Geological, physiochemical, mineralogical, and rheological characterizations of clay deposits in Northeast Libya

This study was conducted on bentonite deposits in Um Al Rozm and Ain Al Ghazala areas that lie between Latitudes º32 “00 ‘30 and º32 “33 ‘30 N and Longitudes º23 “00 ‘30 and º23 “20 ‘30 E in Northeast Libya. The objective of this study is the assessment of geological, physiochemical, mineralogical, and rheological properties and the potentiality of utilizing these rocks as drilling fluids for oil and gas wells. Chemical and mineralogical analyses were performed by XRF and XRD, respectively. Rheological properties are investigated before and after the treatment process by adding additive materials such as Na2CO3 and CMC. The chemical analysis results of bentonite showed a discrepancy in the proportions of the major components. The results after the treatment process for bentonite in Um Al Rozm exhibit rheological properties consistent with those stipulated by API and other standard bentonites, but for Ain Al Ghazala, the results are unsatisfactory. Mineral analysis of bentonite from the two areas revealed a difference in the mineral composition. The bentonite of the Um Al Rozm area is Na-bentonite, while the bentonite of the Ain Al Ghazala area is Ca-bentonite, whose rheological properties aren’t acceptable as drilling fluid properties stipulated by API.