Slickwater Proppant Transport in Complex Fractures: New Experimental Findings & Scalable Correlation

Abstract

Abstract Slickwater hydraulic fracturing is an important technology that has enabled the oil and gas industry to economically develop enormous unconventional resources. Despite its great success, this technology faces challenges, especially with proppant transport in complex fractures. Very limited work exists in literature about slickwater proppant flow in subsidiary fractures or predictive correlations to estimate settled proppant dune heights. This paper provides a scalable correlation to predict dune height across a wide range of flow rates and proppant concentrations. A unique feature about this correlation is its inclusion of the friction effect, as roughness was introduced to the fracture slot walls. 30/70 mesh brown sand was used to conduct the slot flow experiments and build the correlation. This paper also spotlights the proppant transport mechanism during proppant dune development. Understanding this mechanism reveals key information about the horizontal and vertical settled proppant size distribution. In addition, experimental results are presented to answer the debatable question whether slickwater can transport proppant into tertiary fractures or not. In fact, the data shows that proppant in slickwater is not only capable of "turning the corner" but also developing high dune levels exceeding 96% of the tertiary fracture slot heights.