Research on Thermochemical Recovery Techniques for Heavy Oil & Application
The heavy oil reservoirs of District No.6 and District No.9 of Xinjiang oilfield are located in the northwestern margin of Junggar Basin, with shallow burial, unitary oil-bearing lithology, good reservoir properties, strong heterogeneity and high crude viscosity (ranging 2000~2000000mPa·s under reservoir conditions), with components of crude oil families differ significantly with the saturated hydrocarbon content in the heavy oil lower than 55％. In some highly-viscous blocks, the production rate declines quickly by using conventional steam stimulation, and pattern steam flooding, with low GOR and degree of reserve recovery, and the development effect is not ideal. In view of the characteristics of heavy oil reservoir and physical properties of the crude in these areas, comprehensive evaluation was carried out on chemical emulsifiers. Emulsifiers with good adaptability have been selected to conduct performance analysis of emulsion, and the influential factors have been analyzed on the behavior of chemical emulsifiers. Based on the physical and numerical simulation under different steam flooding methods, the parameters for field application and proper moments for application of the chemical emulsifiers have been determined. Field applying parameters and thermochemical production technologies have been optimized in view of the field practice. 303 cyclic chemical-emulsifier stimulation jobs have been conducted in District No.6 and 9 and cumulative incremental oil production of 37845t have been gained. 4 chemical-emulsifier-slug steam drive jobs have been performed and cumulative incremental oil production of 1583t have been gained, the total incremental oil production is 39427t. 641t viscosity breaker have been used and input/output ratio is 1:4.86. Conclusion and suggestion: 1) After the implementation of thermochemical recovery stimulation in heavy oil wells, the oil production rate and liquid production increase in the oil wells, and the oil-steam ratio is enhanced. 2) Before the implementation of chemical emulsifier assisting recovery, comprehensive evaluation on chemical emulsifier performance must be carried out to ensure the field application effect while giving consideration to ground processing technologies and oil reservoir protection. 3) The oil-steam ratio of chemical emulsifier stimulation wells is 0.1 more than the non- stimulated wells in the same cycle. The effect of applying concentration of 0.3％ of chemical emulsifier is better than that of 0.1％ concentration, but relative production increase range of the oil well is insignificant. 4) Consideration must be given to the ratio of stored water in the formations during the development of oil wells when performing over the fourth cycle for chemical emulsifier stimulation. When the ratio of stored water in the formations is less than 10％, the effect of cyclic chemical emulsifier stimulation is ideal. 5) Numerical simulation result indicates that, comparing the chemical emulsifier plugs steam flooding with continuous steam flooding, the recovery ratio enhances by about 17％, oil-steam ratio enhances by about
WANG ZHUOFEI WEI XINCHUN LOAN AIJUN JIANG LI
HEAVY OIL PRODUCTION COMPANY, XINJIANG OILFIELD COMPANY, KARAMAY, XINJIANG, Karamay 834000, PRC
国际会议
首届世界重油大会(The Technical Sessions of the First World Heavy Oil Conference)
北京
英文
1147-1148
2006-11-12（万方平台首次上网日期，不代表论文的发表时间）