Verification of the OOC Mud and Produced Water Discharge Model using lab-scale plume behaviour experiments
Abstract This paper describes comparisons of predictions by the Offshore Operators Committee (OOC) Mud and Produced Water Discharge Model with published data on experimental laboratory-scale observations of plume behavior in flumes, towing tanks, and wind tunnels. The ability of the OOC Model to predict the plume characteristics observed in numerous individual tests of plume behavior covering a wide range of discharge conditions was examined. Data are provided summarizing the predictive ability of the model for all tests. The dimensionless parameters describing the physical characteristics of the plumes were within the range expected for typical Gulf of Mexico produced water and drilling fluid discharges for most of the comparisons. The model was in good to excellent agreement with measurements of plume behavior under most discharge conditions. The model was less accurate for those experimental cases where extreme plume bending occurred. It is believed that turbulence caused by the discharge pipe itself influenced the behavior of these extreme-bending plumes. The predicted density of solids accumulation on the bottom of a towing tank, a lab-scale analogy of the seabed accumulation of drilling solids, was within a factor of two of experimental observations. Excluding the three simulations of extreme bending plumes, the model showed no systematic trend towards either under- or over-estimation of any parameter examined. This suggests that experimental errors or biases may have contributed to observed differences between predictions and observations. The results of the validation testing described in this report increases confidence in the use of OOC Model predictions as an alternative to the difficult and expensive process of performing field measurements for every practical discharge situation.
An experimental investigation into the dynamic collapse phase of drilling fluid discharged into a stratified, flowing environment
approved: Redacted for Privacy Dumping drilling mud from offshore drilling rigs into the ocean could have a negative impact on the marine environment. Due to this possible impact, the Offshore Operators Committee (OOC) has deemed it necessary to predict the fate of drilling mud discharged into the ocean. Through the funding of OOC and Exxon Production Research Company, a computer program was developed which models the fate of discharged drilling mud for a wide variety of ocean conditions. At present, the program has been through a limited amount of testing and still contains modeling coefficients whose validity have not been established. A laboratory simulation of mud discharging into a flowing, stratified environment was designed and tested in the Mechanical Engineering facilities at Oregon State University. The objective of this experiment was to observe and quantitatively describe the behavior of the dynamic collapse phase of the mud. The primary emphasis was given to the shape and position of mud-plume cross sections as they progressed into the dynamic collapse phase. Using a collimated light source and motor driven camera, each cross section was captured on film. Photographs showed that the behavior of the discharged-mud simulation closely matched actual mud discharges into the ocean. It is considered that the measured results would serve as a good check against the 00C computer program's ability to model the dynamic collapse phase of discharged mud. An Experimental Investigation into the Dynamic Collapse Phase of Drilling Fluid Discharged into a Stratified, Flowing Environment
Ocean Sludge Disposal by Barges
A simple model is constructed to examine the dispersion and settling of wastes such as sewage sludge or dredge spoils discharged from barges into the ocean. Several example cases are analyzed using the model; it is found that the proper choice of disposal depends strongly on the local environmental conditions and the characteristics of the waste.