RU30822U1 - Casing pipe (core) - Google Patents

Description

ШНвМПМШПИШ .. „. .. „„

2002131802

, i о о г I 3 1 f Т) 2 М11KE, 21 in 1 // 1о

Casing pipe (core)

The utility model relates to the drilling of exploration wells using their casing.

The closest analogue adopted for the prototype is known, the casing pipe (core), at the opposite ends of which an external and internal thread is made (GOST 6238077, IPK Standards Publishing House, 1997, reprint with Changes, Fig. 1). This design leads to an increase in the wall thickness of the pipe in order to provide the necessary strength when threading, which leads to an increase in the mass of the pipe. In addition, threading directly on the pipe itself limits the possibility of using high-quality steels, as the pipe has a long length and the use of such steels leads to a rise in the cost of the pipe.

The objective of the utility model is to reduce metal consumption and increase strength.

To solve this problem, in the casing pipe (core), at the opposite ends of which the external and internal threads are made, the internal and external threads are made on separate pipe sections fixedly connected to the casing pipe (core), and the internal thread has an internal stop ledge, and the external thread - persistent end.

The utility model is illustrated in the drawing, which shows:

in FIG. 1 is a general view of the casing (core) pipe in FIG. 2 - casing string (casing) assembly Casing (casing) pipe consists of a smooth thin-walled pipe 1, to the opposite ends of which two pieces of pipe 2 and 3 are welded by friction welding with internal 4 and external 5 threads made on them. The internal thread 4 has an internal thrust ledge 6, and the external thread 5 has a thrust end 7.

In addition, there is a stop face 8 on the internal thread 4 of the casing (core) pipe, and a stop ledge 9 on the external thread 5. The pipe sections 2 and 3 are fixedly connected to the casing (core) pipe by a weld 10. In FIG. 2 shows the casing pipes (core) assembly. The pipes form an external stop joint 11 and an additional internal stop joint 12.

The inventive device allows to solve the problem.

Indeed, the execution of external and internal threads on individual pipe sections with subsequent connection to the pipe by friction welding allows the use of a thin-walled smooth pipe (wall thickness of 3.5 mm instead of 5 mm in the prototype), which leads to a decrease in the metal consumption of the structure. In addition, pipe segments before threading are improved (surface hardening with high tempering), thereby ensuring their high strength, respectively, increasing the strength of the entire pipe while reducing the weight of the pipe by more than 40%. The presence on the internal thread 4 of the internal stop ledge 6, and on the external thread 5 of the stop end 7, provides a second (internal) stop joint 12 in the threaded connection (when assembling the pipes), which makes it possible to increase the transmitted torque by 1.5 times, thereby there is an increase in the strength of the casing (core) pipe.

Therefore, the inventive casing pipe (core) provides a decrease in metal consumption and increase strength.

The casing pipe (core) works as follows

When making up pipes of casing (core) in a threaded connection, two thrust joints are formed simultaneously - external 11 (as in the prototype) and additional

internal C7YK 12, resulting from the closure of the internal thrust ledge 6

internal thread 4 and thrust end 7 of external thread 5. The presence of an additional internal joint 12 allows to increase the transmitted torque of the drill string by 1.5 times. Therefore, casing pipes of this design can be used as drill pipes, and after drilling, while remaining in the well, they perform the function of a casing string.

Additional hardening of the threaded joint of the casing (core) pipes is achieved due to preliminary improvement (hardening with high tempering) of the threaded workpieces. The presence of an additional thrust joint and high strength material of the threaded ends provides durability and extractability from the well.

Claims (1)

Casing pipe (core), at the opposite ends of which external and internal threads are made, characterized in that the internal and external threads are made on separate pipe sections fixedly connected to the casing pipe (core), and the internal thread has an internal stop ledge and the external thread - persistent end face.