Measuring the biological impact of drilling waste on the deep seafloor: An experimental challenge

Abstract

The depletion of traditional oil fields is driving the oil & gas industry to explore new exploitation sites previously considered as unprofitable. Deep-sea oil fields represent one of these new areas of exploitation. Well drilling during exploration and production operations generate large quantities of drilling waste whose biological impact on the deep-sea floor remains largely unknown. Because of the harsh abiotic factors characterizing this environment, the evaluation of this impact remains challenging. High hydrostatic pressure is the prominent factor which will affect in-situ biological processes. This review will examine the feedback on the various strategies used to evaluate the biological impact of deep-sea drilling waste deposition as well as the current technological limitations. Given the complexity of this issue, a good perspective strategy would be to trend towards the research and development of more relevant bioassays, especially considering the crucial factor of hydrostatic pressure.Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

Decommissioning Research Needs for Offshore Oil and Gas Infrastructure in Australia

“…The primary sources of contaminants associated with offshore oil and gas infrastructure include: drilling muds, drill cuttings, PW, and occasionally incidental oil spills or pipeline leaks (Cordes et al, 2016;Lelchat et al, 2020). The impacts of oil spills have been reviewed recently (Barron et al, 2020;Hook, 2020), and would be infrequent, so the remainder of the text focusses on PW, drill cuttings and drilling muds.…”

“…Inset image shows a visual rendering of different types of co-located structures. (Lelchat et al, 2020). Drill cuttings are the materials produced during drilling process, and include drilling muds, as well as the material removed from the borehole.…”

“…Drill cuttings are the materials produced during drilling process, and include drilling muds, as well as the material removed from the borehole. This material may have been in contact with the oil in the formation (Lelchat et al, 2020). For the oldest offshore platforms, an oil based lubricant was used in drilling muds, but these have been phased out since the early 1990s in favour of less toxic synthetic based muds and water based muds (Gagnon and Bakhtyar, 2013).…”

Novel Protocol for Acute In Situ Ecotoxicity Test Using Native Crustaceans Applied to Groundwater Ecosystems

“…Several studies are compelled to use field collected organisms in lab testing procedures because many species fail to adapt to lab holding conditions, and due to the lack of culturing methods for non-target species [16,17]. The use of field collected organisms under lab conditions potentially adds an extra stress associated to the manipulation, transportation and lab acclimation [13].…”

“…Establishing lab cultures of organisms for ecotoxicological testing is particularly challenging for a number of ecosystems including subterranean, anchialine, and deep-sea ecosystems [16,17]. Environmental conditions in these difficult-to-access ecosystems cannot be reproduced in the lab and the ecological requirements of many species are not known.…”