| 摘要 |
The invention relates to a valve, which can be opened hydraulically and closes automatically, for circulating treatment fluid in the casing of eruptive crude oil or natural gas wells. According to the state of the art, the killing fluid is pumped "over the top" into the deposit or circulated in via valves which have to be opened mechanically. In many cases this is not possible, such as, for example, in the case of erupting pump wells with a built-in subsurface pump in the string. According to the invention, the technical problem is solved when, according to sheet 1 of the drawing, the killing valve consists essentially of a bevel seat valve (3) and (4), which is connected to the body (1) and is held closed by means of a helical compression spring (2). Internal excess pressure against (F1), opens the valve and, at the same time, starts to act on the surface (F2) which is many times larger, so that the valve (3) is lifted far from its seat (4) and damage due to restriction is avoided. In use, the killing valve is as a rule installed as a constituent part of the flow string, as deeply as possible in the well. <IMAGE>
|
