一种基于“四区”的低渗透油藏CO_(2)埋存量计算方法及应用  

A Calculation Method of CO_(2)Storage Capacity in Low Permeability Reservoirs Based on"Four-zone"Method and Its Application

作　　者：王香增[1] 陈小凡[2] 李剑 陈芳萍[1] 范庆振 王剑 Wang Xiangzeng;Chen Xiaofan;Li Jian;Chen Fangping;Fan Qingzhen;Wang Jian(Shaanxi Yanchang Petroleum(group)co.,ltd.,Xi′an Shaanxi 710075,China;National Key Laboratory of Petroleum Reservoir Geology and Development Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]陕西延长石油(集团)有限责任公司,陕西西安710075 [2]西南石油大学油气藏地质及开发工程全国重点实验室,四川成都610500

出　　处：《特种油气藏》2024年第3期78-84,共7页Special Oil & Gas Reservoirs

基　　金：中国博士后科学基金面上项目“非常规致密气储层多分支井体积压裂多尺度流动耦合模型”(2019M650965)。

摘　　要：CO_(2)驱油和埋存能有效减少温室气体排放量达到碳中和目标,已有的CO_(2)埋存量计算方法主要针对CO_(2)的静态埋存量进行粗略计算,未考虑实际生产过程中CO_(2)埋存量的变化。针对上述问题,运用CO_(2)溶解、CO_(2)波及体积和驱油机理,将CO_(2)驱油与埋存过程分为气相区、两相或近混相区、扩散区和油相区,并基于“四区法”计算CO_(2)埋存量,得到了不同烃类的注入孔隙体积倍数、注入压力、注气速度下的CO_(2)动态埋存量的变化规律。将研究成果应用于W油田低渗储层,结果表明:注入烃类孔隙体积倍数、压力、注气速度与总埋存量呈正相关性,当压力由12 MPa升至30 MPa,CO_(2)埋存总量增加15.53×10^(4)t;当注气速度由5 t/d增加至30 t/d,峰值CO_(2)埋存总量由3.51×10^(4)t提高至12.62×10^(4)t。研究成果可为同类油藏开展CO_(2)驱油与埋存项目提供新的思路。CO_(2)flooding and storage have the potential to significantly mitigate greenhouse gas emissions and contribute to achieving carbon neutrality objectives.Nevertheless,current methods for calculating CO_(2)storage capacity primarily concentrate on rough estimates of static CO_(2)storage,neglecting variations in CO_(2)storage during actual production processes.In view of the above problems,the process of CO_(2)flooding and storage is divided into gas phase zone,two-phase or near-miscible phase zone,diffusion zone and oil phase zone by using CO_(2)dissolution,CO_(2)swept volume and oil displacement mechanism.Based on the four-zone method,the CO_(2)storage capacity is calculated,and the dynamic CO_(2)storage capacity under varying hydrocarbon pore volume multiples,injection pressure and gas injection rate is obtained.The research results are applied to the low permeability reservoir of W oilfield.The results show that the pore volume multiple,pressure and gas injection rate of injected hydrocarbons are positively correlated with the total storage capacity.When the pressure increases from 12 MPa to 30 MPa,the total amount of CO_(2)storage increases by 15.53×10^(4)t;when the gas injection rate increases from 5 t/d to 30 t/d,the total amount of peak CO_(2)storage increases from 3.51×10^(4)t to 12.62×10^(4)t.The research results can provide new ideas for the development of CO_(2)flooding and storage projects in similar reservoirs.

关 键 词：CCUS CO_(2)埋存 “四区”法 低渗储层 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]