周边脱砂压裂模型优化设计

周边脱砂压裂技术是压裂技术从常规压裂到脱砂压裂,再到端部脱砂压裂技术之后发展起来的一种新的技术,只有该技术才可能在压裂中形成相对较短、较宽裂缝。目前对于脱砂压裂裂缝扩展模型的研究大都忽略了裂缝纵向流动。为此,在前人的研究基础上,针对周边脱砂压裂的特点将带缝高压降影响的拟三维模型引入到脱砂后裂缝扩展模型,在脱砂后模型中考虑缝宽方向压降对裂缝扩展的影响,推导了适合周边脱砂压裂的脱砂后新模型;并在此基础上开发了适合周边脱砂压裂扩展的模拟软件,模拟结果与现有商业软件(三维)模拟结果相吻合,证明建立的脱砂后模型考虑因素全面,对脱砂后缝宽预测更符合实际。

Optimization Design of Peripheral Sand-out Fracturing Model

The peripheral sand out fracturing is a new technology evolving after the conventional fracturing,sand-out fracturing and end sand-out fracturing.The technique could form shorter and wider fractures.Most related research on fracture extension model in sand-out fracturing overlooked the vertical flow of cracks.Therefore,based on present studies and aiming at the properties of peripheral sand-out fracturing,the pseudo-three dimensional model considering the fractured high pressure difference was introduced into the sand-out fracture extension model.In the model,the effect of pressure drop in the direction of crack width on the fracture extension was taken into consideration,and a new sand-out model appropriate for peripheral sand-out fracturing was derived.Meanwhile,useful simulation software appropriate for peripheral sand-out fracture extension was developed.Simulation results agreed well with the three dimensional results of available commercial software.It was validated the integrity in factor consideration for the established sand-out model.The model could provide more practical simulation on fracture width after sanding-out.