotate the drill string 20. A rotor of any known design, for example, a hydraulic rotor manufactured by Mashzavod (Russian Federation, the Republic of Bashkortostan, Ishimbay), can be used as a rotor.

At the wellhead, a check mark is set with chalk on the drill pipe string 20. Then, a rotor is launched to rotate the drill pipe string 20. Then, from the wellhead, an axial load of 10.0-50 is applied to the drill string 20 and, accordingly, to the device. , 0 kN = 1.0–5.0 t.

A bottom hole milling cutter 11 located at the end of the hollow body 1 under the influence of axial load and rotation of the drill pipe string 20 is drilled into the bottom hole formation, and the bottom hole deepening begins.

As the bottom deepens, core drilling of the formation rock (core) takes place. The core 21 enters the lower part 16 of the receiving chamber and acts on the seat 5 of the valve 4, after which the plunger 2 rises and compresses the spring 17. The hole in the bottom of the well is fixed by moving the reference mark on the drill string 20 (Fig. 1, 2, 3) . The magnitude of the recess depends on the length L of the lower part 16 of the receiving chamber (from valve 4 to the shoulder 12 of the hollow body) and is selected empirically depending on the required depth of deepening of the face and the height of the core 21, for example, equal to L = 0.5 m. Therefore, in a certain moment, when the reference mark on the drill pipe string 20 at the wellhead moves down 0.5 m, the axial load on the drill pipe string 20 is removed and its rotation is stopped.

As a result of moving the drill string 20 down by 0.5 m, the plunger 2 rises above the annular collar 12 within the inner ring sample 13 of the hollow body 1. As a result, the petals 19 of the core core 14, forcibly spring-loaded radially outward by the plunger 2 in the inner ring sample 13 of the hollow body 1 are released, compressed radially inward, cutting and capturing the core 21 (Fig. 3) from falling out of the lower part 16 of the receiving chamber.

Then the drill pipe string 20 with the device is removed at the wellhead.

After lifting the device, disassemble, core, revise and assemble the device for subsequent work.

In the proposed device, the spring 17 is installed inside the hollow body 1 and is protected from external factors: from corrosion by aggressive media, as well as from mechanical influences, which eliminates the bending and breaking of the spring. This allows you to increase the reliability of the device and the operating time to failure.

The device is structurally equipped with a receiving chamber, divided into upper 15 and lower 16 parts, which allows not only cleaning the bottom of the well from sand, sludge, dirt, remove foreign objects from the bottom of the well into the upper part 15 of the receiving chamber, but also qualitatively pick up core without impurities into the lower part 16 of the receiving chamber, as well as deepening the face in one round trip. An annular gap formed between the inner diameter of the plunger 2 and the diameter of the plate 6 of the valve 4 is several times larger than the radial through holes described in the prototype. This ensures the extraction from the bottom of the well of sand, sludge, dirt, as well as foreign objects such as crackers, jaws, cones that prevent coring.

Obstacles that do not allow to deepen the bottom of the well are eliminated, since it is guaranteed that immediately before the deepening of the bottom, foreign objects such as crackers, jaws, cones get into the bottom of the bottom, and it was also experimentally established that with a ratio of the inner diameter of the plunger 2 to the diameter of the valve plate 6 4, equal to 2: 1, respectively, and a taper angle of 130 ° of the saddle 5, the intensity of absorption from the bottom of the well to the upper part 15 of the receiving chamber of sand, mud slurry increases.

Increases the efficiency of the device associated with the improvement of the design of the valve 4 in which the plate 6 is guaranteed to provide tightness when closing and eliminates the fall back to the bottom of the sludge, sand, metal during the lifting of the device.

The proposed device for deepening the bottom of the well allows you to increase the reliability of the device, expand the functionality, improve the quality of cleaning the bottom of the well from foreign objects, increase the efficiency of the device.

Claims (1)

Device for deepening the borehole bottom, comprising a hollow body, a plunger that is located inside said hollow body, a spring, a collar and a valve, characterized in that the plunger top is equipped with septum and below the septum plunger is equipped with a valve designed as a seat and sealing plates with the guide rod moreover, the guide rod on top is hermetically inserted into the baffle of the plunger, and the plate is spring-loaded from the baffle, while the bottom of the hollow body is equipped with a downhole-ring mill, above which the hollow body is made to a bead, moreover, above the annular bead in the hollow body, an internal annular selection is made, in which a flap core is installed, and inside the plunger is equipped with a receiving chamber divided by the valve into upper and lower parts, and the compression force of the valve spring is less than the compression force of the hollow body spring, while the diameter d of the valve disc is two times smaller than the internal diameter D of the plunger, and the valve seat is made under a cone, tapering from the bottom up with a taper angle of 130 °, and in the transport position, the spring it is inside the hollow body and presses the plunger from the partition to the hollow body, and from below the plunger interacts with the annular collar of the hollow body, restricting the axial movement of the plunger downward, while the core cutter petals are forced radially outwardly by the plunger in the annular selection of the hollow body, and in the working position the plunger has the possibility of limited axial movement upward relative to the hollow body and the release of the core breaker petals from interaction with the plunger and their radial compression inward.

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