Numerical Simulation Of "work" Type Cracks And Analysis Of Pressure Drop After Pressure

Hydraulic fracturing is a preferred method and main measure for coalbed methane production.After the fracturing construction,vertical and horizontal cracks may both appear in the coal seam.H-shaped fracture is one of the special and complex cracks.The correct understanding and accurate simulation of the fracture has important guiding significance to design and improve the fracturing plan.In this paper,we study H-shaped fracture by using numerical modeling and pressure decline analysis,the main research work is as follows:(1)It is show that H-shaped fracture is exist objectively by using field measurement,roadway excavation,analysising of fracturing work pressure.Based on the mechanism of hydraulic fracture,we analyze the reason of H-shaped fracture formation,and explore the field test of H-shaped fracture.(2)According to the characteristics of H-shaped fracture,the connection condition of H-shaped fracture is put forward,at the same time,This paper builds numerical simulation model of H-shaped fracture by means of numerical simulation model of vertical crack and horizontal crack,and the numerical solution is proposed.(3)The connection condition of H-shaped fracture is put forward by analyzing the characteristics of H-shaped fracture,then combined with classical model for pressure decline analysis of vertical crack and horizontal crack,the model for pressure decline analysis of H-shaped fracture is built,at the same time,the numerical solution of the model is given.(4)Based on the established numerical simulation model and pressure decline analysis model of H-shaped fracture,the software is developed,and applied to projects.Taking the microseismic monitoring as a reference,the comparative analysis shows the accuracy and reliability of the two models,at the same time,the calculating results of the two models are small,and they can verify and supplement each other,so that they both form a kind of method to simulating H-shaped fracture and analysising its pressure decline.