Mechanical-Damage Characterization in Proppant Packs by Use of Acoustic Measurements
- Aderonke A. Aderibigbe (Texas A&M University) | Clotilde Chen Valdes (Texas A&M University) | Zoya Heidari (University of Texas at Austin) | Tihana Fuss-Dezelic (Saint-Gobain Proppants)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- May 2017
- Document Type
- Journal Paper
- 168 - 176
- 2017.Society of Petroleum Engineers
- Acoustic Measurements, Mechanical damage, Proppant
- 0 in the last 30 days
- 320 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
The strength and conductivity of proppant packs are key parameters for assessing proppant-pack performance. Mechanical damage in the propping agents, which leads to compaction and crushing, significantly reduces the conductivity of the proppant pack. Mechanical damage of proppants is usually analyzed by use of crush tests. However, measurements from these tests remain questionable because of discrepancies in procedures and test results. Therefore, a need emerges to develop techniques for characterizing the properties and mechanical damage in proppant packs.
In this paper, we introduced a new technique that is based on interpretation of acoustic measurements from a granular effective-media model to quantify mechanical damage in propping agents. We performed uniaxial compression tests in the laboratory and measured the compressional- and shear-wave velocities in proppant packs loaded at axial stresses ranging from 10 to 110 MPa. After unloading the tests in which maximum axial stresses of 28, 55, 69, 97, and 110 MPa were applied, we conducted sieve analysis on the proppant packs. We applied an effective-medium theory modeled after the Hertz-Mindlin granular contact model to approximate the effective elastic properties. We then calibrated the model by use of the elastic properties estimated from the experimental measurements to characterize the mechanical damage of the proppant packs.
We observed that the increase in grain-to-grain contact as the axial stress increases results in compaction and crushing in the proppant pack. We showed that the compaction effects and elastic and plastic behaviors in the stress–strain profile of the proppant pack were in agreement with the analysis of fines generated at different stress levels. The combined effect of compaction and crushing resulted in a reduction of porosity and, consequently, decreased the compressional- and shear-wave velocities of the proppant pack. The Hertz-Mindlin model showed a good approximation of the effective elastic properties estimated from the acoustic-wave velocities when calibrated with the pressure-dependent grain contact and the fraction of nonslipping grains as parameters. We demonstrated that the calibrated parameters can be correlated with the mechanical damage in the proppant pack. The characterization of mechanical damage in proppant packs can improve the design of the propping agents and quantification of proppant performance. Furthermore, the laboratory procedure can be extended to the use of borehole acoustic measurements in providing a real-time in-situ assessment of proppant performance.
|File Size||793 KB||Number of Pages||9|
API RP 19C, Recommended Practice for Measurement of Proppants Used in Hydraulic Fracturing and Gravel-Packing Operations. 2008. Washington, DC: American Petroleum Institute.
API RP 56, Recommended Practices for Testing Sand Used in Hydraulic Fracturing Operations (withdrawn). 1983. Washington, DC: American Petroleum Institute.
Avseth, P. and Bachrach, R. 2005. Seismic Properties of Unconsolidated Sands: Tangential Stiffness, Vp/Vs Ratios and Diagenesis. In SEG Technical Program Expanded Extracts 2005, SEG Annual Meeting, Houston, 6–11 November, 1473–1476. Society of Exploration Geophysicists. https://doi.org/10.1190/1.2147968.
Bachrach, R. and Avseth, P. 2008. Rock Physics Modeling of Unconsolidated Sands: Accounting for Nonuniform Contacts and Heterogeneous Stress Fields in the Effective Media Approximation with Applications to Hydrocarbon Exploration. Geophysics 73 (6): E197–E209. https://doi.org/10.1190/1.2985821.
Bachrach, R., Dvorkin, J., and Nur A. M. 2000. Seismic Velocities and Poisson’s Ratio of Shallow Unconsolidated Sands. Geophysics 65 (2): 559–564. https://doi.org/10.1190/1.1444751.
Berryman, J. G. 1995. Mixture Theories for Rock Properties. In Rock Physics & Phase Relations: A Handbook of Physical Constants, ed. T. J. Ahrens, Vol. 3, 205–228. Washington, DC: American Geophysical Union. http://onlinelibrary.wiley.com/doi/10.1029/RF003p0205/summary.
Biot, M. A. 1962. Mechanics of Deformation and Acoustic Propagation in Porous Media. J. Appl. Phys. 33 (4): 1482–1498. https://doi.org/10.1063/1.1728759.
Brannon, H. D. 2013. Apparatus and Methods for Providing Information About One or More Subterranean Variables. US Patent No. 8,797,037.
Das, B. M. 1941. Principle of Geotechnical Engineering, third edition. Boston, Massachusettes: PWS Publishing.
Deng, J. X., Han, D. H., and Wang, S. X. 2011. A Study of the Influence of Stress Relaxation on the Elastic Properties of Granular Materials and the Calibration of Effective Media Model. Chinese Journal of Geophysics 54 (2): 240–253. https://doi.org/10.1002/cjg2.1606.
