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Transport in Porous Media

, Volume 84, Issue 1, pp 201–218 | Cite as

Displacement of Cr(III)–Partially Hydrolyzed Polyacrylamide Gelling Solution in a Fracture in Porous Media

  • Somenath GangulyEmail author
Article

Abstract

During waterflooding of a fractured formation, water may channel through the fracture or interconnected network of fractures, leaving a large portion of oil bearing rock unswept. One remedial practice is injection of a gelling solution into the fracture. Such placement of a gelling mixture is associated with leak-off from the fracture face into the adjoining matrix. Design of a gel treatment needs understanding of the flow of gelling mixture in and around the fracture. This flow is addressed here for Cr(III)–partially hydrolyzed polyacrylamide formulation through experiments and conceptual model. A fractured slab was used to develop a lab-model, where the flow along the fracture and simultaneous leak-off into the matrix can be controlled. Also, the fracture and matrix properties had to be evaluated individually for a meaningful analysis of the displacement of gelling solution. During this displacement, the gelling fluid leaked off from the fracture into the matrix as a front, resulting in a decreasing velocity (and pressure gradient) along the fracture. With pressure in the fracture held constant with time, the leak-off rate decreased as the viscous front progressed into the matrix. The drop in leak-off rate was rapid during the initial phase of displacement. A simple model, based on the injection of a viscous solution into the dual continua, could explain the displacement of Cr(III)–polyacrylamide gelling mixture through the fractured slab. This study rules out any major complication from the immature gelling fluid, e.g., build-up of cake layer on the fracture face. The model, due to its simplicity may become useful for quick sizing of gel treatment, and any regression-based evaluation of fluid properties in a fracture for other applications.

Keywords

Fracture Flow Gel Porous Pressure 

List of Symbols

A

Dimensionless constant of the flow cell

Ar

Area available for flow (L2)

q

Flow rate (L3T−1)

w

Height of the cell (L)

2h

Fracture aperture width (L)

k

Permeability (L2)

p

Pressure (ML−1T−2)

p

Dimensionless pressure

x

Length along fracture axis (L)

x

Dimensionless length along fracture axis

z

Length along matrix axis (L)

z

Dimensionless length along matrix axis

v

Darcy velocity (LT−1)

2b

Flow cell width (L)

L1

Depth of penetration of viscous front in the matrix (L)

pb

Set back pressure (ML−1T−2)

t

time (T)

Greek Symbols

μ

Viscosity (ML−1T−1)

Φ

Porosity

Subscripts

f

Fracture

m

Matrix

atm

Atmosphere

in

Fracture inlet

out

Fracture outlet

w

Water

D

Dimensionless variable

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References

  1. Grattoni C.A., Al-Sharji H.H., Yang C., Muggeridge A.H., Zimmerman R.W.: Rheology and permeability of crosslinked polyacrylamide gel. J. Colloid Interf. Sci. 240(2), 601–607 (2001)CrossRefGoogle Scholar
  2. Iwai, K.: Fundamental studies of fluid flow through a single fracture. Ph.D. dissertation, University of California, Berkeley (1976)Google Scholar
  3. Seright R.S.: Gel placement in fractured systems. SPE Prod. Facil. 10(4), 241–248 (1995)Google Scholar
  4. Seright R.S.: Polymer gel dehydration during extrusion through fractures. SPE Prod. Facil. 14(2), 110–116 (1999)Google Scholar
  5. Stavland, A. Kvanvik, B.A., Lohne, A.: Simulation model for predicting placement of gels. Proceedings of SPE Annual Technical Conference and Exhibition, Sigma (1) New Orleans, LA (1994)Google Scholar
  6. Sydansk R.D.: A newly developed Chromium (III) gel technology. SPE Reserv. Eng. 5(3), 346–351 (1990)Google Scholar
  7. Sydansk R.D., Xiong Y., Al-Dhafeeri A.M., Schrader R.J., Seright R.S.: Characterization of partially formed polymer gels for application to fractured production wells for water-shutoff purposes. SPE Prod. Facil. 20(3), 240–249 (2005)Google Scholar
  8. Todd B.J., Willhite G.P., Green D.W.: Mathematical model of in-situ gelation of polyacrylamide by a redox process. SPE Reserv. Eng. 8(1), 51–58 (1993)Google Scholar
  9. Vermolen F.J., Bruining J., VanDujin C.J.: Gel placement in porous media: constant injection rate. Transp. Porous Media 44(2), 247–266 (2001)CrossRefGoogle Scholar
  10. Wang, D., Han, P., Shao, Z., Chen, J., Seright, R.S.: Sweep improvement options for the daging oil field. Proceedings of SPE–DOE Improved Oil Recovery Symposium, Tulsa, OK (2006)Google Scholar
  11. Wassmuth F., Green K., Hodgins L.: Gel placement key to success for water shutoff in gas wells. J. Pet. Technol. 56(9), 87–88 (2004)Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Department of Chemical EngineeringIndian Institute of TechnologyKharagpurIndia

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