Properties of a Natural Fracture and its Skins from Reservoir Well Tests
- Michael Prats (Michael Prats & Associates Inc.) | Rajagopal Raghavan (Phillips Petroleum (Ret.))
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- June 2014
- Document Type
- Journal Paper
- 390 - 397
- 2013.Society of Petroleum Engineers
- 5.5.8 History Matching, 5.6.5 Tracers, 5.6.4 Drillstem/Well Testing
- Pressure Tests, Horizontal Wells, Interference Tests
- 1 in the last 30 days
- 622 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
Two well tests are described that are aimed at the in-situ determination of the flow capacity (permeability-thickness product) of a natural fracture and the flow resistance of its skins at the boundaries with the reservoir matrix. Fracture skins tend to disperse flow, thus affecting the distribution of tracers in reservoir tests and contaminants and trace elements in aquifers. We are unaware of any other analytical procedure aimed at obtaining the properties of a natural fracture and its skins from subsurface measurements. Neither well test has been implemented. The well tests are modeled after previously reported analytical expressions for the transient pressure distributions in a three-region composite reservoir in a uniform-thickness reservoir in which (1) the natural fracture is represented by a thin middle region of relatively high permeability, (2) the pressure disturbance is caused by producing from a short interval in one of the outer regions, and (3) the response is measured relatively near the fracture. The source and sensor may be on the same side or on opposite sides of the fracture, distinguishing the two tests. Visualizing special completions in a horizontal well intersecting a natural fracture normally, pressure responses are given for both tests for a wide range of fracture/matrix permeability ratios and skin flow resistances for a source 190 ft from the fracture and 10 ft from the sensor and on either side of the fracture, both at the midplane of the reservoir. A simple graphical procedure, not intended to replace history matching or regression where field data are available, illustrates how the two unknowns--permeability-thickness product of a natural fracture and the flow resistance of its skins--may be estimated from two representative values of an assumed measured pressure response.
|File Size||501 KB||Number of Pages||8|
Al-Anazi, A. and Ershaghi, I. 2005. A Conceptual Sensory System for Cross-Hole Reservoir Characterization Using a Pair of Horizontal Wells. PaperSPE 92296 presented at the SPE Middle East Oil and Gas Show and Conference,Kingdom of Bahrain, 5-7 April. http://dx.doi.org/10.2118/92296-MS.
Al-Khamis, M., Ozkan, E. and Raghavan, R. 2005. Analysis of InterferenceTests With Horizontal Wells. SPE Res Eval & Eng 8 (4):337-347. http://dx.doi.org/10.2118/84292-PA.
Carnahan, B. D., Clanton, R. W. and Koehler, K. D. 1999. Fiber OpticTemperature Monitoring Technology. Paper SPE 54599 presented at the SPE Western Regional Meeting, Anchorage, Alaska, 26-27 May. http://dx.doi.org/10.2118/54599-MS.
Cinco-Ley, H., Samaniego-V., F. and Kuchuk, F. 1985. The Pressure Transient Behavior for Naturally Fractured Reservoirs With Multiple Block Size. Paper SPE14168 presented at SPE Annual Technical Conference and Exhibition, Las Vegas, Nevada, 22-26 September. http://dx.doi.org/10.2118/14168-MS.
Civan, F. and Rasmussen, M. L. 2012. Determining Parameters of Matrix-Fracture Interface Fluid Transfer from Laboratory Tests. SPE J. 17 (2): 540-554. http://dx.doi.org/10.2118/104028-MS.
Fu, L., Milliken, K.L. and Sharp Jr., J. M. 1994. Porosity and Permeability Variations in Fractured and Liesegang-Banded Breathitt Sandstones (MiddlePennsylvanian), Eastern Kentucky: Diagenetic Controls and Implications for Modeling Dual-Porosity Systems. J. Hydrol. 154 (1-4):351-381. http://dx.doi.org/10.1016/0022-1694(94)90225-9.
Gottlieb, J. and Dietrich, P. 1995. Identification of the Permeability Distribution in Soil by Hydraulic Tomography. Inverse Probl. 11(2): 353. http://dx.doi.org/http://dx.doi.org/10.1088/0266-5611/11/2/005.
Kluth, E. L. E., Varnham, M. P., Clowes, J. R., et al. 2000. Advanced Sensor Infrastructure for Real Time Reservoir Monitoring. Paper SPE 65152-MS presentedat the SPE European Petroleum Conference, Paris, France, 24-25 October. http://dx.doi.org/10.2118/65152-MS.
Malekzadeh, D. and Tiab, D. 1991. Interference Testing of Horizontal Wells.Paper SPE 22733 presented at the SPE Annual Technical Conference andExhibition, Dallas, Texas, 6-9 October. http://dx.doi.org/10.2118/22733-MS.
Moench, A.F. 1984. Double-Porosity Models for a Fissured Groundwater Reservoir with Fracture Skin. Water Resour. Res. 20 (7):831-846. http://dx.doi.org/10.1029/WR020i007p00831.
Neville, I. R., Sharp, J. M. Jr. and Ilan Kreisel, I. 1998. Contaminant Transport in Sets of Parallel Finite Fractures with Fracture Skins. J.Contam. Hydrol. 31 (1-2): 83-109. http://dx.doi.org/10.1016/S0169-7722(97)00055-7.
Prats, M. and Scott, J.B. 1975. Effect of Wellbore Storage on Pulse-Test Pressure Response. J Pet Tech 27 (6): 707-709. http://dx.doi.org/10.2118/5322-PA.
Prats, M. and Raghavan, R. 2012. Finite Horizontal Well Crossing a Natural Fracture Normally. SPE J. 17 (2): 555-567. http://dx.doi.org/10.2118/153382-PA.
Prats, M. and Raghavan, R. 2013a. The Effect of Skins at a Natural Fracture Crossed Normally by a Finite Horizontal Well. SPE J. 18(2): 233-242. http://dx.doi.org/10.2118/163070-PA.
Prats, M. and Raghavan, R. 2013b. Finite Horizontal Well in a Uniform-Thickness Reservoir Crossing a Natural Fracture Normally. SPEJ. SPE-163098-PA (in press; posted 23 April 2013). http://dx.doi.org/10.2118/163098-PA.
Shanks, D. 1955. Non-Linear Transformation of Divergent and Slowly Convergent Sequences. J. Math. Phys. 34: 1-42.
Sharp, J. M. Jr., Kreisel, I., Milliken, K. L., et al. 1996. Fracture Skin Properties and Effects on Solute Transport: Geotechnical and Environmental Implications. In Rock Mechanics: Tools And Techniques, eds. M. Aubertin,F. Hassam, and H. Mitri, H. Rotterdam, the Netherlands: A. A. Balkema. Figure 2 in ARMA-96-1329.
Stehfest, H. 1970. Algorithm 368: Numerical Inversion of Laplace Transforms[D5]. Commun. ACM 13 (1): 47-49. http://dx.doi.org/10.1145/361953.361969.
Stehfest, H. 1970. Remark on Algorithm 368: Numerical Inversion of Laplace Transforms. Commun. ACM 13 (10): 624. http://dx.doi.org/10.1145/355598.362787.
Tongpenyai, Y. and Raghavan, R. 1981. The Effect of Wellbore Storage and Skin on Interference Test Data. J Pet Tech 33 (1): 151-160.http://dx.doi.org/10.2118/8863-PA.