低渗透带隔板底水油藏油井见水时间预测

基于底水锥进和低渗透非达西渗流原理,考虑隔板下部底水锥进的半球形径向渗流方式和隔板上部的平面径向渗流方式,运用物质平衡原理,推导低渗透带隔板底水油藏油井见水时间的预报公式。经鄂尔多斯盆地砂岩底水油藏某油井的实际计算,预测的见水时间与实际见水时间接近,相对误差仅7.85%。另对鄂尔多斯盆地huc油田hu152区c3油藏6口带有天然隔板的油井进行了见水时间计算,有5口井预测见水时间与实际见水时间相对误差小于10%。对于低渗透带隔板底水油藏,由于考虑了启动压力梯度项,计算出的油井见水时间要比不考虑启动压力梯度项时的值更小,也更接近实际。

Prediction of water breakthrough time for oil wells in low-permeability bottom water reservoirs with barrier

Based on water coning and non-Darcy flow theory, a water breakthrough time prediction equation for low-permeability bottom water reservoirs with barrier is derived by material balance principle, which takes the hemispherical radial flow below barrier and plane radial flow above the barrier of water coning into consideration. The calculated water breakthrough time of a oil producer in the sandstone bottom water reservoir in the Ordos Basin by this equation is close to the real water breakthrough time, with a relative error of only 7.85%. In addition, the water breakthrough time of six wells with natural barrier in c3 reservoir, Block hu152, Ordos Basin, were calculated, among which the predicted water breakthrough time of five wells has a less than 10% relative error with the real water breakthrough time. For low-permeability bottom water reservoirs with barrier, the calculated water breakthrough time considering start-up pressure gradient is smaller and more accurate than that without considering start-up pressure gradient.