Evaluating the Potentials of Drilling Mud Production from Clayey Solis Derived from Imo Shale Formation in Okada, Near Benin, South Western Nigeria

Abstract

Samples from Okada area in the Southwestern, Nigeria were collected to evaluate their likely potentials in drilling mud production with comparison with some commercial bentonite. In order to carry out this evaluation mineralogical, geotechnical and geochemical analysis were used to assess these drilling mud potential. The geotechnical analysis involving the determination of moisture content, specific gravity, particle size analysis, atterberg/ consistency limits test was combined with geochemical analysis of Xray Fluorescence (XRF) and Xray Diffraction (XRD) to determine the qualitative, (types of clays) and quantitative (compositions of each mineral in clay component) and the mineralogy percentages in the clay. The geotechnical results showed particles size of < 60% with very high plasticity (88-140%) having clay activity of <1.25%. Geochemical analysis shows significant amount of Silicate (SiO2), Alumina (Al2O3), Iron (Fe2O3), Magnesium (MgO), Calcium oxide (CaO), Titanium oxide (TiO2) and Manganese oxide (MnO). In CEC, Ca, K, Na (in order of decrease) oxides in Okada and high LOI (38%). The Okada clay revealed the dominance of montmorillonite (30-35.1%) and Kaolinite (2-20.1%) with Quartz (2-24%), Calcite (7-91%) and a very unique occurrence of Palygorskite (2-33%) in the study area which has never been seen in Nigeria. The attributes of the Okada clay were compared with the natural commercial bentonite of Wyoming and Moscow and it was observed to meet the requirement as drilling mud except in the plasticity and swelling potentials which would have to be taken into consideration in beneficiation of the okada clays.