摘要
针对密闭取心过程中孔隙、流体体积和溶解气随压力下降而改变导致测试饱和度出现较大误差的问题,应用油藏工程和渗流力学等理论与方法,基于溶解气驱理论和多相流分流量原理,建立了综合考虑孔隙、流体体积和溶解气随压力变化的岩心饱和度校正动态模型,编制了相应的计算流程,并评价了各影响因素的敏感性。结果表明:按岩心综合油水饱和度改变率大小排序,影响密闭取心饱和度的因素依次为溶解气体黏度、溶解气油比、原油体积系数、原油黏度、油水相对渗透率、原油压缩系数和岩石压缩系数。密闭取心饱和度校正动态模型能够反映压降过程中岩心的饱和度变化,吻合取心过程中的变化趋势,且校正结果和标定饱和度的相对误差平均为0. 8%,可为分析实际油藏油水饱和度分布提供可靠的依据。
In the process of sealing coring, pore, fluid volume and solved gas vary with the decline of pressure, and consequently the error of measured saturation is larger. To solve this problem, a dynamic model for core saturation correction was developed according to reservoir engineering and seepage mechanics, combined with dissolved gas drive theory and multi-phase fractional flow principle. In this model, the variation of pore, fluid volume and solved gas with the pressure is considered comprehensively. Then, the corresponding calculation procedure was put forward and the sensitivity of all influential factors was evaluated. It is indicated that according to the change rate of composite oil/water saturation of cores, the factors affecting the saturation of sealing cores are ranked from the top to the bottom as dissolved gas viscosity, dissolved gas-oil ratio, crude oil volume factor, oil viscosity, oil/water relative permeability, oil compressibility and rock compressibility. To sum up, the dynamic model for sealing core saturation correction can reflect the variation of core saturation in the process of pressure decline, which is in accordance with the change trend in the process of coring. In addition, the average relative error between the correction result and the calibrated saturation is 0. 8%. Therefore, the dynamic model can provide the reliable basis for analyzing the distribution of oil/water saturation of actual oil reservoirs.
作者
涂彬
李杰
TU Bin, LI Jie(State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China)
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2018年第4期460-467,共8页
Oil Drilling & Production Technology
基金
国家科技重大专项"多气合采钻完井技术和储层保护"(编号:2016ZX05066002)
关键词
岩心物理实验
密闭取心
流体饱和度
校正模型
敏感性分析
physical experiment on cores
sealing coring
fluid saturation
correction model
sensitivity analysis