氨水强化超临界二氧化碳地质埋存方法

Ammonia Water Enhanced Geological Storage of Supercritical Carbon Dioxide

为提高二氧化碳捕集、利用与封存(CO_(2) capture,utilization and storage,CCUS)末期CO_(2)地质埋存能力,提出氨水强化CO_(2)埋存方法,向储层注入氨水,利用氨水与CO_(2)发生化学反应提高CO_(2)埋存量。通过高温高压物理模拟装置和岩心驱替装置,选定实验参数范围为20 MPa、40~80℃、氨水浓度6%~26%,选取高渗岩心进行实验,明确了氨水与CO_(2)的反应规律和岩心中氨水强化CO_(2)埋存效果。结果表明,氨水吸收CO_(2)的量与氨水浓度呈正比,与温度呈反比,但低温会析出碳酸氢铵晶体,减少氨水吸收CO_(2)的量;氨的吸收能力与氨水浓度呈负相关,与温度没有明显的线性相关性;在60℃条件下,6%浓度的氨水表现出最佳的CO_(2)吸收效果;与饱和地层水相比,饱和6%浓度氨水可使岩心的CO_(2)埋存量提高7.5倍;岩心迂曲度每增加0.5,氨水强化埋存的单位岩石孔隙体积CO_(2)埋存量可以增加200 mL,而地层水埋存的单位岩石孔隙体积CO_(2)埋存量仅增加11 mL。该研究首次提出了一种新的二氧化碳埋存模式并开展实验研究,为CCUS项目强化二氧化碳地质埋存提供了一种新思路和新途径。

In the advanced phase of CCUS(CO_(2) capture,utilization and storage),a technique for increasing the CO_(2) geological storage capacity using ammonia water was suggested.Ammonia water was injected into the reservoir,where it reacted with CO_(2) to expand the storage volume.A high-temperature,high-pressure physical simulation device and core flooding apparatus was utilized to narrow down the experimental parameters for 20 MPa,40~80°C,and an ammonia water concentration of 6%~26%.The interaction between ammonia and CO_(2) and ammonia's efficacy in amplifying CO_(2) storage were clarified through the experiments.The results show that the amount of CO_(2) absorbed by ammonia is proportional to the concentration of ammonia,and inversely proportional to the temperature.But ammonium bicarbonate crystals will be precipitated at low temperature,reducing the amount of CO_(2) absorbed by ammonia.The absorption capacity of ammonia is negatively correlated with ammonia concentration,but had no obvious linear correlation with temperature.Saturated 6%ammonia water increases the CO_(2) storage volume in cores by 7.5 times compared to saturated formation water.Moreover,with every 0.5 increase in core tortuosity,the CO_(2) storage volume per unit rock pore volume in ammonia-enhanced storage increases by 200 mL,whereas that in formation water storage only rises by 11 mL.An innovative CO_(2) storage model and conducts experimental research is presented for the first time,which provid a new approach and method for enhancing CO_(2) geological storage in oil and gas field CCUS projects.