摘要
针对南海永乐超深水花岗岩储层裂缝发育而导致钻井液漏失问题,以随钻防漏、储层保护、环保为原则,以聚合物树脂为主要原料,研发出自降解随钻堵漏剂材料。通过承压强度实验、自降解性能评价实验等,研究了堵漏剂抗压、降解性能;通过承压封堵与解堵实验、CT扫描、扫描电镜等,评价了新堵漏剂封堵和储层保护性能,优化了超深水堵漏钻井液体系。实验结果表明:25 MPa下新堵漏剂承压破碎率小于6%;升高温度及pH值有利于新堵漏剂降解,90℃、pH=14条件下,5天基本完全降解;新堵漏剂与超深水钻井液相容性好,3%加量下,0.2 mm、1.0 mm微裂缝承压能力分别可达7.6 MPa和6.9 MPa;降解10天后,裂缝性储层、高渗透储层的渗透率恢复值达99.15%、96.90%,具有优异的暂堵、储层保护效果,可应用于超深水钻井随钻堵漏作业。
Aiming at the problem of drilling fluid leakage caused by the fractures developed in Yongle ultra-deepwater granite reservoir in the South China Sea,a self-degrading lost circulation agent was developed with polymer resin as the main raw material according to the principles of leak protection while drilling,reservoir protection and environmental protection.The compressive and degradable properties of the lost circulation agent were studied by compressive strength test and self-degrading performance evaluation experiment.The plugging and reservoir protection properties of the novel self-degrading lost circulation agent were evaluated by plugging and unplugging under pressure tests,CT scanning and scanning electron microscopy,and the ultra-deepwater LCM drilling fluid system was optimized.The test results show that:the crushing rate of the novel lost circulation agent is less than 6%under 25 MPa;the degradation degree of the novel lost circulation agent could be improved by increasing the temperature and pH,and it can be completely degraded in 5 days at 90℃and pH=14;the novel lost circulation agent has good compatibility with ultra-deepwater drilling fluid,and the pressure bearing capacity of 0.2 mm and 1.0 mm fractures can reach 7.6 MPa and 6.9 MPa respectively with 3%self-degrading lost circulation agent;after 10 days’degradation of the novel lost circulation agent,the permeability recovery rates of fractured reservoir and high permeability reservoir reach 99.15%and 96.90%respectively,suggesting that the novel lost circulation agent has excellent temporary plugging and reservoir protection effects,which can be applied to plugging while drilling in ultra-deepwater reservoirs.
作者
刘书杰
刘和兴
王成文
孟仁洲
王瑞和
LIU Shujie;LIU Hexing;WANG Chengwen;MENG Renzhou;WANG Ruihe(CNOOC China Limited,Hainan Branch,Haikou,Hainan 570311,China;China University of Petroleum,Qingdao,Shandong 266580,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2022年第2期107-115,共9页
China Offshore Oil and Gas
基金
中国海洋石油集团有限公司重大科技专项“南海西部油田上产2000万方钻完井关键技术研究(编号:CNOOC-KJ135ZDXM38ZJ05ZJ)”
中海石油(中国)有限公司科研项目“海上精准空压钻井技术研究及工程示范(编号:YXKY-2021-HN-01)”部分研究成果。
关键词
超深水
裂缝储层
随钻堵漏
封堵剂
自降解
堵漏
储层保护
ultra-deepwater
fractured reservoir
plugging while drilling
lost circulation agent
self-degrading
plugging
reservoir protection
