RECENT DEVELOPMENTS IN INDUSTRY SPONSORED RESEARCH 



Dr. James P. Ray 



Shell Oil Company 



Houston, TX 



Preliminary results were shown from three studies, which have not yet 

 been completed, in the vicinity of drilling operations off the coasts of 

 California, Texas, and Alabama. The California and Alabama studies were done 

 at single well sites. The Texas study was in a field of six development and 

 four exploratory wells. 



The California field study took place in 1984 at Molino, about halfway 

 between Santa Barbara and Pt. Conception, about 3 mi offshore in a water depth 

 of 73 m. The ll,000-ft well used 10,700 bbl of drilling mud containing 860 

 metric tons of barite. 



The results are consistent with earlier studies in a number of ways; for 

 example, plots of barium distribution in the sediments are directly related to 

 currents in the water column. Concentrations decrease rapidly with distance 

 away from the platform. Also, although total barium in the drilling mud 

 ranged up to 350,000 ppm, the soluble quantities obtained by a weak acid leach 

 technique were about two orders of magnitude lower--around 400 to 500 ppm. 

 Background levels of barium in near shore areas along the California coast 

 range from 700 to 900 ppm. 



Other metals--zinc, lead, copper, and cadmium- -follow the barium pattern. 

 Mercury, nickel and chromium show slight increases with distance, but that is 

 not thought to be related to drilling. 



Biological studies were done on three species of bottom organisms-- 

 Cyclocardia, a siphon-feeding clam, and Pectinaria and Nephtys, two deposit- 

 feeding polychaetes--to find out if the metals bioaccumulate, and where in the 

 organism the metals are located. It turned out that more than 97 percent was 



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