Employment of Geochemical Fingerprinting Technology for Dynamic Production Monitoring in Unconventional Wells

Abstract Traditional geochemical methods such as Pyrolysis and Soxhlet extraction techniques have been used for decades to guide development programs of conventional reservoirs. However, these conventional practices cannot be extended to meet the required demands of unconventional reservoirs due to the limitations in predicting fracture growth and dynamic production monitoring in unconventional wells. This study presents an integrated workflow to optimize field development using results of time-lapse geochemical fingerprinting technology in unconventional fields. The methodology involved selecting representative rock samples from tight reservoirs and time-lapse oil samples. Then, high-resolution geochemical fingerprints were acquired from the produced oil samples and the oil samples extracted from the source rocks. By deploying this methodology, a mathematical regression model was built by data mining the resulting fingerprint data based on over 2000 geochemical compounds. Utilizing this model, a group of Reservoir Characterization Indices (RCI) were developed and used as natural tracers to track back the contributing zones of the produced oil and to predict the drainage fracture height to maximize recovery from stacked and staggered reservoir developments. An integrated workflow has been employed to optimize field developments using geochemical fingerprinting technology in unconventional wells. Integrating the dynamic reservoir monitoring data with the geochemical RCI data has greatly assisted to identify key factors driving the performance of unconventional wells and inter-well interference. The high-resolution analysis of both produced and extracted oil from the cores resulted in dynamically capturing the change in drainage height of the stimulated rock volume over the sampling period. Thereby developing a map of the change in production drainage height in the stimulated reservoir as a function of time. Accurate characterization of the drainage fracture height enabled the determination of the optimum landing point for stacked and staggered placements of unconventional wells. This in turn assisted in improving overall hydrocarbon recovery and economics from shale reservoirs. This study presents a pioneering workflow to characterize the dynamic drainage fracture height and zonal relative contribution by measuring the geochemical fingerprints of source rocks and produced oil samples. The employment of this unique approach has significantly assisted to determine the optimal well placement and to improve long-term development strategies of unconventional fields.