The Unconventional Reservoir Engineering Project (UREP) is a research consortium focusing on the unconventional aspects of reservoir engineering to contribute to the long-term, sustainable production from unconventional reservoirs including but not limited to nano-pore resource plays such as shale-gas and liquids-rich formations.
Despite the impressive technological advances to develop tight unconventional resources, our understanding of the physical mechanisms of fluid production from these reservoirs has been limited. Initially, the industry conceived the unconventional-reservoir-engineering as an issue of using conventional concepts with nano-scale reservoir properties and incorporating multiple hydraulic fractures into flow models. This approach became inadequate as the long-term reservoir-management concerns offset the initial hype about unconventional shale-gas and liquids-rich reservoirs. Consequently, the interest in genuinely-unconventional reservoir-engineering-research has started growing.
The objective of the UREP is to attain a more complete reservoir engineering understanding and develop more appropriate reservoir engineering tools and practices for tight unconventional oil and natural gas reservoirs. The focus of the Consortium is on the discerning physical characteristics of nano-pore, nano-permeability, micro-fractured formations, unconventional flow mechanisms and unaccounted capillary and surface-forces relationships in nano-pores, unaccustomed multi-phase flow concepts, and new fluid exchange mechanisms between fractures and the tight rock matrix. Development of unconventional reservoir models, analysis techniques, and prediction tools will be the outcome of the research program.
Although the objectives inevitably include multidisciplinary aspects, the scope of the Consortium is limited to reservoir engineering research. Some good multidisciplinary, integrated programs are already in existence. Furthermore, integrated studies should be more successful after each component accomplishes a sufficient level of maturity.
The following is a broad list of the research focus of the program. These focus areas will be covered in different projects prioritized by the sponsors and depending on the level of funding.
Fundamentals of Fluid-Flow in Unconventional Reservoirs:
- Capillary and surface-force interactions in nano-pores
- Thermodynamics and EOS for multiphase flow in unconventional reservoirs
- Bubble/dew-point (gas-phase formation) in nano-pores
- Capillary evaporation/condensation in nano-pores
- Critical fluid saturations and relative permeabilities in liquids-rich reservoirs
- Diffusion and nucleation in multi-scale pore-networks
- Coupling high- and low-velocity flows across matrix-fracture interfaces
- Flow in layered systems of source and producing rocks
- Flow regimes in unconventional tight reservoirs
Unconventional Reservoir Modeling:
- Analytical and numerical modeling of fractured horizontal wells
- Reservoir modeling with diffusive (slip) flow and desorption
- Incorporating pore-scale thermodynamics into reservoir flow models
- Modeling multi-level fracture systems in tight formations
- Critical data requirements and sensitivities for unconventional reservoir modeling
- Practical unconventional reservoir modeling
Drainage Area and Well-Spacing Issues:
- Drainage areas in shale-gas and liquids-rich formations
- Well interference in unconventional reservoirs
- Optimum well spacing
- Estimation of reservoir volume
Data Analysis and Performance Prediction:
- Production data analysis
- Pressure transient analysis
- Production decline analysis with and without boundary effects
- Average pressure in shale-gas and liquids-rich formations
- Estimation of ultimate recovery
- Design and optimization of horizontal wells with multiple fractures