Proppants are placed in fractures to provide highly conductive paths for hydrocarbons to flow from the reservoir to the wellbore. Hydraulic fracturing technology is constantly improving to achieve better production performance. Ultra-lightweight (ULW) proppants are one of the technologies introduced to improve fracturing effectiveness. Compared to sand, ULW proppants can be carried farther and distributed more evenly within fractures, resulting in more propped fracture area. This paper evaluates the impact of ULW proppants on production performance in tight reservoirs and examines characteristics of formations where ULW proppants are most beneficial.
To explore the advantages of ULW, hydraulic fracture models are developed. These models help in understanding the fracture geometric properties. This information is then incorporated into reservoir production models to evaluate the impact on production performance. Fractures using ULW proppants and the resulting well productivity are compared to those using sand. No technology provides a solution for all situations, and neither do ULW proppants. To better understand if ULW proppants bring the most benefit for production performance, data-mining techniques were used to identify ULW proppant field applications.
Results showed that ULW proppants had better vertical distribution within the fractures than sand (sand had a tendency to settle to the lower part of fractures, leaving the upper part unpropped). In a thick reservoir formation with insufficient vertical conductivity, fractures created by ULW proppants connected larger volumes of rock, leading to higher well productivity and increased EUR.
This study discusses the benefits that ULW proppants can bring to unconventional producers and identifies potential candidate formations where ULW proppant may be very effective. Field cases are included to show the benefits of ULW and the circumstances where they can bring the most value.