ABSTRACT
Operator requirements for cost effective technical solutions to borehole stability problems have historically been the impetus for new product and mud system development by the industry. Oil-based drilling fluids have long been recognized as a sound technical answer to problems encountered in deep-hot holes and, more recently, to stabilize boreholes with thick intervals of reactive clay formations. However, oil-based mud product development was slowing down until the introduction of low toxicity base oils in the late seventies created a need for new investigations. This innovation sparked a resurgence of oil mud research and development which has resulted in oil-based mud (OBM) systems being used routinely in many active drilling areas worldwide.
Concerns for conservation, both economic and environmental, persist even after low toxicity oils have been accepted, based on field performance, as a suitable diesel replacement. These concerns are important to both the operator and contractor alike. Control of intangible costs related to mud expenditures is important to the operator, but rig modification and installation of auxiliary equipment to process the oil-based drilling fluid are equally important to both companies.
This paper discusses a variety of equipment that is currently available for both onshore and offshore locations to improve oil-based drilling fluid conditioning, to aid oil recovery, to reduce pollution, and to maintain a safe working environment. Minor modification of most of these techniques will allow their utilization on land, inland barge, platform, jack-up, semi or floating drilling units.
