苏里格气田孔隙水的可动条件研究

发布时间：2018-10-25 18:59

【摘要】：苏里格气田属于典型的低渗透砂岩岩性气藏,在开发的过程中,部分气井出现不同程度的产水现象。然而,目前对气井产出水的来源及孔隙水的可动条件认识还不够明确,这严重地影响了气田的开发效果和开发进程。本文综合运用试气、生产、测井及水化学分析等资料,在对苏东地区生产现状及气水分布规律研究的基础上,综合判断出苏东地区的产出水主要以盒8段的储层原生沉积水为主,山1段的储层原生沉积水为辅。在此基础上,通过含束缚水状态下气体的渗流规律和气水两相渗流规律实验表明:苏里格东区气藏是亲水气藏,其束缚水饱和度越高气体渗流的非线性渗流特征越明显,气体的渗流阻力也越大。进而通过岩心高压驱替实验、核磁共振实验及压力敏感性实验对储层原生沉积水的可动性进行了实验室研究,研究结果表明:核磁共振T2谱的T2cutoff值直接反应了岩心中束缚水饱和度的大小,小于T2cutoff值为束缚水饱和度,而大于T2cutoff值为可动水饱和度;对同一岩心,驱替压力越大,孔隙中被驱出的水越多,孔隙水的可动性越强;对不同岩心,岩样的孔渗越高,孔隙中原生水的可动性越大。由此可见,孔隙中原生沉积水的可动性与岩样的孔隙度、渗透率及驱替压力密切相关,利用该实验结果得到的可动水饱和度能够有效表征低渗砂岩气藏储层的产水特征,并有效地预测气井的产水规律。上述研究对苏东地区储层原生沉积水的可动条件作出了客观的认识和评价,可以为气田高效建产提供合理的依据。
[Abstract]:Sulige gas field is a typical low permeability sandstone lithologic gas reservoir. However, the current understanding of the source of gas well water and the movable conditions of pore water is not clear enough, which seriously affects the development effect and development process of gas field. In this paper, based on the study of production status and gas-water distribution law in eastern Jiangsu, the data of gas test, production, logging and hydrochemical analysis are synthetically used. It can be concluded that the primary sedimentary water in the reservoir of member 8 is the main source of the produced water in the east of Jiangsu province, and the primary sedimentary water in the reservoir of the first member of Shan 1 is the secondary one. On this basis, the experiments of gas seepage and gas-water two-phase seepage under the condition of bound water show that the gas reservoir in Sulige East District is a hydrophilic gas reservoir, and the higher the irreducible water saturation is, the more obvious the non-linear percolation characteristics of gas percolation are. Gas seepage resistance is also greater. Furthermore, the mobility of reservoir primary sedimentary water was studied in laboratory by high pressure displacement experiment, nuclear magnetic resonance test and pressure sensitivity experiment. The results show that the T2cutoff value of NMR T2 spectrum directly reflects the irreducible water saturation in the core. The irreducible water saturation is smaller than the T2cutoff value and the moveable water saturation is greater than the T2cutoff value. For the same core, the higher the displacement pressure is, the more water is expelled out of the pore, the stronger the mobility of pore water is, and the higher the pore permeability of different core is, the greater the mobility of raw water in pore is. It can be seen that the mobility of proto-sedimentary water in pores is closely related to the porosity, permeability and displacement pressure of rock samples. The movable water saturation obtained from the experimental results can effectively characterize the water production characteristics of low permeability sandstone gas reservoirs. The water production law of gas well is predicted effectively. The above study makes an objective understanding and evaluation of the movable conditions of the primary sedimentary water in the reservoirs in the east of Jiangsu Province, and can provide a reasonable basis for the efficient production of the gas fields.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE312

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