this mud type can be used as a completion and workover fluid, a spotting fluid to relieve a stuck pipe and as packer or casing fluid. they are very good for "gumbo" shales. the mud weight can be controlled from 7–22 lbs/gal. it is sensitive to temperature but does not dehydrate as in the case of water based mud as mentioned before. it has no limit on the drilled solids concentration. the water phase should be maintained above a ph of 7. stability of the emulsion depends on the alkaline value.