摘要
微观水驱油试验可以直观展示油水在致密储层中分布情况。以鄂尔多斯盆地西部姬塬油田T区块延长组致密油储层为例,利用该地区大量核磁共振、相渗及水驱油测试结果,对可动流体饱和度及水驱油微观机理进行了系统研究。根据T_(2)谱分布,研究区目的层致密油储层可分为4类:Ⅰ类(右偏双峰型)、Ⅱ类(单峰或不明显双峰型)、Ⅲ类(左偏双峰型,右峰不显著)、Ⅳ类(左偏双峰型,右峰显著)。油水相渗曲线类型被分为3类:Ⅰ类(K_(w)、K_(o)线下凹)、Ⅱ类(K_(o)线斜直下降、K_(w)线顶拐点斜直上升)、Ⅲ类(K_(w)线缓慢上升、K_(o)线陡直下降)。油水两相渗流区间内,油水两相含水饱和度宽度平均值为27.5%,样品呈现出较窄的油水两相渗流区;此外,共渗点处对应的平均值含水饱和度为49.5%,其相对渗透率平均值为0.138;当仅剩残余油时,样品平均含油饱和度为41.6%,高于束缚水饱和度。镜下观察结果显示,目的层中主要存在4类典型的残余油分布状态,即油膜态、角隅态、绕流态和孤岛态。根据驱油效率计算结果,目的层注入倍数为1 PV时的驱油效率平均值为17.6%,注入倍数为2 PV时的驱油效率平均值为38.5%。
The microscopic water flooding test can visually show the distribution of oil and water in tight reservoirs.From the sample study of the tight oil reservoir of Yanchang Formation in Block T of Jiyuan Oilfield in the western Ordos Basin,a large number of nuclear magnetic resonance,phase permeability and water drive test results in this area are used to investigate the saturation of movable fluid and the microscopic mechanism of water drive.According to the T_(2) spectrum distribution,the tight oil reservoirs of the target layer can be classified into 4 types:TypeⅠ(right-biased bimodal),TypeⅡ(single-peak or inconspicuous bimodal),TypeⅢ(left-biased bimodal with right peak not significant),and TypeⅣ(left-biased bimodal with significant right peak).The types of oil-water permeability curves are divided into three categories:TypeⅠ(K_(w) and K_(o) line are concave),TypeⅡ(K_(o) line obliquely descends and K_(w) line top inflection point slopes up),TypeⅢ(K_(w) line slowly rises and K_(o) line steeply declines).In the oil-water two-phase seepage interval,the average width of oil-water twophase water saturation is 27.5%,and the samples show a narrower oil-water two-phase seepage zone.In addition,the average water saturation corresponding to the co-infiltration point is 49.5%and its relative permeability average is 0.138.When residual oil remains,the average oil saturation of the sample is 41.6%,higher than the irreducible water saturation.The microscopic observation shows that there are four typical residual oil distribution states in the target layer,namely oil film residual oil,corner residual oil,bypass residual oil,and island residual oil.According to the calculation results of oil displacement efficiency,the average oil displacement efficiency is 17.6%when the injection multiple of the target layer is 1 PV,and 38.5%when the injection multiple is 2 PV.
作者
麻宇杰
赵军辉
王勇
赵云刚
李永宗
尹晶
屈乐
MA Yu-jie;ZHAO Jun-hui;WANG Yong;ZHAO Yun-gang;LI Yong-zong;YIN Jing;QU Le(No.8 Oil Recovery Plant of Changqing Oilfield Company,PetroChina,Xi’an 710021,China;Shaanxi Zhongmeng Petroleum Technology Service Co.,Ltd.,Xi’an 710018,China;Xi’an Key Laboratory of Tight Oil(Shale oil)Development,Xi’an Shiyou University,Xi’an 710065,China)
出处
《桂林理工大学学报》
CAS
北大核心
2022年第3期565-571,共7页
Journal of Guilin University of Technology
基金
国家自然科学基金项目(42072173)。
关键词
致密油储层
可动流体
核磁共振
相渗测试
水驱油实验
延长组
鄂尔多斯盆地
tight oil reservoir
movable fluid
nuclear magnetic resonance
phase permeability test
water drive experiment
Yanchang Formation
Ordos Basin
