Evaluation Of Relative Permeability In Fractured Reservoir Rocks

Relative permeability is measurement of the ability of two or more fluid phases to pass through reservoir rock.Darcy's law is often used to describe the fluid flow through reservoir rocks.Permeability is a parameter in Darcy's law to represent the capability of the rock to conduct single phase fluid.When there are more phases coexist,each phase has its own permeability which is also named as effective permeability.Relative permeability,the ratio of effective permeability to absolute permeability,adapts the Darcy's law to multiphase condition.Fractures can significantly affect the mechanism of oil and gas production from petroleum reservoir.Fractures improve the permeability of a reservoir that has poor matrix porosity and permeability,fracture network controls both fluid flow and storage in tight rocks with little or no matrix porosity.Fractures are the major flow channels for fluid in fractured reservoir,so the accurate prediction of multiphase flow in fracture is highly important.In 1966,Romm firstly established relative permeability mode ls for fractures based on the water experimental results and he suggested that two phase flow in fractures can be modeled by straight-line.In 1998,Fourar and Lenormand proposed an analytical model on Stokes equation to describe gas-water relative permeability in fracture systems.Chen et al.(2013)proposed a model to improve relative permeability on coal reservoir and there shows that the relative permeability for coal is also affected by the porosity change,consequently the evolution of wetting phase saturation and the gas production can significantly be affected.This work I analysis the characteristics of relative permeability of two phases in different reservoirs and I fit the data with relative permeability model and we will make comparison of relative permeability evaluation in different fractured reservoir rock.I verified the Chen et al.model,made comparison with Brooks-Corey Model and obtain two get a range.In the end we will have a database for relative permeability data in fractured rocks.Understanding relative permeability model in two phase flow in fractured rock will enable us to do production forecasts through numerical simulations more accurately.This will lead to better information for decision making regarding reservoir,management and development.