Inflow Performance Relationship (IPR) Over Time Development for Fractured Horizontal Wells in the Wolfcamp a Formation, Delaware Basin

Abstract The objectives of this study are listed as follows: (1) to calibrate the Inflow Performance Relationship (IPR) model for fractured horizontal wells under production conditions in the Wolfcamp A formation and to propose a new set of calibration coefficients for the target reservoir; (2) to predict the IPR system’s changes over time for the wells, serving as a basis for optimizing production at different stages. The study begins by simulating the hydraulic fracturing of four wells in the Wolfcamp A formation. Commercial software was used to simulate hydraulic fracturing based on completion data, from which the fracture dimensionless conductivity value was obtained after history matching pressure. Once all the input parameters for the IPR were achieved, the authors calibrated the IPR for the researched wells. An algorithm was proposed to match the operating point with production data. Consequently, a new set of coefficients characteristic of the Wolfcamp A formation was introduced and will be used for future IPR modeling in the area. Afterward, based on Decline Curve Analysis, the authors proposed specific time periods for constructing a family of IPR curves. The results were compared with the computer simulation outcomes, showing a correlation between the analytical and the simulation methods. The IPR model has been calibrated, and a new set of seven coefficients, from a1 to a7, was proposed to characterize the production conditions in the area. Decline curves were developed for each well, and based on this, the production period was divided into four stages: stage 1: 0 – 3 months, stage 2: 3 – 12 months, stage 3: 12 – 24 months, and stage 4: after 24 months. This division allows for IPR modeling specific to each time period by applying the calibrated IPR. For each time period, production data was matched, and the authors successfully developed a set of four IPR curves for each well, reflecting changes from the start of production to the depletion period. The comparison results with the simulation indicate the similarity of the IPR after 3 months, highlighting the complexity of constructing the IPR in the early stages for unconventional formations. Developing an IPR model that accurately reflects key factors such as reservoir pressure and fracture conductivity for a specific reservoir is essential. The study proposed a new approach for developing an IPR system for the fractured horizontal wells in the Wolfcamp A formation. Combining simulation for Wolfcamp A provides a comprehensive research result on the subject. The research contributes to a better understanding of the changing of IPR throughout the production process. Successfully developing a reliable IPR model and a dynamic IPR system for the area plays a significant role in optimizing production and designing artificial lift systems.