Browsing by Author "Anietie, Raphael Etim"

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    Reservoir modelling and uncertainty evaluation of “X” field, Niger Delta, Nigeria.
    (Obafemi Awolowo University, 2015) Anietie, Raphael Etim
    Reservoir Modelling and uncertainty evaluation was carried out using a suite of wireline logs of six wells and seismic sections from “X” Field, Niger Delta. This was with a view to develop a model that could be used to evaluate and quantify the uncertainties in reserve estimation. The base map of the study area, 3D migrated seismic section, composite well logs, checkshot data from six wells (6) wells were used for the study. A combination of Petrel Software, Design Expert and Monte Carlo simulation package were used for the study. Also, three intervals were picked and mapped across the section for the volumetric analysis. These were labeled intervals 32, 36 and 40 for easy recognition. Stratigraphic correlation were carried out across the wells and subsequently seismic to well ties was established. New set of synthetic logs such as the Vshale log, water saturation logs, effective porosity log, total porosity log, facies log and NTG log were generated for all the wells. Possible fluid contacts such as Oil Water Contact (OWC), Gas Oil Contact (GOC), Oil Down To (ODT) within the intervals interpreted were identified. Faults and seismic horizons were mapped across the entire seismic section to generate structure maps both in time and depth domain. Seismic interpretation of the 400 inlines and 200 cross lines and check shot data for the wells revealed that the predominant structure present is a fault dependent closure. The GR- log suggests a fluvial depositional environment and the deposits are distributary channel sands or tidal bar sands which are widely believed to have good reservoir properties. The volumetric estimates obtained from the tested interval 32 shows that 270 mmbbl of STOIIP, 4 BSCF of GIIP was found. The interval 36 shows 337 mmbbl of STOIIP, and 5 BSCF of GIIP while interval 40 shows 274 mmbbl of STOIIP and 1 BSCF of GIIP.Water saturation has a regression coefficient of -0.77 and a regression coefficient of -0.02 for formation volume factor. Porosity has a regression coefficient of 0.58, NTG has a regression coefficient of 0.22 and fluid contact has a regression coefficient of 0.11. The regression analysis results, using the Tornado chart revealed that Water Saturation (SW) and Formation Volume Factor (FVF) had negative influence on STOIIP while Porosity, NTG and Fluid contacts have a positive influence on reservoir modelling. The study concluded that reservoir modelling and uncertainty evaluation plays important role in hydrocarbon exploration especially in the determination of STOIIP.