Experimental Study On The Law Of Settlement And Migration Of Proppant In Fracture

Shall gas is a widely distributed gas resources with tremendous potential for development. Hydraulic fracturing is one of formation stimulation techniques, which plays a very important role in the stimulation of shale gas. As the distribution of proppant is governed by the mechanism of proppant transport, which finally decided the fracturing effect. It is quite necessary to make an in-depth study on the mechanism of proppant transport.Based on plenty of literature investigation and field data collection, we completed the following work:(1) Analyzed the key factors which affecting the transport based on the mechanism of proppants settlement rules and select the main factors of physical experiments.(2) Revealed the limitation of Babcock’s model by using it to evaluate the shape of proppant bank on the base of field operating data.(3) Developed the previous multi-fracture experimental equipment according to the feature of fracture networks and completed the construction of the new equipment.(4) Established a3D model of the developed equipment and used the Fluent software to simulate the proppant transport, which verified the rationality of parameters in physical experiments.(5) Experimental researches were made by using developed equipment under different conditions and the influences of proppant properties, fracturing liquid properties, pumping construction conditions and number of fractures on the distribution of proppant have been analyzed.(6) Further researches of the proppant transport within the fracture patterns have been reveals by means of the combination of physical experiment and numerical simulation.The following three breakthroughs were made in this paper:(1) Design physics experiments of single fracture and multi-fracture in different conditions, which more in line with the characteristics of shale gas fracturing operation.(2) Two new characterization parameters, the slope of the front of the poppant bank and the distance between the entrance of fracture and the front of the proppant bank have been presented.(3) By means of the combination of physical experiment and numerical simulation, comprehensive analysis and evaluation method has been established. It is significant for the establishment of a more rational model of proppant transport and the design of fracturing treatment in the shale reservoir.