深层油藏传热模型及油柱高度计算

Heat Transfer Model of Deep Reservoir and Calculation of Oil Column Height

深层油藏储层埋藏深、厚度大,油井难以钻穿整个油层。针对深层油藏油柱高度的计算问题,考虑在油井投产后从油水界面到井底的垂向传热过程,建立了一个深层油藏传热模型。利用变量代换、分离变量及傅里叶变换等方法对模型进行了求解,获得了油藏油柱高度计算式。只需利用油井投产前和投产一段时间后的井底温度数据,便可计算油柱高度。以塔里木盆地某深层油藏某油井为例,展示了油柱高度的计算与应用。同时,利用该井的基础数据,代入传热模型,模拟计算了油井投产后不同时间下不同油层位置的温度值和温度梯度值,进而绘制了不同生产时间下储层温度分布曲线和不同储层位置处的储层温度动态变化曲线,结果表明油井投产后的储层温度分布呈非线性的动态变化特征。建立的传热模型可为深层油藏油柱高度的计算提供技术支持。

Deep oil reservoir is characteristic of deep buried depth and large thickness,and is hard to drill through the oil formation.To address the issue of oil column height calculation for deep oil reservoirs,we established a heat transfer model of deep reservoir by considering the vertical heat transfer process from the oil-water interface to the wellbore after well production.We solved the model using variable substitution,variable separation and Fourier transform,and then derived the calculation formula of oil column height.By only using the temperature data at the bottom hole before and after well production,we can calculate oil column height.A pilot test was carried out at an oil well of a deep reservoir located at Tarim Basin to demonstrate the calculation process of oil column height.At the same time,by substituting the testing well data into the heat transfer model,we simulated the values of formation temperature and temperature gradient at different location of the oil formation at different production time.Then,we plotted the temperature distribution curve for different production time and the dynamic temperature curve for different formation location.The simulation results showed that formation temperature distribution took on nonlinear dynamic variation characteristics.The established heat transfer model is a good tool to calculate oil column height for deep oil reservoirs.