西藏羌塘盆地托纳木区块地质构造条件与油气保存关系探讨

西藏羌塘盆地具有良好生、储、盖地层,现今勘探任务主要是研究油气的保存条件,油气的保存与地质构造条件有很大的关系,本次工作通过对羌北坳陷的托纳木区块构造特征详查,掌握研究区中各个构造形迹的展布方向、规模、形态及性质等特征,逐一分析其与油气保存的利害关系。结果表明研究区对油气保存影响较大的构造有托纳木藏布断层(F1)、穹隆构造(S4)等,通过构造解析分析应力形成时代与生油期的先后关系,以及构造作用对油气保存的影响,对研究区的构造条件进行正确评价。

Geologic Tectonic Conditions and Hydrocarbon Preservation in the Tuonamu Area, Qiangtang Basin, Tibet

There are well sources, reservoirs, cap strata in the Qiangtang basin, Tibet. Recently, an exploration target is mainly studied on oil-gas preservation conditions. The basin oil-gas preservation has a close relation with tectonics. This paper analyzes the relationship between structures and oil-gas preservation through detailedly surveying structural features. The extentional direction, model and property of the each structural trace are analyzed and we studied their relations one by one. Research results show the Tuonamu river fault(F1) and dome structure(S4) greatly effect oil-gas preservation conditions in this area. By confirming sequence time between the tectonic stress and reservoir-formation period, and geological structures influencing preservation, we evaluated correctly tectonic conditions in the research area.