气藏中CO_2封存过程气水互溶特性实验研究  

Experimental study on gas-water mutual solubility during CO_2 storage in a gas reservoir

作　　者：王长权[1] 杜志敏[1] 汤勇[1] 石立红[2] 孙扬[1] 

机构地区：[1]油气藏地质及开发工程国家重点实验室西南石油大学,四川成都610500 [2]西南石油大学,四川成都610500

出　　处：《特种油气藏》2013年第3期118-122,157,共5页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金项目"废弃气藏CO2地质封存机制及运移规律研究"(51274173);"十二五"国家重大科技专项"CO2驱油与埋存潜力评价及战略规划"(2011ZX05016-006)

摘　　要：利用PVT装置开展了不同CO2含量下CO2-烃-水体系在不同条件下气水互溶特性实验,研究气藏注CO2封存过程中CO2-烃-水体系互溶规律。结果表明,相同温度压力下,随CO2的不断注入,气相中CO2含量和水蒸汽含量不断增加,液相中CO2在水中的溶解度越大,CH4溶解度越小,地层条件下CO2含量为68%物质的量的气样比CO2含量为23%物质的量的气样的CO2溶解度增加1.116%物质的量,而CH4的溶解度减小0.131%物质的量。CO2和CH4在水中的溶解度均随压力升高而增大,随温度升高而减小;在CO2临界点附近,CO2在水中的溶解度变化显著,40℃下CO2含量为23%物质的量的气样的CO2溶解度6～9MPa增加了0.138%物质的量,而9～12 MPa仅增加0.092%物质的量,且压力越大增加量越小。高温低压时受水蒸发作用影响,气相中CO2及CH4含量随温度升高急剧降低,随压力升高缓慢上升,当压力高于18 MPa后,气相中CO2及CH4含量基本保持不变。Experiment study on gas-water mutual solubility in the system of CO2-hydrocarbon-water is carried out under the conditions of different CO2-content with PVT device to study gas-water mutual solubility laws in the system of CO2-hydrocarbon-water of a gas reservoir.The study shows that with the successive injection of CO2,the contents of both CO2 and water vapor in gas phase and CO2 solubility in water increase;CO2 solubility in water for 68% mol CO2 gas sample under formation condition increases by 1.116% compared with 23% mol CO2 gas sample;CH 4 solubility decreases by 0.131%;the solubility of CO2 and CH 4 in water increases with the increase in pressure and decreases with the increase in temperature;near the CO2 critical point,the solubility of CO2 in water varies obviously,under 40℃ the solubility of CO2 in water increases by 0.138% from 6 MPa to 9MPa and increases only 0.092% mol from 9MPa to 12 MPa for 23% CO2 content gas sample and the larger the pressure is,the less the increase in solubility is;under high temperature and low pressure,affected by water evaporation the contents of CO2 and CH 4 in gas phase decrease abruptly and increase slowly with the increase in pressure and remain almost constant when pressure is greater than 18 MPa.

关 键 词：注CO2-EHR 地质封存 气水互溶 

分 类 号：TE135[石油与天然气工程—油气勘探]