致密储层钻井完井过程井筒裂缝宽度变化预测及其应用  

COMPUTER SIMULATION OF FRACTURE WIDTH VARIATION IN TIGHT SANDSTONES RESERVOIR AND ITS APPLICATION

作　　者：汤夏岚[1] 张浩[2] 李显玉[3] 潘用平[3] 

机构地区：[1]中国石油大学石油与天然气工程学院.北京 [2]成都理工大学能源学院 [3]中国石油西南油气田公司

出　　处：《钻采工艺》2010年第3期26-28,141,共3页Drilling & Production Technology

基　　金：中国博士后基金"深层致密砂岩气藏裂缝宽度变化对应力扰动响应研究"的部分成果(编号:20070411164)

摘　　要：裂缝性油气储层钻井完井过程常常发生恶性井漏,给安全钻井和储层保护带来严重的影响。以川西深层裂缝性致密砂岩储层为研究对象,采用有限元数值模拟方法对应力扰动井壁附近成组裂缝宽度变化规律进行预测,找出了裂缝动态宽度与井筒正压差之间的关系。计算机模拟结果表明,井壁处裂缝张开临界应力与储层孔隙压力非常接近;随钻井完井液柱正压差的增加,与井筒连通裂缝宽度变大;同一钻井液正压差作用下储层存在成组裂缝时其与井筒连通的裂缝比单条连通井筒裂缝更容易张开。准确预测不同正压差条件下储层裂缝宽度变化特征,能够为预防漏失保护储层钻井完井液体系设计提供依据。Vicious circulation loss is often occured in fractured reservoir during drilling and completion,which will bring serous affection for safety drilling and reservoirs protection.Taking deep tight sandstone reservoir in west Sichuan as research object,the numerical simulation means was used to forecast the width variation of group fracture,which connected with well bore under stress disturbance,and the relationship between fracture width variation and positive differential pressure in well bore was found.The simulation results showed that critical pressure of gaping fissure in side wall was very near the pore pressure,and the fracture width got wider with the increase of positive differential pressure of drilling and completion fluid column.By the action of positive differential pressure of same drilling fluid,the width of group fracture connected with the well bore was easier open than the one fracture connected with the well bore.The accurate prediction the width variation of group fracture could provide the basis for prevention drilling fluid leakage and reservoir protection under different pressure conditions.

关 键 词：致密砂岩 钻井完井 成组裂缝 裂缝宽度 计算机模拟 

分 类 号：TE257[石油与天然气工程—油气井工程]