Environmental Monitoring Associated With A Production Platform In The Gulf Of Mexico
Authors: Gettleson David A. , Laird Chae E. , E. Russell E. , Abbott Robert E. 
Published: October 2008

The results of a marine environmental monitoring program associated with drilling operations from a production platform near Baker Bank in the northwestern Gulf of Mexico are described. The study represents the first environmental monitoring program conducted in the Gulf of Mexico for a production platform located near (4,000 meters) a sensitive biological area. Current direction and velocity data, amounts of sediment and associated barium and chromium levels deposited in sediment traps, bottom sediment barium and chromium levels, and water column data were used to assess the dispersion and distribution characteristics of discharged drilling muds. Television videotapes and still-camera photographs were used to record the abundance, distribution and health of the biota associated with Baker Bank.

The monitoring program showed that the prevailing near-bottom current was to the southwest, away from Baker Bank. Components in the direction of the Bank were rarely sufficient to transport discharged drilling muds to the Bank. Sediment and water column data also indicated that no drilling muds were transported to the Bank. Camera observations showed no discernable changes in the Bank's biota during the period of the study.

INTRODUCTION

Exploratory and production activities of the oil and gas industry have recently begun to move into the deeper waters of the outer continental shelf in the northwestern Gulf of Mexico. Lease sales in these waters have included blocks near or adjacent to biologically sensitive areas, consisting primarily of isolated reef communities (fishing banks). One such block is A-8S (Mustang Island Area, East Addition). which is near Baker Bank. Concern over possible adverse effects on the Baker Bank com- munities from drilling operations in Block A-8S led to the establishment by the U.S. Geologial Survey. in consultation with the Bureau of Land Management and the U. S. Fish and Wildlife Service. of special protective biological lease stipulations for the block. For any oil and gas exploration or development operations the stipulations require the shunting of drilling muds and cuttings to within 10 meters of the sea floor. the exclusion of halogenated phenol bactericides from the drilling muds and the establishment of an environmental monitoring program. The monitoring program is to provide data on the fate of discharged drilling muds and to detect effects of drilling operations on the biota of Baker Bank.

The data reported herein were taken from February 28. 1978 to September 14. 1979 and represent results from the environmental monitoring program designed for Conoco's Platform "A" in Block A-8S. The program began February 28. 1978 and is on-going. Components of the monitoring program have included qualitative and quantitative reports of drilling muds and cuttings discharged. as _well as measurements of ambient current direction and velocity and sedimentation rates on Baker Bank. Additional measurements have included water column transmissivity, suspended sediment concentration. suspended sediment barium and chromium (components of drilling muds) and benthic sediment barium and chromium between the platform and the Bank.