Effect of wettability of ceramic proppant surface in guar gum solution on the oil flow efficiency in fractures

• Main Authors: Kanjicai Dong, Ming Wang, Chi Zhang
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2019-12-01
• Series: Petroleum
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405656118300968

Guar gum and its derivatives have been the most commonly used polymers to increase the viscosity of fracture fluids. Ceramic proppants are vital products for enhancing oil and gas well productivity in low-permeability reservoirs. In the last several decades, abundant studies have been found in the investigation of proppant size, shape, compositions on the fracture conductivity. However, few types of research can be found to study the proppant wettability effect on the oil and gas flow efficiency. In our research, eight experiments were conducted using traditional guar gum fracturing fluid. Results of this work indicated that ceramic proppant promotes oil flow efficiency from sandstone core samples to proppant packs and thus should promote oil well productivity. The mechanism behind this phenomenon is believed to be the formation of oil flow channels across the fracture face due to the imbibition of oil in the core onto the oil-wet surface of the proppant, promoting oil flow from the core to the fracture. After guar gum was added the results inverted, this phenomenon for water-wet proppant is believed to be increased by the viscosity of fracture fluids which increased the viscosity of water, promoting oil flow from the core to the fracture. Nevertheless, the stimulation effect of oil-wet proppant on oil flow efficiency can be reduced by the presence of guar gum solution. Inside the proppant matrix filled with guar gum fracturing fluid, oil can be blocked inside the proppant matrix as a discontinuous phase while the aqueous phase can be easily mixed with the guar gum fluid and then be transferred out. Keywords: Fracturing, Proppant, Surface wettability, Oil flow efficiency, Guar Gum