大牛地气田煤层失稳机理分析及对策  

Instability mechanism and countermeasures of coal bed in Daniudi gas field

作　　者：王锦昌[1] 邓红琳[1] 袁立鹤[1] 巢贵业[1] 

机构地区：[1]中石化华北分公司工程技术研究院,河南郑州450006

出　　处：《石油钻采工艺》2012年第2期4-8,共5页Oil Drilling & Production Technology

基　　金：国家科技重大专题项目"大牛地气田特殊结构井完井工艺技术研究"(编号:2008ZX05045-003-3)

摘　　要：大牛地气田以山西组、太原组为目的层的水平井,在大斜度井段钻遇煤层,易发生井壁垮塌事故,严重影响了施工安全和施工进度。为了预防钻遇煤层发生垮塌事故,从煤层的层理结构、煤层的裂隙结构分析了煤层失稳的机理,并结合已完钻水平井工程及钻井液技术指标,分析得出了预防煤层垮塌的钻井液技术对策和工程技术对策。得出进入煤层段前50 m钻井液密度应稳定在1.24~1.26 g/cm3,避免上下大幅波动,钻井液滤失量应低于5 mL;控制起下钻速度不超过10 m/min,进入煤层钻井液应遵循大排量、低射流的原则。对以后山西组、太原组水平井的钻井工程设计、钻井施工及其他油气田煤层钻井垮塌问题,具有指导和借鉴意义。When the deviated well section of horizontal wells,targeting Shanxi layer and Taiyuan layer of Daniudi gas field,come across coal bed,it is prone to wellbore collape,which affects significantly the operation safety and operation progress.To prevent the collape accidents,the collapse mechanism of coal seams analyzed from bedding architecture and fracture structure of coal seams.Both the slurry and drilling engineering technical measures are obtained to prevent coal collapse,with the study of the drilling engineering parameters and slurry parameters of the drilled horizontal wells.Fistly,within 50 m from the coal seam,the drilling fluid density should be controlled between 1.24-1.26 g/cm3,avoiding sharp fluctuations,and the filtration of drilling fluid should be less than 5 mL.Secondly,the tripping speed should be controlled not more than 10m/min,and the drilling fluid should followe the principle of large displacement and low jet when penetrating the coal bed.The study supplies some directional experience for future drilling engineering design and drilling operation of horizontal wells in Shanxi layer and Taiyuan layer,and collapse accident of drilling coal bed in other oil and gas fields.

关 键 词：煤层 层理 裂隙 垮塌 大斜度 对策 钻井液 

分 类 号：TD235[矿业工程—矿井建设]