Research and Application of High Wax and Low Permeability Reservoir Protection Technology
摘要
The Banqiao Oilfield has a low permeability and high wax content reservoir, with low viscosity and high wax content in crude oil. The reservoir is characterized by low porosity and permeability, strong water sensitivity, well fluid intrusion changes the temperature field. The crude oil undergoes wax precipitation, crystallization, and aggregation, combined with dispersed clay minerals and sediment, resulting in serious blockage of the wellbore and near wellbore areas. In response to this problem, a high wax content and low permeability reservoir protection technology is formed by combining physical heating with chemical anti waxing, and the synergistic effect of various reservoir protective agents. The experimental results show that after using this technology, the viscosity of high wax crude oil decreased from 187 to 28 mPa s at 20 °C, the anti-wax rate reaches 41%, the anti-swelling rate of the system reaches 90.5%, and an interface tension is as low as 0.126 mN/m. This can effectively prevent damage such as wax deposition blockage, water sensitivity, and water locking. The technology has been applied 18 Wells in Banqiao Oilfield, and the average recovery rate of the applied wells has increased from 85 to 93.2%. The average recovery rate has been shortened from 6 to 4.8 days, and the reservoir protection effect is good.