利用毛细管压力计算低渗储层可动水饱和度

Calculation of mobile water saturation of low permeability reservoir
with capillary pressure curve

王庆勇

Wang Qingyong

上海石油天然气有限公司，上海 200041

Shanghai Petroleum Corporation Limited, Shanghai 200041, China

平湖油气田P11层是一高压低渗储层，试油及常规测井都不能很好地确定该层的产油产水比例，对该油藏的产出流体及生产预测带来了困难。为解决这一问题，提出利用储层流体浮力与毛细管压力平衡的原理求解储层初始含水饱和度。在求解过程中，利用J函数及储层孔、渗资料对毛细管压力参数进行了处理。通过与毛细管压力计算的束缚水饱和度比较，得到储层可动水饱和度，进而定性判断储层是否产水。利用相渗曲线及储层初始含水饱和度，可以计算储层的初始含水率。根据P11层毛细管压力实际资料，利用该方法计算出了储层可动水饱和度及含水率，与实际生产含水率相符，表明计算方法正确。此方法有助于提高低渗储层开发动态指标预测的精度。

P11 reservoir of Pinghu oil and gas field is a reservoir with high pressure and low permeability. Well test and mud logging methods were used to calculate oil production and water cut of this reservoir, but the results did not sound well, which brings the difficulty to predict the produced fluid and production for the oil reservoir. In order to solve this problem, the principle that reservoir fluid flotation is balanced by capillary pressure is used to calculate the initial water saturation of reservoir. In the process of solving, the capillary pressure is processed using J function and porosity data and permeability data of reservoir. By comparing with the bound water saturation calculated by capillary pressure, we can get mobile water saturation, and this can be used to determine whether the reservoir produces water. By using the relative permeability curve and the initial water saturation of reservoir, the initial water cut can be calculated. Based on the actual capillary pressure data of P11 reservoir, mobile water saturation and water cut of the reservoir are calculated through the use of the method. After comparing the actual water cut of P11 reservoir with the calculated results, it shows that this calculation method is correct and is helpful to enhance the prediction accuracy of development index for low permeability reservoir.

10.6056/dkyqt201301021