Devices and methods for electromagnetic measurement of axial flow

摘要

A method for measuring fluid flow in a casing 102 includes inserting a logging tool 100 into the casing 102, where the logging tool 100 has an internal axial flow channel and an electromagnetic flowmeter sensor disposed in the internal flow channel. The method also includes measuring an axial conductive fluid flow through the flow channel with the electromagnetic flowmeter sensor, while allowing bypass axial fluid flow to bypass the internal flow channel substantially unimpeded between an exterior of the logging tool and an interior wall of the casing. Also claimed is a method of measuring fluid flow in a casing by use of a logging tool having an electromagnetic sensor, the sensor having a pair of electrodes disposed on the exterior of the tool where an imaginary line between the pair of electrodes is orthogonal to the axial conductive fluid flow. In another embodiment a logging tool for measuring fluid flow has a number of electromagnetic flow sensors (502, fig 5B) disposed in a first plane perpendicular to the central axis of the body, where each flow sensor 502 has a flow channel axis parallel to the central axis of the body.