| 摘要 |
FIELD: oil and gas industry.SUBSTANCE: adapter for safe removal of a drilling string includes lower and upper housings connected to each other by means of a conical thread. Besides, in the upper housing there is a hollow shaft, the upper end of which has a conical right-hand thread. The lower end is located in the lower housing. The shaft is provided with sections engaged with lower and upper housings to transfer torque moment via the drilling string to the right side to the lower housing and excluding the action of torque moment on thread. Lower and upper housings are connected by means of thread; with that, the shaft is spring-loaded in axial direction by means of a helical cylindrical compression spring. On the shaft there is at least one annular groove to arrange a rubber O-ring in it to seal the space between the shaft and the internal wall of the lower housing. Lower and upper housings are connected to each other by means of a left-hand conical thread. The upper end of the shaft is connected to the drilling string; the lower end of the shaft is provided with a section that has hexagonal cross section. The same section is engaged with the hexagonal section of the inner surface of the lower housing. Above the hexagonal shaft end a provision is made for a cylindrical middle section of the shaft, the diameter of which is equal to diameter of the described circle of the below lying hexagonal cross section. The upper shaft section has a hexagonal cross section engaged with a hexagonal opening in the end wall of the upper housing and the right-hand conical thread on the upper end. The shaft is connected to the drilling steel string by means of a right-hand conical thread. One annular groove for arrangement in it of the rubber O-ring is made on the cylindrical middle section of the shaft. Above them there is an annular groove for interaction with brass shear screws. Screws are located diametrically opposite in the lower housing and included in the above annular groove. Screws retain a shaft against axial movement relative to the lower housing. The screw cylindrical compression spring encloses the upper section of the shaft. The spring is located in the upper housing so that its upper end is borne against internal end surface of the end wall of the upper housing and its lower end is borne against a projection made on the shaft with the cylindrical middle shaft section.EFFECT: simpler design and enhanced operating reliability of an adapter.1 cl, 3 dwg |
