Shale Liquids Production AnalysisIn Development


$52k (USD) per Sponsor


In Development

Principal Investigator(s):

Ian Walton

Value to Sponsors

  • Provide the ability to optimize production strategies to either maximize gas production or condensate production resulting in enhanced long term production.
  • A predictivie tool for asset management teams to evaluate future production characteristics as well as estimating recovery factors as a result of understanding the major factors that control well performance.
  • EGI Corporate Associates having unconventional assets with liquids production will benefit as the results for gas condensate production strategy will be applicable in part for all liquids producing shales.
  1. An analytical tool that captures the physics of two phase production from shales and optimizes production strategy.
  2. Document the main effect of condensate dropout on gas production from shale reservoirs as well as the importance of relative permeability parameters, different gas compositions, reservoir properties, and the relative magnitudesof bottom hole flowing pressure, dew-point pressure (or bubble-point pressure) and initial reservoir pressure.
  3. Sponsors have the option to have a test case of theirproduction and completions data analyzed to improve production.

With the current focus on liquids-rich shale plays in North America and the global importance of gas condensate plays, there is an increased need to develop reservoir engineering methods to analyze production data and to develop optimal methods of producing such reservoirs. Without careful planning a gas condensate reservoir can choke on its own production. Drawdown below the dew point of the reservoir fluid can result in condensate liquid dropout, particularly close to the wellbore, the sand face or the fracture face. The increased liquid saturation leads to reduced permeability to gas and, in some cases, significant choking back of the gas production. The impact on well production is most significant for shale reservoirs where most of the total pressure drop is in the formation. In recent EGI research projects (Shale Gas Production Analysis (SGPA) Phase 1 and Phase 2), we have developed a mathematical model of the gas production process from shales. In Phase 2 of that project we explored the applicability of the ideas developed in Phase 1 to production of saturated oil from shale reservoirs. The model developed provided no more than a first pass at analyzing the complex processes at play in this two-phase production system. Nevertheless the results were sufficiently encouraging that further development is warranted. In this project proposal we suggest that, first, an extension to gas condensate plays should be considered and second, a more detailed and rigorous mathematical analysis is merited.

The overall objective is to develop an analytical or semi-analytical model that captures the most important physics of two-phase production from shales. The expected outcomes of this investigation include:

  • Improved understanding of the major factors that control well performance, including
    • Relative permeability parameters
    • Different gas compositions (richness of condensates), including impact on dew point
    • Reservoir properties (permeability and porosity)
    • The relative magnitudes of pressure (bottom hole flowing, dew-point, and initial reservoir).
  • Assessment of the optimal production strategy to maximize either gas production or condensate production.
  • Prediction of future production characteristics. We anticipate that the optimal strategy may depend on the time scale over which production is to be maximized, requiring careful estimate of future production.
  • Assessment of recovery factors and drainage area for multi-fractured horizontal well completions.