Predicting the Fluid Above Shallowest Known Oil SKO: Integration of PVT, Well Logs and Seismic - Limited Data

Abstract

For reservoirs that are not fully appraised, fluid type and resource volumes above Shallowest Known Oil (SKO) or Deepest Known Oil (DKO) are often unknown. This paper discusses the workflow adapted to predict the fluid type above the SKO with reasonable certainty. This enables to book SPE compliant resource volume (SCRV) above SKO to be proposed for booking and up dip wells to be justified. As part of SCRV estimation for Field-X to book hydrocarbon volumes above the SKO, the oil properties, reservoir pressure data and seismic information were integrated utilizing the limitations and uncertainties around each data for the candidate reservoirs. The fluid properties (specifically bubble point pressure) are the most essential element in this analysis, which sometimes are not available or not of sufficient quality. This article will discuss the methodology and workflow adopted to use the existing limited information with their corresponding uncertainties to circumvent these limitations. This methodology was demonstrated as a reliable technology supporting SCRV for Field X, resulting in the increase of ~ 25-30 % of the oil SCRV. Furthermore it has potential to be applied to other fields with similar circumstances.