Consistent Model for Injection and Falloff Pressure Match of Diagnostic Fracture Injection Tests (DFITs)
- Guoqing Liu (University of Houston) | Christine A. Ehlig-Economides (University of Houston)
- Document ID
- Society of Petroleum Engineers
- SPE Drilling & Completion
- Publication Date
- December 2019
- Document Type
- Journal Paper
- 345 - 355
- 2019.Society of Petroleum Engineers
- DFIT, Friction, Net pressure, step rate test, ISIP
- 6 in the last 30 days
- 330 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
The diagnostic fracture injection test (DFIT), a fracture-injection/falloff test, is a reliable tool for quantifying the formation of closure stress, leakoff coefficient, formation permeability, and pressure. The current analytical DFIT model (used before and after closure) enables one to match the pressure falloff of abnormal leakoff behaviors, and quantifies more formation parameters than a traditional DFIT model. However, this model design addresses only the falloff data after shut-in; thus, analysts have expressed concerns that the net pressure implied by the falloff is inconsistent with the injection pressure behavior. Therefore, this paper provides a model capableof matching both injection and falloff pressure behaviors.
The pressure-falloff model is capable of quantifying essential pressure values including, in order of occurrence, instantaneous shut-in pressure (ISIP), minimum fracture-propagation pressure, one or more closure-stress values, formation minimum principal stress, and pore pressure. The early pressure response represents the dissipation of three kinds of friction—wellbore, perforation, and near-wellbore friction. Each of them is quantified, and, together, they comprise the difference between the pressure at the end of injection and the ISIP. Presence of tip extension enables the quantification of the minimum fracture-propagation pressure. The minimum principal stress is consistent with the final closure stress. Subtracting the closure stress and friction pressure losses from the recorded or calculated bottomhole pressure (BHP) provides the fracture net pressure. The model match for injection pressure behavior incorporates the same pressures and consistent values for 2D fracture geometry and leakoff coefficient.
The global match confirms not only the estimation of formation and fracture properties from the pressure-falloff analysis, but also the friction losses along the wellbore, through the perforations, and in the near-wellbore tortuosity during and after injection. In particular, by matching both injection and falloff, the model incorporates friction pressure losses that can explain apparent excessive net pressure.
The match with both injection and falloff pressure variation addresses concerns that the net pressure implied by the falloff model match cannot be consistent with the observed injection behavior. When the pressure difference between the final DFIT pick for closure stress and the pressure at the end of injection is large, the reason might be tip extension and/or large friction pressure losses, the latter of which can be addressed by the main treatment design.
|File Size||543 KB||Number of Pages||11|
API SPEC 5CT, Specification for Casing and Tubing, ninth edition. 2011. Washington, DC: API.
Bachman, R. C., Walters, D. A., Hawkes, R. et al. 2012. Reappraisal of the G Time Concept in Mini-Frac Analysis. Presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 8–10 October. SPE-160169-MS. https://doi.org/10.2118/160169-MS.
Barree, R. D., Miskimins, J. L., and Gilbert, J. V. 2014. Diagnostic Fracture Injection Tests: Common Mistakes, Misfires, and Misdiagnoses. Presented at the SPE Western North American and Rocky Mountain Joint Meeting, Denver, Colorado, 17–18 April. SPE-169539-MS. https://doi.org/10.2118/169539-MS.
Bourdet, D., Whittle, T. M., Douglas, A. A. et al. 1983. A New Set of Type Curves Simplifies Well Test Analysis. World Oil 196 (6): 95–106.
Craig, D. P. and Blasingame, T. A. 2005. A New Refracture-Candidate Diagnostic Test Determines Reservoir Properties and Identifies Existing Conductive or Damaged Fractures. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, 9–12 October. SPE-96785-MS. https://doi.org/10.2118/96785-MS.
Craig, D. P. and Blasingame, T. A. 2006. Application of a New Fracture-Injection/Falloff Model Accounting for Propagating, Dilated, and Closing Hydraulic Fractures. Presented at the SPE Gas Technology Symposium, Calgary, 15–17 May. SPE-100578-MS. https://doi.org/10.2118/100578-MS.
Cramer, D. D. and Nguyen, D. H. 2013. Diagnostic Fracture Injection Testing Tactics in Unconventional Reservoirs. Presented at the SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, 4–6 February. SPE-163863-MS. https://doi.org/10.2118/163863-MS.
Ehlig-Economides, C. A. and Liu, G. 2017. Comparison Among Fracture Calibration Test Analysis Models. Presented at the SPE Hydraulic Fracturing Technology Conference and Exhibition, The Woodlands, Texas, 24–26 January. SPE-184866-MS. https://doi.org/10.2118/184866-MS.
Feng, Y. and Gray, K. E. 2016. A Comparison Study of Extended Leak-Off Tests in Permeable and Impermeable Formations. Presented at the 50th US Rock Mechanics/Geomechanics Symposium. Houston, 26–29 June. ARMA-2016-033.
Geertsma, J. and De Klerk, F. 1969. A Rapid Method of Predicting Width and Extent of Hydraulically Induced Fractures. J Pet Technol 21 (12): 1571–1581. SPE-2458-PA. https://doi.org/10.2118/2458-PA.
Griffith, A. A. 1921. The Phenomena of Rupture and Flow in Solids. Philos Trans R Soc A 221 (582–593): 163–198. https://doi.org/10.1098/rsta.1921.0006.
