Characterizing Gas Transfer from the Inorganic Matrix and Kerogen to Fracture Networks: A Comprehensive Analytical Modeling Approach
- Jie Zeng (The University of Western Australia) | Jishan Liu (The University of Western Australia) | Wai Li (The University of Western Australia) | Lin Li (The University of Western Australia) | Yee-Kwong Leong (The University of Western Australia) | Derek Elsworth (The Pennsylvania State University) | Jianchun Guo (Southwest Petroleum University)
- Document ID
- Unconventional Resources Technology Conference
- SPE/AAPG/SEG Asia Pacific Unconventional Resources Technology Conference, 18-19 November, Brisbane, Australia
- Publication Date
- Document Type
- Conference Paper
- 2019, Unconventional Resources Technology Conference (URTeC)
- fracture network, gas transfer, inorganic matrix, shale gas reservoir, kerogen
- 1 in the last 30 days
- 72 since 2007
- Show more detail
|SPE Member Price:||USD 9.50|
|SPE Non-Member Price:||USD 28.00|
An appropriate description of gas transfer from shale matrices to fracture networks is one of the most fundamental issues in shale gas extraction modeling. Existing gas transfer functions can be classified into the following categories: (1) direct single-continuum matrix to fracture transfer; (2) kerogen, inorganic matrix, and fracture series gas transfer; and (3) kerogen to fracture and inorganic matrix to fracture parallel gas transfer. The scanning electron microscope (SEM) images of shale samples reveal the heterogeneous distribution of pure inorganic regions, kerogen and inorganic-matrix interwoven regions, and pure kerogen regions. As fracture networks can penetrate different matrix regions at different locations, the mass transfer between matrices and fractures cannot be comprehensively simulated by any of the above methods.
This paper presents a new matrix-fracture transfer function considering type 1: the direct inorganic matrix to fracture network inflow for pure inorganic regions; type 2: the kerogen, inorganic matrix, and fracture series flow for kerogen and inorganic-matrix interwoven regions; type 3: the direct kerogen to fracture network inflow for kerogen-rich regions. The contribution of each type in the transfer function is weighted through the volume percentage of each matrix-region type. Different multi-scale and multi-physics gas flow processes are included in kerogen and inorganic matter respectively. Finally, fluid transfer from fracture networks to hydraulic fractures is coupled through a linear flow system with stimulated reservoir volumes (SRVs).
This model has been validated against field data with an excellent agreement. And the degraded model's calculation matches well with that of a published composite linear flow model. Sensitivity analyses indicate that matrix-fracture gas transfer patterns affect certain flow regimes from the matrix-fracture transient regime to the transient regime before the boundary dominant regime. Types 1 and 2 gas transfer mechanisms with direct inorganic matter and secondary fracture connection exhibit lower dimensionless pressure and higher dimensionless rate values. The effects of the organic matter volume fraction and organic-rich reservoir block allocations on well production are also documented. This approach is a general tool for characterizing the gas transfer from shale matrices to fracture networks.
|File Size||2 MB||Number of Pages||28|
Bazan, L. W., Larkin, S. D., Lattibeaudiere, M. G., & Palisch, T. T. 2010. Improving production in the Eagle Ford Shale with fracture modeling, increased fracture conductivity, and optimized stage and cluster spacing along the horizontal wellbore. In Tight Gas Completions Conference. Society of Petroleum Engineers.
Wang, C., Chen, Z., Yao, J., Sun, H., Yang, Y., & Wu, K. 2014. Organic and inorganic pore structure analysis in shale matrix with superposition method. In Unconventional Resources Technology Conference, Denver, Colorado. Society of Exploration Geophysicists, American Association of Petroleum Geologists, Society of Petroleum Engineers.