深水高孔高渗储层免破胶钻井完井液技术  

Gel-breaking free drill-in fluid technology for deepwater high-porosity and high-permeability reservoirs

作　　者：赵欣[1,2] 耿麒 邱正松[1,2] 耿铁[3] 周国伟[1] 邢希金 ZHAO Xin;GENG Qi;QIU Zhengsong;GENG Tie;ZHOU Guowei;XING Xijin(Shandong Key Laboratory of Oilfield Chemistry,China University of Petroleum-East China,Qingdao,Shandong 266580 China;School of Petroleum Engineering,China University of Petroleum-East China,Qingdao,Shandong 266580,China;China Oilfield Services Limited,Sanhe,Hebei 065200,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]山东省油田化学重点实验室·中国石油大学(华东),266580 [2]中国石油大学(华东)石油工程学院,266580 [3]中海油田服务股份有限公司 [4]中海油研究总院有限责任公司

出　　处：《天然气工业》2021年第4期107-114,共8页Natural Gas Industry

基　　金：国家重点基础研究发展计划(973计划)课题“深水油气井完井与测试优化方法”(编号:2015CB251205);国家自然科学基金项目“裂缝性地层致密承压封堵机理与温敏智能堵漏新方法研究”(编号:51974354);“基于相变蓄冷原理的天然气水合物钻探钻井液智能控温微胶囊研究”(编号:51804331)。

摘　　要：深水钻完井工程成本高、作业条件苛刻、安全风险大,一旦发生严重的储层损害就有可能导致油气产能大幅度降低,造成巨大的经济损失。为了给深水油气钻探开发中制定和实施储层保护技术措施提供支撑,借助X射线衍射、压汞、扫描电镜、水化膨胀分散实验以及储层敏感性流动实验等手段,分析了中国南海某深水气田储层损害的机理,提出了储层保护技术对策,构建了适合该深水气田储层保护的钻井完井液。研究结果表明:①该深水气田储层为高孔高渗砂岩储层,黏土含量平均为12.38%,存在着强速敏性和中等程度的水敏性;②储层损害的主要原因是钻完井工作液中的固相侵入以及工作储层岩石不配伍;③通过理想充填暂堵方法对宽尺寸孔喉有效暂堵是保护储层的关键技术措施;④所构建的水基钻井完井液在2~75℃深水井筒温度下具有稳定的流变性,直接返排解堵岩心渗透率恢复值介于74.5%~92.24%,与隐形酸完井液顺序污染岩心后渗透率恢复值大于86%。现场应用于4口深水井的效果表明,4口井均未发生井下复杂情况,作业结束后直接返排解堵,节约了完井作业时间。结论认为,该钻井完井液可以满足深水高孔高渗储层钻井技术的要求,实现了免破胶作业,储层保护效果优良。Deepwater drilling and completion engineering has high cost and great risk,and severe reservoir damage can cause substantial losses.In this paper,the reservoir damage mechanisms in the deepwater gas fields of the South China Sea were analyzed by means of X-ray diffraction,mercury intrusion,scanning electron microscope,hydration swelling and dispersion experiment,and reservoir sensitivity flow experiment.Then,technical countermeasures for reservoir protection were proposed and the drill-in fluid with the ability of reservoir protection was optimized.And the following research results were obtained.First,this reservoir is a sandstone reservoir of high porosity and high permeability and its average clay content is 12.38%.It has a strong velocity sensitivity and moderate water sensitivity.Second,the reservoir damage mechanisms mainly include the solid invasion of drilling and completion working fluid and the incompatibility between working fluid and reservoir rock.Third,the effective temporary plugging of the large-sized pore throats using the ideal packing bridging method is the key technical measure to protect reservoirs.Fourth,the optimized water based drill-in fluid has stable rheological properties under 2-75℃,the temperature of deepwater wellbore.The recovery ratio of core permeability is in the range of 74.5-92.24% after direct plugging removal by flowback.In addition,the recovery ratio of core permeability is higher than 86% after the core is successively contaminated by the drill-in fluid and chelating acid completion fluid.The field applications in four deepwater wells show that no downhole troubles happen,and plugging removal by flowback is carried out directly after the operation,so the completion operation time is saved.In conclusion,the optimized drill-in fluid can meet the drilling technical requirements of deepwater high-porosity and high-permeability reservoirs.What's more,it is gel-breaking free and its reservoir protection effect is good.

关 键 词：中国南海 深水气田 高孔高渗 储层损害机理 储层保护 钻井完井液 返排解堵 免破胶作业 

分 类 号：TE52[石油与天然气工程—油气田开发工程]