ABSTRACT
To optimise the Rabi Phase II field development plan, uncertainties on key petrophysical parameters had to be reduced below those normally achieved using conventional techniques. Core analysis results were not satisfactory because the reservoir sandstones are unconsolidated. It was decided to determine the petrophysical parameters in-situ, measuring certain reservoir properties using several independent techniques. A dedicated well was drilled specifically for this purpose.
This paper explains why it became necessary to drill the data gathering and monitoring well, and how the well was designed to ensure it would yield representative data. Important objectives were to improve the quality of base-logs, and to reduce environmental effects on time-lapse measurements. Key features of the well are described, including:
A glass-reinforced Plexiglas (GRP) window, for time-lapse resistivity logging;
Latch points over the reservoir section, for precise and repeatable depth-positioning of the Borehole Gravity Meter.
The comprehensive data acquisition programme is discussed, and open-hole logs are compared to initial cased-hole logs recorded in the GRP section.