Dutta, T., Mavko, G., and Mukerji, T. 2010. Improved Granular Medium Model for Unconsolidated Sands Using Coordination Number, Porosity, and Pressure Relations. Geophysics 75 (2): E91–E99. https://doi.org/10.1190/1.3333539.
Fawad, M., Mondol, N. H., Jahren, J. et al. 2011. Mechanical Compaction and Ultrasonic Velocity of Sands With Different Texture and Mineralogical Composition. Geophysical Prospecting 59 (4): 697–720. https://doi.org/10.1111/j.1365-2478.2011.00951.x.
Fortin, J., Gue´guen, Y., and Schubnel, A. 2007. Effects of Pore Collapse and Grain Crushing on Ultrasonic Velocities and Vp/Vs. Journal of Geophysical Research: Solid Earth 112 (B8): B08207. https://doi.org/10.1029/2005JB004005.
Getty, J. and Bulau, C. R. 2014. Are the Laboratory Measurements of Proppant Crush Resistance Unrealistically Low? Presented at the SPE Unconventional Resources Conference. The Woodlands, Texas, USA, 1–3 April. SPE-168975-MS. https://doi.org/10.2118/168975-MS.
Hashin, Z. and Shtrikman, S. 1963. A Variational Approach to the Theory of the Elastic Behavior of Multiphase Materials. J. Mech. Phys. Solids 11 (2): 127–140. https://doi.org/10.1016/0022-5096(63)90060-7.
Hill, R. 1952. The Elastic Behavior of Crystalline Aggregate. Proc. Phys. Soc. A 65 (5): 349–354. https://doi.org/10.1088/0370-1298/65/5/307.
Kurz, B. A., Schmidt, D. D., and Cortese, P. E. 2013. Investigation of Improved Conductivity and Proppant Applications in the Bakken Formation. Presented at the SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, 4–7 February. SPE-163849-MS. https://doi.org/10.2118/163849-MS.
Liang, F., Sayed, M., Al-Muntasheri, G. et al. 2015. Overview of Existing Proppant Technologies and Challenges. Presented at the SPE Middle East Oil and Gas Show and Conference, Manama, Bahrain, 8–11 March. SPE-172763-MS. https://doi.org/10.2118/172763-MS.
Mavko, G., Mukerji, T., and Dvorkin, J., 2009. The Rock Physics Handbook: Tools for Seismic Analysis in Porous Media, 245–264. New York City: Cambridge University Press. https://doi.org/10.1017/CBO9780511626753.011.
Mindlin, R. D. 1949. Compliance of Elastic Bodies in Contact. Journal of Applied Mechanics 16: 259–268.
Palisch, T. T., Duenckel, R. J., Chapman, M. A. et al. 2010. How To Use and Misuse Proppant Crush Tests–Exposing the Top 10 Myths. SPE Prod & Oper 25 (3): 345–354. SPE-119242-PA. https://doi.org/10.2118/119242-MS.
Raysoni, N. and Weaver, J. D. 2013. Long-Term Hydrothermal Proppant Performance. SPE Prod & Oper 28 (4): 414–426. SPE-150669-PA. https://doi.org/10.2118/150669-PA.
Simo, H., Pournik, M., and Sondergeld, C. H. 2013. Proppant Crush Test: A New Approach. Presented at the SPE Production and Operations Symposium, Oklahoma City, Oklahoma, USA, 23–26 March. SPE-164506-MS. https://doi.org/10.2118/164506-MS.
Stephens, W. T., Schubarth, S. K., Rivera, D. I. et al. 2006. Statistical Study of the Crush Resistance Measurement for Ceramic Proppants. Presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA, 24–27 September. SPE-102645-MS. https://doi.org/10.2118/102645-MS.
Stigler, S. M. 1981. Gauss and the Invention of Least Squares. The Annals of Statistics 9 (3): 465–474. https://doi.org/10.1214/aos/1176345451.
Walpole, L. J. 1966. On Bounds for the Overall Elastic Moduli of Inhomogeneous System—II. Journal of the Mechanics and Physics of Solids 14 (5): 289–301. https://doi.org/10.1016/0022-5096(66)90025-1.
Winkler, K. W. 1983. Contact Stiffness in Granular Porous Materials: Comparison Between Theory and Experiment. Geophysical Research Letters 10 (11): 1073–1076. https://doi.org/10.1029/GL010i011p01073.
Wyllie, M. R. J., Gregory, A. R., and Gardner, G. H. F. 1958. An Experimental Investigation of Factors Affecting Elastic Wave Velocities in Porous Media. Geophysics 23 (3): 459–493. https://doi.org/10.1190/1.1438493.
Zimmer, M. A. 2003. Seismic Velocities in Unconsolidated Sands: Measurements of Pressure, Sorting, and Compaction Effects. PhD dissertation, Stanford University, Stanford, California (November 2003).