Experimental Study on the Suitability of Local Egg Shell and Snail Shell as Additives for Drilling Mud pH Control

Abstract

Millions of dollars associated with importation cost has and is still been spent by oil companies carrying out drilling operations in Nigeria, and this if allow to continue unchecked, does not align with the country policy of promoting local content in the oil and gas industry. This study experimentally evaluates the suitability of local eggshell and snail shell ash for use as pH control additives in water base mud by comparing it to that of conventional chemical additives (sodium hydroxide, NaoH) that served as the control experiment. The major drilling mud properties considered in this study are mud density, pH value and rheological properties, with additives concentration of 0.2g to 1.0g each. The result from the study shows that mud prepared with eggshell has a slight increase in density (8.70 – 8.75ppg) while that of snail shell was higher (8.85 – 8.90ppg). These result for the eggshell and snail shell closely compares to that of the control and satisfies the API required minimum standard specification (8.65 – 9.60pp) for drilling mud. At the same concentration, the pH values of mud prepared with eggshell responded positively, compares to that of the control and was within the API required minimum standard specification (9.5 – 12.5) while that of snail shell was seen to give low pH values but was favourable at 1.0g concentration. The result for rheological properties (viscosity and gel strength) shows an improvement with an increase in the concentration of the samples for the eggshell and snail shell. Generally, from the obtained result in this study for all the evaluated mud properties, it is concluded that with respect to API required standard specification for drilling mud, that the eggshell is the most promising and has a good potential for drilling mud purposes when beneficiated in the right amount. This study recommends that government should support and encourage purposeful research on eggshell and snail shell for use as additives in drilling mud formulation with the sole aim of supporting the local content aspiration of the nation.