M-I SWACO released its Deepclean additive in September, a new single-stage well-displacement chemical. Designed primarily for downhole use in oil and gas wells, the additive is used for cleanup during the displacement of oil- or synthetic-base drilling fluids prior to the start of the completion operations.
In Nigeria, one operator used the Deepclean additive to reduce rig inventory and circulation time to clean fluid for a deepwater well. Once the viscosified spacer appeared on the surface, followed by a few cubes of water, the well was confirmed clean with consistently acceptable NTU values below 100. This was accomplished with a single, full circulation using the Deepclean additive.
“The additive, with its solvent-surfactant double emulsion approach, proved to be highly effective in cleaning synthetic-base mud from an over 17,500 ft deepwater well in just one circulation, compared to five circulations with the previous displacement chemistry,” said Adewale Talab, project engineer, M-I SWACO. “This saved both rig time and operations running cost.”
The Deepclean additive forms a double emulsion in brine under shear, where both water-in-oil and oil-in-water emulsions exist simultaneously. The unique structure enhances the mass transfer between oil-base mud film and spacer so that oil film is removed rapidly, solids are dispersed and metal surfaces are water-wetted effectively.
The additive creates a perfect interfacial film between the solvent and aqueous phases. The additive meets all requirements for multi-stage displacement wash train with a single product. The additive can be mixed with freshwater, seawater and with high-density brines.
