Quality assurance evaluation of drilling muds used by some companies in Port Harcourt, Nigeria
Five drilling mud samples were collected from three drilling companies within Port Harcourt metropolis. The physical and chemical properties were analyzed in the laboratory. Results showed that Density ranged from 9.00 to 11.50 ppg, oil: water ratio ranged from 50:50 to 73:27, Emulsion Stability ranged from 175.00 to 470.00 Volts, static filtration was 15.00 mgL-1, alkalinity ranged from 0.40 to 0.80 mgL-1, excess lime 0.50 to 1.03 mgL-1, whole chloride 48000.00 to 52000.00 mgL-1, whole calcium 2600.00 to 22400.00 mgL-1. These results were compared with the mud engineer’s specification and it was found that mud samples from Company A and B met the specification while mud samples from Company C were below specification. It was inferred that some of the samples were contaminated and cannot be used for drilling oil wells to avoid formation pressure which can cause fire hazard in a rig.
Keywords: Drilling fluid, Filtrate alkalinity, Lime, American Petroleum Institute