Raj Banerjee

Production Forecasting and Analysis for Unconventional Resources

Horizontal well drilling with multistage fracturing technology has been the common practice to develop unconventional resources. During the development of such resources, we are often faced with the following questions: How can we optimize the stimulation treatment? How much can the well produce? What are the production data telling us? Answering these questions requires technologies and tools to be able to forecast and analyze the production behavior of fractured wells. We investigate the physics and mathematics involved in production forecasts of both planar fractures and fracture networks that are generated due to stress isotropy and pre-existing natural fractures. We use analytical methods because they give rigorous yet very fast solutions. Since simulation expertise is not required to use our model, it is an accessible tool for multiple disciplines. A new nodal analysis approach is proposed for unconventional resources. Production forecasting enables the optimization of a well stimulation treatment, and helps to determine, for example, the number of fracture stages and the amount of proppant to use. Case studies illustrate the concept and some of the practical aspects of fractured well production, such as the impact of propped conductivity and unpropped conductivity. The composite workflow for diagnosis and analysis of production data specific to unconventional resources was applied to real case examples. The workflow involves flow regime identification, decline curve analysis, and rate transient analysis. The workflow is easily scaled from single-well level to well clusters to full field implementation.

Semi-analytical Solution for Multiple Layer Reservoir Problems with Multiple Vertical, Horizontal, Deviated and Fractured Wells

We present new semi-analytical solutions to the multiple layer reservoir problem, both in real-time and Laplace space. Assuming a vertically stacked system of layers, an analytic solution within each layer can be derived using a method of integral transforms. We fully account for crossflow between layers by coupling these analytic solutions together and solving Fredholm integral equations to obtain the flux field at the layer interfaces. The time evolution of these fluxes is governed by a Volterra integral equation. Also, the form of our equations allows us to stop a model execution and then restart from the exact terminated state.