面积注水开发指标计算方法的改进

应用等值渗流阻力法全面考虑油水渗流阻力的影响,推导出了面积注水油藏见水前后油水井的单井产量公式。考虑水驱过程中油藏内各点含水饱和度的变化,应用物质平衡方法推导出了油井见水的开发时间的计算公式。在开发时间的计算公式中同时引入了面积修正系数并给出了五点井网和反七点井网面积修正系数的计算公式,使油井见水的开发时间的计算精度大大提高——反七点井网的见水时间可减小偏差21%、五点井网的见水时间可减小偏差57%.计算实例表明,应用改进后方法得到的计算结果符合水驱油藏的开发规律。

Improvement of Development Index Calculation Methods for Areal Pattern Waterflooding Process

The single well production formulae for pattern waterflooding reservoirs before and after water breakthrough were derived using equivalent filtrational resistance approach to consider the oil-water filtrational resistances.The theoretical formula for water breakthrough time of a producer was derived by using material balance equation and considering the varied water saturations in various points of a reservoir during waterflooding process,in which the modified area coefficient was introduced and the amended formulae for five-spot and inverted seven-spot patterns were given.The case study shows that the calculation accuracy of water breakthrough time can be greatly improved by deviation reduction of 21%for inverted seven-spot pattern and 57% for five-spot pattern.The results are accordant with the exploitation reality of waterflooding reservoirs.