New Testing Protocols and Regulatory Guidelines to Promote Further Development of Synthetic-Based Fluid Technology

Abstract

Since the introduction of synthetic-based mud (SBM) technology in the Gulf of Mexico, stakeholders have worked toward realization of the pollution-prevention aspects of SBM technology without losing the benefits of enhanced drilling performance. In addressing the issues of SBM in the Coastal Effluent Limitation Guidelines, the U.S. Environmental Protection Agency (EPA) recognized the pollution-prevention potential for SBM technology, but also determined that the exiting test protocols needed to be improved to measure environmental performance. In response to the Coastal Effluent Limitation Guidelines, industry work groups, including EPA scientists and engineers, took on the specific tasks of identifying and modifying test protocols that would allow continued positive development of SBM technology. The resulting test protocols for biodegradation, toxicity and analytical chemistry as described in the Effluent Limitation Guidelines for SBM technology will form the structure for usage of existing non-aqueous fluids and development of new fluids and fluid blends. This paper details the process of protocol and regulatory development, which is a success story applicable to other regulatory arenas and other issues in the U.S. The resulting regulatory framework and technology will lead to U.S. offshore operations becoming the hot bed of pollution prevention in the global offshore drilling community. The authors will show how continued use of SBM technology in the Gulf of Mexico will allow successful development of deepwater petroleum resources in an environmentally responsible manner. Introduction Synthetic-based muds (SBMs), pollution prevention, and zero discharge are all concepts that have become part of the dialog in discussions of offshore drilling. Recent completion of the Effluent Limitation Guidelines (ELG) for SBMs and other non-aqueous fluids (NAFs) has outlined the framework for usage of SBMs and discharge of SBM cuttings in the U.S. Outer Continental Shelf (OCS).1 These new guidelines impact both current operations and the development of future drilling fluids and solids-control technology. The introduction of new permit requirements and limitations can signal the end of some older technologies and open the door for opportunities for both existing and yet-to-be-developed technologies. By understanding the history, development, testing requirements and regulatory drivers, the continued opportunities for development and use of SBM technology as pollution-prevention technology becomes apparent. Background Water-based drilling fluids or muds (WBMs) use water or brine as the continuous or external phase with the critical functions (density, viscosity, filtration, lubricity, etc.) achieved with the addition of various materials. Non-aqueous systems use non-water-soluble base fluids as the continuous phase with water (or brine) emulsified and dispersed in the base fluid. Non-aqueous drilling fluids (NAFs) include diesel, mineral oils, enhanced mineral oils (EMOs), and synthetic base fluids (SBFs). Studies in the North Sea and elsewhere in the 1980s raised concerns about the environmental effects of the original, high-aromatic diesels that drove the introduction of EMOs and, in the 1990s the development of synthetic-based muds (SBMs). The SBMs were developed to deliver the same performance as oil-based muds (OBMs), but with lower environmental impact and enhanced worker safety through lower toxicity, elimination of Polycyclic Aromatic Hydrocarbons (PAHs), faster biodegradability, and lower bioaccumulation potential.

An investigation on environmentally friendly biodiesel-based invert emulsion drilling fluid

“…For example, the U.S. Effluent Guidelines proposed that the retention of drilling fluid on cuttings (ROC) for ester fluids should not be over 9.4 % (by wet weight), while this limitation for internal olefin fluids is 6.9 % (Friedheim et al 2001;Klein et al 2003). This implies that BBDF is easier to be treated and disposed than other non-aqueous-based drilling fluids, which makes it acceptable for drilling contractors.…”

Field Verification: Invert-Mud Performance from Water-Based Mud in Gulf of Mexico Shelf

“…6 The permit requirements focus on two issues: stock limitations on base fluids and discharge limitations on cuttings. 6 The permit requirements focus on two issues: stock limitations on base fluids and discharge limitations on cuttings.…”

Field Verification: Invert Mud Performance from Water-Based Mud in Gulf of Mexico Shelf

“…6 The permit requirements focus on two issues: stock limitations on base fluids and discharge limitations on cuttings. The base fluids used in SBM have to pass three different tests: sediment toxicity, anaerobic biodegradation and content of polynuclear aromatic hydrocarbons (PAH).…”