塔河油田碳酸盐岩储层中聚合物凝胶堵漏技术  

Control Mud Losses into Carbonate Reservoirs with Polymer Gels in Tahe Oilfield

作　　者：李亮[1,2] 方俊伟[1,2] 彭博一 于培志[3] 耿云鹏[1,2] LI Liang;FANG Junwei;PENG Boyi;YU Peizhi;GENG Yunpeng(Petroleum Engineering Technology Research Institute,Northwest Oilfield Company,Sinopec,Urumqi,Xinjiang 830011;Key Laboratory of Enhanced Recovery for Fracture-cave Oil Reservoir,Sinopec,Urumqi,Xinjiang 830011;College of Engineering and Technology China University of Geosciences(Beijing),Beijing 100083)

机构地区：[1]中国石化西北油田分公司石油工程技术研究院,乌鲁木齐830011 [2]中国石化缝洞型油藏提高采收率重点实验室,乌鲁木齐830011 [3]中国地质大学(北京)工程技术学院,北京100083

出　　处：《钻井液与完井液》2024年第4期437-443,共7页Drilling Fluid & Completion Fluid

基　　金：国家自然科学基金面上项目“绳索取心钻杆内壁结垢机理与控制方法”(J218076)。

摘　　要：塔河油田地质条件复杂,缝洞性碳酸盐岩储层孔缝洞发育,在此储层钻进过程中常出现放空、发生井漏,并引发井喷、井塌、卡钻等复杂事故,常规桥堵技术难以有效封堵。针对塔河油田老井修完井过程中的漏失难题,研制了一种抗高温聚合物凝胶堵漏剂,对其进行性能评价可知,聚合物凝胶成胶前基液黏度在13~14.5 mPa·s范围内,150℃下成胶时间在30~150 min内可控,成胶后失去流动性,形成高强度凝胶塞,具有较高承压强度,使用3 mm裂缝钢铁岩心(长5 cm)模拟储层进行封堵能力评价,封堵压力可达2.1 MPa/42 cm;凝胶具有较好的抗污染性能,稳定性良好;凝胶破胶性能显著,加入碱液改变环境pH值后,可实现48 h破胶成为低黏流体,破胶后的凝胶可满足岩心渗透率恢复值≥85%。该耐温聚合物凝胶既能实现高效封堵,也能有效解堵,在修井作业、恶性漏失等方面具有较好的应用前景。Carbonate reservoirs in the Tahe oilfield are developed with fractures and vugs,drilling into vugs and lost circulation which in turn inducing blowout,borehole wall collapse and stuck pipe have frequently been encountered,and conventional bridging techniques cannot be used to effectively control the mud losses.To deal with the mud loss problem encountered in well workover and completion of old wells,a high temperature polymer gel lost circulation material(LCM)has been developed.Evaluation of the performance of the polymer gel LCM shows that before gelling,the viscosity of the polymer base fluid is in a range of 13–14.5 mPa∙s.At 150℃,the gelling time of the polymer can be adjusted between 30 min and 150 min.After gelling,the polymer gel loses its mobility and forms a high-strength gel plug.The polymer gel is tested on a 5 cm long iron-made core with 3 mm fractures,which simulates fractures found in the carbonate reservoirs,and a pressure bearing capacity of 2.1 MPa/42 cm is obtained.The polymer gel has good contamination resistance and good stability.The gel of the polymer can be easily broken,by adding alkaline solution into the gel to change the pH value,the gel becomes a low viscosity fluid in 48 h.After gel breaking,the permeability recovery of the rock cores that have been plugged with the gel can be greater than 85%.This high temperature polymer gel can be used to effectively plug formation pores and vugs,it can also be effectively removed away,thus making it a good choice for severe mud losses controlling in workover operations.

关 键 词：聚合物凝胶 修井作业 自破胶 高温储层 

分 类 号：TE282[石油与天然气工程—油气井工程]