Publications

The Wiriagar Deep (WD) field is in Bintuni Basin, Papua Barat province of Indonesia. The field comprise of Jurassic and Paleocene reservoirs, and this paper is only focusing on the Paleocene. The reservoir comprises of complex deep-water depositional system ranging from lobe, and slope channel to shelf edge environments. Reservoir quality is one of the key uncertainty in WD Paleocene. Available data comprises of sedimentology, routine core analysis, petrology, XRD, stable isotope, and burial history that suggest a variation in reservoir quality throughout the zonation. Understanding the mechanism generating this variation is essential as a feed in to future geomodelling work. A systematic workflow was used to understand the reservoir quality variation, starting with relational database building, followed by reservoir characterization, reservoir quality trend, reservoir quality control, and provenance interpretation. Reservoir characterization encompass porosity-permeability and facies-stratigraphy relationship. Reservoir trend and control are focused on reservoir quality with depth, depositional influence, compaction, and diagenetic modification. The work indicates that the slope channel sand facies has better reservoir quality compared with shelf and basin floor fan environments. Major reservoir quality degradation is related to compaction and calcite cementation. The presence of significant lithic grains in the Paleocene sediments result in susceptibility to compaction and cementation. The interplay between various sedimentological and paragenetic processes make the reservoir quality variation more pronounced.