Macro Insights from Interval Pressure Transient Tests: Deriving Key Near-Wellbore Fracture Parameters in a Light Oil Reservoir Offshore Norway
- Alfredo Freites (Heriot-Watt University) | Patrick Corbett (Heriot-Watt University) | Sebastian Geiger (Heriot-Watt University) | Jens-Petter Norgard (Lundin Norway AS)
- Document ID
- Society of Petroleum Engineers
- SPE Europec featured at 81st EAGE Conference and Exhibition, 3-6 June, London, England, UK
- Publication Date
- Document Type
- Conference Paper
- 2019. Society of Petroleum Engineers
- Near-Wellbore Fractures, Geological Well Testing, Interval Pressure Transient Tests
- 35 in the last 30 days
- 36 since 2007
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Fractures can be first-order controls on fluid flow in hydrocarbon reservoirs. Understanding the characteristics of fractures such as their aperture, density, distribution, conductivity, connectivity, etc, is key for reservoir engineering and production analysis.
Well testing plays a key role in the the characterisation of fractured reservoirs, especially. New advances in the Pressure Transient Analysis (PTA) have enabled the interpretation of production data in a way where the resulting geological scenarios are in better agreement with fracture patterns observed in outcrop analogues.
Traditionally, Drill Stem Test (DST) data have been the primay source of information for well testing. However, we hypothesise that wireline conveyed tools designed for Interval Pressure Transient Testing (IPTT) could yield a more throrough description of the near-wellbore heterogeneities, including fractures.
Hence, we investigate the applicability of IPTT for characterising fractured reservoirs using detailed numerical simulations models with accurate wellbore representation to generate synthetic IPTT responses that can obtained through a next-generation wireline testing tool called SATURN. We particularly focus on cases where fractures are present in the near-wellbore region but do not intersect the wellbore. The study included parameters such as fracture densities and conductivities, distance between fractures and wellbore and the vertical extension of the fractures across geological beds.
The impact of the different fracture scenarios on the pressure transient tests was recorded as characteristic signatures on diagnostic plots (pressure derivative curves). We have called these curves "IPTT-Geotypes"; they can be used to assist the interpretation process of IPTT responses. To the best of our knowledge, this is the first time pressure derivative type curves for IPTT in fractured reservoirs are presented in the literature.
A field example of an IPTT case was analysed using the concept of geological well testing. We integrated the information from petrophysical logs and the IPTT-Geotypes to assist the calibration of a reservoir model developed to represent the geological setting of the tested reservoir interval. The results provided a sound interpretation of the reservoir geology and quantitative estimation of the matrix and fracture parameters.
|File Size||3 MB||Number of Pages||32|
Cantini, S., Baldini, D., Beretta, E., Loi, D., & Mazzoni, S. 2013. Reservoir Permeability from Wireline Formation Testers. Society of Petroleum Engineers. doi: 10.2118/164924-MS
Corbett, P. W. M., Geiger-Boschung, S., Borges, L. P., Garayev, M., Gonzalez, J. G., & Valdez, C. 2010. Limitations in numerical well test modelling of fractured carbonate rocks. Society of Petroleum Engineers. doi: 10.2118/130252-MS.
De Swaan O. 1976. Analytic Solutions for Determining Naturally Fractured Reservoirs Properties by Well Testing. SPE J. 16 (3): 117-122. http://dx.doi.org/10.2118/5346-PA
Egya, D., Geiger, S., & Corbett, P. 2018. Effect of Variation in Fractures Conductivity and Well Location on Pressure Transient Response from Fractured Reservoirs. Society of Petroleum Engineers. doi: 10.2118/190884-MS
Gringarten, A. 1984. Interpretation of Tests in Fissured and Multilayered Reservoirs with Double-Porosity Behavior: Theory and Practice. J. Pet Tech. 36 (4) : 549-564. http://dx.doi.org/10.2118/10044-P
Joseph, J. A., & Koederitz, L. F. 1985. Unsteady-State Spherical Flow with Storage and Skin. Society of Petroleum Engineers. doi: 10.2118/12950-PA
Kuchuk, F., & Biryukov, D. 2015. Pressure-Transient Tests and Flow Regimes in Fractured Reservoirs. Society of Petroleum Engineers. doi: 10.2118/166296-PA
Kuchuk, F. J., & Habashy, T. 1997. Pressure Behavior of Laterally Composite Reservoirs. Society of Petroleum Engineers. doi: 10.2118/24678-PA.
Kurtoglu, B., Kazemi, H., Boratko, E. C., Tucker, J., & Daniels, R. 2013. Minidrillstem Tests to Characterize Formation Deliverability in the Bakken. Society of Petroleum Engineers. doi: 10.2118/159597-PA
Streltsova-Adams, T. D. 1979. Pressure Drawdown in a Well with Limited Flow Entry. Society of Petroleum Engineers. doi: 10.2118/7486-PA
Streltsova, T. D. 1983. Well Pressure Behavior of a Naturally Fractured Reservoir. Society of Petroleum Engineers. doi: 10.2118/10782-PA
Wei, L., Hadwin, J., Chaput, E., Rawnsley, K., & Swaby, P. 1998. Discriminating Fracture Patterns in Fractured Reservoirs by Pressure Transient Tests. Society of Petroleum Engineers. doi: 10.2118/49233-MS.
Zeybek, M., Kuchuk, F. J., & Hafez, H. 2002. Fault and Fracture Characterization Using 3D Interval Pressure Transient Tests. Society of Petroleum Engineers. doi: 10.2118/78506-MS