Abstract: A drilling, drill-in, or completion fluid comprising water as a continuous phase, said continuous phase comprising a gas hydrate inhibiting amount of a blend comprising an ethylene glycol derivative and a propylene glycol derivative. The propylene glycol derivative is present in an amount effective to inhibit hydration of shale by the water base. The density of the fluid may be reduced by substituting the blend for salt, and by increasing the amount of propylene glycol derivative in the blend. The blend preferably should comprise at least about 10 vol % of the fluid, and a preferred ratio in the blend is about 35 vol % tripropylene glycol bottoms to about 65 vol % ethylene glycol.

Abstract: The present invention provides a method for suppressing the formation of hydrates during drilling operations under conditions that are conducive to hydrate formation comprising using a water based fluid selected from the group consisting of a drilling, a drill-in, and a completion fluid, wherein said water based fluid comprises as an integral component a hydrate suppressing amount of a water-soluble organic compound having a molecular weight below about 800 and said fluid has effective rheology and fluid loss control properties.