Petrophysical Analysis of XYZ Field, South-East, Niger Delta Using Well Logs

Abstract

The Niger Delta is a prolific oil province within the West African subcontinent. Exploration activities have been concentrated in the onshore part of this basin but as the delta becomes better understood exploration influences are gradually being shifted to the offshore. This study essentially helps understand the physical properties of the reservoir units of the XYZ field in Niger Delta Basin. PETREL Software and suites of seven geophysical well log data and pressure data obtained from an active oil company in Nigeria, recorded at various locations within the XYZ field, Niger Delta basin was used for this work. The petrophysical analysis was carried out on seven wells using geophysical wireline logs and pressure data to evaluate the reservoir potentials of the XYZ field in the south east Niger Delta. The main petrophysical parameters include; estimation of volume of shale, net to gross, porosity, fluid identification, water saturation and net pay thickness. The Wireline logs employed in this work include Gamma Ray, Density, Neutron log and Resistivity log. Two reservoirs designated P0.5 and P1 were delineated and correlated across wells in the field using the gamma ray logs and resistivity logs. The following procedures were followed for the data analysis; Well data import, Well Normalization, well log Analysis and correlation, Identification of reservoirs, differentiation of hydrocarbon and non-hydrocarbon bearing zones and Petrophysical Analysis. The analysis revealed that the reservoir sand bodies have good reservoir characteristics as shown by their petrophysical properties with an average porosity ranging from 0.30-0.36, average water saturation ranging from 0.08-0.3. The net/gross of the reservoirs is between 0.06-0.6. Wells B1, A5X, A4X, A8X(P0.5) reservoir are oil and gas bearing, well A4X(P1) reservoir is gas bearing, well A8X(P1) reservoir is oil bearing and well B1(P1) reservoir is a wet sand. The petrophysical properties of reservoirs in XYZ field suggest a good reservoir quality which is satisfactory for further exploration and production.