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Effect of advective flow in fractures and matrix diffusion on natural gas production
Author(s) -
Karra Satish,
Makedonska Nataliia,
Viswanathan Hari S.,
Painter Scott L.,
Hyman Jeffrey D.
Publication year - 2015
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2014wr016829
Subject(s) - advection , diffusion , fracture (geology) , production (economics) , flow (mathematics) , matrix (chemical analysis) , mechanics , geology , environmental science , petroleum engineering , geotechnical engineering , materials science , economics , physics , thermodynamics , composite material , macroeconomics
Although hydraulic fracturing has been used for natural gas production for the past couple of decades, there are significant uncertainties about the underlying mechanisms behind the production curves that are seen in the field. A discrete fracture network‐based reservoir‐scale work flow is used to identify the relative effect of flow of gas in fractures and matrix diffusion on the production curve. With realistic three‐dimensional representations of fracture network geometry and aperture variability, simulated production decline curves qualitatively resemble observed production decline curves. The high initial peak of the production curve is controlled by advective fracture flow of free gas within the network and is sensitive to the fracture aperture variability. Matrix diffusion does not significantly affect the production decline curve in the first few years, but contributes to production after approximately 10 years. These results suggest that the initial flushing of gas‐filled background fractures combined with highly heterogeneous flow paths to the production well are sufficient to explain observed initial production decline. These results also suggest that matrix diffusion may support reduced production over longer time frames.