Variation in the physicochemical and rheological properties of clays from kanje and doka tofa areas, northcentral Nigeria and implications for use as drilling mud

Abstract

" The physico-chemical and rheological properties of clays derived from the weathering of basalts around Kanje, Nasarawa State and Doka Tofa, Plateau state, North Central Nigeria were studied. Fifty-one samples were collected from pits dug to a maximum depth of 5m. The following chemical and rheological parameters were determined in the laboratory: basic cations present, cation exchange capacity, pH, Specific Gravity, plastic viscosity, apparent viscosity , yield point, filtration, liquid and plastic limits. The samples have a predominance of calcium over sodium as the basic cations and showed tremendous improvement in the rheological properties after treatment with sodium carbonate. The filtration properties were tested to be good. 62% of the samples from Kanje were found suitable for the drilling of water wells, 14% would need further improvement with viscosifiers while only one sample was found to be outrightly useful as drilling mud. 53% of the samples from Doka Tofa were found useful for drilling oil and water wells while the remaining 47% could be useful for drilling water wells. "