Abstract: Sensing systems include a tube defining a Fabry-Perot cavity and an optical fiber including a distal end disposed within the Fabry-Perot cavity and a proximal end. A corrodible material caps the Fabry-Perot cavity. Devices for sensing corrosion of downhole equipment include an optical fiber with a corrodible material disposed over a distal end of the optical fiber. Systems for sensing a condition in equipment include an optical fiber with a fiber Bragg grating proximate a distal end thereof and a mass of sensor material coupled to the distal end of the optical fiber. The mass of sensor material is suspended from above the fiber Bragg grating. Other systems for sensing a condition in a wellbore include an optical fiber and a plurality of fiber Bragg gratings along a length thereof. A plurality of sensor materials are coupled to the optical fiber and surround respective fiber Bragg gratings.

Abstract: An apparatus for estimating a first property in a borehole penetrating the earth is described. The apparatus includes a carrier configured to be conveyed through the borehole. The apparatus also includes a first sensor disposed at the carrier and configured to perform a first measurement of the first property, the first sensor having a first direction of sensitivity; a second sensor disposed at the carrier and configured to perform a second measurement of a second property, the second sensor having a second direction of sensitivity; and a processor configured to receive the first and second measurements and to correct the first measurement using the second measurement in order to estimate the first property.

Abstract: A well pump assembly includes a pump and a motor that contains a dielectric motor lubricant and a pressure equalizer containing a bellows. The bellows has an interior in fluid communication with the motor lubricant and an exterior immersed in well fluid. The bellows is axially extendable and contractible in response to a pressure differential between the well fluid and the motor lubricant. A tube has a lower end secured to a tube port in the pressure equalizer housing and an upper end secured to a lower end of the bellows. The tube has a center line that makes at least one curved flexible bend between the tube upper end and the tube lower end to enable the tube to flex as the bellows extends and contracts.