Research On The Law Of Proppant Settlement And Migration In Fractures Of Horizontal Wells In Tight Reservoir

Hydronic fracturing in horizontal wells is widely used in tight reservoir stimulation.Slick water and linear gel which have different characteristics compared with conventional cross-linked fluid are generally chosen to be the fracture fluid.How proppant sets and transports in the slick water & linear gel and how the sand distributes in the fracture have not been understood clearly which makes it necessary to have a deep study on.In this paper,the rheological properties of slick water & linear gel are tested and how the temperature,concentration and standing time affect rheology are studied.Meanwhile both flow index and consistency index of slick water are acquired in the experiment.The fracturing fluid rheological characterization models of slick water have been established.Experiments are designed to handle the law of proppant settlement in slick water & linear gel,Danish's law is proved to be an accurate method in predicting the proppant settlement velocity in certain fracturing fluid.The influence of facture wall and proppant sphericity on proppant settling velocity are obtained and the setting law of proppant in the slick water & linear gel is established.Single-straight fracture model is designed and established to study the law of proppant transport.Besides,how the construction affects transport velocity,sand shape and height at the state of equilibrium can be analyzed.New methods are proposed to describe the overall velocity of proppant and the degree of filling near wellbore,while the formation of the sand bank is observed and analyzed.Cross-fracture model is also established to study the distribution law of proppant in the simple fracture network and the influence of the angle of hydronic fracture and nature fracture are also been discussed.