CHEMIRESISTIVE SENSORS, DOWNHOLE TOOLS INCLUDING SUCH SENSORS, AND RELATED METHODS

摘要

A method of detecting an analyte includes vaporizing at least a portion of a fluid within a wellbore, passing the vaporized fluid adjacent a chemiresistive sensing element coupled to a drill string within the wellbore and sensing a resistivity of the chemiresistive sensing element. A sensor for detecting an analyte includes an expansion device for vaporizing a portion of a fluid within a wellbore, a chemiresistive sensing element configured to contact the vaporized fluid within the wellbore and a controller configured to pass a current through the chemiresistive sensing element and calculate a resistance of the chemiresistive sensing element in contact with the gaseous portion of the fluid. An earth-boring tool may include a bit body coupled to a drill string and the sensor.

主权项

1. A method of detecting an analyte, comprising:
passing a vapor within a wellbore adjacent a chemiresistive sensing element within the wellbore, the chemiresistive sensing element configured such that a resistivity of the chemiresistive sensing element changes in response to a presence of an analyte in proximity to the chemiresistive sensing element; and sensing the resistivity of the chemiresistive sensing element.