The calculation methods of permeability variation coefficient taking Ningdong Oilflied in Mahuangshan west block as an example

Permeability variation coefficient V_k is the most important parameter to evaluate reservoir heterogeneity.The article describes three calculation methods of permeability variation coefficient such as statistical method Dykstra H method and Lorenz curve method which are used to calculate permeability variation coefficient of the Y8 and Y9 layers of No.2 and No.3 well area in Ningdong Oilflied.The advantages and disadvantages of the three methods and the scope of application are identified.Practice shows that the Lorenz curve method is more suitable for this area because the value of V_k calculated by it is between 0 and 1 which can reflect the degree of heterogeneity clearly,and is applicable for any type of reservoirs.