储量动用程度对理论水驱递减规律的影响分析

Analysis on the influence of reserves utilization degree on the theoretical water flooding decline law

针对目前常用的水驱油藏理论递减率的计算方法假设条件过于理想化的问题,从理论递减率表达式出发,引入水驱储量动用程度,推导得到了理论递减率修正公式。以定液量开发为例,结合渤海SZ油田基础数据,绘制了不同水驱储量动用程度影响下的理论递减曲线,可以看出,在相同的采液速度条件下,水驱动用储量越低,递减率越大;相反,若油田水驱动用程度得到提高,那么其理论递减率将减小。渤海28S油田应用结果表明,新的公式评价结果更加科学、合理,对油田实际工作中的动态分析与开发评价更具有现实意义。因此,对于储层横向变化快、注采连通性较差的油田,建议应充分考虑水驱储量动用程度的影响,以使评价结果客观、合理。

Aiming at the problem that the calculation method for the theoretical decline rate of water flooding reservoirs is too idealized,stemming from the expression of theoretical decline rate,and by introducing the idea of water flooding reserves utilization degree,it is able to deduce the revised formula of theoretical decline rate.Taking the development of fixed liquid volume as an example,combined with the basic data of Bohai SZ oilfield,the theoretical decreasing curves under the influences of different water flooding reserves utilization degrees were plotted.It can be seen that under the same liquid production speed,the lower the water flooding reserves utilization degree,the larger the decline rate;on the contrary,if the utilization degree of water flooding in the oilfield is increased,the theoretical decline rate will be decreased.The application results of this formula in Bohai 28S oilfield show that the evaluation results of new formula are more scientific and reasonable,and it exhibits more practical significance for the performance analysis and development evaluation of oilfield.Therefore,for oilfields with rapid lateral variations of reservoirs and poor injection-production connectivity,it is suggested that the influence of the reserves utilization degree of water flooding should be fully considered to make the evaluation results more objective and reasonable.