Experimental Study on Diverter Transport Through Perforations in Multicluster Fracturing of Horizontal Well

Temporary plugging and diverting fracturing of the horizontal well is the primary option to promote production for tight reservoirs. Successful entry of diverters into the perforation is the basis and prerequisite for effective plugging. However, the transport behavior of the diverter during multicluster fracturing remains unclear. In this paper, we build a large--scale diverter transport experimental system, capable of conducting experiments with large flow rates and high pressures. The concerned factors include the injection rate, perforation flow ratio (PFRO), fluid viscosity, and perforation angle. The results show that the diverter transport effect is significantly different because of different flow distribution among perforations. Also, the diverter can enter the perforation only when the flow rate of the perforation reaches a certain value. In addition, the minimum critical PFRO has an oblique L-shaped relationship with the injection rate. Although it is difficult for the diverter to enter the perforation on the high side of the horizontal wellbore, increasing the viscosity of the carrying fluid or using a multidensity mixed diverter can effectively solve this problem. Furthermore, the field case shows that the experimentally obtained diverter transport pattern can be applied to the field to predict the location of the diverter and improve the temporary plugging effect. The findings of this work lay a theoretical foundation for subsequent temporary plugging and diverting fracturing control.

Automated summary

This paper investigates the transport behavior of diverters during multicluster fracturing and establishes a large-scale experimental system to study diverter transport. The results show that the transport effect of diverters is significantly influenced by different flow distribution among perforations, and the entry of the diverter is only possible when the flow rate of the perforation reaches a certain value. Additionally, the difficulty of the diverter entering the high side of the horizontal wellbore can be overcome by increasing the viscosity of the carrying fluid or using a multidensity mixed diverter. Field case confirmation demonstrates the applicability of the experimentally obtained diverter transport pattern in predicting the location of the diverter and improving temporary plugging.