安塞油田王窑老区特低渗透油藏储层厚砂体精细解剖  

Configuration Delineation of Thick Sandbody within Ultra-Low Permeability Reservoir,Wangyaolaoqu,Ansai Oilfield

作　　者：李佳鸿[1] 宋新民[1] 王友净[1] 惠钢[1] 

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《地质科技情报》2014年第1期129-136,共8页Geological Science and Technology Information

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目(2011B-1205)

摘　　要：三叠系延长组长61时期,鄂尔多斯盆地安塞三角洲广泛发育于浅水台地之上,沉积以细砂岩为主的似块状连片厚砂体。厚砂体内部叠置多期单砂体,横、纵向上物性差异明显,造成剩余油分布复杂,因此对储层厚砂体进行精细解剖尤为重要。首先论证了单砂体对水淹的控制作用及单砂体刻画的必要性;结合实际开发状况制定了一套小层细分方案。在识别出水下分流河道、河口坝和溢岸砂等不同沉积微相的基础上,从沉积微相组合的角度,将长61分为主力河道、分支河道和河道间3类相带;同时进一步分析了不同期次、不同成因单砂体间包括河道切割河口坝、削截式、侧向拼接、侧向斜叠和堆叠等组合模式;最后总结了长61的地质沉积模式和长611的砂体沉积特征:长61时期的安塞三角洲是快速进积的建设性三角洲,长611为砂包泥的拼合板状,长621则为泥包砂的迷宫状;长611沉积以多种规模的水下分流河道为主体的条带状砂体,河口坝不发育或残留发育。Ansai delta widely spreads above the shallow platform during the time of C61, sedimentation of Triassic Yanchang Formation, depositing massively sheet-like thick sand bodies. Plenty of single sandbod ies inter-superimposing in the thick sandbodies and apparent vertically and laterally physical property dis crepancy results in complex distribution of remaining oil. This paper argues the controlling of single sand- body on water-flooding and the necessity of depicting single sandbody, and then draws up a single-layer di- vision plan considering practical reservoir development. On the basis of identification of different microfa cies, the authors divide the C61 into 3 facies belts as main channel, distributary channel and inter-channel. Then further analyses different sandbody assembly model from different periods and genesis, such as chan nel cutting mouth bar and lateral splicing of channels. At last we summarize the geologically depositional model of C61 and depositional characteristics of its sandbodies.. Ansai delta of C61 is a river-delta of fast- progradation, sandbodies of C61 is jointly sheet-like with sand enveloping mud, while sandbodies of C6 is discreet with mud enveloping sand, and channel sanbodies of different scales mainly constitute sandbodies of C6 with mouth bar remains or seldom deposits.

关 键 词：安塞油田 浅水三角洲 长6 单砂体 砂体组合模式 隔夹层 

分 类 号：P618[天文地球—矿床学]