ABSTRACT
The sea-bed is an important component of the biosphere, and safeguarding it is an integral part of waste management responsibility when offshore activities may result in its contamination. A study is in progress to assess the distribution of waste on the sea-bed resulting from the underwater discharge of mud-contaminated cuttings during offshore drilling. The study involves the development of a numerical model of particle dispersion and deposition complemented by measurements of their agglomeration and settlement characteristics. This activity is, in part, directed to the improving of environmental impact assessment methodology.
This paper outlines the development of the numerical model and the accompanying experimental measurements. Application of the results to date show that up to 95% of the mass of the cuttings drilled with oil-based mud discharged from a platform can be ac-counted for in the calculations. Comparisons between the simulation results and field data obtained from a three-dimensional sonar survey of the cuttings mound under the Fulmar "A" platform show encouraging agreement. Certain processes, such as granular material slippage, have been identified as significant features that need to be incorporated in the model to improve the agreement between simulation and field data. Nevertheless, the model, in its present state, has been shown to be an effective tool for assessing the impact of drilling operations on the sea-bed.
