A New Technique To Characterize Fracture Density by Use of Neutron Porosity Logs Enhanced by Electrically Transported Contrast Agents
- Hewei Tang (Texas A&M University) | John E. Killough (Texas A&M University) | Zoya Heidari (University of Texas at Austin) | Zhuang Sun (University of Texas at Austin)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- August 2017
- Document Type
- Journal Paper
- 1,034 - 1,045
- 2017.Society of Petroleum Engineers
- Fracture Density, Neutron Porosity, Contrast Agents
- 1 in the last 30 days
- 353 since 2007
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Fracture-density evaluation has always been challenging for the petroleum industry, although it is a required characteristic for reliable reservoir characterization. Production can be directly controlled by fracture density, especially in tight reservoirs. Previous publications showed that use of high thermal neutron-capture cross-sectional (HTNCC) contrast agents can enhance the sensitivity of neutron logs to the presence of fractures. However, all these studies focus on locating the proppants. In this paper, we introduce a method of injecting electrically transported charged boron carbide (B4C) contrast agents to naturally fractured formations to enhance the propagation of the contrast agents into the secondary-fracture (natural and induced) network by use of an externally applied electric field and to characterize the fracture density in the unpropped region by use of the enhanced neutron porosity logs.
We perform numerical simulations to validate the feasibility of the proposed technique. A physical model derived from electrophoretic velocity and material-balance formulations is proposed and solved to simulate the spatial distribution of contrast agents. Furthermore, we simulate neutron porosity logs by solving the neutron-diffusion equation, which allows a fast analysis for the proposed technique.
The simulation results confirmed that an external electric field can significantly enhance the transport of charged contrast agents into the secondary-fracture network. Sensitivity analysis revealed that increasing particle f-potential can efficiently decrease the transport time. Furthermore, we applied the introduced technique on synthetic cases with variable secondary-fracture density ranging from 1 to 8%. The relative variation in the simulated neutron porosity before and after applying the electric potential field was up to 50% in a formation with 8% fracture density after applying an electric field for 6 hours. The proposed technique can potentially enable application of neutron porosity logs in fracture characterization, including assessment of secondary-fracture density, if combined with other well logs.
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Allen, L., Tittle, C., Mills, W. et al. 1967. Dual-Spaced Neutron Logging for Porosity. Geophysics 32 (1): 60–68. https://doi.org/10.1190/1.1439857.
Amba, S. A., Chilingar, G. V., and Beeson, C. M. 1964. Use of Direct Electrical Current for Increasing the Flow Rate of Reservoir Fluids During Petroleum Recovery. J Can Pet Technol 3 (1): 8–14. PETSOC-64-01-02. https://doi.org/10.2118/64-01-02.
An, C., Alfi, M., Yan, B. et al. 2016. A New Study of Magnetic Nanoparticle Transport and Quantifying Magnetization Analysis in Fractured Shale Reservoir Using Numerical Modeling. J. Nat. Gas Sci. Eng. 28 (January): 502–521. https://doi.org/10.1016/j.jngse.2015.11.052.
Bell, J. 1996. Petro Geoscience 2. In Situ Stresses in Sedimentary Rocks (Part 2): Applications of Stress Measurements. Geosci. Can. 23 (3).
Chen, H. and Heidari, Z. 2015. Quantifying the Directional Connectivity of Rock Constituents and Its Impact on Electrical Resistivity of Organic-Rich Mudrocks. Math. Geosci. 48 (3): 285–303. https://doi.org/10.1007/s11004-015-9595-9.
Cheng, K., Aderibigbe, A., Alfi, M. et al. 2014. Quantifying the Impact of Petrophysical Properties on Spatial Distribution of Contrasting Nanoparticle Agents in the Near-Wellbore Region. Petrophysics 55 (5): 447–460. SPWLA-2014-v55n5a5.
Chi, L., Elliott, M., Heidari, Z. et al. 2014. Assessment of Micro-Fracture Density Using Combined Interpretation of NMR Relaxometry and Electromagnetic Logs. Presented at Unconventional Resources Technology Conference, Denver, 25–27 August. URTEC-1922804-MS. https://doi.org/10.15530/URTEC-2014-1922804.
Chilingar, G. V., Haroun, M., Shojael, H. et al. 2014. Electrokinetics for Petroleum and Environmental Engineers, first edition. New York City: John Wiley & Sons.
Cho, N. 2006. Processing of Boron Carbide. PhD dissertation, Georgia Institute of Technology, Atlanta, Georgia (July 2006).
