RU206444U1 - Colmating circulation sub - Google Patents

Abstract

The utility model relates to the construction of oil and gas wells, namely to the circulation subs as part of the assembly used for plugging the wellbore during drilling or drifting in order to prepare the wellbore for lowering the casing to the planned depth. the model consists in increasing the activation and deactivation cycles of the circulation sub, in increasing the rigidity of the assemblies with the inclusion of a clogging device, in increasing the efficiency of strengthening the walls of the wellbore, in the appearance of an additional function for working out the intervals of wells with increased local deviation. This is achieved by the fact that the clogging circulation sub contains a body with side holes, a spool, a seat, a spring, plugs with through holes, an activation ball, a ball receiving device, a diaphragm and a calibrator body. There is a cavity inside the body and the spool through which the primary fluid path passes. The spool has a first position, in which the through holes of the plugs are closed, and a second position, in which the primary trajectory of the fluid movement is blocked, and the through holes of the plugs communicate with the internal cavity of the sub to supply the entire volume of fluid into the annular gap of the wellbore. On the outside, at the level of the device for receiving balls of activation, a calibrating part is located. The length of the bridging circulation sub is no more than one meter, due to which it has the ability to be part of the gauging assembly instead of one of the calibrators, due to its possession of the necessary rigidity, which, in turn, allows additional strengthening of the well walls by rubbing in the bridging layer. The balls for activating the bridging circulation sub are made of degradable (soluble) material, so that one ball is used to control the cycle of activation and deactivation of the sub. The regulation of the duration of the stay of the sub in the activated state is carried out by selecting the composition of the material of the activation ball, based on the parameters of the working environment in which the process of decomposition (dissolution) of the ball takes place. Also, the time spent by the sub in the activated state can be adjusted by pumping a highly mineralized pack, which contributes to an increase in the rate of decomposition (dissolution) of the ball. columns.

Description

The utility model relates to the construction of oil and gas wells, namely, circulation subs as part of a rotary assembly used for drilling a wellbore for the purpose of trouble-free lowering of the casing to the planned depth.

Known flushing calibrator (Patent RU No. 145681, IPC E21B 10/26, published 09/27/2014), consisting of a hollow cylindrical body with connecting tool joints for screwing with a non-magnetic drill collar downhole telemetry system and drill pipes. There are five blades on the body and two flush holes in the bottom of the body. All blades have the same length and width (have the same geometric dimensions), the shape of the blades is trapezoidal - the base of the blade is longer than the upper part. The outer surface of the blades is reinforced with rock-destroying elements; polycrystalline diamond teeth (PDC) are used as rock-breaking elements. PDC teeth are fixed in the blades by pressing. The flushing holes located in the lower part of the body are made with the possibility of installing replaceable nozzles in them, the inner channel of the flushing holes has a rectangular shape.

In the process of lifting the bottom hole assembly (BHA) after drilling or drifting, when puffs appear, circulation of the drilling fluid is caused, the drilling fluid passes through the central channel of the calibrator body and at the level of the nozzles is divided into two streams: the first, the main stream, rushes to the bottom of the drilling of the column, and the second stream, which is less powerful, passes through the flushing holes in the lower part of the calibrator and enters the annulus, increasing the velocity of the upward flow in the annulus. Reverse development of the wellbore is carried out: PDC teeth located on the blades destroy the narrowed sections of the wellbore, and the flow through the flushing holes promotes the removal of drilled cuttings to the surface. The use of replaceable nozzles allows you to adjust the flow rate of the drilling fluid.

The disadvantage of the known design is the impossibility of overlapping the internal space, as a result of which part of the drilling fluid circulates through the central flushing hole, while there is a loss of flow velocity in the side holes and, thus, there is no possibility of effective regulation of both the operation of the hydraulic downhole motor and the clogging strengthening the borehole walls. In addition, in the process of pumping a drilling solution with a filler intended for clogging the walls of the wellbore, there is a risk of clogging the downhole motor with filler and causing equipment failure.

The closest technical solution is a circulation sub of the drill string (Patent RU No. 155225, IPC E21B 21/10, published on September 27, 2015), containing a tubular body equipped with external holes, a stepped spool with radial holes, a spring, a saddle, deformable activation balls , deformable blocking balls, hard deactivation balls, ball receiving device.

In the known design, the circulation sub is controlled by means of control balls made in the form of a deformable activation ball, deformable blocking balls and rigid deactivation balls. A device for receiving balls is attached at the end thread below the spool.

