Improving Rheological Properties of Gambe Clay for Drilling Fluid Application Using Fermentable Polymers

Abstract

There are abundant bentonitic clay deposits in Nigeria. However, it does not meet commercial standard for drilling mud formulation, because it is composed of calcium montmorillonite. Therefore, there is need for the clay to be enhanced and polymers have been identified as enhancement agents. The work was aimed at improving the rheological properties of Gambe clay for drilling fluid formulation using the fermentable polymers (xanthan gum, locust bean gum and tamarind seed gum). The clay was obtained from Gambe town in Adamawa State, Nigeria. The clay was beneficiated for quartz removal and chemical beneficiated with 6 wt% of Na2CO3. The mineral composition and the cation exchange capacity of the clay was determined using X-ray diffraction analysis and ammonium acetate saturation method, respectively to find out its quality for drilling mud formulation. Drilling mud was formulated by mixing of 22.5 g of the clay to 350 ml of water with a high speed mixer to obtain a homogenous mixture. The polymer enhancers were also added to the mixture. The effect of the fermentable polymer at different concentration on the rheological properties of the formulated drilling fluid was investigated employing FANN 35SA viscometer. It was found that 0.93 wt% of the tamarind seed gum, locust bean gum and xanthan gum in the formulated drilling fluid enhanced the yield point from 0.72 Pa to 7.2 Pa, 12.48 Pa and 16.36 Pa, and the gel strength from 0 Pa to 8.35 Pa, 10.44 Pa and 68.92 Pa of the formulated mud respectively. The mud enhanced with 0.80 wt% of the enhancers had high rheological properties than imported clay.