WITHDRAWN: Diverting agents in the oil and gas industry for well treatment: A comprehensive review

Abstract

During the life of the well, well treatments are carried out to boost the productivity by stimulating initially unproduced zones. These treatments include hydraulic fracturing, multi-stage fracturing, matrix acidizing, fracture acidizing etc. These treatments allow existing wells to sustain hydrocarbon production without new wells being drilled. During these treatments certain specialized particles or mechanical objects are used in order to isolate a pre-existing perforation or to divert the fluid flow. These particles or objects are generally called diverting materials, diverting agents or diverters. Diverters, when employed efficiently, can prevent the use of a rig to provide momentary physical barriers, lowering the cost of the workover. Recent improvements in diversion technology make use of a variety of degradable particles that act as a momentary bridge, either at the perforation entry or inside the existing fracture. This increases the pressure inside the fracture and redirects the next stage of fluid to the zone with a higher degree of stress that has not yet been covered by the fracture. The goal of diverters in well treatment is to improve fracture complexity, especially in vertical wells with a lot of variation in the formation's geomechanical parameters. This review discusses about diverting agents, their origin, types, applications and certain case studies where the use of diverters have turned out to be effective.