Journal of Petroleum Exploration and Production Technology (Jul 2020)
Assessment of clay materials for suitability in drilling mud formulation from part of Ondo State, South-West Nigeria
Abstract
Abstract Bentonite used for drilling operations in the oil and gas industry in Nigeria is mainly imported into the country. This project evaluated the efficiency of additives and their function in enhancing the rheological and flow properties of local bentonite clay, obtained from Ibule-soro in Ondo State, Nigeria. X-Ray diffraction analysis of clay samples from previous research around the study area indicated large amount of silica, alumina, and iron contents suggesting that the clays were kaolinite in nature. The clay samples were analyzed for their rheological properties and subsequently compared with the imported bentonite with American Petroleum Institute (API) specifications as standard. The results obtained showed that the local bentonite exhibited low viscosity and high filtration loss. Therefore, to enhance the quality of the clay, it was beneficiated with sodium carbonate ( $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 ) and carboxymethyl cellulose (CMC). Seven different formulations were made: (20 g of Imported bentonite), (20 g of local Bentonite Clay), (20 g of local Bentonite Clay + 3.3 g of $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 + 10 g of CMC), (25 g of local Bentonite Clay + 4.2 g of $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 + 10 g of CMC), (30 g of local Bentonite Clay + 5.0 g of $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 + 10 g of CMC), (35 g of local Bentonite Clay + 5.8 g of $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 + 10 g of CMC), and (40 g of local Bentonite Clay + 6.7 g of $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 + 10 g of CMC).The addition of additives (CMC and $${\text{Na}}_{2} {\text{CO}}_{3}$$ Na 2 CO 3 ) reduced the calcium content via the cation exchange process and enhanced the rheological properties of the mud samples. The research work revealed that beneficiation of local bentonite with sodium carbonate, the addition of polymer (CMC), and an increase in clay concentration influenced the rheological and flow properties of mud samples. With proper beneficiation of local bentonite in Nigeria, they can be made suitable for drilling operations in the oil and gas industry.
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