Annular BOP (spherical / conical)
1. Under the supporting use of hydraulic control system, the annular space of different sizes can be closed when there are drilling tools in the well; when there is no drilling tool in the well, the annular space formed by Kelly, coring tools, cables, wire ropes and the wellbore can be completely closed. With the cooperation of pressure reducing and regulating valve and buffer accumulator, the drill pipe can be forced to trip through 18 degree non fine thread butt welded drill pipe.
2. Working principle of annular BOP. The annular BOP is operated by hydraulic control system. When closing, the high-pressure oil enters the lower closing cavity of the piston from the oil port in the middle of the housing to push the piston upward, and the conical surface of the piston squeezes the rubber core. Due to the limitation of the top cover, the rubber core can not go up and can only be squeezed to the center of the wellhead until the drilling tool is tightly held or the wellhead is completely closed to achieve the purpose of sealing the well. When it is necessary to open the well, the directional valve of the hydraulic control system is manipulated to make the high-pressure oil enter the open cavity at the upper part of the piston from the upper oil port of the shell to push the piston downward and close the chamber for pressure relief. The extrusion pressure acting on the conical surface of the rubber core is eliminated, and the rubber core is gradually reset under the action of its own elastic force to open the wellhead.
According to the structure of rubber core, annular BOP can be divided into conical rubber core and spherical rubber core
a. Structural features of conical rubber core annular BOP:
(1) the rubber core is completely interchangeable with htdril.
(2) the wear-resistant belt protection is added to the original structure, which can prevent and improve the cylinder drawing caused by eccentric load.
(3) the lifting ring is strengthened, which can be used to lift the BOP stack as a whole. (4) the clamping block connection mode is adopted to facilitate the disassembly and replacement of rubber core.
b. Structural features of spherical rubber core annular BOP:
(1) the rubber core and Shaffer are completely exchanged.
(2) the wear-resistant belt protection is widened on the original structure, which can prevent and improve the cylinder drawing caused by eccentric load.
Basic parameters
Nominal size: 7-1 / 16 "~ 30"
Working pressure: 1000PSI ~ 10000psi