Analytical forced imbibition model considering flow rate in fracture and oil droplet detachment

Abstract The analysis of forced imbibition efficiency has always been a hotspot in various research domains. The difficulty of forced imbibition lies in the nonlinear imbibition equations coupling with the dynamic flows in fracture. This paper proposed an analytic solution for forced imbibition by coupling spontaneous imbibition and flow rate in fracture, using the relationship between flow velocity, detachment of oil droplet and boundary saturation of matrix. This method gives an efficient computational method for forced imbibition efficiency evaluation, the saturation distribution at any time, any location in matrix could also be obtained. Results verified that forced imbibition has a better efficiency than spontaneous imbibition, depending on the flow velocity in fracture, fracture width, wettability, interfacial tension and droplet size, the relationship between those parameters are also given. The flow velocity affects imbibition efficiency by changing boundary saturation. Higher velocity in fracture, lower interfacial tension and contact angle are beneficial for forced imbibition efficiency.