异常高压特低渗透油藏产量递减规律预测方法

Forecasting method of production decline law of the ultra-low permeability oil reservoirs with abnormal pressure

异常高压特低渗透油藏多采用人工压裂开采,以获得较高的产能。此类油藏一般注水困难,多依靠较充足的天然能量开发,开发过程中油井产能受地层能量衰减、压敏效应、启动压力以及压裂裂缝导流能力衰减等因素的影响。在充分考虑其影响因素的基础上,以稳态渗流为基础,建立了产量递减规律的半解析方法和流固耦合渗流数学模型,实现了利用数值模拟方法来预测异常高压特低渗透油藏产量递减规律。应用这2种方法对博兴洼陷高89区块的12口井产量递减规律进行拟合和预测,根据预测的产量递减规律,优化出井底压力保持在13MPa时,累积产油量最高。

Ultra-low permeability oil reservoirs with abnormal pressure are mainly developed with artificial fracturing for achieving high productivity. This type of oil reservoir has enough natural energy for development and is difficult for water flooding. The productivity is affected by many factors,such as the formation energy declining,pressure sensitive effect,actuating pressure and the decreasing of fracture flow capacity. Semi-analytic method and mathematic model of fluid-solid coupling flow were established based on the influencing factors and time invariant seepage. Numerical simulation method can be used for forecasting production decline law in the uhra-low permeability oil reservoirs with abnormal pressure. The two methods were applied to the matching and prediction of production decline laws in 12 wells,Block Gao89 in Boxing Depression. When bottom pressure is defined at 13MPa,cumulative oil production is the highest.