USE OF SELECTED ESTER OILS IN BORE-FLUSHING FLUIDS, PARTICULARLY FOR THE DEVELOPMENT OF OFFSHORE OIL AND GAS FIELDS (I)

摘要

The invention concerns the use of selected esters which are free-flowing and pumpable over the temperature range 0-5 DEG C as the oil phase in invert oil muds suitable for use in the development of oil and gas fields and which do not damage the environment. The esters are prepared from monofunctional C2 to C12 alcohols and unsaturated C16 to C24 monocarboxylic acids, the latter with one or more olefinic double bonds. The oil muds contain, in a closed oil phase, a dispersed aqueous phase as well as emulsifiers, weighting agents, fluid-loss additives and, if required, other customary additives plus an alkali reserve subject to the condition that use is not made of significant quantities of strong, hydrophilic bases such as an alkali-metal hydroxide and/or diethanolamine, and chalk, if added, is limited to a maximum of about 2lb/bbl of flushing oil.