三重介质油藏垂直裂缝井产量递减曲线

Production decline curve for wells with vertical fractures in triple-porosity reservoir

为解决三重介质油藏水力压裂后形成的有限导流垂直裂缝的不稳定渗流问题,建立考虑裂缝表皮因数的三重介质油藏有限导流垂直裂缝井数学模型,求得三重介质油藏有限导流垂直裂缝井无因次产量表达式,并绘制无因次产量随时间变化的双对数特征曲线图,对影响三重介质油藏有限导流垂直裂缝井产能的诸多影响因素进行分析.结果表明,裂缝表皮因数和无因次导流能力对垂直裂缝井产能的影响主要集中在生产早中期;三重介质油藏垂直裂缝井产量递减曲线类似于普通直井,具有2个相对平缓的递减阶段和2个快速递减阶段;用一算例说明预测三重介质油藏垂直裂缝井在未来某一时间的产量的方法.

In order to deal with the unsteady flow in wells with finite conductivity vertical fractures in triple-porosity reservoirs,mathematical models were developed,taking the fracture skin factor for wells with finite conductivity vertical fractures in triple-porosity reservoirs into consideration.The equation for bottom pressure of vertical fractured wells in triple-porosity reservoirs could be achieved using Laplace transformation.Then,the type curves of dimensionless rate to time could be drawn and influence factors could be discussed.The result indicated that fracture skin factor and dimensionless fracture conductivity are the obvious affecting factors to deliverability performance at early-middle production stage.It is shown that the type curves of dimensionless rate to time are similar to ordinary vertical wells.The curves have two relative mild decline stages and two speediness decline stages.Concrete methods of the decline applications,illustrated by an example of a fractured well in triple-porosity reservoirs,can be employed to obtain the fractured well production prediction.