Proppant Placement Using Alternate-Slug Fracturing
- Sahil Malhotra (University of Texas at Austintin) | Eric R. Lehman (University of Texas at Austin) | Mukul M. Sharma (University of Texas at Austin)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- October 2014
- Document Type
- Journal Paper
- 974 - 985
- 2014.Society of Petroleum Engineers
- 3.2.3 Hydraulic Fracturing Design, Implementation and Optimisation, 2.5.2 Fracturing Materials (Fluids, Proppant), 5.3.2 Multiphase Flow, 4.1.2 Separation and Treating
- proppant , alternate-slug fracturing, viscosity, hydraulic fracturing, viscous fingers
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- 998 since 2007
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New fracturing techniques, such as hybrid fracturing (Sharma et al. 2004), reverse-hybrid fracturing (Liu et al. 2007), and channel (HiWAY) fracturing (Gillard et al. 2010), have been deployed over the past few years to effectively place proppant in fractures. The goal of these methods is to increase the conductivity in the proppant pack, providing highly conductive paths for hydrocarbons to flow from the reservoir to the wellbore. This paper presents an experimental study on proppant placement by use of a new method of fracturing, referred to as alternate-slug fracturing. The method involves alternate injection of low-viscosity and high-viscosity fluids, with proppant carried by the low-viscosity fluid. Alternate-slug fracturing ensures a deeper placement of proppant through two primary mechanisms: (i) proppant transport in viscous fingers, formed by the low-viscosity fluid, and (ii) an increase in drag force in the polymer slug, leading to better entrainment and displacement of any proppant banks that may have formed. Both these effects lead to longer propped-fracture length and better vertical placement of proppant in the fracture. In addition, the method offers lower polymer costs, lower pumping horsepower, smaller fracture widths, better control of fluid leakoff, less risk of tip screenouts, and less gel damage compared with conventional gel fracture treatments. Experiments are conducted in simulated fractures (slot cells) with fluids of different viscosity, with proppant being carried by the low-viscosity fluid. It is shown that viscous fingers of low-viscosity fluid and viscous sweeps by the high-viscosity fluid lead to deeper placement of proppant. Experiments are also conducted to demonstrate slickwater fracturing, hybrid fracturing and reverse-hybrid fracturing. Comparison shows that alternate-slug fracturing leads to deepest and most-uniform placement of proppant inside the fracture. Experiments are also conducted to study the mixing of fluids over a wide range of viscosity ratios. Data are presented to show that the finger velocities and mixing-zone velocities increase with viscosity ratio up to viscosity ratios of approximately 350. However, at higher viscosity ratios, the velocities plateau, signifying no further effect of viscosity contrast on the growth of fingers and mixing zone. The data are an integral part of design calculations for alternate-slug fracturing treatments.
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Blackwell, R.J., Rayne, J.R., and Terry, W.M. 1959. Factors Influencing the Efficiency of Miscible Displacement. Trans. AIME 217: 1–8.
Booth, R.J.S. 2010. On the Growth of the Mixing Zone in Miscible Viscous Fingering. J. Fluid Mech. 655: 527–539. http://dx.doi.org/10.1017/S0022112010001734.
Chouke, R.L., Van Meurs, P., and Van Der Poel, C. 1959. The Instability of Slow, Immiscible, Viscous Liquid-Liquid Displacements in Permeable Media. Trans. AIME 216: 188–194.
Ely, J.W., Hargrove, J.S., Wolters, B.C. et al. 1993. “Pipelining”: Viscous Fingering Prop Fracture Technique Finds Wide Success in Permian and Delaware Basins. Paper SPE 26528 presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 3–6 October. http://dx.doi.org/10.2118/26528-MS.
Fayers, F.J., Jouaux, F., and Tchelepi, H.A. 1994. An Improved Macroscopic Model for Viscous Fingering and Its Validation for 2D and 3D Flows—I. Non-Gravity Flows. In Situ 18: 43–78.
Gidley, J.L., Holditch, S.A., Nierode, D.E. et al. 1989. Recent Advances in Hydraulic Fracturing, SPE Monograph Series Vol. 12, Richardson, Texas: Monograph Series, SPE.
Gillard, M., Medvedev, O., Pena, A. et al. 2010. A New Approach to Generating Fracture Conductivity. Paper SPE 135034 presented at the SPE Annual Technical Conference and Exhibition, Florence, Italy, 20–22 September. http://dx.doi.org/10.2118/135034-MS.
Gupta, D.V.S. 2009. Unconventional Fracturing Fluids for Tight Gas Reservoirs. Paper SPE 119424 presented at the SPE Hydraulic Fracturing Technology Conference, Houston, Texas, 19–21 January. http://dx.doi.org/10.2118/119424-MS.
Homsy, G.M. 1987. Viscous Fingering in Porous Media. Ann. Rev. Fluid Mech. 19: 271–311. http://dx.doi.org/10.1146/annurev.fl.19.010187.001415.
Johnson, J., Turner, M., Weinstock, C. et al. 2011. Channel Fracturing—A Paradigm Shift in Tight Gas Stimulation. Paper SPE 140549 presented at the SPE Hydraulic Fracturing Technology Conference and Exhibition, The Woodlands, Texas, 24–26 January. http://dx.doi.org/10.2118/140549-MS.
Koval, E.J. 1963. A Method for Predicting the Performance of Unstable Miscible Displacement in Heterogeneous Media. SPE J. 3 (2): 145–154. http://dx.doi.org/10.2118/450-PA.
Lajeunesse, E., Martin, J., Rakotomalala, N. et al. 1997. 3D Instability of Miscible Displacements in a Hele-Shaw cell. Phys. Rev. Lett. 79 (26): 5254–5257.