In the deactivated state of the known design, the entire fluid flow is directed along the inner cavity of the housing from the inlet and then through the ball receiving device to the outlet of the circulation sub, forming the primary path of the fluid. Communication of the internal cavity of the circulation sub with the annular gap of the wellbore is excluded. To move to the activated position, a deformable activation ball is dropped into the string, which is carried by the drilling fluid to the seat of the stepped spool. After the activation ball lands on the seat, the underlying channels are cut off, after which the pressure above the stepped spool is increased, leading to compression of the spring, moving the stepped spool to the lowest position and opening the side holes in the sub body. As a result, a hydraulic channel is formed connecting the interior of the drill pipes with the annular gap of the wellbore. In the absence of flow, the step spool returns to the first position under the action of the spring, providing separation of the inner space of the drill pipes from the annular gap of the wellbore. To return the circulation sub to its original state, two hard deactivation balls are used, which are dropped into the drill string and carried by the drilling fluid to the radial holes in the stepped spool. The overlap of the radial holes by hard balls of deactivation causes an increase in pressure, leading to the pushing of the deformable ball of activation through the seat. After the deformable activation ball passes through the seat, the stepped spool returns to the first position, and the circulating sub returns to its original state. The deformable activation and deactivation balls pass downward and are delayed by the ball receiving device. If necessary, the operations to activate and deactivate the sub are repeated.

A disadvantage of the known design is the limitation on the capacity of the device for receiving balls, which determines a limited number of cycles of changing the direction of the fluid flow. Also, the disadvantages of the sub include the need to disassemble and assemble it to remove the balls from the receiving device. An increase in the capacity of the ball receiving device leads to an increase in the length of the circulating sub, and, consequently, to a decrease in the rigidity of the BHA, which in turn contributes to the emergence of complications and unproductive tripping operations due to the increased curvature of the bore.

Patent RU No. 155,225 IPC E21B 21/10 was adopted as a prototype.

The technical problem to be solved by the claimed utility model consists in increasing the activation and deactivation cycles of the circulation sub, in increasing the rigidity of the assemblies with the inclusion of a clogging device, in increasing the efficiency of strengthening the walls of the wellbore, in the appearance of an additional function for working out the intervals of wells with increased local deviation ...

This is achieved by the fact that the bridging circulation sub contains a body with side holes, a spool, a seat, a spring, plugs with through holes, an activation ball, a ball receiving device, a diaphragm, and a calibrator body. There is a cavity inside the body and the spool through which the primary fluid path passes. The spool has a first position, in which the through holes of the plugs are closed, and a second position, in which the primary trajectory of fluid movement is blocked, and the through holes of the plugs communicate with the internal cavity of the sub to supply the entire volume of fluid into the annular gap of the wellbore. On the outside, at the level of the device for receiving balls of activation, a calibrating part is located. The length of the bridging circulation sub is no more than one meter, thanks to which it has the ability to be part of the gauging assembly instead of one of the calibrators, due to the possession of the necessary rigidity, which, in turn, allows additional strengthening of the well walls by rubbing in the bridging layer. The balls for activating the bridging circulation sub are made of degradable (soluble) material, so that one ball is used to control the cycle of activation and deactivation of the sub. The regulation of the duration of the stay of the sub in the activated state is carried out by selecting the composition of the material of the activation ball, based on the parameters of the working environment in which the process of decomposition (dissolution) of the ball takes place. Also, the time spent by the sub in the activated state can be adjusted by pumping a highly mineralized pack, which helps to increase the rate of decomposition (dissolution) of the ball.

In contrast to the prototype, in the proposed bridging circulation sub, a ball made of a decomposable (soluble) material is used for activation, and in case of a need for a single processing of the barrel - from a non-decomposable material, there is a calibrating part on the outer surface of the sub, which makes it possible to calibrate and additionally strengthen the walls wells due to rubbing in the clogging screen while walking and rotating the assembly with the clogging sub.

In contrast to the prototype, only one ball is used to perform the activation and deactivation cycle of the device, which simplifies the control of the trajectory of the fluid supply, and also, due to the use of a degradable (soluble) material, leads to a decrease in the length of the device for receiving balls, and the presence of a membrane eliminates the possibility of washing out. dissolving ball of activation. The material and dimensions of the initiating ball can be selected individually for the well conditions, with the predicted rate of decomposition and operation of the bridging device in the activated position, which ensures the required period of operation of the device and there is no need to pump the deactivating balls provided in the prototype under consideration.

