摘要
基于水平最大主应力(SH)、水平最小主应力(Sh)和垂向应力(SV)数据,探讨了济阳坳陷的地应力状态。济阳坳陷中,埋深小于2 600 m的地层总体处于Ⅰ类地应力状态(SV>SH>Sh),埋深大于3 200 m的地层一般处于Ⅲ类地应力状态(SH>SV>Sh),在不同地区由Ⅰ类地应力状态转换为Ⅲ类地应力状态的深度不同。利用岩心资料分析了Ⅲ类地应力状态下的动力学特征,动力学作用表现为横向挤压和错动,并识别出5类典型的Ⅲ类地应力裂缝,即脆性层竖直缝、非均质层竖直主干缝+水平分支缝、雁列式方解石透镜体充填缝、挤压逆冲派生缝和复杂网状缝。由于陆相泥页岩的组成和力学性质在纵向上具有强烈的非均质性,在Ⅲ类地应力状态下更容易形成多样性裂缝。
Based on the data of maximum horizontal principal stress(SH),minimum horizontal principal stress(Sh)and vertical stress(SV),this study explores the geostress characteristics of Jiyang depression.The strata with the burial depth less than 2 600 m are generally under the typeⅠgeostress(SV>SH>Sh),and that with the burial depth greater than 3 200 m are generally under the typeⅢgeostress(SH>SV>Sh).The depth of geostress transforming from typeⅠto typeⅢis different for various regions.The kinematic feature of shales under typeⅢgeostress was analyzed by coring data,shown as lateral compression and displacement,and five categories of typical typeⅢgeostress factures were identified,i.e.,vertical joints in brittle layer,vertical main fractures jointed by horizontal branch fractures in anisotropic shale,fractures filled with en echelon calcite crystals in lenticular forms,overthrusting fractures and complex reticular fractures.The continental shale has strong heterogeneity in composition and mechanical properties in the vertical direction.Therefore,continental shale is prone to form various fractures under typeⅢgeostress.
作者
包友书
Bao Youshu(Exploration and Development Research Institute,Sinopec Shengli Oilfield Company,Shandong Dongying 257015,China)
出处
《石油学报》
EI
CAS
CSCD
北大核心
2019年第7期777-785,共9页
Acta Petrolei Sinica
基金
国家科技重大专项(2016ZX05006-001,2017ZX05049-004)
中国石油化工股份有限公司科技攻关项目(KL17035)资助
关键词
地应力
裂缝
陆相泥页岩
古近系
济阳坳陷
geostress
fracture
continental shale
Paleogene
Jiyang depression