Cipolla, C. and Wright, C. 2000. Diagnostic Techniques to Understand Hydraulic Fracturing: What? Why? and How? Presented at SPE/CERI Gas Technology Symposium, Calgary, 3–5 April. SPE-59735-MS. https://doi.org/10.2118/59735-MS.
Cipolla, C. L., Mack, M. G., Maxwell, S. C. et al. 2011. A Practical Guide to Interpreting Microseismic Measurements. Presented at the North American Unconventional Gas Conference and Exhibition, The Woodlands, Texas, 14–16 June. SPE-144067-MS. https://doi.org/10.2118/144067-MS.
Cipolla, C. L., Warpinski, N. R., Mayerhofer, M. J. et al. 2008. The Relationship between Fracture Complexity, Reservoir Properties, and Fracture Treatment Design. Presented at SPE Annual Technical Conference and Exhibition, Denver, 21–24 September. SPE-115769-MS. https://doi.org/10.2118/115769-MS.
Clennell, M. B. 1997. Tortuosity: A Guide Through the Maze. Geol. Soc. Lond. Special Pub. 122 (1): 299–344. https://doi.org/10.1144/GSL.SP.1997.122.01.18.
Dahi Taleghani, A., Ahmadi, M., and Olson, J. E. 2013. Secondary Fractures and Their Potential Impacts on Hydraulic Fractures Efficiency. Proc., ISRM International Conference for Effective and Sustainable Hydraulic Fracturing, Brisbane, Australia, 17 May, Chap. 38. https://doi.org/10.5772/56360.
DoymuS, K. 2007. The Effect of Ionic Electrolytes and pH on the Zeta Potential of Fine Coal Particles. Turk. J. Chem. 31 (6): 589–597.
Duenckel, R., Smith, H. D. Jr., and Smith, M. P. 2012. Methods of Identifying High Neutron Capture Cross Section Doped Proppant in Induced Subterranean Formation Fractures. US Patent No. WO2010120494 A1.
Dunn, K.-J. 1989. A Diffusion Model for Pulsed Neutron Logging. Geophysics 54 (1): 100–113. https://doi.org/10.1190/1.1442567.
Elbel, J. and Mack, M. 1993. Refracturing: Observations and Theories. Presented at SPE Production Operations Symposium, Oklahoma City, Oklahoma, 21–23 March. SPE-25464-MS. https://doi.org/10.2118/25464-MS.
Ellis, D. V. and Singer, J. M. 2007. Well Logging for Earth Scientists, first edition. Berlin: Springer Science+Business Media.
Gadekea, L., Gartner, M., Sharbak, D. et al. 1991. The Interpretation of Radioactive-Tracer Logs Using Gamma-Ray Spectroscopy Measurements. The Log Analyst 32 (1). SPWLA-1991-v32n1a3.
Gale, J. F., Laubach, S. E., Olson, J. E. et al. 2014. Natural Fractures in Shale: A Review and New Observations. AAPG Bull. 98 (11): 2165–2216. https://dx.doi.org/10.1306/08121413151.
Gardner, R. P. and Verghese, K. 1991. Monte Carlo Nuclear Well Logging Benchmark Problems with Preliminary Intercomparison Results. Int. J. Rad. Appl. Instrumen. E 5 (4): 429–438.
Henry, D. 1948. The Electrophoresis of Suspended Particles. IV. The Surface Conductivity Effect. Trans. Faraday Soc. 44: 1021–1026. https://doi.org/10.1039/TF9484401021.
Hill, R. J. 2007. Electric-Field-Enhanced Transport in Polyacrylamide Hydrogel Nanocomposites. J. Colloid Interf. Sci. 316 (2): 635–644. https://doi.org/10.1016/j.jcis.2007.09.020.
Huotari, H., Trägårdh, G., and Huisman, I. 1999. Crossflow Membrane Filtration Enhanced by an External Dc Electric Field: A Review. Chem. Eng. Res. Des. 77 (5): 461–468. https://doi.org/10.1205/026387699526304.
Matyka, M. and Koza, Z. 2012. How to Calculate Tortuosity Easily? AIP Conf. Proc. 1453: 17–22. https://doi.org/10.1063/1.4711147.
Mayerhofer, M. J., Lolon, E., Warpinski, N. R. et al. 2010. What Is Stimulated Reservoir Volume? SPE Prod & Oper 25 (1): 89–98. SPE-119890-PA. https://doi.org/10.2118/119890-PA.
