GB1445603A - Sagety means for well flow control - Google Patents

Abstract

1445603 Valve SCHLUMBERGER TECHNOLOGY CORP 10 Aug 1973 10399/76 Divided out of 1445602 Heading F2 [Also in Division E1] A valve 50 for regulating flow through a well conduit comprises a closure member 70 movable between open and closed positions, movable control means 80 connected through connecting means to the closure member 70, the control means 80 including means such as fluid-filled bellows 112, for moving the member 70 to the closed position when the pressure within the conduit acting on the control means exceeds a first level, and means included with the control means for permitting the reopening of the closure member when the pressure acting on the control means exceeds a second, higher, level. The valve is locked when open by locking balls 95 held in place by shaft 92 connected to the bellows 112, which communicates with reservoir 120 containing compressible fluid. As the pressure acting on the bellows rises, shaft 92 is moved upwardly, a pin 150 moving in a slot 151 in stem 93 of the member 70; when the first level is exceeded the shaft 92 will have moved so as to release the locking balls and the pin will have reached the end of the slot so that further movement causes the closure member 70 to meet valve seat 157, at the same time compressing spring 153. If the pressure then rises above the second level, since the shaft 92 cannot move further upwardly, further contraction of the bellows causes resilient fingers 114 on adapter to release the shaft 92; the valve is held closed by the pressure beneath it, until the pressure above it is raised to that level when it is opened by the spring 153. The valve may be used in a well conduit together with a valve (20), Fig. 1 (not shown), which closes in response to the pressure falling below a lower level; such a system and a method using it are claimed in Specification 1,445,602.