Virtually Unplugging Perforations: High-Resolution Acoustic Imaging Enabling Statistical Analysis of Calibration and Post-Frac Perforation Entry and Exit-Hole Datasets.

High-resolution acoustic imaging technology provides operators the ability to extract submillimetric measurements of perforations at any depth into the casing wall. Due to its three-dimensional nature, submillimetric acoustic data permits the extraction of highly accurate area-based measurements at any radial distance into the perforation, with key distances at the inner and outer casing boundary. This novel technology is fluid agnostic and is unaffected by fluid opacity or clarity. The platforms robust 3D measurement capabilities have made it into an ideal means to evaluate casing and perforations in challenging environments such as hydraulically fractured wells. The integration of high-resolution acoustic imaging into numerous operators’ hydraulic fracture and completions evaluation workflows has resulted in a highly insightful aggregate submillimetric perforation dataset. This large dataset has led to the development of a method to virtually unplug perforations by using a well-specific "perforation entry and exit-hole area correlation". The correlation established can only be extracted using acoustic based imaging as it requires submillimetric resolution of both the ID and OD profile of each perforation Using this correlation, the resulting set of post-frac perforation exit-hole measurements improves an operators’ ability to complete a holistic well completion evaluation, even when well conditions cause perforations to be plugged. The outcome is improved operational insight through the ability to directly compare stages with plugged perforations to those without. This approach can be applied at any point in the well's life cycle, which allows operators to revisit assessments and virtually unplug obscured and proppant-filled perforations. The methodology requires a sound baseline knowledge of the performance of the downhole perforating charges. The baseline is commonly obtained through a calibration stage, which is a stage of charges that are shot but left unstimulated to provide the control measurements for the specific charge in the given well conditions. Current industry performance of downhole perforating charges is investigating through the aggregated dataset of calibration charges. To validate this solid-state acoustic technology and demonstrates its high degree of accuracy for entry and exit-hole perforation measurements, machined samples were scanned with this technology, and with a metrology-grade laser scanner for comparison. This paper presents a novel virtual unplugging methodology, enabled by highly accurate and validated entry-hole measurements, as well as other insights garnered from the aggregate analysis of the world's largest calibration perforation datasets.