The contraction force will be produced in unsetting of hydraulic packer by lifting tubing string because of effect pressure and pumping and so on. 采用上提管柱解封的液壓式封隔器管柱，由于壓力效應及泵抽等因素影響，將產(chǎn)生一定的收縮力。
The paper introduces a new type slim - hole MWD tool, which is capable of accurately measuring downhole annular pressure and pressure effect caused by swabbing and waveness. 文章介紹一種新型小井眼隨鉆測井儀，它能夠精確測量井底環(huán)空壓力以及抽吸和波動(dòng)引起的壓力效應。
