The Study Of Hydraulic Fracture Propagation Influenced By Gravel In Sand-gravel Reservoir

Because of high buried depth heavy thickness significance inhomogeneous of reservoir layer and existence of micro-fracture, it bring lots of difficulties for fracturing design and optimizing in-situ construction work. The existence of gravel contributing to low success ratio high probability of sand bridge and out of control of fracture propagation ,all of this could find answer in obscure understand of mechanism and regularity of fracture propagation in sand-gravel reservoir.As to theoretical analysis, we could get high nonlinear fluid-solid coupled partial differential equation, hard to resolve and may get void non-valuable results for engineering application. What's more, different situation may different restriction for in-situ testing. So laboratory testing and numerical simulation play important role and may have more valuable and effective results. In this paper we will first use artificial core sample to do laboratory experiments so we could get some knowledge of the influence of different type of gravel in fracture propagation. Then we will design the numerical simulation of fracture propagation in sand-gravel reservoir. With different gravel content and particle we could see the different influence in fracture propagation. Taking experiment and simulation results into consideration, we may find some rule of fracture propagation in sand-gravel reservoir. At last, we succeed in guiding the implementing of five in-situ sand-gravel well fracturing treatment in yan-22 and yong-920 in shengli oil field.