Quantitative Characterization Method for Interwell Connectivity Change Based on Improved Capacitance-Resistance Model

In the late stage of waterflooding development, identifying the causes of oil well inefficiency is an important means to improve oilfield development effect. In view of the problem that the solution result of the capacitance-resistance model is only the contribution rate of water injection, the capacitance-resistance model is improved, and the calculation formula of the interwell connectivity is derived. According to the formula, the proportion of external energy supply is calculated to determine whether there is sufficient energy supply around the oil well. Then the dimensionless interwell connectivity is introduced to realize the quantitative characterization of interwell connectivity change between wells. It can further identify whether the cause of oil well inefficiency is reservoir blockage, preferential flow path, or just pump efficiency problems. Finally, according to the reasons of low efficiency, the corresponding governance strategies are made. The research has been applied in the southern Bohai Sea oilfield, 13 wells were effectively guided to implement corresponding measures, including plug removal, profile control, pump inspection, etc. After the adjustment, the total daily oil production has increased by 508 cubic meters per day.