为什么生产井要进行压裂?
参考答案:
为了改造生产井井底附近油层,提高地层的渗透能力,降低液体在地层的流动阻力,增加油井的产量或水井的注水量。
I think it ______ that she should be knowledgeable about computers for her present job.
A.urgent
B.normal
C.gifted
D.essential
Y441-114封隔器的最小通径为()。
A、38mm
B、42mm
C、48mm
D、52mm