DRILLING FLUIDS BASED ON ESTER OILS AND THE USE OF SELECTED ESTER OILS IN DRILLING FLUIDS, PARTICULARLY FOR THE OFFSHORE DEVELOPMENT OF OIL AND GAS SOURCES

摘要

THE USE OF SELECTED ESTERS- FLOWABLE AND PUMPABLE AT TEMPERATURES OF 0 TO 5°C- OF MONOFUNCTIONAL ALCOHOLS CONTAINING 2 TO 12 ATOMS AND MORE ESPECIALLY 4 TO 12C ATOMS AND ALIPHATICALLY SATURATED MONOCARBOXYLIC ACIDS CONTAINING 12 TO 16 ATOMS OR MIXTURES THEREOF WITH AT MOST SUBSTANTIALLY EQUAL QUANTITIES OF OTHER MONOCARBOXYLIC ACIDS AS THE OIL PHASE OR AS AT LEAST A SUBSTANTIAL PART OF THE OIL PHASE OF INVERT DRILLING MUDS WHICH ARE SUITABLE FOR THE ENVIRONMENTALLY SAFE OFFSHORE DEVELOPMENT OF OIL AND GAS SOURCES AND, IN A CONTINUOUS OIL PHASE, CONTAIN A DISPERSE AQUEOUS PHASE TOGETHER WITH EMULSIFIER, WEIGHTING AGENTS, FLUID LOSS ADDITIVES AND, IF DESIRED, OTHER STANDARD ADDITIVES. THE INVENTION ALSO RELATES TO MINERAL-OIL-FREE INVERT DRILLING FLUIDS WHICH ARE SUITABLE FOR THE OFFSHORE DEVELOPMENT OF OIL AND GAS SOURCES AND WHICH, IN A CONTINUOUS OIL PHASE BASED ON ESTER OILS, CONTAIN A DISPERSE AQUEOUS PHASE TOGETHER WITH EMULSIFIER, VISCOSIFIERS WEIGHTING AGENTS, FLUID LOSS ADDITIVESAND IF DESIRED OTHER STANDARD ADDITIVES, CHARACTERIZED IN THAT THE OIL PHASE CONSISTS AT LEAST SUBSTANTIALLY OF ESTERS OF MONOFUNCTIONAL ALCOHOLS CONTAINING 2 TO 12 C ATOMS AND ALIPHATICALLY SATURATED MONOCARBOXYLIC ACIDS CONTAINING 12 TO 16 C ATOMS, THESE ESTERS OF THE OIL PHASE HAVING A BROOKFIELD (RVT) VISCOSITY AT 0 TO 5°C OF NO MORE THAN 50 MPA.S.