东方1-1气田伴生CO_2盐水层埋存可行性研究

Feasibility study on associated CO_2 geological storage in a saline aquifer for development of Dongfang 1-1 gas field

通过筛选论证，将位于莺歌海盆地的岭头13—1构造作为盐水层埋存体，用于处置东方1-1气田在海南岛陆上终端分离出的CO2。油藏数值模拟结果表明，CO2年埋存量在10～20万t时，可实现20a的安全稳定注入。根据矿场条件，采用岛上处理加压、海底管线长距离液态输送、海底井1：3注入的工艺流程，整个流程中的节点压力低于25MPa；海底管线内径采用0．10m或0．13m，注入水平井油管管径采用0．115m。由于管线费用较大，CO2埋存成本稍高于国外，为211—229形t，引入碳税将会非常有利于中国CO2埋存工程的开展。

Dongfang 1-1 gas field, in the west of South China Sea, is associated with high concentration of CO2. After screening and assessment, the LT13-1 structure located in Yinggehai Basin was chosen as the saline aquifer to sequestrate the CO2 discharged from the terminal of gas field on Hainan Island. The reservoir simulation results show that CO2 can be injected safely and steadily for 20 years at the rate of （ 10 -20） × 10^4 t/a. According to field conditions, CO2 is considered to be processed at first and compressed on the island, and then transported by long-distance subsea pipeline at liquid state, finally injected into LT13-1 saline aquifer via a subsea wellhead. In the whole process, the node pressure is lower than 25 MPa. The recommended pipeline internal diameter and horizontal well tubing diameter are 0. 10 m （or 0. 13 m） and 0. 115 m respectively. The economic analysis results show that CO2 storage cost is 211 -229 RMB/t, a little higher than that of other overseas demonstration projects because of the huge pipeline capital. If carbon tax is implemented in China, it will promote CO2 geological storage projects to be put into practice.