破解塔里木盆地群库恰克地区井壁失稳难题的钻井液技术  

Drilling fluid technology in preventing the wellbore instability in the Qunkuqiake area,Tarim Basin

作　　者：谢水祥[1] 蒋官澄[1] 陈勉[1] 邓皓 李再钧[3] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室 [2]中国石油集团安全环保技术研究院 [3]中国石油塔里木油田公司

出　　处：《天然气工业》2011年第10期68-72,121-122,共5页Natural Gas Industry

基　　金："十一五"国家科技支撑课题"陆地油气开采生态风险评估与污染控制关键技术研究"(编号:2008BAC43B02);"十二五"国家科技重大专项"复杂结构井储层损害评价与保护技术研究"(编号:2011ZX05009-005-03A)

摘　　要：塔里木盆地群库恰克地区油气产层主要位于石炭系和泥盆系,岩性复杂,已完钻的几口探井钻进过程中共发生了200次井下复杂及钻井事故,严重影响了钻井工程进度、增加了钻井成本。采用X射线衍射仪、页岩线性膨胀分析仪等对该地区失稳井段的地层矿物组分及其理化性质进行了分析测试,结合泥页岩线膨胀率评价试验、滚动回收率评价试验、失稳井段岩石黏土矿物和全岩矿物分析,找到了井壁失稳的原因:①失稳井段泥页岩的矿物成分以伊利石为主,其次为伊/蒙间层、高岭石和绿泥石,缺失蒙脱石,岩样泥页岩膨胀率低;②井壁不稳定的原因主要是伊利石的分散作用;③现场所用水基钻井液体系滤液进入地层是导致井壁不稳定的重要原因之一。据此认为:采用抑制能力和封堵能力强钻井液是预防和减少该区块井壁失稳的重要措施,具体的技术对策包括:①筛选合适的防塌钻井液处理剂及体系;②分地层设计和使用钻井液体系。现场应用结果表明,防塌钻井液和分地层钻井液设计较好地满足了该地区钻井工程的实际要求,降低了井下复杂和钻井事故的发生概率,缩短了钻井周期,提高了钻井效率,节约了钻井成本,经济效益显著。The main payzones in the Qunkuqiake area of the Tarim Basin are Carboniferous/Devonian strata with complex lithology,so almost 200 downhole accidents occurred during the drilling of several completed exploratory wells,which seriously affected the drilling progress and increased the drilling cost.In view of this,this paper studies the rock mineral composition and the physiochemical properties of the unstable formations by using an X-ray diffractometer and a shale linear swell meter,and in combination with shale linear swelling rate tests,recycle rate tests,and unstable formation rock's mineral composition analysis,the causes of the wellbore instability are concluded as follows.(1) The unstable shale is dominated by illites,then by illites/smectites interbeds,kaolinites,and chlorites,without sectites bed,so the swell rate of the shale sample is low.(2) The dispersion of illites is the main reason.(3) The drilling fluid filtrate entering the formation is also one of the main reasons.Therefore,it is believed that the drilling fluid system with a strong inhibition effect and an anti-blockage capacity should be the best solution to the wellbore instability problem in this area.So proper anti-sloughing additives and systems are selected and proper drilling fluid systems are determined for different formations(namely a formation-specific drilling fluid program).The field application proves that the improved drilling fluid program helps reduce the downhole accidents,shorten the drilling cycle,improve the drilling efficiency,and save a lot of costs,with a remarkable economic effect as a result.They can be referred to as solutions to similar problems at other oil/gas fields.

关 键 词：塔里木盆地 群库恰克地区 石炭纪 二叠纪 井壁失稳 技术对策 防塌钻井液 分地层钻井液 

分 类 号：TE254[石油与天然气工程—油气井工程]