幂律型稠油在压敏油藏中的压力及产能研究

Pressure distribution and oil well productivity in pressure-sensitive reservoir with heavy oil of power law seepage feature

为了解决已有的压敏油藏压力及油井产能计算方程无法考虑幂律型稠油的问题,基于压敏油藏以及具有幂律型稠油油藏的渗流理论,推导了压敏油藏中幂律型稠油油藏压力分布和产能方程,并通过实例进行了验证.对压力分布特征及影响油井产能的因素进行了分析.结果表明,稠油幂律性对压力分布影响明显,同时,由于压降漏斗的存在,渗透率在生产井附近也呈漏斗状分布.地层原油的幂律指数越小,压敏指数越大,生产井产能越低.压敏油藏的生产井存在最优生产压差,在实际生产中应予以考虑.

The existing pressure distribution and oil well productivity equations for pressure-sensitive reservoirs can not describe the effect of heavy oil of power law seepage feature.Based on the seepage theories in the pressure-sensitive reservoirs and the reservoirs with heavy oil of power law seepage feature,the pressure distribution and oil well productivity equation in the pressure-sensitive reservoirs with heavy oil of power law seepage feature are derived,and they are verified by examples.The pressure distribution features and the influencing factors of the oil well productivity are analyzed.The analysis shows that the power law character of heavy oil seepage has a great effect on the pressure distribution,and the permeability distribution around production wells presents a funnel shape because of the funnel-shaped pressure distribution.The less the power law index and the greater the pressure-sensitive index,the lower the oil well productivity.There is an optimal production pressure difference of the oil wells in pressure-sensitive reservoirs,which must be considered in the production design of oil wells.