Assessing The Extent Of Regeneration Of Clay And Water Contaminated Drilling Fluids For Reuse
Achadu M. Abah
Dept. of Chemical Engineering, University of Port Harcourt
Osadolor D.I
Dept. of Engineering Management, University of Port Harcourt, Rivers State, Nigeria.
Keywords: drilling mud, contamination, clay, mud weight, emulsion stability, fluid loss oil - water ratio, Plastic viscosity and yield point
Abstract
The article assessed the extent of regeneration of clay and water contaminated drilling fluids for reuse. Preformulated drilling fluid samples were contaminated with 15% and 20% of clay and water then analyzed for mud weight, emulsion stability, fluid loss and oil - water ratio as well as rheological and gel strength measurements while plastic viscosity and yield point were computed from the rheological parameters. All the analysis were carried out in line with America Petroleum Institute (API) standards for testing. The value obtained for the uncontaminated base mud, 15% and 20% clay contaminations were 9.5 lb/gal, 10.3 lb/gal and 10.5 lb/gal respectively. The other corresponding results were; ES: 405v, 292v and 286v, 6-rpm reading: 13cP, 20cP and 24cP, 10-seconds’ gels reading: 17 lb/100ft2 , 25 lb/100ft2 and 29 lb/100ft2, 10 minutes’ gels reading: 27 lb/100ft2, 34 lb/100ft2 and 36 lb/100ft2 , PV value: 25cP, 40cP and 42cP, YP value: 27 lb/100ft2, 37 lb/100ft2 and 38 lb/100ft2 , OWR value: 66/34, 71/29 and 73/27, HPHT value: 5mls, 17.6ml and 20.8ml. Similar values were recorded for water contaminations. Complete deviations from the mud program were observed for all the parameters tested due to the contamination especially 15% to 20% water and clay contaminations that were entirely intolerable. The treatments significantly improved the characteristics of the drilling mud. These results implied that contaminated drilling fluid can be regenerated to function optimally thereby reducing cost of purchase and preparation of new drilling mud.