玛湖油田致密砾岩油藏压裂数值模拟研究

为全方位掌握玛湖油田致密砾岩储层条件,减小井间裂缝干扰,实现精准压裂并完成产能预测,采用地质、地应力、压裂耦合的模拟方法,建立三维数值模型。以玛湖致密油藏试验区为例,依据现有地质资料完成单井地应力模型,在此基础上建立准确的三维地应力模型,并加载人工裂缝模型,通过耦合压裂模型,研究区域压裂施工完成后地应力随时间与空间的变化规律,并与静态地质条件下的人工裂缝形态进行对比。研究表明:三维数值模型拟合得到的生产指标准确性高,具有实用价值。利用三维数值模型得到玛湖致密油藏试验区X井工程参数并进行压裂施工,投产后300 d内平均日产油量为23.4 t/d,平均油压为22.3 MPa,稳产时间长。该研究对于优化压裂设计、降低应力阴影的干扰具有指导意义。

Numerical Simulation on Fracturing in Tight Conglomerate Reservoir of Mahu Oilfield

In order to fully understand the conditions of tight conglomerate reservoir in the Mahu Oilfield, reduce the interference of inter-well fractures, achieve precise fracturing and complete productivity prediction, a three-dimensional numerical model was established with the simulation of geology, in-situ stress, and fracturing coupling. Taking the experimental area of the Mahu tight oil reservoir as an example, a single well in-situ stress model was completed according to the existing geological data, an accurate three-dimensional in-situ stress model was established on the in-situ stress model, and an artificial fracture model was loaded. With the coupled fracturing model, the rule of in-situ stress changing with time and space after the fracturing was completed in the study area was analyzed and compared with the artificial fracture morphology under static geological conditions. It was found in the study that the production indicators obtained by fitting the three-dimensional numerical model were highly accurate, with practical significance. The three-dimensional numerical model was used to obtain the engineering parameters of Well X in the experimental area of the Mahu tight oil reservoir. After the reservoir was put into production, the average daily oil produced was 23.4 t/d within 300 days, the average oil pressure was 22.3 MPa, and the stable production duration was long. This study will be in favor of optimizing the fracturing design and reducing the interference of stress shadow.