Pressure Transient Analysis of Hydraulically Fractured Wells: The Cost of Missing Flow Rate Measurements During Flowback

Abstract Hydraulic fracturing treatments have been extensively studied and are therefore relatively well understood. However, evaluating hydraulic fractures can still present challenges. This paper presents methodologies based on pressure transient analysis (PTA) to assess fracture quality and optimize hydrocarbon production. We analyzed production comebacks in several hydraulically fractured wells and highlighted the impact of missing or insufficient flow rate measurements, particularly in exploration wells. Using real field examples from hydrocarbon reservoirs, we demonstrate the significance of accurate flow rate measurements on PTA during well cleanup and flowback operations. We analyzed various well tests conducted after fracturing operations to assess the effects of missing flow rate data. To complement our analysis, we incorporated PVT data, petrophysical well logs, and core data. Additionally, we utilized large-scale production tests, such as drill stem tests, to evaluate different scenarios. We also simulated the effects of missing or averaged flow rate histories on various PTA cases. Testing wells after hydraulic fracturing treatments is crucial for both near-wellbore and far-field characterization. Well testing with downhole pressure data has provided invaluable insights into hydraulically fractured wells in tight reservoirs worldwide. Various parameters influencing the efficiency and quality of hydraulic fracturing treatments have been studied and identified. The impact of missing flow rate measurements on accurate PTA has been demonstrated and quantified, highlighting the risks of misleading interpretations. Practical drawbacks have been identified, and appropriate remedies proposed. The importance of accurately recording flow rate history, at least to a reasonable extent, has been emphasized to ensure meaningful conclusions in reservoir characterization. Furthermore, it has been shown that implementing an engineered approach to flowback operations can significantly enhance productivity and improve ultimate hydrocarbon recovery. Such optimized well testing and flowback strategies have been successfully applied following hydraulic fracturing treatments in multiple wells. We present a real field case study from a tight gas reservoir, demonstrating the impact of missing flow rate measurements on well test analysis and methods to identify such gaps. Additionally, we illustrate how erroneous flow rate data can be corrected to enhance analysis accuracy and overcome these challenges. Practical well testing and flowback guidelines are also provided, which can be easily adapted and applied to similar reservoirs.