日本三级片视频在线观看,131美女爽爽爽,中文字幕亚洲高清精品一区在线,亚洲中文字幕无线无码毛片,最新的黄色网址,潘金莲之性与欲,台湾少妇伦欲电影

    The float shoe or float collar is a kind of casing shoe or coupling which can produce buoyancy . With advantages of high temperature resistance , good sealing feature and easy connection , it can be used to replace guide shoe or casing shoe . The float shoe and float collar can be not only used in unclassified technical casing ,oil layer casing but also in deep well , extra-deep well and special technology well.
    The float shoe which is connected at end of casing string functions as guide or back pressure valve. The float collar which is connected at 20-30 meters from the end of casing serves the functions of supporting ring and back pressure valve .

Technical parameters and specifications for float shoe

Technical parameters and specifications for float collar