南川地区页岩储层构造裂缝特征及其定量预测  

Structural fracture characteristics and quantitative prediction of shale reservoir in Nanchuan Area

作　　者：刘明[1] 李彦婧[1] 潘兰[1] 刘昊娟 孟庆利[1] LIU Ming;LI Yanjing;PAN Lan;LIU Haojuan;MENG Qingli(Exploration and Development Research Institute,Sinopec East China Oil&Gas Company,Nanjing 210019,China)

机构地区：[1]中国石化华东油气分公司勘探开发研究院,南京210019

出　　处：《非常规油气》2023年第3期8-14,共7页Unconventional Oil & Gas

基　　金：中国石油化工股份有限公司科技开发部项目“常压页岩气地球物理评价技术研究”(P21087-3)。

摘　　要：构造裂缝是影响页岩气单井产能的重要因素,查明裂缝分布规律有助于提高水平井压裂改造效果。结合岩心观察和成像测井裂缝发育情况,采用有限单元法模拟了南川地区不同构造裂缝形成时期的应力场,基于岩石破裂准则建立了构造应力与岩心裂缝密度的转换关系,对构造裂缝进行了定量预测。结果表明,南川地区主要发育2期构造裂缝,以剪切裂缝为主,被方解石半充填-全充填,第1期北东—南西走向裂缝形成于燕山中期,最大水平主应力为140~158 MPa;第2期北西—南东走向裂缝形成于燕山晚期,最大水平主应力为88~156 MPa。构造裂缝分布受褶皱及断层共同控制,平桥背斜构造裂缝发育程度最高且有效性好,天然气产量也最高。Structural fracture is an important factor affecting single well productivity of shale gas.Finding out the distribution of fractures is helpful to improve the fracturing effect of horizontal wells.Combined with core observation and imaging logging fracture development,the finite element method was used to simulate the stress field of different tectonic fracture formation periods in Nanchuan Area.Based on rock failure criterion,the relationship between tectonic stress and fracture density from core was established,and the tectonic fracture was quantitatively predicted.The results show that there are two stages of tectonic fractures in Nanchuan Area.They are mainly shear fractures and half-filled to full-filled by calcite.The first stage fractures with orientation strike in NE-SW are formed in Middle Yanshanian,and the maximum horizontal principal stress ranges from 140 to 158 MPa.The second stage fractures with orientation strike in NW-SE are formed in Late Yanshanian,and the maximum horizontal principal stress ranges from 88 to 156 MPa.The distribution of structural fractures are controlled by folds and faults.The structural fractures in Pingqiao anticline are mostly developed and effective,and the natural gas production is the highest.

关 键 词：构造裂缝特征 有限单元法 构造裂缝预测 五峰组—龙马溪组 南川地区 

分 类 号：P631[天文地球—地质矿产勘探]