Reliving flow safety pressure reducing device

Abstract

The invention belongs to a petroleum production appliance in the petroleum industry and particularly relates to a reliving flow safety pressure reducing device. A retaining cap (1) is in threaded connection with the right end of the inner hole of an anti-seizing nut (2). A valve bush (6) is installed in the inner hole of the anti-seizing nut (2) and is limited by using a shear pin (5). A valve bush through hole (6-1) is arranged on the valve bush (6). An anti-seizing nut through hole (2-1) is arranged on the anti-seizing nut (2). The valve bush through hole (6-1) and the anti-seizing nut through hole (2-1) are communicated in an overlapped way. An iron wedge (3) is in threaded connection with the outer circumference of the right end of the sleeve bush (6). A locking ring (4) is installed between the iron wedge (3) and the anti-seizing nut (2). A valve stem seat (10) is in threaded connection with the left end of the inner hole of the valve bush (6). A valve stem seat liquid inlet hole (10-1) is arranged on the valve stem seat (10). A valve stem (9) is installed on the valve stem seat (10). After a spring (8) is sheathed on the valve stem (9), the valve stem (9) penetrates through the inner hole of the valve stem seat (10) and is in threaded connection with a valve plate (11). Since the reliving flow safety pressure reducing device has a one-way unlocking function when the reliving flow safety pressure reducing device enters a well, the reliving flow safety pressure reducing device has the function of the existing blind plate.

Description

technical field [0001] The invention belongs to oil production equipment in the petroleum industry, in particular to a deflow safety decompression device. Background technique [0002] At present, in the cementing of horizontal wells, the drilling-free blind plate cementing does not need to drill the plug after cementing, but the blind plate can be lifted only by fishing, and the wellbore can be opened to complete the well. The cementing efficiency is high, safe, reliable, and economical. Therefore, the drillable blind cementing method has been gradually replaced by the non-drillable blind. However, the non-drilling blind tool still has the same defect that it is difficult to enter the well when going into the well. Because the entry end of the casing is blocked by the blind, the casing is under the effects of internal and external pressure differences and buoyancy and The hydraulic shock generated to satisfy the running speed will become more and more obvious with the incr...

AI Technical Summary

Problems solved by technology

However, the non-drilling blind tool still has the same defect that it is difficult to enter the well as the drillable blind when going downhole. Since the entry end of the casing is blocked by the blind, the casing is under the influence of internal and external pressure difference and buoyancy and The hydraulic shock generated to satisfy the running speed will become more and more obvious with the increase of the running depth. Excessive pressure difference and shock may damage the blind plate and casing and cause cementing accidents

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