INTEGRATED GEOMODELING TO IDENTIFY TIDAL SAND COMPLEX RESERVOIR DISTRIBUTION AND WATERFLOODING PLAN SCENARIO OF 33-6 SAND RESERVOIR, GITA MEMBER, TALANG AKAR FORMATION, ASRI BASIN, SOUTHEAST SUMATRA, INDONESIA

摘要

Reservoir complexity and depleted reservoirrnpressure are the most challenges issues to appliedrnwaterflood project in Widuri field, Asri Basin,rnSoutheast Sumatra. The water flooding project hasrnbeen established in Widuri Field, Asri Basin sincernyear 2000 and focused on the Miocene Gita memberrnTalang Akar Formation, where 33-6 sand reservoirrnwas deposited. The reservoir distribution trend isrnsimply identified by acoustic impedance.rnThe combination of log and detailed core analysisrnthorough Widuri B-10 well, which has 100%rnrecovery of 56 ft core length, have contributed tornthe comprehensive analysis of depositional settingrnof the reservoir. 33-6 sand interpreted as a productrnof tidal channel sand in lower part and coarseningrnup tidal bar in upper portion, characterized byrncoupled sand coarsening - fining feature in GammarnRay log. The heterogeneity resulted different flowrnbehavior, either in oil production performance andrnwater flooding application. It is perform the uniquernreservoir behavior, reservoir compartmentalizationrnand heterogenic reservoir connectivity.rnDepleted pressure regime in 33-6 sand could bernidentified using advance seismic methods. In thisrncase, seismic 4-D is used to monitor waterfloodingrnand pressure depletion effect. There are three datarnset of seismic 4D (1991, 2000, 2004) for waterfloodrnmonitoring, the difference of the amplitude could bernused to justify the trend of waterflooding.rnQuantitatively 33-6 sand categorized as AVO classrnIV, indicated by positive gradient value, due to therncalcareous shale overlain at the top sand asrnmentioned in the core data. In geomodeling aspect, integrated seismic attribute combined with thrivedrnfacies analysis used to comprehend the detailrnreservoir and porosity-permeability relationship.rnIntegrated subsurface work involving all aspects ofrnGeology - Geophysical and Reservoir Engineeringrnwere established to understand the reservoirrncomplexity and behavior. This work implementedrnto enhance the production performance and futurernreservoir management in 33-6 sand reservoir,rnWiduri Field.