An Integrated Working Fluid for Blocking Removal and Sand Control in Offshore Wells Blocked by Particle Migration

In view of the serious decline in productivity of wells blocked by particle migration in offshore oil fields, the conventional technological measures of sand control after acid plugging removal often have shortcomings such as long operation period, high cost and poor construction effect. Therefore, the integrated technological measures of understanding plugging and controlling sand are studied. With compound organic acid HCW-2, resin HWR301S and curing agent HWR302S as main treating agents, a set of integrated working fluid system for removing blockage and controlling sand suitable for wells blocked by particle migration in offshore oil fields was developed, and its comprehensive performance was evaluated. The results show that the system has strong sand control ability and can still maintain high sand control efficiency under high flow rate (120 mL/min) and long time (720 min) displacement. Injection of integrated working fluid for plug removal and sand control can effectively remove the plug damage caused by particle migration, and the greater the injection flow rate, the better the plug removal effect; In addition, the system has low viscosity, pH value and surface tension, which is beneficial to its injection and flowback. The system has good anti-swelling performance, corrosion inhibition performance and stable iron/calcium ion performance, which can ensure the safety of the construction process and will not cause secondary damage to the formation. According to the comprehensive analysis of the research results, the developed integrated working fluid system for plug removal and sand control can not only remove the blockage caused by particle migration, but also play a good role in sand control, thus achieving the purpose of long-term plug removal and increasing production.