Effect of surface wettability of ceramic proppant on oil flow performance in hydraulic fractures

Abstract

Ceramic proppants are critical products for holding induced fractures open and enhancing hydrogen productivity in low‐permeability reservoirs. Though the effects of proppant size and proppant type on the well productivity have been well studied in the past, the role of the proppant surface wettability in the oil flow performance has not been thoroughly investigated. To help the readers and the industries understand the wetting behavior of ceramic proppants, this research was designed to analyze the effect of the proppant wettability on the flow efficiencies of oil and water under different conditions (for example, various proppant size, water saturation, and waterflooding). Also, it was required to determine the optimal wettability of proppants in the available candidates for the enhancement of oil recovery in the hydraulic fracturing process. Results of the work indicate that the proppant wettability plays an essential role in the productivities of water and oil in tight sandstones. Compared with the same‐size oil‐wet proppants, the mixed‐wet proppants contribute to increasing the oil flow efficiency and reducing the produced volume of water. However, an increased value of proppant size can significantly enhance the oil recovery. Besides, using the oil‐wet proppants, the waterflooding phenomenon can lead to a lower oil recovery than that of the non‐water‐flooded specimen. Based on the findings of the microscopic structural characteristics of the proppant surface, a fluid channel mechanism was proposed to help understand the proppant wettability effect on the flow behaviors of oil and water. This research can provide guidance on the determination of proppants in the designs of hydraulic fracturing operations. These findings can help the reservoir engineers dealing with hydraulic fracturing better design the surface wettability of the proppants, especially for those reservoirs with a multi‐phase flow.

Dynamic capillarity during displacement process in fractured tight reservoirs with multiple fluid viscosities

“…[1][2][3][4] During the fluid flow process, fluid viscosity varies caused by the mixing of different kinds of fluids, which can have strong influence on the dynamic capillarity and fluid flow. [1][2][3][4] During the fluid flow process, fluid viscosity varies caused by the mixing of different kinds of fluids, which can have strong influence on the dynamic capillarity and fluid flow.…”

Effect of surface wetting behavior of ceramic proppant on the two‐phase flow across the interface of sandstone and fracture

“…The effects of oil‐wet and water‐wet fracture proppants on the competing flow of water and oil from Parker and Upper Gray sandstones to fracture were investigated in this study using PC (code for provider) proppants. The following conclusions are drawn: Similar to the CC oil‐wet proppants, the PC oil‐wet ceramic proppants have the property of AORW effect on the water‐oil two‐phase flow from sandstones to proppant‐packed fractures. This effect is attributed to the surface property of the oil‐wet proppants.…”

“…1. Similar to the CC oil-wet proppants, 6 the PC oil-wet ceramic proppants have the property of AORW effect on the water-oil two-phase flow from sandstones to proppant-packed fractures. This effect is attributed to the surface property of the oil-wet proppants.…”

“…Dong conducted a number of tests in small scale focusing on the interface between sandstone and proppant packs to study the effect of surface wettability of ceramic proppant on the oil flow efficiency from core samples to fractures filled with CC (code for major proppant provider) proppants. He observed that oil‐wet proppant increased oil flow efficiency from sandstone to proppant packs.…”

“…They concluded that the residual guar gum in the fractures has negative effect on improving oil flow efficiency. Dong et al investigated the effects of oil‐wet and mixed‐wet surfaces of ceramic proppants on the oil flow using SEM and energy‐dispersive system and found that the resin‐coated oil‐wet proppant surface is much smoother than that of the mixed‐wet proppant. Based on the result of oxide analysis, there is a layer of oleophilic materials which causes the oil affinity of the oil‐wet proppants.…”