Determination of rheology of fluid in an oil or gas well
AssigneeConocoPhillips Company
InventorGunvald Nesheim
Life of this patent
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Abstract
The invention relates to the measurement of the rheology of drilling fluid down a hydrocarbon well in real time during operations. A sensor device comprising a pipe rheometer with multiple diameters is installed in a bottom hole assembly tool, such that a portion of the total flow of drilling fluid passes through it. In this way the rheological properties of the drilling fluid can be determined under the high pressures and elevated temperatures encountered downhole.
Claims8
A method of determining rheology characteristics of a non-Newtonian drilling fluid at a point down an oil or gas well in real time while drilling, the method including the steps of:
- a) installing in a drillstring a test apparatus comprising a housing having either (i) a bore having different diameter bore sections along its length or (ii) more than one bore, each bore having a different diameter;
- b) arranging for a known flow of the drilling fluid to pass through the or each bore while drilling;
- c) for each different diameter bore or bore section, while drilling, sensing the pressure difference between two points along the bore or bore section;
- and
- d) calculating from the bore or bore section diameter, flow rates, sensed pressure differences and distance between pressure sensing points a viscosity value for each diameter bore or bore section.
A method of determining rheology characteristics of a non-Newtonian drilling fluid at a point down an oil or gas well in real time while drilling, the method including the steps of:
- a) installing in a bottom hole assembly on a drillstring a test apparatus comprising a housing having either (i) a bore having different diameter bore sections along its length or (ii) more than one bore, each bore having a different diameter;
- b) arranging for a known flow of the drilling fluid to pass through the or each bore while drilling;
- c) for each different diameter bore or bore section, while drilling, sensing the pressure difference between two points along the bore or bore section;
- and
- d) calculating from the bore or bore section diameter, flow rates, sensed pressure differences and distance between pressure sensing points a viscosity value for each diameter bore or bore section.
Dependencies are inferred from the claim text.