RECENT DEVELOPMENTS IN 

 INDUSTRY SPONSORED RESEARCH 



J. P. RAY 



SHELL OIL COMPANY 



HOUSTON, TX 



TJiis presentation will introduce and summarize several industry sponsored projects relating 

 to drilling fluids and cuttings that have been conducted over the past two years. Some of 

 this work has been submitted for journal publication, some will be relegated to the gray 

 literature. 



Included in this summary are near and far-field rig morutoring programs conducted in the 

 Gulf of Mexico off Alabama and Texas. These include fate and effects monitoring relating 

 to both exploratory and development drilling. Sediment contamination (metals and 

 hydrocarbons) were considered in several of the studies in addition to benthic community 

 analysis. One location monitored exploratory discharges prior too, immediately after, and 

 one year post-drilling, in water depths of 10 m. Another assessed impacts due the discharges 

 from 10 wells into in a water depth of 28 m. 



The industry, as part of their data gathering for corrunent submission on the proposed EPA 

 offshore effluent guidelines, have developed an extensive database on drilling mud 

 composition and acute toxicity from systems in field use for the past two years. 

 Generalizations regarding the general toxicity of field muds can be extracted from this 

 database and will be preserUed. This information is relevant to hazard assessment 

 considerations for the North and mid-Atlantic, and the related canyon areas. 



A brief overview will be given of a major study conducted in California which quantified 

 sediment metals contamination, and their bioaccumulation and intra-cellular fate in three 

 different species of benthic infauna. Based on over 100,000 metals analyses, the data 

 suggests that barium is being accumulated as barium sulphate, and not the more soluble and 

 toxic barium ion. All sediment and faunal samples were taken from a discharge site in 

 water depths of > 70m. 



Recent laboratory studies have explored the solubility and bioavailability of trace 

 contaminants, especially mercury and cadmium, from barite (the primary weighting agent used 

 in drilling muds). Because barite is the only mud component measurable in marine 

 sediments at distances beyond a few hundred meters, these studies have special relevance to 

 hazard assessments. 



B-8 



