Application of Advanced Sectorial Electromagnetic Scanning Addressing Well Integrity Challenges

This paper explores the application of the sectorial electromagnetic scanning tool in diagnosing well integrity issues, such as metal loss and deformation in gas wells. The tool enhances the detection of defects in the well’s first barrier (the innermost pipe that the scanning tool directly evaluates), providing azimuthal resolution and localized measurements of wall thickness. Existing conventional electromagnetic corrosion logging methods associated with averaged circumferential measurements may overlook localized anomalies, potentially leading to underestimated integrity risks. The study includes laboratory and field validation of the tool’s performance. Laboratory tests were conducted on various pipe configurations, including single-barrier and dual-barrier setups, as well as chrome-alloy completions, to assess the tool’s sensitivity and accuracy. Additionally, it provides differentiation between uniform and localized metal loss, offering enhanced diagnostic capability compared to averaging electromagnetic methods. Field applications were conducted in a gas-producing well with a 4.5-in. tubing string and a perforated 4.5-in. liner. The tubing is the smaller-diameter pipe installed inside the cemented larger strings of a well, primarily used to transport reservoir fluids from the production zone to the surface. The liner is a cemented pipe segment placed within another cemented pipe, extending only through specific sections of the wellbore rather than running the entire depth. Liners are commonly used to isolate certain intervals, reinforce the wellbore structure, prevent fluid migration between layers, or facilitate production from targeted reservoir zones. The sectorial tool was deployed alongside traditional mechanical multifinger caliper (MFC) and averaging electromagnetic methods. The tool also detected deformation in the liner, correlating with ovalization observed on the caliper log. The sectorial measurements revealed inconsistent metal responses across the radial sensors, indicating an uneven distance between the sensors and the pipe wall, an effect characteristic of mechanical distortion. The sectorial electromagnetic scanning tool provides several advantages, including full circumferential coverage, azimuthal resolution measurements, and the ability to operate in all fluid environments, including gas-filled wells. Its non-contact nature ensures compatibility with coated and internally lined pipes. The findings of this study highlight the tool’s potential to improve well integrity management by enabling early detection of localized defects, reducing maintenance costs, and enhancing well safety and performance.