密闭取心饱和度校正新模型

A new saturation correction model for the samples from sealed coring wells

为准确求取密闭取心饱和度,在前人分析流体饱和度损失变化主要影响因素的基础上,考虑岩心从地下至地面压力系统变化引起的岩心孔隙体积、流体体积的变化及降压脱气排液对密闭取心饱和度的影响,引入了应力敏感效应对孔隙体积的影响,同时考虑了流体在地下始终遵循物质平衡原理,从渗流力学角度推导了一种新的密闭取心饱和度校正模型。利用本文模型对南海西部W油田A井78块密闭取心饱和度进行了校正,结果表明,不论是未开发层还是已处于高含水阶段的层位,本文模型校正结果相对于实验校正结果均更符合油田开发实际,证实了本文方法的合理性和推广价值。

To accurately calculate the saturation of the sealed core sample, a mathematical model of satura- tion correction with material balance and seepage mechanics principle is derived based on the previous study about the main factors influencing the loss of fluid saturation change, in which the effect of stress on pore volume has been introduced, and the effects of core pore volume change with pressure, the fluid volume variation caused by pressure decreasing, and degasification on saturation are considered. With this model, saturation corrections of 78 sealed cores have been completed for Well A in W oilfield, and the results indicate that the correction model results are more applied to oilfield compared with experiment calibration in both undeveloped layers and high water cut layers.