海上油藏流场评价方法

Study on Evaluation Method of Flow Field in Offshore Oil Reservoirs

针对海上油藏流场优势通道及驱替的不均匀性评价难的问题,该文利用基于海上高含水阶段油田评价的新参数,分析水分流量关系曲线规律,得到水分流量、动用系数和通量强度3个用于表征海上油藏流场的参数。通过特征分级点法对流场进行分级,由通量强度与水分流量关系曲线的线性段特征、油水相渗比值半对数曲线直线段上拐点确定3个特征分级点,建立起“三点四级”指标流场表征法。将研究成果应用于海上油藏的流场评价中,结果表明:3个分级点水分流量为22%、73%和90%时能够分别对流场的潜力情况、动用状况和优势与否给出明确的界限。该流场评价方法为海上油田后期的流场重构和开发效果改善具有一定的理论指导意义。

Aim to the difficulties during the evaluation of favourable channels and displacing heterogeneity,namely water fractional flow,development coefficient and flux intensity were obtained to characterize the flow field of offshore oil reservoir,by the law of the water fractional flow relationship curve,in combination with new parameters based on the evaluation of offshore oil oilfields in the high water-cut stage.The flow field was classified with feature classification point method.Three feature classification points were determined by the characteristics of the linear section of the relationship curve of flux intensity and water flow rate and the inflection points on the linear section of the semi-logarithmic curve of the oil-water permeability ratio,and a"three-point and four-level"index flow field characterization method was established.The study results were applied to the flow field evaluation of offshore oil reservoirs,and the results showed that when the water fractional flow of the three classification points was 22%,73% and 90%,respectively,the potential,development status and dominance of the flow field can be clearly defined.This flow field evaluation method is of certain theoretical guiding significance for the flow field reconstruction and development effect improvement in the later stage of offshore oilfields.