Mulkern, M. E., Masnyk, B., Kramer, H. et al. 2010. A Green Alternative for Determination of Frac Height and Proppant Distribution. Presented at SPE Eastern Regional Meeting, Morgantown, West Virginia, 13–15 October. SPE-138500-MS. https://doi.org/10.2118/138500-MS.
Nakashima, Y. and Kamiya, S. 2007. Mathematica Programs for the Analysis of Three-Dimensional Pore Connectivity and Anisotropic Tortuosity of Porous Rocks Using X-Ray Computed Tomography Image Data. J. Nucl. Sci. Technol. 44 (9): 1233–1247. https://doi.org/10.3327/jnst.44.1233.
Nikitin, A., Yudin, A. V., Latypov, I. et al. 2009. Hydraulic Fracture Geometry Investigation for Successful Optimization of Fracture Modeling and Overall Development of Jurassic Formation in Western Siberia. Presented at Asia Pacific Oil and Gas Conference & Exhibition, Jakarta, 4–6 August. SPE-121888-MS. https://doi.org/10.2118/121888-MS.
Pyzik, A. J. and Aksay, I. A. 1989. Microdesigning of B4C-Al Cermets. Oral presentation given at the Symposium on Advances in Processing of Ceramic and Metal Matrix Composites, Halifax, UK, 20–24 August.
Saldungaray, P., Palisch, T., and Duenckel, R. 2012. Novel Traceable Proppant Enables Propped Frac Height Measurement While Reducing the Environmental Impact. Presented at SPE/EAGE European Unconventional Resources Conference & Exhibition, Vienna, Austria, 20–22 March. SPE-151696-MS. https://doi.org/10.2118/151696-MS.
Scheidegger, A. E. 1974. The Physics of Flow Through Porous Media, first edition. Toronto, Canada: University of Toronto Press.
Sharma, M. M. and Manchanda, R. 2015. The Role of Induced Un-Propped (IU) Fractures in Unconventional Oil and Gas Wells. Presented at SPE Annual Technical Conference and Exhibition, Houston, 28–30 September. SPE-174946-MS. https://doi.org/10.2118/174946-MS.
Smoluchowski, M. 1924. Contribution À la Théorie de L’endosmose Électrique et de Quelques Phénomènes Corrélatifs. Pisma Mariana Smoluchowskiego 1 (1): 403–420.
Sun, J. and Schechter, D. 2015a. Investigating the Effect of Improved Fracture Conductivity on Production Performance of Hydraulically Fractured Wells: Field-Case Studies and Numerical Simulations. J Can Pet Technol 54 (6): 442–449. SPE-169866-PA. https://doi.org/10.2118/169866-PA.
Sun, J. and Schechter, D. 2015b. Optimization-Based Unstructured Meshing Algorithms for Simulation of Hydraulically and Naturally Fractured Reservoirs with Variable Distribution of Fracture Aperture, Spacing, Length, and Strike. SPE Res Eval & Eng 18 (4): 463–480. SPE-170703-PA. https://doi.org/10.2118/170703-PA.
Tittle, C. W. 1992. Diffusion Theory Models of Invasion for Nuclear Porosity Tools. Presented at SPWLA 33rd Annual Logging Symposium, Oklahoma City, Oklahoma, 14–17 June. SPWLA-1992-N.
Williams, P. D. and Hawn, D. D. 1991. Aqueous Dispersion and Slip Casting of Boron Carbide Powder: Effect of pH and Oxygen Content. J. Am. Ceram. Soc. 74 (7): 1614–1618. https://doi.org/10.1111/j.1151-2916.1991.tb07147.x.
Wittle, J. K., Hill, D. G., and Chilingar, G. V. 2011. Direct Electric Current Oil Recovery (EEOR)—A New Approach to Enhancing Oil Production. Energ. Source. A 33 (9): 805–822. https://doi.org/10.1080/15567036.2010.514843.
Wright, C. A., Davis, E. J., Golich, G. M. et al. 1998. Downhole Tiltmeter Fracture Mapping: Finally Measuring Hydraulic Fracture Dimensions. Presented at SPE Western Regional Meeting, Bakersfield, California, 10–13 May. SPE-46194-MS. https://doi.org/10.2118/46194-MS.
Yan, B., Alfi, M., Cao, Y. et al. 2015. Extended Abstract: Advanced Multiple Porosity Model for Fractured Reservoirs. Presented at International Petroleum Technology Conference, Doha, 6–9 December. IPTC-18308-MS. https://doi.org/10.2523/IPTC-18308-MS.