位错模型在低渗透储层裂缝预测中的应用

Application of dislocation model in fracture prediction of low-permeability reservoir

分析了位错模型在低渗透储层裂缝预测分析中的可行性,基于位错模型,给出了裂纹附近应力场计算方法,并利用位错塞积机制和断裂力学模型,建立了储层裂缝预测模型。通过定义储层裂缝发育指数及采用等级划分的方法,对储层裂缝发育情况进行评价分析。以江苏油田W油区阜一段储层为试验研究对象,利用多目标约束的最优化方法,分析了该断块油藏构造应力场分布规律以及储层裂缝发育程度和分布规律,确定了裂缝相对发育区域。模拟结果与研究区块关键井点处的实测值吻合较好,计算精度能够满足实际工程的需求。

The feasibility of dislocation model was analyzed in the prediction of fractures in low-permeability reservoir. A calculating method of stress nearby the crack was deduced using the dislocation model. A predicting model for fractures was established on the basis of the dislocation pile-up mechanism and fracture mechanics theory. The fracture-developing index and the grade classification method of fracture were proposed and applied to evaluate the development degree of reservoir fractures. Taking the reservoir of E1 f Member in W Block of Jiangsu Oilfield as the studied object, the development and distribution laws of reservoir fractures were analyzed with the multi-objective constraint optimization method,and the fracture-developed zones were determined. The simulated data are in good agreement with the measured values in some wells of this reservoir. The calculating accuracy of the dislocation model can meet the demand of actual project.