Liu, G. and Ehlig-Economides, C. 2015. Comprehensive Global Model for Before-Closure Analysis of an Injection Falloff Fracture Calibration Test. Presented at the SPE Annual Technical Conference and Exhibition, Houston, 28–30 September. SPE-174906-MS. https://doi.org/10.2118/174906-MS.
Liu, G. and Ehlig-Economides, C. 2016. Interpretation Methodology for Fracture Calibration Test Before-Closure Analysis of Normal and Abnormal Leakoff Mechanisms. Presented at the SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, 9–11 February. SPE-179176-MS. https://doi.org/10.2118/179176-MS.
Liu, G. and Ehlig-Economides, C. 2018. Practical Considerations for Diagnostic Fracture Injection Test (DFIT) Analysis. J Pet Sci Eng 171: 1133–1140. https://doi.org/10.1016/j.petrol.2018.08.035.
Liu, G. and Ehlig-Economides, C. 2019. Comprehensive Before-Closure Model and Analysis for Fracture Calibration Injection Falloff Test. J Pet Sci Eng 172: 911–933. https://doi.org/10.1016/j.petrol.2018.08.082.
Liu, G., Ehlig-Economides, C., and Sun, J. 2016. Comprehensive Global Fracture Calibration Model. Presented at the SPE Asia Pacific Hydraulic Fracturing Conference, Beijing, China, 24–26 August. SPE-181856-MS. https://doi.org/10.2118/181856-MS.
Mack, M. G. and Warpinski, N. R. 2000. Mechanics of Hydraulic Fracturing. In Reservoir Stimulation, third edition, ed. M. J. Economides and K.G. Nolte, Chap. 6, 1–49. Chichester, England: John Wiley & Sons Ltd.
Marongiu-Porcu, M., Retnanto, A., Economides, M. J. et al. 2014. Comprehensive Fracture Calibration Test Design. Presented at the Hydraulic Fracturing Technology Conference, The Woodlands, Texas, 4–6 February. SPE-168634-MS. https://doi.org/10.2118/168634-MS.
Mayerhofer, M. J., Ehlig-Economides, C. A., and Economides, M. J. 1995. Pressure Transient Analysis of Fracture Calibration Tests. J Pet Technol 47 (3): 229–234. SPE-26527-PA. https://doi.org/10.2118/26527-PA.
Menouar, N., Liu, G., and Ehlig-Economides, C. 2018. A Quick Look Approach for Determining Instantaneous Shut-In Pressure ISIP and Friction Losses From Hydraulic Fracture Treatment Falloff Data. Presented at the SPE International Hydraulic Fracturing Technology Conference and Exhibition, Muscat, Oman, 16–18 October. SPE-191465-18IHFT-MS. https://doi.org/10.2118/191465-18IHFT-MS.
Mohamed, I. M., Azmy, R. M., Sayed, M. A. I. et al. 2011. Evaluation of After-Closure Analysis Techniques for Tight and Shale Gas Formations. Presented at the North American Unconventional Gas Conference and Exhibition, The Woodlands, Texas, 24–26 January. SPE-140136-MS. https://doi.org/10.2118/140136-MS.
Naidu, R. N., Guevara, E. A., Twynam, A. J. et al. 2015. Understanding Unusual Diagnostic Fracture Injection Test Results in Tight Gas Fields—A Holistic Approach to Resolving the Data. Presented at the SPE Middle East Unconventional Resources Conference and Exhibition Muscat, Oman, 26–28 January. SPE-172956-MS. https://doi.org/10.2118/172956-MS.
Nolte, K. G. 1979. Determination of Fracture Parameters From Fracturing Pressure Decline. Presented at the SPE Annual Technical Conference and Exhibition, Las Vegas, Nevada, 23–26 September. SPE-8341-MS. https://doi.org/10.2118/8341-MS.
Nolte, K. G. 1986. A General Analysis of Fracturing Pressure Decline With Application to Three Models. SPE Form Eval 1 (6): 571–583. SPE-12941-PA. https://doi.org/10.2118/12941-PA.
Nolte, K. G., Mack, M. G., and Lie, W. L. 1993. A Systematic Method for Applying Fracturing Pressure Decline: Part I. Presented at the SPE Rocky Mountain Regional Low Permeability Reservoirs Symposium, Denver, 26–28 April. SPE-25845-MS. https://doi.org/10.2118/25845-MS.
Nordgren, R. P. 1972. Propagation of a Vertical Hydraulic Fracture. SPE J. 12 (4): 306–314. SPE-3009-PA. https://doi.org/10.2118/3009-PA.
Pang, W., Du, J., Zhang, T. et al. 2016. Actual and Optimal Hydraulic-Fracture Design in a Tight Gas Reservoir. SPE Prod & Oper 31 (1): 60–68. SPE-168613-PA. https://doi.org/10.2118/168613-PA.
Perkins, T. K. and Kern, L. R. 1961. Widths of Hydraulic Fractures. J Pet Technol 13 (9): 937–949. SPE-89-PA. https://doi.org/10.2118/89-PA.
Xue, H. and Ehlig-Economides, C. 2013. Permeability Estimation From Fracture Calibration Test Analysis in Shale and Tight Gas. Presented at the Unconventional Resources Technology Conference, Denver, 12–14 August. URTEC-1569587-MS. https://doi.org/10.1190/URTEC2013-023.
Zheltov, A. K. 1955. Formation of Vertical Fractures by Means of Highly Viscous Liquid. Presented at the 4th World Petroleum Congress, Rome, 6–15 June. WPC-6132.