Lajeunesse, E., Martin, J., Rakotomalala, N. et al. 1999. Miscible Displacements in a Hele-Shaw Cell at High Rates. J. Fluid Mech. 398: 299–319.
Lake, L.W. 1989. Enhanced Oil Recovery, Englewoods Cliff, New Jersey: Prentice-Hall.
Leitzell, J.R. 2007. Viscoelastic Surfactants: A New Horizon in Fracturing Fluids for Pennsylvania. Paper SPE 111182 presented at the SPE Eastern Regional Meeting, Lexington, Kentucky, 17–19 October. http://dx.doi.org/10.2118/111182-MS.
Li, H., Maini, B., and Azaiez, J. 2006. Experimental and Numerical Analysis of the Viscous Fingering Instability of Shear-Thinning Fluids. Can. J. Chem. Eng. 84: 52–62.
Liu, Y., Gadde, P.B., and Sharma, M.M. 2007. Proppant Placement Using Reverse-Hybrid Fracs. SPE Prod & Oper 22 (3): 348–356. http://dx.doi.org/10.2118/99580-PA.
Loggia, D., Rakotomalala, N., Salin, D. et al. 1995. Evidence of New Instability Thresholds in Miscible Fluid Flows. Europhys. Lett. 32: 633–638.
Malhotra, S. and Sharma, M.M. 2011. A General Correlation for Proppant Settling in VES Fluids. Paper SPE 139581 presented at the SPE Hydraulic Fracturing Technology Conference and Exhibition, The Woodlands, Texas, 24–26 January. http://dx.doi.org/10.2118/139581-MS.
Malhotra, S. and Sharma, M.M. 2012. Settling of Spherical Particles in Unbounded and Confined Surfactant-Based Shear Thinning Viscoelastic Fluids: An Experimental Study. Chem Eng. Sci. 84: 646–655.
Mayerhofer, M.J., Richardson, M.F., Walker Jr., R.N. et al. 1997. Proppants? We Don’t Need No Proppants. Paper SPE 38611 presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 5–8 October. http://dx.doi.org/10.2118/38611-MS.
Menon, G. and Otto, F. 2005. Dynamic Scaling in Miscible Viscous Fingering. Commun. Math. Phys. 257: 303–317.
Palisch, T.T., Vincent, M.C., and Handren, P.J. 2010. Slickwater Fracturing: Food for Thought. SPE Prod & Oper 25 (3): 327–344. http://dx.doi.org/10.2118/115766-PA.
Peters, E.J. 1979. Stability Theory and Viscous Fingering in Porous Media. PhD dissertation, University of Alberta, Alberta, Canada.
Pope, D.S., Leung, L.K., Gulbis, J. et al. 1996. Effects of Viscous Fingering on Fracture Conductivity. SPE Prod & Fac 11 (4): 230–237. http://dx.doi.org/10.2118/28511-PA.
Rhein, T., Loayza, M., Kirkham, B. et al. 2011. Paper SPE 145403 presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, 30 October–2 November. http://dx.doi.org/10.2118/145403-MS.
Saffman, P.G. and Taylor, G.I. 1958. The Penetration of a Fluid Into a Porous Medium or Hele-Shaw Cell Containing a More Viscous Liquid. Proc. R. Soc. Lond. A. 245: 312–329.
Samuel, M., Card, J.C., Nelson, E.B. et al. 1997. Polymer-Free Fluid for Hydraulic Fracturing. Paper SPE 38622 presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 5–8 October. http://dx.doi.org/10.2118/38622-MS.
Sharma, M.M., Gadde, P.B., Sullivan, R. et al. 2004. Slick Water and Hybrid Fracs in the Bossier: Some Lessons Learnt. Paper SPE 89876 presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 26–29 September. http://dx.doi.org/10.2118/89876-MS.
Smirnov, N.N., Nikitin, V.F., Maximenko, A. et al. 2005. Instability and Mixing Flux in Frontal Displacement of Viscous Fluids From Porous Media. Phys. Fluids 17: 08412.
Tanveer, S. 2000. Surprises in Viscous Fingering. J. Fluid Mech. 409: 273–308.
Todd, M.R. and Longstaff, W.J. 1972. The Development, Testing, and Application of a Numerical Simulator for Predicting Miscible Flood Performance. J. Petrol. Tech. 24: 874–882.
Walker Jr., R.N., Hunter, J.L., Brake, A.C. et al. 1998. Paper SPE 49106 presented at the SPE Annual Technical Conference and Exhibition, New Orleans, Louisiana, 27–30 September. http://dx.doi.org/10.2118/49106-MS.
Wooding, R.A. 1969. Growth of Fingers at an Unstable Diffusing Interface in a Porous Medium or Hele-Shaw Cell. J. Fluid Mech. 39: 477–495. http://dx.doi.org/10.1017/S002211206900228X.
Yang, Z.M., Yortsos, Y.C., and Salin, D. 2002. Asymptotic Regimes in Unstable Miscible Displacements in Random Porous Media. Adv. Water Resour. 25: 885–898.
Yortsos, Y.C. and Salin, D. 2006. On the Selection Principle for Viscous Fingering in Porous Media. J. Fluid Mech. 557: 225–236.
Zimmerman, W.B. and Homsy, G.M. 1991. Viscous Fingering in Miscible Displacements: Unification of Effects of Viscosity Contrast, Anisotropic Dispersion, and Velocity Dependence of Dispersion on Nonlinear Finger Propagation. Phys. Fluids A 4: 2348–2359.