摘要
玛东冲断带属典型的后展式叠瓦冲断带,前三排断裂冲断作用形成于桑塔木组沉积之前,第④和第⑤排断层形成于奥陶纪末。冲断带南部位于和田古隆起岩溶斜坡,奥陶系岩溶储层充填程度低,前三排构造在海西晚期内有活化特征,有助于缝洞型储层形成。冲断带南部中寒武统膏盐层厚度比北部小,断裂活化与中下寒武统烃源岩主生烃期配合良好,油气垂向输导能力大于北部,奥陶系风化壳油气丰度大于北部。整个冲断带由于寒武系膏盐层封盖作用,滑脱断层向上输导油气的数量有限,大部分油气仍滞留在中下寒武统中,具较大勘探潜力。
Madong thrust belt is a trailing imbricate fan developed from NW to SE, the No.l,No.2 and No.3 fault were tbrmed just before Sangtamu lbrmation deposited. The No.4 and No.5 fault were formed after Sangtamu formation de- posited. The south part of the thrust belt were in the karst slope of Hetian paleo uplift, the Ordovician karst reservoir most non filled. The No.l,No.2 and No.3 fault in south part were reactive in late Hercynian, which could formed many fracture-cave system. The salt of middle Cambrian in the south part were thinner than that in the north part of Madong thrust belt, and the Cambrian source rock＇s peak oil generation window were just in late Hercynian, oil can migrated eas- ier from source rock to the lower Ordovician formation by the reactive faults than by the non-reactive fault of north part, so there should more oil cumulated in weathered karst of Ordovician in the south part. In Madong thrust belt, capping by the salt of Middle Cambrian, only part of the hydrocarbon could migrated to upper formations, a considerable part of hy- drocarbons were still in the Middle-Lower Cambrian, which have good exploration potential.
出处
《新疆地质》
CAS
CSCD
北大核心
2013年第3期180-185,共6页
Xinjiang Geology
基金
国家油气专项"四川
塔里木等盆地及邻区海相碳酸盐岩大油气田形成条件
关键技术及目标评价"(2008ZX0500404)资助
关键词
玛东冲断带
演化序列
海西晚期
中下寒武统
勘探潜力
Madong thrust belt
Evolution series
Late Hercynian
Middle-Lower Cambrian
Exploration potential
