Integrated Workflow Towards Characterizing Hydraulic Fractures in Tight Gas Reservoirs-Modeling, Uncertainty Analysis, History Matching Production Forecasting

摘要

This paper details real field case of an integrated approach followed in near wellbore modeling with the aim of characterizing hydraulic fractures in tight gas reservoirs. Uncertainties in the geology, inability to draw conclusions from data obtained and how to effectively integrate data from different sources (cores, logs, geological model, well test & production data) were the challenges. The steps taken to overcome these challenges and addressing the uncertainty, using both analytical and numerical modeling, resulting in improved well and reservoir characterization, is presented in this paper. The work done and outlined in this paper provides an integrated workflow for fracture modeling and performance prediction through a probabilistic approach. The work involves: 1. Analyzing and incorporating the data and their uncertainty from varied sources. 2. Generating multiple realizations of the static model. 3. Selection of the appropriate static model based on an error function. 4. Near wellbore modeling to account for hydraulic fracture. 5. Probabilistic Model validation by replicating the well testing sequence. This integrated workflow provided enhanced fracture characterization and performance prediction while incorporating the impacts of uncertainty. Reservoir structure and depositional environment understanding were improved. In tight gas reservoirs in the early stage of development this approach is more comprehensive towards modeling hydraulic fractures parameters and hence production optimization from the reservoir. The value information gained from this workflow is then integrated into the full field dynamic model.