Integration of Seismic Inversion Attributes in Field Development Planning at Malay Basin-Asia and North Sea Fields

Abstract

A major and very important stage in exploration and production projects of any given field is the field development planning program. Conventionally most Field Development Planning (FDP’s) are performed without the use of high resolution and fidelity data, such as seismic inversion products. This paper demonstrates the need for integration of seismic inversion products into FDP’s and its added values in the process. The lithology and fluid volumes were computed using seismic inversion products, acoustic impedance (AI) and Poisson’s ratio (PR). The volume obtained shows oil, gas or water probabilities, which are crucial in well placement program and optimal well planning (FDP’s common goals). The values of seismic inversion integration added to FDP includes improved volumetrics from high fidelity porosity and permeability volumes, better lithology and fluid discrimination, Proper placement of oil water contact for better history matching for flow simulation. Also the rock property changes were estimated from seismic inversion to determine reservoir behavior over time, the acoustic impedance was observed to decrease with an increase in Poisson ratio, when pore pressure increases and vice versa. But with decrease in pore pressure, both the acoustic impedance (AI) and poisson’s ratio (PR) thus increase, thereby causing the lighter fluid (oil) to be replaced by heavier fluid (water). Based on the obtained 4-D inversion result, the oil water contact was shifted downwards in the reservoir model, which subsequently gives a better history matching for flow simulation. The study shows the robustness of using seismic attributes in FDP’s.