Abstract: The present patent application discloses a low toxicity and high biodegradability drilling fluid composition in the form of an inverse emulsion containing an oil phase and an aqueous phase, wherein said oil phase comprises a mixture of at least two diesters obtained from the esterification of a carboxylic acid and an alcohol. The selected diesters are suitable for use in drilling of crude oil or natural gas deposits, exhibiting good stability in the formulations assessed under conditions of high pressure and high temperature and in the presence of divalent salt brines.

Abstract: The invention discloses a sequestrant composition for application to the elimination and/or reduction of hydrogen sulfide and/or mercaptans in fluid, particularly the reduction or elimination of hydrogen sulfide from gases and liquids, including gaseous and liquid hydrocarbons, and sewage gases, especially from natural gas and liquid hydrocarbon streams. The composition uses a main scavenger agent and sequestration rate accelerator additive that also acts as a precipitation prevention agent. The use of the composition is described as being the main scavenger agent for a 1,3-dioxolane alkyl, alkenyl and/or hydroxyl derivative and ketone-based accelerator additives that include ?-diketones and cyclic ketones, saturated and/or ?-unsaturated.

Abstract: The present patent application discloses a low toxicity and high biodegradability drilling fluid composition in the form of an inverse emulsion containing an oil phase and an aqueous phase, wherein said oil phase comprises a mixture of at least two diesters obtained from the esterification of a carboxylic acid and an alcohol. The selected diesters are suitable for use in drilling of crude oil or natural gas deposits, exhibiting good stability in the formulations assessed under conditions of high pressure and high temperature and in the presence of divalent salt brines.