Vision iO (Norway)

Abstract This work introduces an innovative Flow-Thru downhole camera solution that utilizes a hybrid electro-optical cable integrated within Coiled Tubing (CT) strings. This technology enables a wide range of downhole intervention and remedial operations while providing real-time footage in high resolution. The paper also includes a case study that highlights the successful application of this camera system during a complex live gas well fishing operation. This advanced downhole camera solution, developed for robust deployment via CT, incorporates a single Hemispherical lens located at the tip of the tool string, offering a 360° field of view to allow comprehensive diagnostics. The design also includes a "Coil Sleeve" or "flow-by housing", allowing the passage of pumped fluids over the camera's electronics and enabling flow exit around the camera dome. This unique feature not only ensures the lens remains clear of debris and wellbore contaminants but also provides active electronics cooling, enhancing performance in challenging downhole conditions. The ‘pump-thru’ capability opens opportunities to seamlessly combine routine CT pumping and well displacement operations with camera diagnostics, delivering substantial time and cost savings to operators. Moreover, the clamp-on style centralizers integrated into the camera housing serve to centralize the captured images and facilitate navigation through wellhead, tubing hangup points and tubing transitions. The camera technology was instrumental in a demanding operation to recover wireline cable and remove a bottom hole assembly in a live gas well. Extensive preparations over several months, besides planning on paper, included integration tests and yard trials. These preparations culminated in successful diagnostic runs, which encompassed inspecting the integrity and operation of the subsurface safety valve, examining top-of-liner features for BHA hang-up points, and assessing the top of the fish. High-definition pictures and videos were captured for all these critical features. During the diagnostic runs, the camera allowed to unveil changes in casing geometry through LED light reflection analysis. This finding guided the decision to adjust the BHA configuration, resulting in successful progression in wire removal and fish displacement to the rathole. The operation also required a custom long-range telemetry system for reliable communication over extended hybrid cable lengths exceeding 24,000 FT. The paper highlights two camera lens dome configurations with internal and external LED image lighting, discussing the benefits of each.

This chapter contains sections titled: Introduction Wave Motion. The Electromagnetic Spectrum The Plane Wave. Light Rays Phase Difference Complex Notation. Complex Amplitude Oblique Incidence of a Plane Wave The Spherical Wave The Intensity Geometrical Optics The Simple Convex (Positive) Lens A Plane-wave Set-up Problems

This chapter contains sections titled: Introduction Refraction at a Spherical Surface The General Image-forming System The Image-formation Process Reflection at a Spherical Surface Aspheric Lenses Stops and Apertures Lens Aberrations. Computer Lens Design Imaging and the Lens Formula Standard Optical Systems Problems