RU2149252C1 - Disconnecting device for tail components being cemented with resting on bottom-hole - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: device actually relates to construction and repair of wells. Device has internal body and external body which can telescopically interact. Ball-type detents are provided between bodies. There is also seat adapted for telescopic interaction with internal body and ball-type detent. Made in lower part of external body are openings. Located above openings in through-passage of external body is seat for non-return valve which interacts with internal case. Made in walls of internal body are by-pass passages which communicate with external space via through-passage of seat and openings in external body. Application of embodiment of disconnecting device allows at minimal labour input and time for carrying out technological operations such as lowering and cementation of tail components with purpose of isolation of flooded beds with use of only one cementation plug in vertical, incline, and horizontal wells. In performing of operations, device allows for reducing capital input by 1.8-2.0 times together with minimizing occurrence of emergency situations. Disconnecting device is simple in design, easy to manufacture and operate. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to the field of oil and gas industry, specifically to the construction and repair of wells with cemented liners.

 Known "Disconnecting device of the drill string" (see av. St. N1062370, according to MKI E 21 B 17/00, 08/04/1980), including the upper and lower telescopically connected cases with a stop between them, located in the respective sockets, and a hollow sleeve configured to interact with said stopper.

 Closer to the proposed development is "Disconnecting Device" (see the book "Handbook of a Drilling Engineer", Volume 2, edited by V.I. Meshchevich, N.A. Sidorov, M., "Nedra", 1973, p. 187, Fig. XIX.4), which includes a telescopic interaction between the inner and outer bodies with a ball retainer between them, a saddle made with the possibility of telescopic interaction with the inner body and the ball retainer.

 Both the analogue and the prototype cannot be used to install casing shanks during well cementing, since an excessively narrowed central channel prevents the passage of the cork plug during cementing.

 The objective of the invention is to create the design of a disconnecting device designed to install casing shanks with cementing supported on the bottom, and to eliminate the disadvantages of the prototype.

 The problem is solved by the described disconnecting device, including made with the possibility of telescopic interaction with each other, the inner and outer bodies with a ball retainer between them, a saddle made with the possibility of telescopic interaction with the inner body and a ball retainer. New is that in the lower part of the outer casing there are windows over which in the passage channel of the casing there is a seat for a check valve interacting with the inner casing, while in the walls of the inner casing there are bypass channels communicating with the outer space through the passage channel of the seat and windows of the outer casing.

 Studies of patent and scientific and technical literature have shown that such a combination of essential features is new and has not been used before, and this, in turn, allows us to conclude that the technical solution meets the criterion of "novelty."

 In FIG. 1 shows a General view of the proposed device in partial section and its cross section in FIG. 2 along line AA.

 The disconnecting device of the pipe string contains an inner 1 and an outer 2 housing, telescopically connected to each other by a ball retainer 3, located in the sockets 4 and 5 made in the housings 1 and 2 in the form of coaxial holes, from falling out the ball retainer holds the screw 6, the seat 7 with the inside ball 8, made with the possibility of telescopic interaction with the inner housing 1 and the ball lock 3. In the transport position, the saddle 7 is held by a shear screw 9. In addition, a thread 10 is made in the inner case connections with the tubing string 11 and the bypass channels 12, and the outer casing 2 is threaded 13 for connection with the necessary set of casing pipes 14. Windows 15 are made in the lower part of the outer casing, over which in the passage channel of the casing 2 is made a seat 16 for a check valve 17, which has the possibility of telescopic movement relative to the housing 2 and is preloaded by the spring 18. The valve 17 in the transport state abuts against the inner housing 1, while remaining constantly open when the structure is assembled . The disconnecting device is equipped with the necessary seals 19 and 20. The number of ball clips 3 can vary, symmetrically spaced across the cross section depending on the operating conditions.

 The device operates as follows.

 On the thread 13 of the outer casing 2, the necessary set of casing pipes 14 is attached, lowering into the well. After that, the tubing string 11 is lowered inside and connected to the inner casing 1 on the thread 10. The device thus connected is lowered to a predetermined depth, filling inside the pipe space during descent takes place through windows 15, open valve 17 and the seat hole 7. Then, inside the tubing string 11 the pressure is created, which causes the screw 9 to be cut off and the saddle 7 to move down, which causes the sockets 5 to open and the ball clips to fall into the inside of the device, this, in turn, causes the inner 1 and outer 2 cases to disengage, resulting in ultimately the outer casing 2 with the casing 14 is lowered to the bottom. Next, the inner casing 1 is lowered to the stop, opening the valve 17, and cement mortar is injected, which from the in-pipe space through the bypass channels 12 of the inner casing 1, the open valve 17 and the openings 15 of the outer casing 2 passes into the annulus. The injection of cement mortar ends with the passage of the squeeze plug 21 (conventionally shown in the drawing) and the closure of the bypass channels 12. Next, the tubing with the inner casing 1 and with parts 3, 7, 8, 21 is removed to the surface without leaving unnecessary items inside the well, and the valve 17 under the action of the spring 18 overlaps the seat 16 and the passage of cement from the annulus into the casing string. The outer casing 2 with parts 6, 17, 18 remains in the well.

 The use of a disconnecting device will allow carrying out technological work (lowering and cementing the shanks of the “flaps” to shut off water-filled formations using only one cementing plug, etc.) with minimal labor and time costs) in vertical, deviated and horizontal wells. When performing the above work, the device will reduce costs by 1.8-2.0 times and reduce emergency situations. The device is simple in design, technologically advanced in manufacture and operation.

References:
1. Analogue: "Disconnecting device of the drill string", ed. St. N1062370, according to MKI E 21 B 17/00, from 04/08/1980

 2. Prototype: "Disconnecting Device", book "Handbook of a Drilling Engineer", volume 2, edited by V.I. Meshchevich, N.A. Sidorova, M., "Nedra", 1973, p. 187, fig. XIX. 4.

Claims (1)

 Disconnecting device for cemented shanks supported by a face, including telescopic interaction between the inner and outer bodies with a ball retainer between them, a saddle made with the possibility of telescopic interaction with the inner housing and the ball retainer, characterized in that in the lower part of the outer the windows are made over the casing, above which, in the passage channel of the said casing, a seat is made for the check valve interacting with the inner casing at the same time, bypass channels are made in the walls of the inner case, communicating with the outer space through the passage channel of the saddle and the windows of the outer case.

Images