Invert biodegradable n-alkane(s) wellbore fluid containing less than 10 percent by weight of cycloparaffing isoparaffing and aromatic compounds, and method of drilling with such fluid
AssigneeDowell, a division of Schlumberger Technology Corporation
InventorChristopher Alan Sawdon
Life of this patent
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Abstract
The invention concerns wellbore fluids suitable for use in the oil and gas exploration and production industries and embraces fluids used for drilling, completion, workover or packing of wellbores. The invention is especially concerned with biodegradable wellbore fluids the liquid phase of which consists of an oil, or of water-in-oil "invert" emulsions, where the oil phase comprises n-alkanes.
Claims22
A biodegradable wellbore fluid comprising a continuous oil phase containing a dispersed hydrophilic liquid, the continuous oil phase comprising at least 50 percent by weight of an n-alkane having from 10 to 20 carbon atoms, or mixture of n-alkanes having from 10 to 20 carbon atoms, the continuous oil phase containing less than 10 percent by weight of cycloparaffins, isoparaffins, and aromatic compounds, and not greater than 20 percent by volume of polyalphaolefin.
A method of drilling a well comprising attaching a cutting bit to a length of drill pipe;
- rotating the cutting bit to produce cuttings;
- and removing cuttings from around the cutting bit with a drilling fluid which is a biodegradable wellbore fluid comprising a continuous oil phase containing a dispersed hydrophilic liquid, the continuous oil phase comprising at least 50 percent by weight of an n-alkane having from 10 to 20 carbon atoms, or mixture of n-alkanes having from 10 to 20 carbon atoms, the continuous oil phase containing less than 10 percent by weight of cycloparaffins, isoparaffins, and aromatic compounds, and not greater than 20 percent by volume of polyalphaolefins.
A biodegradable wellbore fluid which is an emulsion of a dispersed hydrophilic liquid in a continuous oil phase comprising at least 50 percent by weight of the oil phase of an n-alkane having from 10 to 20 carbon atoms, or a mixture of such alkanes, wherein the oil phase contains less than 10 percent-by weight of cycloparaffins, isoparaffins, and aromatic compounds, and no more than 20 percent by volume of polyalphaolefin.
Dependencies are inferred from the claim text.