A New Integrated Reservoir Model for F-H Sands in Oritupano B Field, Eastern Venezuela Basin

摘要

The objective of this work was to create an integratedrnmodel of the F4U, F4L, F5, F67, F8, H12 and H3U,L clasticrnreservoirs, within the Lower Miocene Oficina Formation ofrnthe Oritupano B field (Eastern Venezuela Basin) in order tornevaluate different development alternatives for thesernreservoirs.rnBased on the 3D seismic data reinterpretation, a newrnmodel was developed integrating new structural data andrnsequence stratigraphy as well as defining the differentrndepositional sequences. A new sedimentological interpretationrnand stratigraphic framework from correlations and twornavailable cores were used to determine the main sedimentaryrnbodies and trends of deposition.rnThe static model was developed using geostatisticalrntechniques and incorporating the new structural andrnsedimentological models as well as the available petrophysicalrndata. Stochastic simulations were performed in order to obtainrnthe areal and vertical properties distribution for the differentrndeposits. The results showed consistency with the depositionalrnmodel previously defined.rnTwo numerical simulation models were created: arnstochastic model, based on the results of the geostatisticalrnanalysis, and a deterministic model, based on the newrnconventional static model. Both simulations yielded similarrnresults. The adjustment of the static/dynamic models allowedrnthe determination of oil reserves associated with thesernreservoirs and the refinement of the optimal exploitationrnstrategy.rnThe new geological model indicates that the mainrnstructural features of the field are normal faults and rnextensional reverse drag folds, unlike the preexisting model inrnwhich a gentle homocline structure was suggested. A SW-NErndepositional trend for the erosive channels and NW-SErndepositional trend for coastal bars, parallel to thernpaleocoastline, were determined. In addition, four depositionalrnsequences were defined formed by transgressive and highstandrnsystems tracts.rnBoth, the stochastic and the deterministic model suitablyrnrepresent the dynamic behavior of the studied reservoirs. Therncommunication between the F-H sands of the up-thrownrnblock, with the A9-A13 sands of the down-thrown block, wasrndemonstrated through both dynamic models, which alsornimproved the characterization of the aquifers within thernreservoirs. Based on the results of this study, 3 new verticalrnwells and 5 additional workover wells were recommended. Itrnis expected that these wells will increase the recovery factor ofrnthe F-H sands by 12 %.