New Opportunities for the Drilling Industry Through Innovative Emulsifier Chemistry

Abstract

Abstract As the drilling industry operates in more stringent environmental constraints and conservative economical environment, the industry is poised to take advantage of innovative emulsifiers for new opportunities in solving the environmental problems and offer economical advantages over conventional invert emulsion drilling fluids. We have developed various innovative invert emulsion drilling fluids using novel emulsifiers. These systems provide a quantum leap in new drilling fluid technology in solving environmental problems while offering economical advantages over conventional invert emulsion drilling fluids. Since, the inception of invert emulsion drilling fluids decades ago, emulsifier technology for these systems has not advanced much. The focal points in development in past history have been in base fluids, O/W ratios and some in weight materials, however very little has been changed in emulsifier chemistry. Only step-changes in technology have been achieved with changes in base-fluids and other parameters of invert emulsion drilling fluids. It is time to move on. Using innovative emulsifier chemistry has produced novel invert emulsion fluids, which address the environmental as well as performance and cost-related issues in drilling operations. This paper discusses the systematic design, development and testing of novel emulsifiers for innovative invert emulsion drilling fluids. The overall impact of manipulation of emulsifier chemistry in invert emulsion drilling fluids to meet the environmental and functional requirements of drilling operation is presented. The formulations and applications of lime-free high temperature invert emulsion drilling fluid, negative alkalinity ester-based fluid, and reversible invert emulsion drilling fluids in laboratory experiments as well as field trials are highlighted. Introduction Oil-based muds (OBM) and invert emulsion drilling fluids have been used for a number of years, primarily because of their superior performance when compared to water-based muds (WBM). Invert emulsion drilling fluids provide formation of a thinner filter cake, excellent lubricity, enhanced rate of penetration, and superior hole stability. However, there are many disadvantages associated with conventional invert emulsion fluids, such as filtercake cleanup, cementing, environmental issues associated with oil retention on cuttings, toxicity to human health and marine environment, and disposal of cuttings and used fluids. Since the inception of OBM many attempts have been made to combat the environmental problems associated with OBM. Synthetic-based muds (SBM) were developed in 1990's in an attempt to balance the performance benefits of conventional oil-based muds and the pollution prevention characteristics of water-based muds. During past decades, the contribution of SBM to both minimizing the environmental impact of discharges and improving health and safety conditions on the rig has been well documented in literature. Despite the advantages of SBM, the extent of their environmental impact remains steeped in controversy. The primary focus to combat the environmental problems, while balancing the performance characteristics of invert emulsion fluids, has been on the chemistry of base fluids,1–2 weight materials,3 and S/B ratios.4 Such changes have produced only step changes in invert emulsion technology. However, since the inception of invert emulsion drilling fluid in early 20th century, very little has changed in either emulsifier chemistry5 or basic invert emulsion drilling fluid technology in spite of fair amount emulsifier chemistry and invert emulsion technology has advanced in other areas of science. It is time to move on and look into new and existing emulsifier chemistries to bring a quantum leap in invert emulsion drilling fluid technology.