Petrophysical Evaluation Using Well Logs 3D Models and Mud Log Hydrocarbon Typing Analysis: Case Study of an Onshore Niger Delta Field

Abstract

Petrophysical evaluation is essential to the upstream sector of every exploration company in the oil industry because accurate formation evaluation enables reserve development models for uptimal well production and management. The study was carried out on an onshore Niger Delta field using eight wells with the objectives of  identifying possible reservoir units with the potential to contain hydrocarbons, delineate hydrocarbon type(oil and gas), and quantify the identified hydrocarbons for possible viable reservoir development and production using both well logs and mud logs as data sets.  Formation evaluation using fluorescence and hydrocarbon typing/potential (qualitative) of the mud logs revealed oil and gas zones (SMKs 6, 13 and 14) and oil zones (SMK 12) corroborated excellently by quick look well log formation evaluation using Density-Neutron Overlays. Quantitative petrophysical evaluation for all wells was made using models from Wireline/MWD logs of the case study reservoir (SAND_O) to account for delineated hydrocarbon zones and results showed sufficient porosity (0.15 – 0.28), Volume of shale (0 – 0.2%), hydrocarbon saturation (60% to 90%) for possible well development with a STOIIP estimate of about 15MBO (million barrels oil equivalent).

Keywords: Petrophysical Evaluation, Fluorescence, Hydrocarbon potential, Stock Tank Oil Initially In Place, Niger Delta