四川盆地海相页岩水平井压裂裂缝研究进展及认识  

Research progress and understanding of fracturing fractures in horizontal wells of marine shale in Sichuan Basin

作　　者：杨兆中[1] 袁健峰 张景强 李小刚[1] 朱静怡[1,3] 何建冈 YANG Zhaozhong;YUAN Jianfeng;ZHANG Jingqiang;LI Xiaogang;ZHU Jingyi;HE Jiangang(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000,China;College of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]西南石油大学油气藏地质及开发工程全国重点实验室,四川成都610500 [2]中国石油塔里木油田公司,新疆库尔勒841000 [3]西南石油大学化学化工学院,四川成都610500

出　　处：《油气藏评价与开发》2024年第4期600-609,共10页Petroleum Reservoir Evaluation and Development

基　　金：四川省科技计划项目“页岩压裂的损伤力学特征研究”(2020JDJQ0059)。

摘　　要：页岩气作为清洁、低碳的非常规天然气,规模化开发有利于推动中国实现“碳达峰、碳中和”。经过近10a的理论与技术体系攻关,中国页岩气压裂实现了从无到有、从跟跑到部分领跑的跨越。从页岩气压裂工艺出发,围绕裂缝布局、压裂造缝、支撑裂缝3个方面进行了详细阐述,得到以下几点认识:①储层改造体积和裂缝复杂程度的最大化是缝网特征的2个优化目标,进而实现页岩气产能的最大化;②压裂造缝时,需要保证各簇裂缝均匀起裂,同时由于地应力场的非均质性与天然裂缝等结构弱面的存在,压裂裂缝会发生簇间串通或重叠,导致裂缝缝间距并不等于簇间距;③在密切割、强加砂条件下,极限限流压裂适用性不强,缝口暂堵压裂、缝内暂堵压裂、狭窄分叉缝铺砂均涉及复杂的液固两相流的科学问题尚需解决;④对于含支撑剂的支撑裂缝,需要根据产能或产量的需求,确定导流能力需求值与分布模式,进而优化支撑剂参数和铺砂工艺。结论认为:持续加强深层、超深层页岩储层压裂改造的相关理论研究和工艺技术攻关,精细化、精准化、差异化设计相关压裂施工参数,明确支撑剂在复杂裂缝网络的运移机制及分布模式,综合优化各级裂缝导流能力至关重要。研究成果对中国深层、超深层页岩气开发实现降本—提质—增效具有参考意义。The rapid development of shale gas,a clean and low-carbon unconventional natural gas,plays a key role in supporting China’s goals for achieving a carbon peak and carbon neutrality.Over the past decade,China has made significant strides in the theoretical and technical aspects of shale gas fracturing,progressing from non-existence to existence and evolving from followers to partially leading the field.This paper discusses three critical aspects of the shale gas fracturing process:fracture layout,fracture creation,and support fracture,yielding several key insights:①The primary objectives in optimizing the characteristics of the fracture network are to maximize reservoir modification volume and fracture complexity.This maximization is crucial for enhancing the shale gas production capacity.②During the fracturing process,it is essential to ensure uniform fracture initiation across each cluster.However,due to the non-homogeneity of the ground stress field and the presence of structural weak surfaces such as natural fractures,inter-cluster collusion or overlap of fractured fractures often occurs.This results in the actual fracture seam spacing being unequal to the planned cluster spacing.③Under conditions of close cutting and strong sand addition,the applicability of limit flow restriction fracturing is limited.The scientific challenges related to temporary plugging at the fracture mouth,temporary plugging within the fracture,and sand placement in narrow bifurcation seams remain unresolved.These challenges involve complex liquid-solid two-phase flow dynamics.④For fractures containing proppant,it is necessary to determine the inflow capacity demand and distribution mode based on the reservoir’s capacity or production demands.Subsequently,optimizing the proppant parameters and the sand placement process is crucial.The paper concludes that ongoing enhancement in theoretical research and process technology related to the fracturing transformation of deep and ultra-deep shale reservoirs is essential.It is impera

关 键 词：页岩储层 水平井压裂 裂缝布局 压裂造缝 支撑裂缝 

分 类 号：TE37[石油与天然气工程—油气田开发工程]