Improving carbonate reservoir characterization by applying rock typing methods: a case study from the Nam Con Son Basin, offshore Vietnam
- Authors: Man Quang Ha 1*, Hoa Minh Nguyen 2, Dung Viet Bui 3, Hong Viet Nguyen 4, Hoa Khac Truong 1, Ngoc Quy Pham 3,
1 PetroVietnam Exploration Production Corporation, Hanoi, Vietnam
2 Hanoi University of Mining and Geology, Hanoi, Vietnam
3 Vietnam Petroleum Institute, Hanoi, Vietnam
4 Schlumberger Vietnam, HoChiMinh City, Vietnam
- Received: 26th-July-2022
- Revised: 7th-Nov-2022
- Accepted: 15th-Dec-2022
- Online: 1st-Feb-2023
- Section: Oil and Gas
Understanding the permeability-porosity relationships is the key to improving reservoir prediction and exploitation especially in carbonate reservoirs, which are known for their complex textural and diagenetic variation. Rock type classifications have long been proven to be an effective technique for establishing permeability- porosity relationships, enhance the capability to capture the various reservoir flow behavior and prediction for uncored reservoir zones. This study highlights some of those practical and theoretically-correct methods, such as Hydraulic Flow Unit (HFU); Global hydraulic element (GHE), Winland’s R35 method, Pittman method, Lucia method. They are proposed and tested for identification and characterization of the rock types using a database of 555 core plugs from the Miocene carbonate reservoir in the Nam Con Son basin. It is a large isolated carbonate build-up structure which were deposited within a shallow marine platform interior and are dominated by coral, red algal and foraminiferal packstones, wackestones and grainstones. Hydrocarbons in this reservoir have been found in the upper most part of the late Miocene formation. Conventional core data were first used to define and display the cross plot of permeability and porosity. Different charts and cutoff thresholds were used to classified, defined number of rock type and the linear and non-linear equations were established. The predicted core permeability was calculated using different methods and compared with the actual core permeability for each rock type. The predicted reservoir rock type and permeability predictions of HFU method was recognized to give better matching of measured core permeability with coefficient of more than 89%.
Abdallah, S., Sid Ali, O., and Benmalek, S. (2016). Rock type and permeability prediction using flow-zone indicator with an application to Berkine Basin (Algerian Sahara). In SEG Technical Program Expanded Abstracts 2016 (pp. 3068-3072). Society of Exploration Geophysicists.
Amaefule, J. O., Altunbay, M., Tiab, D., Kersey, D. G., and Keelan, D. K. (1993). Enhanced reservoir description: using core and log data to identify hydraulic (flow) units and predict permeability in uncored intervals/wells. In SPE annual technical conference and exhibition. OnePetro.Houston, TX, USA, p. SPE-26436-MS.
Bui, V. D., Hoang, A. T., Nguyen, V. K., Ha, Q. M., Nguyen, T. T. T., Pham, T. D. H. (2018). Depositional environment and reservoir quality of Miocene sediments in the central part of the Nam Con Son basin, Southern Vietnam shelf. Marine and Petroleum Geology, v. 97, p. 672-689.
Corbett, P., Ellabad, Y., Mohammed, K. and Pososyaev, A. (2003). Global Hydraulic Elements - Elementary Petrophysics for Reduced Reservoir Modelling. The 65th EAGE Conference and Exhibition, 2-5 June 2003, Stavanger, Norway, p. cp-6-00256.
Guo, G., Diaz, M.A., Paz, F.J., Smalley, J., Waninger, E.A., (2007). Rock typing as an Effective Tool for Permeability and Water-Saturation Modeling: A Case Study in a Clastic Reservoir in the Oriente Basin. SPE Reserv. Eval. Eng., 10, 730-739.
Ha, Q. M., Doan, H. H., Kieu, D. T., Bui, V. D., Nguyen, M. H., Truong, K. H., Nguyen, V. K. and Pham, Q. N. (2021b). Hydraulic Flow Unit Classification and Prediction Using Machine Learning Techniques: A Case Study from the Nam Con Son Basin, Offshore Vietnam. Energies, 14(22), 7714.
Haikel, S., Rosid M.S., Haidar, M.W. (2018). Study comparative rock typing methods to classify rock type carbonate reservoir Field “S” East Java. In Journal of physics: conference series,1120(1), 012047. IOP Publishing.
Hartmann, D. J., and Beaumont, E. A. (1999). Treatise of Petroleum Geology/Handbook of Petroleum Geology: Exploring for Oil and Gas Traps. Chapter 9: Predicting Reservoir System Quality and Performance.American Association Of Petroleum Geologists, 1-154.
Kolodzie, S. (1980). Analysis of pore throat size and use of the Waxman-Smits equation to determine OOIP in Spindle Field, Colorado. The SPE Annual Technical Conference and Exhibition, September 1980, Dallas, Texas, USA. SPE 9382.
Matthews, S.J., Fraser, A.J., Lowe, S., Tood, S.P., Peel, F.J. (1997). Structure, stratigraphy and petroleum geology of the SE Nam Con Sonbasin, offshore Vietnam. Geol. Soc. Lond. Spec. Publ. 126, 89-106.
Palabiran, M., Sesilia, N., and Akbar, M. N. A. (2016). An analysis of rock typing methods in carbonate rocks for better carbonate reservoir characterization: a case study of Minahaki carbonate formation, Banggai Sula basin, Central Sulawesi. 41st Scientific Annual Meeting of Indonesian Associatation of Geophysicists. Lampurg.
Rebelle, M. and Lalanne, B. (2014). Rock-typing in carbonate: a critical review of clusteringmethods. Abu Dhabi International Petroleum Exhibition and Conference, November 2014, Abu Dhabi, UAE, SPE-171759-MS.
Shenawi, S., Al-Mohammadi, H., Faquehy, M. (2009). Development of Generalized Porosity-Permeability Transforms by Hydraulic Units for Carbonate Oil Reservoirs in Saudi Arabia. In Proceedings of the SPE/EAGE Reservoir Characterization and Simulation Conference, 19-21 October 2009. Abu Dhabi, UAE.
Svirsky, D., Ryazanov, A., Pankov, M., Corbett, P. W. M., Posysoev, A. (2004). Hydraulic Flow Units Resolve Reservoir Description Challenges in a Siberian Oil Field. In Proceedings of the SPE Asia Pacific Conference on Integrated Modelling for Asset Management, 29-30 March 2004, Kuala Lumpur, Malaysia, p. SPE-87056-M.