致密油藏储层驱替特征及开发效果——以鄂尔多斯盆地上里塬地区延长组长7油层组为例  

Displacement characteristics and development effect of tight oil reservoir: a case from Chang 7 oil layer of the Yanchang Formation in Shangliyuan area,Ordos Basin

作　　者：韩永林[1] 刘军锋[1] 余永进[1] 王胜华[1] 沈强[1] 

机构地区：[1]中国石油长庆油田分公司第二采油厂,甘肃庆阳745100

出　　处：《石油与天然气地质》2014年第2期207-211,共5页Oil & Gas Geology

基　　金：国家科技重大专项(2011ZX05007-004)

摘　　要：为了研究致密油藏储层驱替特征及其开发效果,以鄂尔多斯盆地上里塬地区上三叠统延长组长7油层组为例,通过测试分析及模拟实验对致密油藏储层的敏感性、渗流特征及水驱油特征进行了分析。结果表明,研究区储层为弱速敏、弱酸敏性,无水敏、盐敏性。致密油藏单相渗流启动压力梯度达2.0 MPa/cm,与渗透率呈负相关;束缚水饱和度和残余油饱和度偏高,共渗区较窄,等渗点较低,含水饱和度增大会导致油相渗透率快速下降。根据其不同驱油阶段含水率和驱油效率的变化,将长7储层的水驱油开发大致划分为无水期、含水快速上升期及高含水期等3不同的开采阶段。无水期驱油效率为18.1%,最终驱油效率较低,仅为31.7%。同时,研究区储层润湿相为弱亲油,对后期的注水开发会产生深远影响。In order to study displacement characteristics and development effect of tight oil reservoir ,this paper analyzed the sensitivity ,fluid percolation and water-driving displacement characteristics of Chang 7 oil layer of the Triassic Yan-chang Formation in Shangliyuan area ,Ordos Basin .The results show that Chang 7 oil layer has weak velocity sensitivity , weak acid sensitivity ,no water sensitivity and no salt sensitivity .The starting pressure gradient of single-phase flow is up to 2.0 MPa/cm,and negatively correlates with permeability .The saturation of irreducible water and residual oil is high , the oil-water simultaneous vadose region is narrow ,and the isoperm point is low ,thus the increasing of water saturation can cause the rapidly decreasing of oil phase permeability .According to the changes of WC （ water cut ） and oil displace-ment efficiency in different displacement period ,the water-driving in the Chang 7 oil layer can be divided into three dif-ferent periods including no water period , WC-increasing-rapidly period , and high WC period .The oil displacement effi-ciency in no water period is 18.1%,and the final oil displacement efficiency is as low as 31.7%.In addition ,the weak oil wettability of the oil layer will have a profound impact on later waterflooding .

关 键 词：储层敏感性 渗流特征 水驱油特征 致密油藏 延长组 上里塬地区 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]