鄂尔多斯盆地镇北油田长8_1油藏电阻率差异成因  

Analysis on Causes of Reservoir Resistivity Differences of Chang 8_1 Reservoir in Zhenbei Oilfield,Ordos Basin

作　　者：冯渊[1,2] 杨伟伟[1,2] 刘一仓 王晔[1,2] 焦廷奎[1,2] 张海波[1,2] 

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,西安710021 [2]中国石油长庆油田分公司低渗透油气田勘探开发国家工程实验室,西安710021 [3]中国石油长庆油田分公司第十一采油厂,甘肃庆阳745000

出　　处：《新疆石油地质》2015年第5期526-530,共5页Xinjiang Petroleum Geology

基　　金：国家科技重大专项(2011ZX05001-002)

摘　　要：鄂尔多斯盆地镇北油田长81超低渗油藏电阻率差异较大,油藏西部电阻率明显小于油藏东部,部分油层电阻率甚至接近水层,使得西部油层难以识别,给油田开发带来一定难度。为此,对油藏东、西部储集层电阻率差异成因进行了研究。研究结果表明,造成该油藏西部电阻率明显偏低的主要原因是:油藏西部储集层地层水矿化度高于油藏东部;西部储集层中阳离子交换能力较强的伊利石和绿泥石含量更高,其附加导电作用较强;由于油藏西部储集层中吸附水分子能力强的黏土矿物含量高、储集层孔隙结构更为复杂以及成藏动力弱等因素,导致其束缚水饱和度偏高。这一研究成果,对超低渗低阻油藏的勘探与开发具有重要意义。The ultra-low permeability reservoir of Chang 81 in Zhenbei oilfield of Ordos basin is characterized by distinct formation resistiv-ity which in west part of the reservoir is obviously lower than that in east part,even part of it closes to that of aqueous layers,which allowsthe western reservoir＇s pay zone to be difficultly identified and developed. This paper analyzed the genesis of the resistivity differences inthis reservoir. The results show that the causes of lower resistivity in the western reservoir compared with the eastern reservoir include threeaspects as below： 1） The salinity of formation water in the western reservoir is higher than that in the eastern reservoir; 2）the western reser-voir contains higher content of illite and chlorite with stronger capacity of cation exchange and additional conductivity; and 3） it containshigher clay minerals and more complex pore structures as well as weaker hydrocarbon accumulation dynamics,which result in higher irre-ducible water saturation in it. This could be of significance for exploration and development of ultra-low permeability reserfvoirs.

关 键 词：鄂尔多斯盆地 镇北油田 电阻率差异 地层水矿化度 黏土矿物 束缚水饱和度 

分 类 号：TE112.23[石油与天然气工程—油气勘探]