高闭合压力下深层页岩气促缝网强支撑压裂工艺  

Fracturing technology with enhanced fracture network and reinforced support for deep shale gas under high closure pressure

作　　者：李德旗 刘春亭 朱炬辉 胥云[3] 王荣 张俊成 吴凯 潘丹丹 LI Deqi;LIU Chunting;ZHU Juhui;XU Yun;WANG Rong;ZHANG Juncheng;WU Kai;PAN Dandan(PetroChina Zhejiang Oilfield Company,Hangzhou 232322,Zhejiang,China;Downhole Services Company,PetroChina Chuanqing Drilling Engineering Company,Chengdu 610052,Sichuan,China;PetroChina Research Institute of Exploration and Development,Beijing 100083,China;Jinzhou Oil Production Plant,PetroChina Liaohe Oilfield Company,Panjin 121209,Liaoning,China)

机构地区：[1]中国石油浙江油田分公司,浙江杭州232322 [2]中国石油集团川庆钻探工程有限公司井下作业公司,四川成都610052 [3]中国石油勘探开发研究院,北京100083 [4]中国石油辽河油田分公司锦州采油厂,辽宁盘锦121209

出　　处：《石油钻采工艺》2024年第3期336-345,共10页Oil Drilling & Production Technology

基　　金：国家自然科学基金区域创新发展联合基金“四川深层页岩气水平井缝网压裂填砂暂堵物理机制研究”(编号:U19A2043);国家自然科学基金“页岩气藏体积压裂缝网表征及复杂裂缝动态交互机理研究”(编号:U23B20156);中国石油川庆钻探工程有限公司科研课题“提升3500~4500 m页岩储集层水力裂缝复杂程度和有效性工艺技术研究”(编号:CQ2021B-39-Z2-4)。

摘　　要：D区块深层页岩气井储层改造效果不理想,存在高水平地应力差及天然裂缝欠发育导致的裂缝形态单一、高垂向应力导致的高破裂压力及高施工压力、高闭合压力导致的裂缝支撑效果不理想等问题。采用真三轴模拟试验系统开展了页岩水力压裂裂缝扩展模拟实验,探索了高应力差条件下裂缝扩展影响因素,利用自主研发的相场法裂缝扩展软件分析了小簇间距对裂缝扩展的影响。现场试验4口井,采用密集多簇射孔(8~11簇/段)、高排量(17~18 m^(3)/min)、限压不限排量初期造缝模式、压裂综合实时判定与调控的暂堵转向策略可以促进裂缝复杂,前置酸液、粉砂打磨以及优化孔眼数(44~50孔/段)可以有效降低破裂压力及施工压力,采用高强度加砂设计(3.6~4.0 t/m)、组合类型支撑剂可以有效保障裂缝导流能力需求。D区块4口井采用上述技术措施后,测试平均产气量均超过20×10~4 m^(3)/d,储层改造效果良好。该系列化技术措施为高闭合压力下深层页岩气井储层改造提供了技术借鉴和现场经验,具有良好的推广应用价值。In Block D,the reservoir stimulation results in deep shale gas wells are suboptimal,mainly reflected in simplistic fracture geometries due to high horizontal stress difference and underdeveloped natural fractures,high fracture pressure and operational pressure due to high vertical stress,and unsatisfactory fracture supporting effect because of high closure pressure.To address these challenges,a series of hydraulic fracturing experiments were conducted using a true triaxial simulation system to investigate fracture propagation under high-stress difference conditions.Furthermore,the impact of narrow cluster spacing on fracture propagation was analyzed by using the facies field fracture propagation software.Field trials were conducted on four wells,implementing a dense multi-cluster perforation design(8-11 clusters per stage),high displacement rates(17-18 m^(3)/min),a fracture initiation pattern with pressure-limited but non-restricted injection rates,and a real-time temporary plugging and diversion strategy for comprehensive real-time judgment and control of fracturing to increase fracture complexity.The use of pre-acid treatment,sandblasting,and optimizing perforation numbers(44-50 holes per stage)effectively reduced fracture pressure and operational pressure.Additionally,high-intensity proppant injection design(3.6-4.0 t/m)and combined proppant types ensured sufficient fracture conductivity.Following the application of these technologies,all four wells in block D exhibited average gas production rates exceeding 200000 m^(3)/d,demonstrating successful reservoir stimulation.These technical measures provide valuable insights and field experience for reservoir stimulation in deep shale gas wells under high closure pressure conditions and offer significant potential for broader application.

关 键 词：页岩气 深层 体积压裂 复杂裂缝 加砂强度 施工压力 

分 类 号：TE37[石油与天然气工程—油气田开发工程] TE357.1