Well production after hydraulic fracturing in sandstone rocks in the north of the Perm region

Abstract

Hydraulic fracturing is one of the most popular ways of increasing well production. The article investigates the results of hydraulic fracturing (HF) in sandstones of the northern Perm region territory (Tula–Bobrikovian oil reservoirs of the Visean stage). The oil of these sites has a high and medium gas content, and the rocks have a wide range of permeability values as well as natural cracking. Based on the value of the linear Spearman correlation coefficient, the most significant parameters affecting the efficiency of the HF are determined. A ranking of these parameters has been performed. The greatest influence on well productivity after HF is the bottomhole pressure and productivity indices before HF. The relationships between the geometrical dimensions of HF cracks and the volume of the injected proppant are shown. The dependencies of well parameters after HF on well parameters before HF are constructed. The permeability coefficients of the reservoir remote zone do not actually change much after HF and the permeability coefficients of the bottom-hole zone increase on average by 30%. The impact of the formation and bottomhole pre ssure values on productivity indices after HF has been noted. At the same time, the rate of oil production decrease after HF is also dependent on bottomhole pressures. Recommendations have been made on the selection of wells for HF at the site under study and similar production targets as well as their post-operation technology practices. Changes in well production after HF are forecasted depending on geological and technological parameters. The study was supported by the Russian Science Foundation, Project No. 19-79-10034.