摘要
针对致密油油藏水平井CO_2吞吐产能预测缺少合适计算模型的现状。通过建立CO_2扩散区和非扩散区的复合流动模型,考虑原油在不同区域的黏度差异,提出了水平井CO_2吞吐单井产能预测解析模型,推导出基于CO_2扩散影响的致密油藏水平井产能预测的数值模型。研究表明:无因次扩散距离与扩散系数和扩散时间均呈正相关;采油指数与扩散系数呈正相关,增加幅度随扩散系数的增大而减缓。对单一扩散系数而言,井距越短采油指数越大,并随黏度不断降低而单调增加;水平井的井距和水平段长度对采油指数影响较大。通常情况采油指数随扩散半径的增大而单调增加,井距越小扩散半径对采油指数的影响越大;采油指数与水平段长度呈正相关,水平段长度为350 m的采油指数是长度为100 m的2.52倍。水平井水平段长度越小扩散半径对采油指数的影响增大。
In view of the current situation of the lack of a suitable calculation model for the CO 2 huff-n-puff prediction of horizontal wells in tight oil reservoirs,By establishing a composite flow model of CO 2 diffusion zone and non-diffusion zone and considering the viscosity difference caused by the diffusion of crude oil in different regions,an analytical model for single well productivity prediction of horizontal well CO 2 huff-n-puff was proposed and a numerical model for horizontal well productivity prediction in a tight reservoir based on the influence of CO 2 diffusion was derived.Research shows that dimensionless diffusion distance is positively correlated with diffusion coefficient and diffusion time.Oil recovery index is positively correlated with diffusion coefficient,and the increase rate slows down with the increase of diffusion coefficient.For a single diffusion coefficient,the shorter the well spacing is,the greater the oil production index is,and it increases monotonically with the continuous decrease of viscosity.The well spacing and horizontal section length of horizontal wells have a greater impact on the oil production index.Generally,the oil production index increases monotonously with the increase of the diffusion radius.The smaller the well spacing is,the greater the impact of the diffusion radius is on the oil production index.The oil production index is positively correlated with the length of the horizontal section,and the oil production index with a horizontal section length of 350 m is 2.52 times more than that of a length of 100 m.The smaller the length of the horizontal section of a horizontal well is,the greater the influence of the diffusion radius is on the oil production index.
作者
罗永成
孙灵辉
吴振凯
赵新礼
萧汉敏
LUO Yong-cheng;SUN Ling-hui;WU Zhen-kai;ZHAO Xin-li;XIAO Han-min(College of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Porous Flow and Fluid Mechanics,University of Chinese Academy of Sciences,Langfang 065007,China;Research Institute of Petroleum Exploration&Development,Beijing 100083,China)
出处
《科学技术与工程》
北大核心
2021年第9期3588-3594,共7页
Science Technology and Engineering
基金
中国石油天然气股份公司科技管理部(2018A-0908)
国家科技重大专项(2017ZX05013-001)。
关键词
致密油藏
CO_(2)吞吐
水平井产能预测
扩散系数
采油指数
tight reservoir
CO_(2)huff-n-puff
horizontal well productivity prediction
diffusion coefficient
oil recovery index
