Abstract
The article presents the results of the industrial application of gel polymer treatment of injection wells to enhance the oil recovery of high-viscosity oil in one of the fields of the Mangystau region (Kazakhstan). The theoretical foundations of the formation of the spatial gel structure of polyacrylamide in interaction with trivalent chromium ions are considered. The results of treatment of four injection wells with a viscoelastic compound (VC) based on polyacrylamide grade FP-307 and chromium acetate with a total volume of 300 m3 each are presented. It has been shown that the injection of gel–polymer compositions makes it possible to redistribute filtration flows in the bottomhole zone, involve low-permeability layers in development, and increase the oil flow rate of responding offset production wells by an average of 0.3-0.6 t/day while reducing the produced-fluid water cut by 2–10 percentage points. The duration of the effect on individual wells exceeds 200 days. A comparative analysis was carried out with global polymer flooding projects, including Pelican Lake (Canada), Daqing (China) and Uzen (Kazakhstan) fields. The technology has shown high adaptability and the absence of critical injection complications associated with premature gelation in the equipment, which confirms the correctness of the selected rheological parameters of the composition for reservoir conditions. The results obtained confirm the expediency of using gel polymer technologies to recover hard-to-recover viscous oil reserves from heterogeneous reservoirs of viscous oils from heterogeneous reservoirs.