中国油气田古岩溶与油气储层  

The Paleokarst Reservoirs of Oil/Gas Fields in China

作　　者：陈学时 易万霞 卢文忠 

机构地区：[1]中国石油集团杭州石油地质研究所,杭州310023

出　　处：《沉积学报》2004年第2期244-253,共10页Acta Sedimentologica Sinica

摘　　要：在我国油气田勘探中 ,与不整合面有关的碳酸盐岩古岩溶储层普遍发育 ,并占有十分重要的地位。着重讨论我国鄂尔多斯盆地奥陶系、塔里木盆地轮南潜山奥陶系和四川盆地震旦系等典型油气田古岩溶储层发育特征与油气关系 ,指出我国油气田古岩溶储层具有以下几个特征 :(1)古岩溶垂向分带明显 ,地表残积带、垂直渗流—水平潜流带等发育齐全。 (2 )储集空间主要由岩溶作用形成的半充填或未充填残余溶蚀孔洞缝组成。优质储层类型以裂缝 溶蚀孔洞型储层为主 ,为各大油气田高产、稳产的最重要储层和主力产气层。 (3)储层受古岩溶地貌和断层裂缝的控制明显。古岩溶斜坡和断裂发育区 ,古岩溶发育强烈 ,是溶蚀孔洞层和储层发育的有利地区。 (4 )埋藏有机溶蚀作用形成的次生孔隙为有效孔隙 ,它的发育与烃类的形成、演化和运聚相匹配。 (5 )古风化壳岩溶作用和埋藏有机溶蚀作用的多期次叠加和改造 ,是古岩溶储层及油气藏形成的最佳组合模式。古岩溶储层为中国深层油气勘探提供了一个新的勘探领域。There widely exists paleokarst reservoir associated with regional unconformitiesduring the oil and gas exploration in China. Based on the analysis of the paleokarst reservoirs in Ordovician gas field in Ordos basin, Ordovician oil/gas field in Tarim basin and Sinian gas field in Sichuan basin, the authors have found that the paleokarst reservoirs in China are common in the following characteristics: (1) The paleokarst zone can be explicitly divided into three subzones in vertical, i.e. the surface remnant karst zone, the vertical vadose zone and the horizontal phreatic zone.(2) The reservoir space is remnant dissolved pores, vugs and fissures. The most favorable reservoir for oil and gas accumulation is the fissure-dissolved vug reservoir. (3)The distribution of paleokarst reservoirs is controlled by paleokarst morphologyand fault fissures. The most favorable place for reservoir development is on karst slopes and in fault belts.(4) Dissolution during deep burial coincides with the maturation of source rocks, hydrocarbon evolution and migration.Porosity enhancement related to the burial organic dissolution takes place just prior to the arrival of hydrocarbons in reservoirs, so it is of economic concern. (5) Karstification and burial organic dissolution are the most important diagenesis for the paleokarst reservoir development. The formeris a prerequesite factor, while the latteris adominant factorin the reservoir construction.The paleokarst reservoiris a new domain for the deep exploration of oil and gas in China.

关 键 词：油气储层 油气田 岩溶 震旦系 奥陶系 古风化 

分 类 号：TE122.221[石油与天然气工程—油气勘探]