神华鄂尔多斯CO_2地质封存场地多井并注模拟初探

Numerical investigation of geological CO_2 storage with multiple injection wells for the Shenhua Ordos CCS project

中国首个陆上咸水层CO_2地质封存示范项目的成功实施使得在鄂尔多斯盆地开展大规模CO_2地质封存成为可能.为探讨在鄂尔多斯盆地典型低渗砂岩储层中实施50万t以上CO_2年封存量的注入封存方案,基于神华CCS项目的场地储层结构和监测数据,采用储层多相流模拟软件TOUGH2-MP/ECO2N模拟了神华场地5点布井方案下进行50万t·a^(-1)的注入封存情景.分析了储层非均质性对模拟结果的可能影响.基于模拟结果的分析,认为在该场地实施多井注入方案时井间距应大于2 059m,为安全计,建议最少为3 000m.若实施100万t·a^(-1)的封存规模,初步估计需要采用10口井进行同时注入.

A CCS demonstration project was implemented in 2010 by injecting 0.1million tonnes of supercritical CO2 per annum into the brine-saturated sandstones at depths of more than 1 600 min the northeastern Ordos Basin,China.The successful implementation of the first demonstration project for onshore geological CO2 sequestration in China justifies the feasibility of large-scale development of the geological CO2 sequestration in the Ordos Basin.To gain insight into the operational plans for geological CO2 sequestration at a scale of more than 500 000 tonnes of CO2 per annum in low-permeability settings that is typical of the Ordos Basin,two fivespot well schemes were simulated with the reservoir simulator TOUGH2-MP/ECO2 Nfor the Chenjiacun site of the Shenhua CCS project,with site-specific data.Reservoir heterogeneity and associated effects on simulation results were analyzed.Analysis of modeling results suggested that spacing of injection wells should be significantly larger than 2 059 m and typically 3 000 m or more.While further investigation is needed,the present preliminary suggestion of about million tonnes of sequestration of CO2 per annum would be that around10 injection wells with spacing of no less than 3 000 mbe adopted for successful injection and secure storage.