THE SUITABILITY OF EGG SHELL AND SNAIL SHELL WASTE AS LOCAL MATERIALS IN IMPROVING THE PH OF MUD
1.1 BACKGROUND OF STUDY
Far way back in 1900, while drilling an oil well in Spindle tops Texas, the drilling crew used various muddy slurs of water and clay as drilling mud. Today drilling fluids are still called drilling mud, but engineers no longer rely only on a mixture of water and clay. Instead, they carefully design compounds and mixtures with both local and foreign materials to meet specific needs of drilling operation under various drilling conditions. Modern and modified drilling fluids are truly life blood of the wells.
Drilling mud is a mixture of two or more phases consisting of a liquid phase (water, oil, or other synthetic oil) and a solid phase consisting of clay mixed with addition of certain chemical substances (additives). Drilling mud performs several functions, some of which are lubricating the bit, transporting cuttings to the surface, control of formation pressure. It is also called the life blood of the rotary drilling operation, in the sense that without it, drilling is almost impossible.
Considering the desired formation condition and reactive chemical compounds encountered by the drilling mud during the drilling operation, it is necessary to continually monitor the mud properties and prescribe possible solution to keep the fluid in good condition. Properties that must be monitored include; mud weight, viscosity, filtration properties, pH. Certain materials are used to improve these properties.
This project is concerned with enhancing the pH of drilling mud using egg shell and snail shell as local additives for the substitution of imported chemicals such as potassium hydroxide (KOH), sodium hydroxide (NaOH). The control of pH is very essential in the drilling operation as most of the equipment used are made of metal and pH is the degree of acidity or alkalinity of a substance, hence if the drilling mud is acidic ( pH less than 7), corrosion of the drilling equipment is bound to take place. Therefore when drilling operation is being performed in an acidic formation, the drill pipe, drill collars and drilling bit will corrode as a result of the acidity of the subsurface, hence the need of enhancing or improving the pH of the drilling mud have to be properly taken care of, by certain pH enhancers or modifiers.