An equivalent single-phase flow for oil-water two-phase flow and its potential application in well test
Journal Title: Advances in Geo-Energy Research - Year 2018, Vol 2, Issue 2
Abstract
In this work an equivalent single-phase flow model is proposed based on the oil-water two-phase flow equation with saturation-dependent parameters such as equivalent viscosity and equivalent formation volume factor. The equivalent viscosity is calculated from the oil-water relative permeability curves and oil-water viscosity. The equivalent formation volume factor is obtained by the fractional flow of the water phase. In the equivalent single-phase flow model, the equivalent viscosity and phase saturation are interdependent when the relative permeability curves are known. Four numerical experiments based on PEBI grids show that equivalent single-phase flow has a good agreement with the oil-water two-phase flow, which shows that the equivalent single-phase flow model can be used to interpret oil-water two-phase pressure data measured in the wellbore during the buildup period. Because numerical solution of single-phase flow model is several times faster than that of the two-phase flow model, whether the new model interprets the pressure data directly or offers good initial values for the true oil-water two-phase pressure data interpretation, it will obviously improve the efficiency of the interpretation of oil-water pressure data and decrease the burden of engineers.
Authors and Affiliations
Wenshu Zha, Daolun Li, Zhiwei Lu, Bao Jia
Keywords
Related Articles
- EP ID EP427929
- DOI 10.26804/ager.2018.02.09
- Views 56
- Downloads 0
Numerical simulations for analyzing deformation characteristics of hydrate-bearing sediments during depressurization
Natural gas hydrates have been treated as a potential energy resource for decades. Understanding geomechanical properties of hydrate-bearing porous media is an essential to protect the safety of individuals and devices d...
Review on gas flow and recovery in unconventional porous rocks
This study summarizes gas flow process in unconventional porous rocks, including the transportation in tight or shale reservoirs and the spontaneous imbibition happened in them. Fluids flow is greatly affected by the por...
Insights on the gas permeability change in porous shale
Due to abundant nanoscale pores developed in shale, gas flow in shale presents a complex dynamic process. This paper summarized the effects from effective stress increase, shale matrix shrinkage, gas slippage and Knudsen...
A critical review on fundamental mechanisms of spontaneous imbibition and the impact of boundary condition, fluid viscosity and wettability
Spontaneous imbibition (SI) is one of the primary mechanisms of oil production from matrix system in fractured reservoirs. The main driving force for SI is capillary pressure. Researches relating to SI are moving fast. I...
Quantitative characterization of micropore structure for organic-rich Lower Silurian shale in the Upper Yangtze Platform, South China: Implications for shale gas adsorption capacity
The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for shale gas storage and adsorption capacity, especially micropores having widths less than 2 nm, which contribute to...