Experimental Study of Microproppant Transportation in a Fracture with Operational Factors and Application in a Shale Gas Field

Abstract

Summary When using hydraulic fracturing technology, microproppants (MPs) are crucial in filling and propping natural and deep-location fracture channels. In the last decades, numerous studies focused on the transportation mechanism of conventional-sized proppants (CPs) with 20/40-mesh, 40/70-mesh, and 70/140-mesh sizes using fracture models with different operational factors such as pump rate, fluid viscosity, proppant size, proppant concentration, inlet number, inlet location, and alternating injection mode. However, the effects of these operational factors on MP transportation mechanisms remain unclear. This study used the experimental method to test how these factors affect proppant placement in the fracture model. Some new findings showed that unlike CPs piling up in the fracture models, MPs exhibited no accumulation/piling-up behavior. Moreover, the change in viscosity of fracturing fluid did not affect the MP transport capacity, making it possible to use slickwater with lower viscosity as the carrier liquid for MPs. Finally, adding MPs with optimal operational parameters to fractures in the case study well significantly improved gas production compared with adjacent wells, proving the feasibility of the proposed approach.