Halliburton Energy Services, Inc.

Davidson Instruments Inc.

David B Needham

John W Berthold

Larry A Jeffers

Richard L Lopushansky

Jeffrey S Wells

Jon W Sroufe

Paul K Robinson

A method of pressure testing a well tool can include applying positive or negative pressure to an internal chamber of the well tool, or determining a reference pressure, and monitoring the pressure in the internal chamber using a pressure sensor in the internal chamber. Another method can include applying pressure to an internal chamber of a well tool at a surface location, thereby creating a pressure differential in one direction across a seal, and installing the well tool in a well, thereby creating another pressure differential in a possibly opposite direction across the seal. A well system can include a well tool including an internal chamber, and a pressure sensor disposed in the chamber, whereby the pressure sensor detects pressure within the chamber.

Well tool pressure testing

Apparatus, methods, and other embodiments associated with measuring multiple Fabry-Perot gaps to determine environmental parameters are described herein. In one embodiment, a system for measuring environmental parameters includes an optical fiber, a first reflective surface, a second reflective surface, a third reflective surface, and a light source. The first reflective surface is positioned proximate to a first end of the optical fiber. The second reflective surface is positioned to form a first Fabry-Perot gap between the first reflective surface and the second reflective surface. The third reflective surface is positioned to form a second Fabry-Perot gap between the second reflective surface and third reflective surface. The light source provides light to the optical fiber, wherein the optical fiber delivers light from the light source to the first Fabry-Perot gap and the second Fabry-Perot gap and the optical fiber receives reflected light from the first Fabry-Perot gap and the second Fabry-Perot gap.

Methods and apparatus for measuring multiple Fabry-Perot gaps

A dual cantilevered beam structure is attached to a silicon frame. An optical fiber extends from a borosilicate wafer bonded to the bottom of the frame. A second borosilicate wafer is bonded to the top of the frame. The bottom borosilicate wafer is bonded to the optical fiber with a bonding agent having an index of refraction between the refractive index of the fused silica optical fiber and the refractive index of the borosilicate wafer. In an embodiment, the bonding agent has a refractive index substantially similar to optical cement. Light is reflected into the optical fiber from the beam structure for measuring seismic changes.

Fiber optic seismic sensor based on MEMS cantilever

An algorithm and method for calculating an interferometric gap is disclosed that comprises providing an interferometric sensor having a first gap and an interferometric correlation element having a second gap placed in series with the first gap. A correlation burst waveform is generated having a plurality of features wherein the shape of the burst waveform evolves across the range of the second gap. Means are provided for tracking the features across the entire range of gaps and determining the dominant peak or dominant valley to determine the first gap.

Tracking algorithm for linear array signal processor for Fabry-Perot cross-correlation pattern and method of using same

A signal conditioner to measure the length of an interferometric gap in a Fabry-Perot sensor (interferometer). The invention includes a light source, a Fabry-Perot interferometer capable of spanning a range of gaps in response to physical changes in the environment, a second interferometer that is placed in series with the Fabry-Perot interferometer which does not filter any particular wavelengths of light but acts as an optical cross-correlator, a detector for converting the correlated light signal into electronic signals, and an electronic processor which controls system elements and generates a signal indicative of the length of the gap spanned by the Fabry-Perot sensor.

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Magnolia, TX, United States of America

David B Needham