原油体积系数理论方程推导及应用

Derivation and Application of Crude Oil Volume FactorTheoretical Equation

原油体积系数是勘探开发过程中认识、评价油藏的重要参数,由于直接获取原油体积系数数据的原油高压物性(PVT)分析法受取样成本和取样条件等限制,造成绝大多数评价单元该资料缺失,目前最常用的类比法或经验公式法确定的原油体积系数精度明显偏低。为解决这一问题,以原油体积系数定义为理论基础推导并建立了原油体积系数理论方程。在实际应用方面,新建原油体积系数理论方程明显优于体积系数定义给出的理论方程,新方程涉及的参数均可以在地面条件下通过取样分析等方式获取。用新方程计算原油体积系数不仅大幅降低了原油PVT取样分析成本,计算精度也由经验公式的89.4%提升到新方程的96.5%,应用范围可扩展到油藏勘探开发任何阶段,具有推广应用价值。

The volume factor of crude oil is an important parameter for the understanding and evaluation of oil reservoirs in the process of exploration and development.Most of the evaluation unit information is missing due to the limitations of the high-pressure physical property(PVT)analysis of crude oil with direct access to crude oil volume factor data,such as sampling costs and conditions.The accuracy of the volume factor of crude oil determined by the currently most commonly used analogy or empirical formula method is significantly lowered.In order to solve this problem,the theoretical equation of crude oil volume factor is derived and established based on the definition of crude oil volume factor.In practical application,the newly established theoretical equation of crude oil volume factor is obviously superior to the one given in the definition of volume factor.The parameters involved in the new equation can be obtained by sampling analysis under ground conditions.The crude oil volume factor calculated by the new equation not only significantly reduces the cost of crude oil PVT sampling analysis,but also increases the calculation accuracy from 89.4%in the empirical formula to 96.5%in the new equation.The application range can be widened to any stage of oil reservoir exploration and development,and embraces great value for promotion.