鄂尔多斯盆地东部山西组页岩气成藏特征及勘探对策  

Geological characteristics and exploration countermeasures of shale gas in the Shanxi Formation of the Ordos basin

作　　者：刘洪林[1,2,3] 王怀厂 张辉[4] 赵伟波[4] 刘燕[4] 刘德勋[1,2,3] LIU Honglin;WANG Huaichang;ZHANG Hui;ZHAO Weibo;LIU Yan;LIU Dexun(Research Institute Petroleum Exp.&Dev.,Petrochina,Beijing,100083;PetroChina Key Laboratory for Unconventional Oil and Gas,Beijing,100083;National Energy Shale Gas Research and Development(Experiment)Center,Langfang,Hebei,065007;Exploration and Development Research Institute,Changqing Oilfield,Petrochina,Xi'an,710021)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油非常规油气重点实验室,北京100083 [3]国家能源页岩气研发(实验)中心,河北廊坊065007 [4]中国石油长庆油田勘探开发研究院,西安710021

出　　处：《地质学报》2020年第3期905-915,共11页Acta Geologica Sinica

基　　金：国家科技重大专项(编号2017ZX05035);中国石油科技重大专项(编号2019B-49)资助的成果。

摘　　要：我国海陆过渡相页岩气资源量约占全国资源总量的三分之一,勘探开发前景广阔。鄂尔多斯盆地过渡相页岩分布范围广、厚度大,受到广泛关注,勘探开发一直未能获得突破。为查明过渡相页岩地质特征与海相页岩储层特征及成藏规律的差异,本文以鄂尔多斯盆地东部山西组页岩为例,通过总有机碳、镜质组反射率、矿物组成、微观孔隙和含气量分析开展页岩气生成、储集和成藏过程的对比研究,分析认为山西组页岩成藏过程有其特殊性,其干酪根来源于Ⅲ型高等植物,液态烃产量很少,缺乏气泡成孔过程,有机质纳米孔数量少,砂泥煤互层的沉积特征排烃效率高,影响页岩含气性。山西组页岩气形成后,大部分页岩气已运移到附近砂岩中形成致密气,致密砂岩、煤层和页岩呈三明治式成藏。预测研究区内东南部为有利区域。在勘探山西组页岩气时考虑煤系"含气带",通过立体勘探寻找有利的富气层段。Shale gas resources of the transitional facies account for about one-third of the total amount in China,and have broad prospects for exploration and development.A breakthrough in exploration and development has not been achieved despite the large thickness and wide distribution of the transitional facies in the Ordos basin.This study aims to determine differences in the geological characteristics between the transitional and marine shale gas reservoirs and their reservoir-forming principles by analyzing the total carbon content,vitrinite reflectance,mineral composition,micropore texture and gas content in the eastern Ordos basin.The comparative study of shale gas generation,storage and accumulation processes between transitional and marine shale gas reservoirs shows that the shale reservoir formation process of Shanxi Formation has its particularity.Its kerogen belongs to type III originating from higher plants,with little liquid hydrocarbon production,which is bubble pore formation process with a small amount of organic nanopore.Interbeds of sand-mud-coal in the formation mean that the source rock has a high efficiency of hydrocarbon expulsion,resulting in low content in the shale.The shale gas accumulation process of the Shanxi Formation is quite different from that of the marine shale gas because of its high expulsion efficiency and influence on shale gas content.After generation within the Shanxi Formation shale,a lot of gas has migrated to the overlying or underlying tight sandstones.The tight sandstones,coals and shale reservoirs resemble a sandwich.It is predicted that the southeast of the study area is a favorable area.When exploring the shale gas in Shanxi Formation,the"gas bearing zone"of coal series should be comprehensively considered,which means favorable shale gas-rich zones should be investigated together with tight sandstones and coals using three-dimensional exploration strategy for commercial production.

关 键 词：鄂尔多斯 山西组 页岩 有机质纳米孔 

分 类 号：P618.13[天文地球—矿床学]