According to this problem, casing oil stolen prevention sealing valve was developed, matching with down-hole oil-gas separator and gas lift valve lift technology.
针对这一难题，研制了套管防盗油密封阀，并配套应用了井下油气分离器与气举阀助流举升工艺技术。
2
If the exhaust system is under a vacuum, the casing must be warmed by gradually introducing the steam, after opening the exhaust valve.
如果排气系统处于真空下，必须在打开排气阀后，逐渐引蒸汽来加热壳体。
3
A valve installed in the wellhead assembly to provide access to the casing annulus of non-producing casings.