Density Estimation from Compressional Velocity Using New Gardner Factors for Two Carbonate Formations, Amara Oil Field.

Abstract

Bulk density (matrix density and pores fluid density) is a very important physical property that is used as main parameter to estimate physical characteristics (porosity, water and hydrocarbons saturation, shale volume and many others). The compensation from bulk density and sonic velocity is used to calculate acoustic impedance, reflection coefficient, and other elastic properties. Gardner equation have default values for (a) (factor) = 0.31 if Vp in (m/sec) and (b) (exponent) = 0.25 for Vp (m/sec) and these values change according to the lithology condition in the study area to give more accurate results, for this reason The object of the presented work is to calculate new (a) factor and (b) exponent to measure bulk density from compressional velocity using Gardner1974 equation for two formations from middle Cretaceous age, the data was taken from two open hole well logs Am-6 and Am-10 in Amara oil field. Techlog 2015 software was used to complete this work. The results showed that the new values for Mishrif Formation factor (a) were (1.21) in Am-6 and (1.32) in Am-10 and (b) exponent values were (0.46) in Am-6 and (0.40) in Am-10, while for Rumiala Formation factor (a) were (1.35) in Am-6 and (1.333) in Am-10 and (b) exponent value was (0.40) in both Am-6 and Am-10, these values give best fitting with minimum err with field measuring bulk density logs data and these values can used to measure bulk density log in the study area when field measuring bulk density log is not available.