Blast furnace slag is a unique hydraulic material which is a by-product of the steel-making process. A new method of mud to cement conversion technology utilizing slag as the hydraulic material has been developed, and the technical merits of this slag mix are briefly reviewed. This slag mix technology is economically, technically, and environmentally superior to conventional Portland cements and has been used in many fields.
The major environmental benefit is the reduction of mud disposal volume. Since the application of slag mix at Prospect Auger in the Gulf of Mexico, excess whole mud discharge has been reduced by about 70% (4,530 barrels per well). Approximately 15,000 barrels of excess drilling mud was recycled into slag mix at Auger.
In addition, a new drilling waste management method to reduce or eliminate drilling waste at the rig-site has been developed. A new type of slag-supplemented drilling fluid containing 40 to 60 lb/bbl slag can produce slag-laden cuttings which are self-setting with time. The in-situ solidification method seems to be environmentally acceptable and potentially cost-effective.