Feasibility report preparation for Cenomanian to Danian age chalk reservoirs in PL616 through petro physical and rock physical analysis using wire line logs.

Abstract

PL 616 is a production License located in Southern North Sea of Norwegian territory which was awarded to Edison International S.P.A in APA 2011 round. This area is surrounded by discoveries like Eldfisk, Embla, Valhall and Hod etc. The elastic properties such as velocity, density, impedance and Vp/Vs ratio take an important role in reservoir characterization because they are related to the reservoir properties (Xin-Gang & De-Hua Han, 2009). It is helpful to recognize reservoirs on Seismic data because of their different acoustic and shear impedances. Fluid saturated rocks also show variation on seismic with increase of offset (AVO). The purpose of study is to do petrophysical analysis of surrounding wells to get well understanding about subsurface geology, porosity, saturation, pressure and temperature etc. Rock physical analysis is helpful to predict the shear velocity for brine, oil and gas saturated rocks and to understand elastic parameters relations with velocities and impedance of Cenomanian to Danian chalk reservoirs. Greensberg Castagna (1992) equation is helpful to model shear velocity while Gassman fluid substitution method is good to see the model shear velocity, density and primary velocity trend in case of reservoir saturated with different fluids like water, oil and gas. Synthetic gathers is helpful to observe the effect of fluids on seismic data from zero to far offsets (AVO). Cross plots of Shear and acoustic impedance and velocities are useful to characterize the reservoirs more confidently. Integration of this work is helpful for seismic interpreter to recognize lithology related or fluid related bright spots on seismic sections more confidently.