Measuring Wellhead Displacement Using Shadowgraphy
AssigneeSaudi Arabian Oil Company
InventorsSameeh Issa Batarseh, Damian Pablo San Roman Alerigi
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Abstract
Systems and methods for performing contactless wellhead displacement measurements include receiving a shadowgraph from an imaging sensor based on a shadow generated by a portion of a wellhead blocking light from a coherent infrared light source, the infrared light having a wavelength away from water absorption wavelengths and solar maxima wavelengths. A feature is detected in the shadowgraph based on interference patterns in the shadowgraph caused by diffraction of the light. The feature represents an edge of the portion of the wellhead. A displacement of the wellhead is measured based on the location of the feature in the shadowgraph and a previously detected location of the feature.
Claims20
A method for performing contactless wellhead displacement measurements, the method comprising:
- receiving a shadowgraph from an imaging sensor based on a shadow generated by a portion of a wellhead blocking light from a coherent infrared light source, the infrared light having a wavelength away from water absorption wavelengths and solar maxima wavelengths;
- detecting a feature in the shadowgraph based on interference patterns in the shadowgraph caused by diffraction of the light, the feature representing an edge of the portion of the wellhead;
- and
- measuring a displacement of the wellhead based on the location of the feature in the shadowgraph and a previously detected location of the feature.
A system for performing contactless wellhead displacement measurements, the system comprising:
- an illumination system positioned on a first side of a portion of a wellhead, the illumination system comprising:
- a coherent infrared light source to illuminate the portion of the wellhead, the infrared light source configured to produce light at wavelengths away from water absorption wavelengths and solar maxima wavelengths;
- a detection system positioned on a second side of the portion of the wellhead opposite the first side, the detection system comprising:
- a beam splitter to divide incoming light into a first part and a second part;
- optical components positioned in an optical path of the first part to focus and condition the light;
- a first imaging sensor positioned to collect the first part of the light after propagating through the optical components;
- a Wollaston prism positioned in an optical path of the second part;
- a lens to collect the second part of the light and focus the light onto a second imaging sensor;
- and
- a computer system configured to measure a displacement of the wellhead based on a shadowgraph generated by the first part and a schlieren image generated by the second part.
Dependencies are inferred from the claim text.