Descriptive statistics and probability distributions of volumetric parameters of a Nigerian heavy oil and bitumen deposit

Abstract

The absence of geostatistical modeling of volumetric parameters of the long-discovered Nigerian heavy oil and bitumen deposits is responsible for the inconsistencies surrounding estimates of hydrocarbon-in-place contained therein. An exploratory data analysis (EDA) is a pre-cursor to such modeling. As part of EDA, this work presents the descriptive statistics and probability distributions of the volumetric parameters of a Nigerian heavy oil and bitumen deposit. Raw data from the existing works have been assembled into a database. Using basic principles, porosity have been computed, from the raw data, for several core samples retrieved from the two bituminous horizons in the deposit. The computed database has been partitioned into the two horizons, using depth-to-top and thickness data. Furthermore, this work has conducted detailed analyses and offers robust discussions on the descriptive statistics and probability distributions of the porosity, depth-to-top, and thickness databases. The statistics and distribution curves obtained are observed to exhibit good correlations with existing geologic, stratigraphic, and textural data. An hypothesis suggesting the two horizons belong to same geological population has been formulated and tested at field and well levels; with results affirming the hypothesis. The descriptive statistics and probability distributions obtained offer a significant understanding of the characteristics and features of the available data. In addition, the distributions now become prior information to which reservoir descriptions would be constrained, in the future conditional simulation stage of this work. The correlation of core data obtained here with the existing geologic, stratigraphic, and textural data would promote data integration in the characterization of this deposit.

Extraction modeling, kinetics, and thermodynamics of solvent extraction of Irvingia gabonensis kernel oil, for possible industrial application

“…In Nigeria, prior to the commencement of crude oil exploration and production in February 1958 by Shell British Petroleum at Oloibiri and Afam oil fields in Port Harcourt; agriculture was the main stay of theeconomy. 1,2 As a result of this drop in the global crude oil price, Nigerian government have introduced measures and polices that are geared toward the diversification of the economy, with special attention given to agricultural development. This government initiative has led to the development of the agricultural sectors aimed at achieving food security, industrial utilization of its products, job creation, as well as products processing for export purposes.…”

“…This is because the oil and gas sector contributes about 35% of Nigeria's gross domestic product (GDP) and an estimated 92% of total export revenue. In Nigeria, prior to the commencement of crude oil exploration and production in February 1958 by Shell British Petroleum at Oloibiri and Afam oil fields in Port Harcourt; agriculture was the main stay of theeconomy 1,2 . As a result of this drop in the global crude oil price, Nigerian government have introduced measures and polices that are geared toward the diversification of the economy, with special attention given to agricultural development.…”

Determination of the Chemical Compositions of Condensate-like Oils with Different API Gravities by Using the Distillation, Precipitation, Fractionation Mass Spectrometry (DPF MS) Method

“…For all standard deviation measurements in this study, the data were assumed to be normally distributed. Since the mean values provided for all measurements in this study are an estimate of the population mean, we provided the 95% confidence interval of the mean at α = 0.05. , When considering the average gravimetric wt % of different types of compounds in all five condensate-like oils, heavy saturated hydrocarbons corresponded to the majority of the compounds (Table ; 81.0% in the lightest condensate-like oil (with the greatest API gravity) vs 69.9% in the heaviest condensate-like oil (with the lowest API gravity)), followed by alkyl aromatic hydrocarbons (Table ; 6.9% in the lightest condensate-like oil vs 10.3% in the heaviest condensate-like oil). The gravimetric wt % of compounds in the volatile hydrocarbon, heteroaromatic compound, and polar compound classes was each found to be less than 4.0%.…”

On the optimum operating temperature for steam floods

“…13), we employed the 3D numerical model to investigate the existence of an optimum injection temperature for steam floods. As an example, a sector of the heavy-oil and bitumen belt in the Eastern Dahomey Basin, southwestern part of Nigeria is considered [16,30]. A layer-cake stratigraphy is assumed with an 8-m oil shale unit sandwiched between two sand-rich units, each with a thickness of 15 m. A uniform average porosity of 30% is considered while oil saturations are 68 and 80% in the oil shale and sandy units, respectively.…”