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 TEMPERATURE OF 0 TO 5°C - OF MONOFUNCTIONAL ALCOHOLS CONTAINING 2 TO 12 C ATOMS AND OLEFINICALLY MONO- AND/OR POLYUNSATURATED MONOCARBOXYLIC ACIDS CONTAINING 16 TO 24 C ATOMS OR MIXTURES THEREOF WITH SMALL QUANTITIES OF OTHER, IN PARTICULAR SATURATED, MONOCARBOXYLIC ACIDS AS THE OIL PHASE OR AS 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 AND ALSO EMULSIFIERS, WEIGHTING AGENTS, FLUID-LOSS ADDITIVES AND, IF DESIRED, OTHER STANDARD ADDITIVES TOGETHER WITH AN ALKALI RESERVE, WITH THE PROVISO THAT SIGNIFICANT QUANTITIES OF STRONG HYDROPHILIC BASES, SUCH AS ALKALI HYDROXIDE AND/OR DIETHANOLAMINE, ARE NOT USED AND ANY ADDITION OF LIME IS LIMITED TO A MAXIMUM OF ABOUT 2 IB/BBL OIL MUD. 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 EMULSIFIERS, WEIGHTING AGENTS, FLUID LOSS ADDITIVES AND, IF DESIRED, OTHER STANDARD ADDITIVES,CHARACTERISED IN THAT THE OIL PHASE CONSISTS AT LEAST SUBSTANTIALLY OF ESTERS OF MONOFUNCTIONAL ALCOHOLS CONTAINING 2 TO 12 C ATOMS AND OLEFINICALLY MONO- AND/OR POLYUNSATURATED MONOCARBOXYLIC ACIDS CONTAINING 16 TO 24 C ATOMS AND IN THAT THE W/O EMULSION IS MILDLY ALKALIZED AND, WHERE LIME IS ADDED AS ALKALI RESERVE THE QUANTITY ADDED SHOULD NOT EXCEED ABOUT 2 IB/BBL (LIME/OIL MUD) AND IS PREFERABLY SLIGHTY SMALLER.