Impact of Fluid, Rock and Hydraulic Fracture Properties on Reservoir Performance in Liquid-Rich Shale Oil Reservoirs
Conference Paper
Overview
Identity
Other
View All
Overview
abstract
Copyright 2015, Unconventional Resources Technology Conference. Conventional methods for analysis of two-phase flow in reservoirs, with underlying simplifying assumptions, are generally not applicable for unconventional Liquid Rich Shale (LRS) oil reservoirs. These reservoirs exhibit multiple PVT systems and complex rock-fluid properties in nano-pores due to pore size effects. It is crucial to understand the production mechanisms and controlling rock and fluid parameters that impact long term production performance to efficiently manage LRS resources and to forecast the ultimate hydrocarbon recovery accurately. We have conducted comprehensive reservoir numerical simulation studies to investigate the impact of rock and fluid properties and production conditions on the performance of LRS oil wells. We used a compositional simulator to model fluid flow in the matrix and in hydraulic fractures. Logarithmic local grid refinement in the matrix allowed us to track pressure and fluid saturation changes accurately. Matrix grids were divided into nano-pores and macro pores based on pore size distributions reported for the Bakken play. Separate phase behaviors, rock compaction and relative permeability systems were assigned to each pore system based on pore sizes to account for the impact of nano-pores on reservoir performance. We used a wide range of fracture, matrix and fluid properties in several cases. The results show that the use of multiple relative permeability, rock compaction and PVT systems for different types of pores accurately represent the fluid flow behavior of LRS oil reservoirs, in which gas production and GOR trends remain stable for long times. We found that confined phase behavior and fracture spacing impact the initial oil rate while ultimate oil recovery is affected by flowing BHP, fracture geometry, initial solution gas oil ratio and relative permeability. Well productivity is sensitive to pore size distribution, especially for highly volatile reservoir fluids, but is not significantly affected by propped fracture permeability. Our study revealed that areas beyond the stimulated zone are likely to play only a limited role in overall hydrocarbon production and that completion design and production scenarios can significantly affect short-term production. The study explored the factors that have the biggest impact unconventional oil reservoir production. The results of the study enhance our understanding of fluid flow and performance of LRS oil wells and should help the industry to improve field planning and management.
name of conference
Proceedings of the 3rd Unconventional Resources Technology Conference
