Ezperimental and Simulation Studies on Fluid Flow Mechanisms in Highly Sour Gas Reservoirs
- 作者：Du ZhiminGuo XiaoZhang YongYang Xue Feng
- 会议时间：2007-10-20
- 关键词：Ezperimental ; Simulation Studies ; Fluid Flow Mechanisms ; Highly Sour Gas Reservoirs ; 高酸气藏 ; 油藏管理 ; 多孔介质
- 作者单位：State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation
- 母体文献：2007年油气藏地质及开发工程国家重点实验室第四次国际学术会议论文集
- 会议名称：2007年油气藏地质及开发工程国家重点实验室第四次国际学术会议
- 会议地点：成都
- 主办单位：中国石油学会
- 语种：chi
摘要
Highly sour gas production plays an important role in China's natural gas industry. Highly sour gas reservoirs have been discovered widely in Sichuan Basin, such as Luojiazhai Gas Reservoir and Puguang Gas Reservoir. Due to extreme poison, strong corrosion, and complex precipitation and deposition of H2S in the reservoir, it is very difficult and risky to investigate and explore drilling, completion, production, workover, and gas transportation. Meanwhile, varying phase behavior and sulfur deposition cause the complicated fluid flow in porous medium and consequently challenge reservoir management. This paper focuses on sour gas phase behavior and sulfur deposition through laboratory experiment and numerical simulation. The carbonate cores are obtained from real field with permeability ranges from 0.85md to 20md. The fluid injection rates are 0.82cm3/minute, 1.25cm3/minute, and 3.50cm3/minute, respectively. Scanning Electro Microscope (SEM) is used to quantify sulfur deposition in the core. On the basis of experimental work, three-dimensional multi-component mathematical model for sour gas reservoir is developed. Gas flow rate and sulfur deposition impacted by initial H2S concentration and formation permeability are further simulated. Experimental study on phase behavior demonstrates that Z factor of sour gas firstly decreases and then increase when pressure continuously increases. Experiment illustrates that high gas flow rate reduces sulfur deposition while high H2S concentration generates severe sulfur deposition. In addition, sulfur depositionspeeds up with the reduction of rock permeability. Finally, sulfur deposition is predicted in Gaoqiao Gas Reservoir located in Sichuan Basin using the developed mathematical model in this paper. The simulation results show that sulfur start precipitating once reservoir pressure drops. At low gas flow rate, the deposited sulfur particles occur in the pores. The deposition severely impedes production. However, the main damage area is near wellbore. Our study is helpful for predicting production performance in the sour gas reservoir.