Defect Detection Using High-Resolution Dual Caliper across Multiple Pipes in Single Descent

Abstract Traditionally, multifinger caliper tools are designed for specific pipe sizes, necessitating the use of multiple tools with different outer diameters to accommodate varying pipe dimensions. This design limitation prevents a single tool from being deployed across multiple pipe sizes in a single descent, thereby requiring multiple runs. Additionally, traditional multifinger calipers often suffer from limited circumferential coverage, which often results in failure to detect smaller defects such as pinholes and minor pitting. This paper presents a novel high-resolution dual caliper designed to address challenges in detecting defects within downhole tubulars, completion components, and casings. The innovative tool features an 80-finger arrangement within a compact 2 1/8-inch outer diameter, enabling it to cover a broad range of pipe sizes, from 2 5/8-inch tubing to 10-inch casing, without compromising radial measurement accuracy. Eccentricity effects are minimized through the equal azimuthal spacing of the fingers, supported by a specialized data processing algorithm. For highly deviated wells, motorized centralizers ensure precise tool centering, further enhancing measurement reliability. As part of this study, multiple wells were successfully logged using the novel high-resolution dual caliper technology, capable of inspecting various pipe sizes in a single descent. The dual caliper's enhanced circumferential coverage and higher inner radius resolution significantly improved the detection of minor defects such as localized pitting and pinholes, outperforming traditional multifinger calipers in accuracy and resolution. The dual caliper's advanced data processing incorporates specialized merge algorithms, enabling seamless visualization of data from all 80 fingers. Advanced data processing facilitates rapid interpretation of critical zones, supporting informed decision-making for subsequent operations. The processing algorithms also provide quick-look diagnostics, including maximum penetration depth, metal loss per joint, and minimum inner diameter, ensuring efficient evaluation of pipe integrity. The field performance of this novel technology demonstrates a significant advancement in downhole evaluation technology, delivering reliable and actionable insights. By delivering precise and reliable data, this advanced technology equips exploration and production (E&P) companies with critical insights for designing effective intervention strategies. The multi-well study has proven invaluable in enabling E&P companies to better assess the condition of internal tubing and casing, facilitating timely and informed decisions regarding necessary remedial actions. The novel high-resolution dual caliper tool demonstrated its efficiency by evaluating multiple pipe sizes in a single descent, significantly reducing operational time and costs. The dual caliper's ability to provide the most accurate information enhances well integrity management, ensuring optimal performance and long-term asset reliability.