水驱油田产量理论自然递减规律研究

Natural decline regularity study on water drive oilfield production

从水驱油田递减率方程出发,结合含水上升率方程及相对渗透率曲线,从理论上推导出定液量和定生产压差条件下的自然递减率与含水上升率的关系表达式,使其与目前含水上升规律研究成果及相渗研究成果相匹配。在定液量的条件下,自然递减率与含水上升率的变化规律一致;在定生产压差的条件下,自然递减率主要受无因次采油指数的影响,随含水率的变化呈现出三种形态特征。

Starting from decline rate equation of water drive oilfield,combining with water cut rising rate equation and the relative permeability curve,the relationship expression between natural decline rate and water cut rising rate has been theoretically deduced under the condition of certain liquid quantity and certain production pressure difference so as to match up with the current law of water cut rising research results and relative permeability results.Under the conditionof fixed fluid volume,natural decline rate is in accordanc with the change rule of water cut rising rate.Under the con dition of constant production pressure difference,the natura decline rate is mainly influenced by dimensionless oil produc tion index,and presents three kinds of morphological charac teristics along with the water cut variance.