龙岗地区完钻层位的识别

LOCATING COMPLETION INTERVALS AT LONGGANG AREA

至目前为止龙岗地区所钻各井其主要目的层是飞仙关组及长兴组,设计要求进入龙潭组20m完钻,由于长兴组底界分层位置的差异、层内岩性及组合特征、厚度变化较大,目前没有说服力很强的分层标准,由此而难于判断完钻的具体位置。文章分析了龙岗地区长兴组和龙潭组的沉积相;详细地总结了龙岗地区已钻各井长兴组与龙潭组岩性、电性及分层特征,通过与川东、川中地区长兴组和龙潭组地层岩电关系对比,结合龙岗地区目前完钻的实际情况,提出了完钻层位追踪对比的一些识别方法,供录井现场在实际工作中借鉴和参考,实践证明这些方法在超深井钻探中及时把握井底层位行之有效。

The major target zones of wells drilled at Longgang area up to now are Feixianguan and Changxing.The drilling planning requires completion 20m after entering Longtan.Due to different low bounds determinated for Changxing,different lithologies and combi nations,and large thickness variation,there are still no convictive stratification standards.The depth where completion should be done is therefore hard to decide.In this paper the sedimentation phases of Changxing and Longtan formations at Longgang area are analyzed,the lithology,electrical properties,and stratification features of Changxing and Longtan formations in wells completed already at Longgang area are summarized.After comparison of rock-electrical property relations of Changxing and Longtan at east and central Si chuan area,and taking the actual completion cases at Longgang into consideration,some identification methods for completion interval comparison and tracking are proposed for future application at logging sites.The actual practice has proves those methods are effective to locate the TD interval in time during ultra-deep drilling.