X油田低饱和度复杂油水层测井识别及产能预测方法

Logging identification and productivity prediction method for low-saturation complex oil-water layers in X Oilfield

为解决X油田S油层组低饱和度油层复杂油水层识别及两相流体产能预测这个难题,笔者应用岩心配套实验资料,考虑含泥、含钙的影响建立变指数“新三水饱和度模型”。同时对传统的相渗计算方法进行改进,在此基础之上,创建了双饱和度交会法、饱和度动态下限法及可动流体含油饱和度法等多种油水层判识技术,融合反映储层品质、原油性质及压裂规模的多参数建立了两相流体压前及压后产能预测技术。10口井验证结果表明:流体识别符合率由75.0%提高到87.2%,产能预测级别符合率达到83.3%,实现了油水同层精细识别、分级评价及油水产出比例定量评价。

To address the challenge of identifying low-saturation oil layers and complex oil-water layers in the S reservoir group of X Oilfield,as well as predicting the productivity of two-phase fluids,the authors applied experimental data from core analysis and considered the effects of clay and calcium content to establish a variable exponent“new three-water saturation model”.At the same time,improvements were made to the traditional relative permeability calculation methods.Based on these improvements,several oil-water layer identification techniques were developed,including the dual saturation crossplot method,the dynamic saturation lower limit method,and the movable fluid oil saturation method.By integrating multiple parameters that reflect reservoir quality,crude oil properties,and fracturing scale,a two-phase fluid productivity prediction technology was established for both pre-fracturing and post-fracturing conditions.The verification results from ten wells showed that the fluid identification accuracy improved from 75.0%to 87.2%,and the productivity prediction accuracy reached 83.3%,achieving precise identification of oil and water within the same layer,graded evaluation,and quantitative assessment of the oil-water production ratio.