Technology Focus: Well Testing (February 2025)

This year’s Well Testing feature highlights three papers chosen from more than 70 presented over the last year at SPE conferences. While many worthy candidates exhibited technical novelty and innovation, these papers provided insights and advances into field-operations automation, machine-learning-assisted petrophysical characterization, and fluid-distribution analysis in unconventional assets. Paper IPTC 24454 describes a novel workflow integrating static logging data (i.e., petrophysical and image log data) with dynamic pressure transient data. This integration was performed in a 3D single-well numerical model, honoring the geology of reservoir sands. Another key feature of this study was the use of deep-transient-testing data, which had a larger radius of investigation compared with conventional formation-testing pressure data. Conventionally, in a numerical history-matching method for single-well models, pressure data is matched; however, in this study, the authors went a step further to match the pressure derivative from numerical-model and actual pressure data recorded downhole using pressure gauges. The use of machine-learning-based automatic facies classification narrowed the layer’s petrophysical uncertainties, which led to faster history matching in the numerical model. The presence of faults could be integrated with geological image logs and further confirmed by pressure-derivative responses. Another key feature of this study was that, with the help of a history-matched numerical model, the authors were able to estimate full reservoir zone productivity and minimum hydrocarbon in place, both vitally important to operators during the early phases of exploration campaigns, with single to very few wells having been drilled. The study presented in paper URTeC 4044415 explores advanced strategies for well-testing operations in high-pressure/high-temperature gas wells in the Middle East, focusing on efficient solids separation, fluid recovery, and sour service. It introduces an innovative cleanup and flowback testing approach using compact cyclonic technology with enhanced metallurgy, automation, and safety. Computational fluid dynamics simulations highlight the effect of density and viscosity on separator performance, providing recommendations for efficient gas-flow rates. The approach improves separation efficiency under high-viscosity, high-hydrogen-sulfide (H2S) conditions with nitrogen and H2S scavengers. This interdisciplinary effort advances well-testing and solids management for conventional and unconventional gas resources. In the third selected paper, IPTC 23404, innovative evaluation techniques were developed for shale and sand laminated reservoirs, addressing limitations in traditional logging methods. Using sandstone wireline-formation-test (WFT) data, four aspects were assessed: fluid properties of shale-oil laminae, permeability evaluation by calibrated nuclear-magnetic-resonance data, pressure profiling to inform development strategies, and fluid-distribution analysis. This approach clarified reservoir accumulation models, led to successful testing in six exploration wells, and is applicable to similar reservoirs worldwide. This novel shale-oil-evaluation approach bridges the limitations of traditional methods by using sandstone WFT data for integrated laminated reservoir analysis. Key innovations include equilibrium-based property assessment, calibrated permeability modeling, and advanced pressure- and fluid-distribution profiling. This methodology enhances reservoir understanding, guides fracturing design, and supports efficient resource extraction. Its successful application in the Weixinan Sag field highlights its potential for broader use in similar geological settings. These papers represent the importance of the ongoing research shared in technical papers presented at SPE conferences each year. I hope you enjoy them and encourage you to search the OnePetro online library to find other papers, both recent and historical, that might pique your interest. Recommended additional reading at OnePetro: www.onepetro.org. SPE 222390 - First Multizone Drillstem Test in the UAE Improves Operational Efficiency and Enhances Value of Information by Ahmed Hassan, Abu Dhabi National Oil Company, et al.