摘要
采用SYS-1型碳酸盐岩溶蚀速率测定仪,选取四川东北地区5种碳酸盐岩样进行溶蚀实验,研究了三种主要TSR流体产物对碳酸盐岩的改造作用。H2S的溶蚀能力相对较强,在120℃温度下对微晶灰岩的溶蚀率可达17.09%;CO2的溶蚀能力次之;水的溶蚀作用可以忽略不计。H2S和CO2这两种酸性溶液的溶蚀能力从常温到200℃呈较强—强—弱的变化趋势,其中CO2的最大溶蚀率所处温度范围为60～90℃,H2S的最大溶蚀率所处温度范围为60～150℃。TSR产物中的酸性气体可以对储层进行改造,但不一定能够改良储层,而TSR过程中石膏向方解石的转变可以使储层孔隙度增加,从而改良储层物性。
Thermochemical sulfate reduction（TSR） is believed to be the main generation mechanism of high-concentrate hydrogen sulfide in gas reservoirs. During the process of TSR, hydrogen sulfide, carbon dioxide and fresh water are the main kinds of products which might meliorate reservoir property of carbonate rock. Five types pf carbonate rock samples from northeastern Sichuan are chosen to determine the alteration of TSR products to carbonate rock with SYS-1 Dissolution Velocity Measurer of Carbonate Rock. Through a serial of simulation experiments, the alteration capability of the same kind of liquid on different types of carbonate rocks at different temperature and the alteration capability of the three different kinds of liquid on different types of carbonate rocks are compared. The dissolution ratio of H2S can be up to 17.09% to micrite at a temperature of 120℃, which shows that H2S has a higher solubility than CO2 and fresh water has a low one to be ignored. The solubility of acidic H2S and CO2 solution to carbonate rocks shows a high-higher-low trend with increasing from the room temperature to 200℃. The solubility of CO2 is maximum at the temperature range of 60-90℃ and that of H2S at the range of 60-150℃. It is concluded that the TSR-generating acidic gas can play an active role in alteration of reservoir rock but it cannot always meliorate reservoir property. The TSR process that leads to alteration of gypsum into calcite can increase porosity of reservoirs, which means melioration of reservoir property.
出处
《海相油气地质》
2008年第2期57-61,共5页
Marine Origin Petroleum Geology
