注水油藏水平井含水变化规律研究  

Research on the Law of Water Cut Change in Horizontal Well of Waterflooding Reservoir

作　　者：吴晓慧 王雨 杨明 周凤军 陈存良 Wu Xiaohui;Wang Yu;Yang Ming;Zhou Fengjun;Chen Cunliang(Tianjin Branch of CNOOC Ltd.,Tianjin,300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《天然气与石油》2020年第5期58-63,共6页Natural Gas and Oil

基　　金：国家科技重大专项“渤海油田加密调整及提高采收率油藏工程技术示范”(2016 ZX 05058001)。

摘　　要：目前水平井含水率研究多集中在边底水油藏,而关于注水油藏水平井的研究较少。针对上述问题,首先统计分析注水油田实际数据,发现储层非均质性是水平井含水率台阶跃升的主要影响因素,然后建立数值模拟机理模型,分别就储层渗透率级差和不同渗透率带储量比例对水平井含水率的影响进行研究,并据此建立无因次含水率台阶跃升时间的理论图版,实现水平井含水台阶跃升时间的准确预测。研究结果表明:在储量比例一定的条件下,渗透率级差越大,见水越早,见水后含水率台阶跃升越晚;在渗透率级差一定的条件下,低渗储量占比越小,见水越晚,见水后含水率台阶跃升越晚;当渗透率级差≤1.5或相对低渗储量比例≤33%时,含水率不会出现明显的台阶跃升。利用BZ油田实际生产数据进行验证,实际水平井含水变化与理论研究基本一致,含水率台阶跃升出现时间预测精度高。研究成果可用来预测注水油藏水平井含水变化趋势,指导水平井水淹动态认识及剩余油挖潜。At present,the research on the water cut change of horizontal well is mostly concentrating on the reservoir with edge or bottom water,while there is little research on the water cut change of horizontal well in water injection reservoir.Aiming at this issue,the actual data of the oilfield is statistically analyzed.And it is found that the reservoir heterogeneity has the greatest influence on the water cut step rise for horizontal well.Then,a model for the numerical simulation mechanism is established to study the effects of reservoir permeability ratio and proportion of reserves in different permeability areas on the horizontal well water cut.Based on this,a theoretical chart of the dimensionless occurrence time of water cut step rise is established.It can accurately predict the occurrence time of water cut step rise.The results show that given constant low-permeability reserve ratio,the greater the permeability ratio is,the earlier the water breakthrough occurs,and the later the water cut step rises after the water breakthrough.Under constant permeability ratio,the smaller the ratio of low-permeability reserve is,the later the water breakthrough occurs,and the later the water cut step rises after the water breakthrough.When the permeability ratio is up to 1.5 or the relative low-permeability reserve ratio is up to 33%,the horizontal well water cut will not increase significantly.Then the actual production data of oilfield BZ is used for verification analysis.The actual water cut change of horizontal well is basically consistent with the theoretical research,and the prediction for water cut step rise time is of high accuracy.The research results can be used to predict the change trend of horizontal well water cut in water injection reservoir and guide the understanding of flooding dynamic.

关 键 词：注水油藏 水平井含水变化规律 渗透率级差 高低渗储量比例 无因次含水率台阶跃升时间 

分 类 号：TE53[石油与天然气工程—油气田开发工程]