_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 220746, “Paraffin Production in Eagle Ford: Learning, Applying, and Executing Out-of-Box Strategies for Living With This Challenging Issue, ” by Jesus D. Contreras, SPE, Javier R. Vasquez, and Trey W. Harton, ConocoPhillips, et al. The paper has not been peer reviewed. _ Since the beginning of Eagle Ford development, paraffin production has created significant production losses in wells downhole, well pads, and gathering systems. In 2020, a dedicated team began investigating a more-proactive approach with the creation of an integrated hydraulic model to improve pigging operations within the gathering system. The complete paper explains that, through the discovery of specific pressure trends at pad level (surface), combined with an unconventional approach for analyzing gas compositional data, it was possible to both detect and predict paraffin deposition at the pad level and in the gathering system, including conditions where paraffin was in suspension. Introduction Between 2011 and 2018, the operator’s Eagle Ford team implemented several projects with the objective of mitigating production losses associated with paraffin plugs in the gathering system, including testing a different surface-facility pad configuration. This configuration is equivalent to having a miniature central facility for each well where fluids are completely separated and measured before leaving the pad area. The original idea behind this approach was to collect as much data as possible to accelerate understanding of this shale formation. This pad configuration, combined with a high level of instrumentation, automation, and real-time data availability, features three different flow streams: - A high-pressure system handles high-pressure gas produced by the wells and gas lift for injection (duality). - A low-pressure system collects low-pressure gas produced by the wells. - A liquid-line system collects water and oil produced by the wells. The focus of the complete paper is understanding paraffin production on the surface throughout the liquid-line system. Traditional and Conventional Approaches Between 2014 and 2016, facilities for pigging liquid pipelines were installed as part of normal field development. The goal was to increase the probability of mitigating possible plugs. This approach provided the Eagle Ford organization with the flexibility to create a simple maintenance plan to keep the pipelines free of plugs. However, rapid field development, which included a growing number of wells, pipelines, midfield headers, and central facilities, heightened the challenge of understanding the paraffin problem in Eagle Ford. Between 2016 and 2019, the team focused on understanding the complexity of the gathering system. A graphical model was created that tracked different connections between pads, departing headers, midfield headers, and central facilities. The project also included a full-field plan for using chemical injection at the well-pad level to mitigate potential plugs throughout the gathering system. This approach, however, lacked the capability to explain fluid movement because it was not a network solver. Fig. 1 shows a representation of the Eagle Ford Customizable Asset Network Visualization and Analysis System (CANVAS) developed by the asset-integrity team. However, the complexity of the gathering system exceeded the capacity of the CANVAS system to explain or predict locations and conditions where paraffin accumulated.
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