A model for effective permeability in an unconsolidated hydrate reservoir

• Published in: Journal of natural gas science and engineering Vol. 72; p. 103033
• Main Authors: Hinz, Deniz, Arastoopour, Hamid, Abbasian, Javad
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2019
• Subjects: Effective permeability; Hydrate; Mallik; Simulation; Unconsolidated; Mallik; Effective permeability; Hydrate; Simulation; Unconsolidated
• ISSN: 1875-5100
• DOI: 10.1016/j.jngse.2019.103033

Numerous experimental studies have shown that hydrate dissociation can result in significant strength reduction leading to sediment failure and unconsolidated flow behavior. In this work, a constitutive model for the effective permeability is developed that is capable of accurately modeling the evolution of permeability in hydrate reservoirs exhibiting unconsolidated behavior. A production phase that promotes sand production from an unconsolidated hydrate reservoir will result in a significant increase in permeability, such that the reservoir essentially behaves like a naturally fracking reservoir. Furthermore, installation of a sand screen to prevent sand production will throttle gas production due to the significant decrease in permeability as solids accumulate and compact at the sand screen. Our model was developed and verified using experimental data from the Mallik 2007/2008 production tests and can be applied in simulations of the coupled hydrodynamics, heat transfer, mass transfer, and geomechanics in the unconsolidated hydrate reservoir. •Solid movement greatly affects production from unconsolidated hydrate reservoirs.•Solid deformation can result in formation or closure of high-permeability zones.•High-permeability zones evolve due to dilation and compaction of the sediment.•Solid movement affects production whether sand is produced or not.•A hydrate reservoir with sand production behaves like a naturally fracking reservoir.