海上稠油油田化学驱潜力评价方法及其应用

Chemical flooding potential evaluation method in offshore heavy oilfields and its application

在平台有限的寿命期内采用常规注水方式开采,渤海稠油油田原油采收率只能达到25%左右,如何提高最终采收率是面临的问题。针对渤海稠油油藏不同类型油藏地质、开发条件,筛选出能够精确反映累积增油量曲线变化趋势的数学模型(即Gompertz模型),采用单因素分析方法讨论了各影响因素(注聚时机、原油黏度、地层温度、地层水矿化度和钙镁离子含量)对模型特征参数的影响;在此基础上,通过多元非线性回归,分6个区间建立了化学驱提高采收率潜力预测模型。利用该模型对渤海稠油油藏化学驱技术适应性和潜力进行了评价,结果表明渤海油田实施化学驱的潜力巨大,平均提高采收率幅度为6.46%。本文研究为扩大提高采收率技术在渤海油田的应用规模提供了技术依据。

The recovery factor of heavy oilfield in Bohai Bay can only reach 25 % by conventional water flooding in the limited life cycle of platform. How to improve the ultimate recovery is a facing problem. Gompertz model which can accurately reflect the cumulative increased oil production curve variation trend is selected for different types of reservoir geology and development conditions. The impact of such factors as polymer injection timing, oil viscosity, formation temperature, and calcium and magnesium ions content in formation water on the characteristic parameters is discussed using single factor analysis method. The potential prediction models of enhanced oil recovery by chemical flooding for 6 divided intervals are established with multivariate nonlinear regression. The adaptability and potential of chemical flooding in Bohai oilfield is evaluated with the model. The results show that the potential of chemical flooding is tremendous and the average enhanced oil recovery rate is 6.46 %, which indicates that enhanced oil recovery technology in Bohai oilfield should be expanded.