河南理工大学学报（自然科学版）2024，Vol.43Issue(2)：49-56,8.DOI:10.16186/j.cnki.1673-9787.2021120118
准噶尔盆地齐古背斜深浅层泥岩裂缝发育差异性及其制约下油气保存条件
Differences in the development of deep and shallow mudstone fractures in Qigu anticline in the Junggar Basin and their constraints on oil and gas preservation conditions
摘要
Abstract
The foreland thrust belt is rich in oil and gas resources,but the differences in the sealing capac-ity of the caprock under the action of complex structures has hindered the process of oil and gas explora-tion.Objectives Aiming at the current situation of surface oil and gas seriously leakage and insufficient ex-ploration in the thrust belt in southern Junggar basin,Methods the deep and shallow mudstone caprock of Qigu anticline was taken as the research object.Based on the stratigraphic model,combined with logging data inversion and actual measurement data,a numerical model of the mechanical parameters of the study area was constructed,and the finite element method was used to simulate the paleo and present tectonic stress fields in the Qigu anticline.The obtained stress field data was combined with fracture parameter theory to analyze the formation period of fractures in the caprock and calculate the transformation results of the current stress field on the fractures in the caprock.Results The results showed that the paleo and pres-ent stress distributions of the Qigu anticline were all controlled by buried depth,tectonic location,fault strike,and fault convergence location;under the current stress field,the shallow caprock of Qigu anticline was not easy to break,and only played a role in reforming the fractures formed by the paleotectonic stress field;the degree of fracture development in deep and shallow caprocks varied greatly,and the development of fractures at high points of the anticline may be the main cause of shallow oil and gas leakage;the frac-ture zone was more developed near the fault,and the fracture permeability near the fault zone was much higher than that of the normal formation,which may provide a channel for the migration and even loss of deep oil and gas to the shallow layer;the deep caprock was relatively stable,and the caprock condition wass not the key factor to restrict the success of exploration in the lower Junggar Basin.Conclusions The re-search results can provide some references for deep oil and gas exploration in the thrust belt of the southern margin of the Junggar Basin.关键词
地应力/裂缝预测/盖层评价/数值模拟/侏罗系/齐古背斜Key words
in-situ stress/fracture prediction/caprock evaluation/numerical simulation/Jurassic/Qigu anticline分类
天文与地球科学引用本文复制引用
吴伟,周永,冯阵东,鲁雪松,卓勤功,刘惟庆,王光绪..准噶尔盆地齐古背斜深浅层泥岩裂缝发育差异性及其制约下油气保存条件[J].河南理工大学学报（自然科学版）,2024,43(2):49-56,8.基金项目
国家自然科学基金资助项目(41872112) （41872112）
