Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs

Jie He, John E. Killough, Sunhua Gao, Mohamed Fadlelmula, F. Michael Fraim

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Flow simulation in carbonate reservoirs presents many challenges due to the frequent occurrence of vugs and natural fractures therein. In conventional reservoir simulation practices, fluid flow in vugs and fractures is usually assumed as Darcy flow, and permeability values are estimated for vuggy regions and fractures. Although such estimations are often accomplished in reasonable ways, no physical or mathematical basis exists for them, and even the assumption of Darcy flow itself is questionable. In this paper, we propose a novel workflow for the simulation of fluid flow in naturally fractured carbonate karst reservoirs. The workflow is based on simulation results of a single-phase transient Brinkman model, which provides the correct and complete description of the coupled flow in vuggy and fractured reservoirs by unifying Stokes flow in vugs and fractures with Darcy flow in the rock matrix. The new workflow proceeds through an iterative procedure by increasing the permeability values of vugs and fractures without the disadvantages of accurately estimating them, and attains the final simulation results when a convergence pattern is observed. The novel workflow is implemented and compared with the conventional approaches in commercial reservoir simulators. The workflow is first applied to single-phase flow simulations in a fine-scale 3D geological model which is generated using the multiple-point geostatistical modeling technique, and then extended to immiscible two-phase flow and other multi-phase cases. Simulation results show that in most cases our new workflow yields higher production rate predictions than conventional approaches. This is due to the fact that the permeability values of vugs and fractures estimated by conventional methods are usually lower than the permeability values required for the iterative convergence of the new workflow. The results also have further implications on the history matching process that more focus should be put on fracture geometry, i.e. fracture width and half-length, since the use of fracture permeability alone has lost its physical meaning in the novel workflow according to the Brinkman equation.

Original languageEnglish
Title of host publicationSociety of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016
PublisherSociety of Petroleum Engineers
Volume2016-January
ISBN (Electronic)9781510844803
Publication statusPublished - 1 Jan 2016
EventAbu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2016 - Abu Dhabi, United Arab Emirates
Duration: 7 Nov 201610 Nov 2016

Other

OtherAbu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2016
CountryUnited Arab Emirates
CityAbu Dhabi
Period7/11/1610/11/16

Fingerprint

Carbonates
fluid flow
karst
Flow of fluids
carbonate
simulation
permeability
Flow simulation
single-phase flow
fracture geometry
two phase flow
simulator
Two phase flow
Simulators
Rocks
matrix
Geometry
history
prediction
rock

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Fuel Technology
  • Geochemistry and Petrology

Cite this

He, J., Killough, J. E., Gao, S., Fadlelmula, M., & Michael Fraim, F. (2016). Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs. In Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016 (Vol. 2016-January). Society of Petroleum Engineers.

Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs. / He, Jie; Killough, John E.; Gao, Sunhua; Fadlelmula, Mohamed; Michael Fraim, F.

Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016. Vol. 2016-January Society of Petroleum Engineers, 2016.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

He, J, Killough, JE, Gao, S, Fadlelmula, M & Michael Fraim, F 2016, Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs. in Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016. vol. 2016-January, Society of Petroleum Engineers, Abu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2016, Abu Dhabi, United Arab Emirates, 7/11/16.
He J, Killough JE, Gao S, Fadlelmula M, Michael Fraim F. Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs. In Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016. Vol. 2016-January. Society of Petroleum Engineers. 2016
He, Jie ; Killough, John E. ; Gao, Sunhua ; Fadlelmula, Mohamed ; Michael Fraim, F. / Confronting the simulation of fluid flow in naturally fractured carbonate karst reservoirs. Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference 2016. Vol. 2016-January Society of Petroleum Engineers, 2016.
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