鄂尔多斯盆地西部奥陶系海相碳酸盐岩地质特征与成藏模式研究  

Geological characteristics and accumulation model of Ordovician marine carbonate in western Ordos Basin

作　　者：张道锋[1] 刘新社[1,2] 高星[1] 崔子岳[1] 闫小雄[1] 

机构地区：[1]中国石油长庆油田分公司,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018

出　　处：《天然气地球科学》2016年第1期92-101,共10页Natural Gas Geoscience

基　　金：国家科技重大专项"大型油气田及煤层气开发"(编号:2011ZX05007-004)资助

摘　　要：鄂尔多斯盆地西部余探1井在奥陶系克里摩里组缝洞体储层中获3.46×10~4 m^3/d天然气流,通过烃源岩地球化学特征和天然气碳同位素对比分析,发现属于原生油型气,对重新认识盆地西部海相碳酸盐岩勘探领域具有极其重要的地质意义。通过对该区奥陶系古地理演化、海相烃源岩特征、储层类型及成藏模式等进行综合研究,研究表明:1盆地西部发育上、下古生界2套有效的烃源岩,下古生界海相烃源岩具备较好的生烃能力;2研究区内发育岩溶缝洞型、白云岩型、礁滩型等3种类型的储集体,储集性能较好,其中岩溶缝洞型储层和白云岩型储层分布范围广、规模较大;3盆地西部奥陶系发育上生下储和自生自储2套有效成藏组合,在西缘冲断带和天环坳陷西翼,以奥陶系内幕气藏为主,即自生自储的成藏组合,天环坳陷东翼以上生下储成藏组合为主,岩溶缝洞体气藏和白云岩气藏是下一步有利的勘探目标。Well Yutan-1 obtained 34 600m^3/d natural gas production in the karst porous fractured reservoir of Kelimoli Formation in western Ordos Basin.According to the geochemical characteristics of source rock and a comparative analysis on carbon isotope of natural gas,it belongs to the oil type gas.This work has the extremely important geological significance for us to rediscover the marine carbonate exploration field of the western Ordos Basin.Through the analysis of the Ordovician paleogeographic evolution,the marine hydrocarbon source rock characteristics,reservoir characteristics and reservoir forming patterns in western Ordos Basin,the article concluded：（1） The western Ordos Basin develops two sets of effective hydrocarbon source rocks：Upper and Lower Paleozoic groups.The Upper Paleozoic marine hydrocarbon source rocks have good hydrocarbon generation ability.（2）This area develops karst porous fractured reservoir,dolomite reservoir and reef -type reservoir.Reservoir performance is better.The karst porous fractured reservoir and dolomite reservoir widely distributed.（3）The western basin develops two sets of effective accumulation patterns,“upper-generation and ldown-preservation type” and “self-generation and self-preservation type”.The western thrust zone and the western part of Tianhuan Sag,belong to self-generation and self-preservation type.The Eastern part of Tianhuan Sag belongs to upper-generation and down-preservation type.Karst porous fractured reservoir and dolomite reservoir are the favorable exploration target area.

关 键 词：鄂尔多斯盆地西部 奥陶系 海相碳酸盐岩 海相烃源岩 岩溶缝洞体储层 白云岩储层 礁滩体储层 成藏模式 

分 类 号：TE122.1[石油与天然气工程—油气勘探]