摘要
中国深层页岩气资源量丰富,但其储层中裂缝带、断层等结构弱面发育,井工厂水平井压裂作业模式下井间窜扰频发,严重影响了深层页岩气井产能的发挥。为此,针对当前深层页岩气井井间裂缝交汇及其对气井产能影响规律认识不清的问题,基于有限离散元方法和嵌入式离散裂缝模型构建了复杂裂缝扩展—渗流一体化模型,采用微地震数据及商业软件验证了模型的可靠性和准确性,并研究了裂缝窜扰对页岩气水平井产能的影响机制,基于对4类典型储层的分析,定量优化了不同类型压裂段施工规模。研究结果表明:①天然裂缝和小断层越发育,响应井压裂裂缝长度、停泵后裂缝二次扩展长度越长,引发井间裂缝窜扰发生时间越早,压力涨幅越高,激动井压裂后储层改造效率越低;②压窜后继续增加压裂规模对提高激动井页岩气产量效果有限,对于低风险窜扰段,激动井累计产气量随压裂规模呈近线性增加,对于中、高风险窜扰段,激动井累计产气量在压窜前呈近线性增加,在压窜后呈缓慢增加或不增加趋势;③随着窜扰风险增加,激动井第一次压裂最优规模逐渐降低,后续可采用一次或多次暂堵压裂措施以提高页岩储层改造效率。结论认为,该认识厘清了井间窜扰程度对气井产能的影响,提出了针对不同窜扰风险储层的最优施工方案及暂堵等应对措施,为深层页岩气开发工艺优化提供了理论指导和实践依据。
Abundant deep shale gas resources in China are usually endowed in reservoirs with week structural planes such as fracture zones and faults,which lead to frequent inter-well fracture intersection during horizontal well fracturing under the well-plant mode,thereby seriously affecting the well productivity.Considering the inadequate understanding of fracture intersections between deep shale gas wells and their impact on well productivity,the finite discrete element method(FDEM)and embedded discrete element model(EDEM)were employed to construct a complex fracture propagation-flow integrated simulation model.The model was validated using microseismic data and commercial software.The mechanism by which fracture intersection affects well productivity was analyzed,and the treatment scales for different types of fracturing stages were quantitatively optimized after investigation on four types of typical reservoirs.The following results are obtained.First,the more developed the natural fractures and small faults,the longer the induced fracture length and the secondary propagation length of fractures after pump shutdown for the response well,the earlier the occurrence time it takes to trigger inter-well fracture intersection,the higher the pressure rise,and the lower the reservoir stimulation efficiency of the stimulated well.Second,further increasing the treatment scale after inter-well fracture intersection has a limited effect on improving the shale gas production of the stimulated well.For stages with low risk of fracture intersection,the cumulative production of the stimulated well increases nearly linearly with the treatment scale.For stages with medium to high risk of fracture intersection,the cumulative production of the stimulated well increases nearly linearly before inter-well fracture intersection,and shows a slow or no increase after fracture intersection.Third,as the fracture intersection risk increases,the optimal scale for the first fracturing treatment in the stimulated well gradually decreases.Subsequently,one or more temporary plugging fracturing treatments can be adopted to improve the efficiency of shale reservoir stimulation.This study provides theoretical and practical support for optimizing the deep shale gas development process by clarifying the impact of inter-well fracture intersection on well productivity and proposing the optimal treatment schemes and measures(e.g.temporary plugging)for reservoirs susceptible to different risks of fracture intersections.
作者
王强
王玉丰
赵金洲
宋毅
沈骋
胡永全
李小伟
杨郁
WANG Qiang;WANG Yufeng;ZHAO Jinzhou;SONG Yi;SHEN Cheng;HU Yongquan;LI Xiaowei;YANG Yu(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation//Southwest Petroleum University,Chengdu,Sichuan 610500,China;Shale Gas Research Institute,PetroChina Southwest Oil&Gas Field Company,Chengdu,Sichuan 610056,China)
出处
《天然气工业》
北大核心
2025年第8期53-66,共14页
Natural Gas Industry
基金
国家自然科学基金联合基金项目“深层超深层页岩气水平井压裂缝网高效建造理论与方法研究”(编号:U21B2071)
国家自然科学基金项目“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)
油气藏地质及开发工程全国重点实验室开放基金项目“页岩油压后焖井促进与抑制采油竞争机理研究”(编号:PLN202329)。
关键词
深层页岩气
有限离散元
嵌入式离散裂缝模型
压裂窜扰
产能模型
拉链式压裂
Deep shale gas
Finite discrete element method
Embedded discrete fracture model
Fracture intersection
Productivity model
Zipper fracturing
作者简介
王强,1990年生,副研究员,博士,主要从事非常规油气储集层改造技术与理论等方面的研究工作。地址:(610500)四川省成都市新都区新都大道8号。ORCID:0000-0002-3805-0463。E-mail:swpu_wq@163.com;通信作者:王玉丰,1999年生,博士研究生,主要从事非常规油气储集层改造技术与理论等方面的研究工作。地址:(610500)四川省成都市新都区新都大道8号。ORCID:0009-0002-8336-9358。E-mail:2430720039@qq.com。
