SUMMARY
More than 80 bentonite clay deposit sites had been identified in Nigeria. Yet, almost all clay and additives used for drilling oil well are imported. The reason is partly that in their natural states, they do not swell while polymers in their raw forms remain unstable at high temperatures. This study aimed at evaluating the potentials of chemically modified Nigerian bentonite for application in the oil and gas industry. The Gombe bentonite from Gombe State was beneficiated using NAHCO3 and slurries were made by dispersion in distilled water. In the presence of other local additives, evaluation of the slurries was carried out on the basis of filtration loss and rheology at different temperatures (30, 60 and 85 oC) using a Central Composite Design (CCD). The clay sample was characterized for mineral and elemental compositions using X-ray diffractometer (XRD) and X-ray fractometer (XRF) while proximate analysis was carried out on the additives. At the optimum condition, the result shows a significant improvement in mud rheology and fluid loss at various temperatures which are in close agreement with the API recommended standard.