Mechanical Modeling of Fracturing Proppant in Horizontal Well and Study on Mechanism of Reflowing Sand

Abstract:
Horizontal well staged fracturing technology has become the main technologies of exploiting low permeability oil and gas reservoirs since its emergence. However, the fracturing effect cannot be correctly evaluated due to the fracturing backflow of sand, which seriously restricts the development of technical advantages. In this paper, the particle dynamics theory and fluid mechanics theory are applied to the establishment of sand production prediction model for horizontal wells according to the different stress state of horizontal wells and diameter proppant particles before and after fracture closure. Considering the factors such as fracturing fluid loss and fluid physical properties, the mechanical model of horizontal well fracturing proppant and the mechanism of sand body flowback are emphatically analyzed. The critical flow rate prediction formula of proppant backflow in horizontal well fracturing fluid is derived, and the sand production analysis and prediction software is compiled. The accuracy of the model is verified by the actual sand production monitoring data of gas wells in the second gas production plant of Changqing Oilfield. The results confirm that the calculation results of the mechanical modeling and the flowback critical flow model in this paper are close to the actual sand production field data. The calculation model in this paper can provide a reference for formulating a reasonable staged fracturing fluid backflow system in horizontal wells to effectively control proppant backflow.