稠油油藏吞吐中后期流体特性分析及参数设计

ANALYSIS OF FLUID CHARACTERISTICS AND PARAMETER DESIGN IN VISCOUS OIL RESERVOIR SOAKING IN MIDDLE-END PERIOD

稠油油藏经过多轮注汽开发后 ,其物性及流体性质都存在着较大的变化。现有的开发方案无法适应这种变化 ,直接影响到油藏的开发效果 ,主要表现为原油产量大幅度下降、含水升高、油汽比降低、原油开发的经济性越来越差。通过油藏数值模拟并结合油井生产动态对这一时期储层的渗透性、压力、温度及原油粘度等特性的变化进行分析 ,将油层分为主力油层、潜力油层、非潜力油层 ,根据分析结果提出对注汽参数 (注汽量、注汽速度 )的调整方案 ,对主力油层采取隔离强制注汽 ,潜力油层采取保持温度、低压缓慢注汽 ,非潜力油层采取控制汽量经济注汽的策略 ,实现合理注汽 ,最大限度地减少无效注汽 。

After viscous reservoir have been developed for many times, its physic and flow property have been changed greatly. Now the production methods can't be adapted to these changes which influenced reservoir development directly. This can be seen from sharp decreasing of crude oil production, increasing of water cut and decrease of oil-gas ratio, economy of crude development become worse and worse. The assay analyzed the characteristic changes of permeability of formation, pressure, temperature and crude viscosity by numerical modeling and production condition these ways. It also divided the oil formation into main oil formation, potential oil formation, non-potential oil formation. Thus the parameters, amount and velocity can be adjusted by the conclusions. The intensive gas-injection was operated on main-oil formation which was isolated. The temperature was kept and low-pressure slow gas injection was taken on potential oil formation. We control the amount of gas on non-potential oil formation with economic aim. So we can make full use of the steam and improve the development effects in middle-end period.