An Integral Approach Boosts the Value of Heavy Oil Core Analysis

摘要

The Large Scale Steamflood Pilot (LSP) is a project aimed to determine the feasibility of economically steamflooding the Wafra First Eocene carbonate reservoir. The field is located in the Partitioned Neutral Zone, between Kuwait and Saudi Arabia. The reservoir is a dolomite, with 14-20 °API oil. The LSP consists of sixteen inverted 5-spot injection patterns. A fully integrated workflow was matured to maximize the value of information provided by four full cores that were collected when drilling the LSP wells. Core work will support reservoir characterization and dynamic simulation, essential tools for project decision-making. High-level workflow consisted of the following phases: (i) define field, laboratory and office activities, (ii) identify and prioritize stakeholders, (iii) delineate project schedule and assign responsibilities. Coring and core analysis for heavy oil involves short, mid and long term activities, that may require several years of planning and execution. Planning and frequent communication engaged core experts very early in the work process. Their input was used to shape the project, assuring reliable execution of dependent and independent tasks as work progressed. Synergies between subject matter experts were promoted, and proved to add value to the project. Due to the organizational efforts, the project schedule was not affected by personnel changes. Concerning lab measurements, the operator's heavy oil experts recommend Best Practices for the determination of relative permeability. Long equilibrium times, crude oil instabilities, and viscous fingering are challenges unique to heavy oil systems. Limited capability for such measurements exists in the industry. Heavy oil tests are not routine and should be carefully assessed. We hope that the integrated workflow proposed in this paper provides guidance to similar projects on planning and execution of heavy oil coring programs and analysis.