FACILITATING MUD DESIGN, CEMENTING JOB DESIGN AND THE ENTIRE DRILLING OPERATIONS BY MODELLING THE RHEOLOGICAL PROPERTIES OF WATER-BASED MUD AND OIL-BASED MUD WITH TEMPERATURE

Abstract

The increasing rental cost of drilling Rig and the associated painful cost of downtime during drilling operations are some of the major concerns of the oil & gas companies. Improper rheological properties of drilling mud may cause a variety of problems including insufficient cuttings transport, limited solids suspension, poor hole-cleaning and excess filtrate loss into the formation. Facilitating mud design, cementing job design and the entire drilling operations will save Rig time and associated cost and prompt management of oil & gas companies to devote more of their useful time and resources to other significant aspects of their operations. The aforesaid prompted this work to invent a method for developing mathematical models representing the rheological parameters of drilling mud (water-based mud and oil-based mud) to enable prediction of the rheological properties in emergency situations where and when Laboratory services are not immediately available. The methods applied include Laboratory testing and mathematical modelling. Results revealed that the mathematical models can be confidently applied to predict the Plastic viscosity and Yield stress of water based mud and oil-based mud as the correlation coefficient (R-squared value) obtained for each of the aforesaid rheological properties was higher than 95% Therefore, as the rheological properties of water-based mud and oil-based mud depend on their composition, physical and chemical properties, mathematical models should be proactively developed for the Plastic viscosity and Yield stress for every mud in hole to enable prediction of the its rheological parameters when and where laboratory services are not immediately available.