CAJ | 학술논문

董8井是中石化部署在准噶尔盆地的一口重点预探直井，完钻井深5580 m，该井上部地层起下钻遇阻频繁，下部侏罗系煤层发育，且地层压力异常，施工中井壁失稳严重；三工河组存在高压盐水层及碳酸氢根流体污染，高密度下钻井液流变性不易调控。针对该井地质特点，通过室内研究，确定使用铝胺强抑制防塌钻井液体系和抗高温成膜防塌钻井液体系，现场应用结果表明，采用的钻井液体系解决了上部地层软泥岩缩径、砂岩段阻卡及侏罗系井壁失稳的难题，全井平均井径扩大率仅为7.02%，满足了施工的需要。
동8정시중석화부서재준갈이분지적일구중점예탐직정，완찬정심5580 m，해정상부지층기하찬우조빈번，하부주라계매층발육，차지층압력이상，시공중정벽실은엄중；삼공하조존재고압염수층급탄산경근류체오염，고밀도하찬정액류변성불역조공。침대해정지질특점，통과실내연구，학정사용려알강억제방탑찬정액체계화항고온성막방탑찬정액체계，현장응용결과표명，채용적찬정액체계해결료상부지층연니암축경、사암단조잡급주라계정벽실은적난제，전정평균정경확대솔부위7.02%，만족료시공적수요。
Well Dong-8 is an important exploratory vertical well placed in Junggar Basin bySINOPEC. Its total depth is 5 580 m. Tight hole was frequently met during tripping in the upper part of the well, and in the lower part, the Jurassic coalbeds were deposited. Moreover, the formation pressure was anomalous and wellbore instability was severe during drilling. The Sangonghe Formation has high-pressure saltwater layers and is contaminated by bicarbonate lfuid, so the rheology of drilling lfuid under high density is not easily controlled. In view of its geologic characteristics and through indoor studies, it was determined that the aluminum-amine strong inhibition and anti-sloughing drilling lfuid system and high-temperature iflm forming anti-sloughing drilling lfuid system are used. Field application results show that the drilling lfuid systems used have overcome the dififculties of tight hole in the upper soft mudstone, sticking in sandstone section and instability of Jurassic wellbore. The average enlargement rate of the entire hole was only 7.02%, which was quite satisfactory.