Data-Driven Integration to Delineate Zonal Isolation and Casing Deterioration Using Advanced Ultrasonic Technology – A Blueprint to Well Integrity Evaluation

Abstract State-of-the-art advanced ultrasonic measurement through the Leaky-Lamb wave imaging technique (more commonly known as the flexural waveform analysis) was introduced nearly two decades ago to expand the envelope beyond which the classical pulse-echo evaluation operated. This technology has proven to be a game-changer in cement evaluation through provision of an integrated analysis which deconvolutes beyond the casing-cement interface and investigates further into the third interface. In this work, we integrate the cutting-edge analysis provided by ultrasonic flexural mode with the classical pulse-echo approach to yield a novel well-integrity evaluation blueprint. Subsequently, it is shown how this workflow is applied to an ultra-high pressure (UHP) exploratory well for integrity evaluation which will aid in future optimization of completion strategies and constitute a continuous improvement cycle for other wells. The subject well faced potential integrity related uncertainties due to fishing and cementing related issues. A three-tier approach was adopted to develop the blueprint, starting off with problem identification with respect to the various operations and incidents that occurred on this well. Next, based on the anticipated problems, associated solutions to evaluate the same were investigated by considering the technologies and standard procedures practiced by the industry. Finally, based on the previous two steps, a multi-physics approach was adopted that makes use of a combination of pulse-echo and flexural ultrasonic analysis, in addition to multiple well integrity workflows. Consequently, combination of flexural attenuation and acoustic impedance allows for a comprehensive evaluation of the medium behind the casing through the Solid-Liquid-Gas map. Simultaneously, it is possible to quantify casing thickness and internal radius variations through pulse-echo amplitude and resonance frequency characterization. Furthermore, the Third-Interface-Echo analysis is conducted to determine annulus geometry descriptions and produce a unique in-situ casing centralization measurement. The proposed well integrity blueprint contains various building blocks that are key to evaluation processes and provide a linkage-based approach to delineate potential problems. Accordingly, application of this blueprint illustrated the investigative approach it delivers with respect to cement barrier classification and casing condition assessment