The proposed utility model, due to the presence of a calibrating part, of a small length, can be included in the rotary gauging assembly instead of one of the calibrators, which makes it possible to perform operations to develop intervals with increased local curvature and clog the wellbore walls in one trip.

FIG. 1 shows a bridging circulation sub in its initial position.

FIG. 2 shows a general view of the bridging circulation sub.

FIG. 3 shows the bridging circulation sub at the time of activation.

FIG. 4 shows the bridging circulation sub in the activated position.

FIG. 5 shows a bridging circulation sub after returning to its original position.

The bridging circulation sub (Fig. 1) consists of a body 1 in which there are side holes 2. In the side holes 2 there are plugs 3 having through internal holes. Plugs 3 have several designs that differ in the size of the through holes in them. This is necessary to control the flow rate of the fluid through the through holes. A slide valve 4 is installed in the body 1, which has the ability to slide. A seat 5 is installed in the spool 4. To prevent the spool 4 from turning, it has a longitudinal groove, which includes a guide 6, fixed in the body 1. A spring is installed between the end of the spool 4 and the shoulder of the body 1. (Fig. 2), inside which a device for receiving balls 9 (Fig. 1) is installed. The control of the bridging circulation sub is carried out using the activation ball 10 (Fig. 3). A membrane 11 is installed above the device for receiving balls (Fig. 1).

During the operation of the bridging circulation sub, hydraulic channels A, B, C are formed.

The device works as follows.

In the initial state of the bridging circulation sub (Fig. 1), the spool 4 is in the first upper position, the entire fluid flow is directed to the outlet of the calibrator body along the AB channel, forming the primary trajectory of the fluid movement, communication of the inner cavity of the bridging circulation sub with the annular clearance of the barrel wells (not shown) excluded. To move to the activated position, the activation ball 10 (Fig. 3) is dropped into the string, which is carried by the drilling fluid to the seat 5 of the spool 4. After the activation ball 10 lands on the seat 5, the underlying channel B is cut off. Subsequently, an increase in pressure above the spool 4 leads to compression the spring 7 and the movement of the spool 4 until its end touches the shoulder of the housing 1 (Fig. 4). When the spool 4 is in the second position, the through internal holes of the plugs 3 are opened, forming a hydraulic channel AB connecting the inner space of the pipes with the annular gap of the wellbore (not shown). In the absence of flow, the spool 4 under the action of the spring 7 returns to the first position, providing separation of the internal space of the sub from the annular gap of the wellbore. To return the clogging circulation sub to its original state, the time interval necessary for the decomposition (dissolution) of the upper layer of the activation ball 10 is held to a size that allows the ball to pass through the saddle 5. The decomposition (dissolution) of the upper layer of the material of the activation ball can be performed when pumping a highly mineralized pack, contributing to an increase in the rate of decomposition (dissolution) of the ball. After decomposition (dissolution) of the upper layer, the activation ball 10 is pushed through the seat 5, while the spool 4 returns to the first position, and the clogging circulation sub returns to its original position, a hydraulic channel AB is formed (Fig. 5). After pushing, the activation ball 10 is retained in the device for receiving balls 9, where it further dissolves by the time the next activation operation of the bridging circulation sub starts.

Thus, the proposed utility model of a bridging circulation sub with the specified distinctive features in combination with known features allows an unlimited number of activation cycles to be performed, to simplify the control of the fluid supply trajectory, to increase the efficiency of strengthening the walls of the wellbore, to eliminate intervals of wells with increased local curvature as part of a rotary gating pattern. layout, improve the operation and functionality of the device.

Claims (1)

A bridging circulation sub containing a body in which there are side holes, plugs installed in the side holes and having through internal holes, while the plugs have several designs differing in the size of the through holes in them to regulate the fluid flow rate, a spool that has the ability sliding inside the body, and through which the primary trajectory of movement of the fluid passes, while the spool has a longitudinal slot to prevent it from turning, and the spool has a first position in which the through holes of the plugs are closed, and a second position in which the primary trajectory of movement of the fluid is blocked medium, and the through holes of the plugs communicate with the internal cavity of the sub for the flow of the entire volume of fluid into the annular gap of the wellbore, a saddle installed in the spool, a guide fixed in the body and entering the spool groove, a spring installed between the end face h a valve body and a ledge of the body, a dumped activation ball to close the primary trajectory of the fluid movement, characterized in that a calibrator body is threaded under the body, inside which a ball receiving device is installed, above which a membrane is installed to prevent the dissolving ball from being washed out, and also by the fact that The activation ball is made of a degradable soluble material, while the sub has a length of no more than one meter.

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