Alkaline activation of different type bentonites, rheological properties and using in drilling

In this study, five bentonite samples were supplied quarries from Wyoming (USA), Eldivan, Reşadiye, Niksar and Ünye; coded as WB, EB, RB, NB, and UB, respectively. These samples were evaluated in two parts as crude and activated. Raw bentonites were prepared by grinding and sieving processes under 75-50-25 µm particle sizes (d100). Activated bentonites were prepared by reducing the grain size of raw bentonites to 150 µm by pre-treatment, and activation with 2.5% Na2CO3 and 0.5% MgO by alkaline activation method. Then, the activated samples were reduced to 75-50-25 µm particle sizes and prepared for experiments. The characterizations were made with XRF, XRD, SEM, BET, TGA, FT-IR and CEC analyzes. With the prepared bentonites for, suspensions were prepared depending on different particle sizes, additive ratios and aging times. The rheological properties of these suspensions were measured by viscometer and filtration kit, and rheograms were created by calculating shear stresses at different shear rates and also static filtrate amounts were measured at different times. In addition, the shear stress values obtained from the analyzes were evaluated according to common rheological flow models using the least squares method; the results obtained were supported as statistically. Also, flow properties of the suspensions were determined by apparent viscosity (AV), plastic viscosity (PV), yield point (YP), gel strength (10 sec and 10 min), LPLT static filtration and thixotropy (STI and TI) analyzes according to API and usability of the bentonite samples in drilling applications was investigated. In addition, 0.25%; 0.50% and 0.75% rates PAC LV, Guar Gum and Xanthan Gum were added to the suspensions and effects on the flow properties were evaluated.