亚洲最深直井——蓬深6特超深井钻井液技术  

Drilling Fluid Technology for the Deepest Vertical Well in Asia-The Ultra-Deep Well Pengshen-6

作　　者：徐毅 何涛 王君 欧猛 严福寿 周华安 黄旭耀 XU Yi;HE Tao;WANG Jun;OU Meng;YAN Fushou;ZHOU Huaan;HUANG Xuyao(CCDC Drilling Fluid Technology Service Company,Chengdu,Sichuan 610051)

机构地区：[1]中国石油集团川庆钻探工程有限公司钻井液技术服务公司,成都610051

出　　处：《钻井液与完井液》2025年第2期180-186,共7页Drilling Fluid & Completion Fluid

摘　　要：蓬深6井是中石油西南油气田分公司部署的重点预探井。完钻井深9026 m,目的层位主探震旦系灯影组储层。该井六开完钻,其钻井液技术难点主要包括:①上部井段存在大段泥岩,地层水敏性强;②同一裸眼段多压力系统共存;③上部超大尺寸井眼,钻井液上返速度低,井眼清洁困难;④大段盐膏层污染钻井液;⑤多压力系统并存导致的井漏复杂;⑥二叠系以下井段酸性气体污染严重、超高密度下钻井液流变性控制困难;⑦超深井段,超高温超高压(216℃、150 MPa)下,油基钻井液流变性、沉降稳定性控制难;⑧震旦系灯影组地层破碎等难题。针对以上难点,通过大量室内实验,优选出3套钻井液体系:上部地层采用有机盐聚合物钻井液体系优化钻井液的包被抑制性、中部地层采用有机盐聚磺钻井液体系优化钻井液的抗高温、抗污染特性、目的层采用抗超高温油基钻井液体系优化钻井液的沉降稳定性、流变性以及携砂特性。在该井现场应用时,表现出上部地层钻井液流变性受控,井壁稳定;高密度水基钻井液流变性好、抑制封堵能力强、抗盐/钙/CO_(2)酸气污染能力强;超高温超高压下低密度油基钻井液流变性受控、沉降稳定性好、防塌能力强的特点。Well Pengshen-6,a six-interval well with a total depth of 9,026 m,is a key exploration well deployed by the PetroChina Southwest Oil&Gasfield Company.The projected reservoir is mainly the Dengying Formation in the Sinian System.The main technical difficulties of the drilling fluid operation include:1)a thick mudstone with strong water sensitivity in the upper part of the well,2)coexistence of multiple pressure systems in the same open hole section,3)poor hole cleaning in the upper extra-large hole because of low annular flow velocity,4)drilling fluid contamination by long section of salt/gypsum formation,5)lost circulation resulted from the coexistence of multiple pressure systems,6)serious acid gas contamination in the well section below the Permian System and difficulties in controlling the rheology of the ultra-high density drilling fluids,7)difficulties in controlling the rheology and sedimentation stability of the oil-based drilling fluid under ultra-high temperature ultra-high pressure(the bottom hole temperature reaches 216℃and the bottom hole pressure reaches 150 MPa)in the ultra-deep well section,8)the broken Dengying Formation in the Sinian System.To deal with these difficulties,three sets of drilling fluid formulations were selected through many laboratory experiments:an organic salt polymer drilling fluid with good encapsulating and inhibitive properties was used to drill the upper section of the well,an organic salt polymer-sulfonate drilling fluid with good high temperature and contamination resisting performances was used to drill the middle section of the well,and an ultra-high temperature-resistant oil-based drilling fluid with good sedimentation stability,rheological properties and cuttings-carrying capacity was used to drill the target zones.In field application of these drilling fluids,the rheology of the drilling fluid in the upper section was under control,and the wellbore was stable;the high-density water-based drilling fluid had good rheology,strong inhibitive and plugging capacities,and

关 键 词：蓬深6井 多压力系统共存 CO_(2)酸气污染 特深井 有机盐聚合物 有机盐聚磺 抗超高温油基钻井液 

分 类 号：TE254[石油与天然气工程—油气井工程]