Abstract
Introduction: An improved understanding of complex clastic reservoirs has led to more detailed reservoir description using integrated approach. In this study, we implemented cluster analysis, geostatistical methods, reservoir quality indicator technique and reservoir simulation to characterize clastic system with complex pore architecture and heterogeneity. Methods: Model based clustering technique from Ward’s analytical algorithm was utilised to transform relationship between core and calculated well logs for paraflow units (PFUs) classification in terms of porosity, permeability and pore throat radius of the reservoir. The architecture of the reservoir at pore scale is described using flow zone indicator (FZI) values and the significant flow units characterized adopting the reservoir quality index (RQI) method. The reservoir porosity, permeability, oil saturation and pressure for delineated flow units were distributed stochastically in 2D numerical models utilising geostatistical conditional simulation. In addition, production behaviour of the field is predicted using history matching. Dynamic models were built for field water cut (FWCT), total field water production (FWPT) and field gas-oil-ratio (FGOR) and history matched, considering a number of simulation runs. Results: Results obtained showed a satisfactory match between the proposed models and history data, describing the production behaviour of the field. The average FWCT peaked at 78.9% with FWPT of 10 MMSTB. Consequently, high FGOR of 6.8 MSCF/STB was obtained. Conclusion: The integrated reservoir characterisation approach used in this study has provided the framework for defining productive zones and a better understanding of flow characteristics including spatial distribution of continuous and discrete reservoir properties for performance prediction of sandstone reservoir.
Highlights
An improved understanding of complex clastic reservoirs has led to more detailed reservoir description using integrated approach
This paper introduced integrated methodology utilising clustering algorithm analysis, geostatistical methods, reservoir quality indicator technique to evaluate significant flow units from core and calibrated log data and combining these methods with dynamic simulation to predict the performance of marine sandstone reservoir
This research focused on the use of an integrated approach combining cluster analysis, geostatistical methods, reservoir quality indicator technique and simulation to provide a petrophysical description and properties that can be used for performance prediction
Summary
An improved understanding of complex clastic reservoirs has led to more detailed reservoir description using integrated approach. The ability to adequately characterize petroleum reservoirs, especially for clastic reservoir systems with complex pore architecture and heterogeneity remains a key challenge. These type of reservoirs exhibit lateral and vertical variations in properties making it very difficult to predict the distribution. The concept of flow units has been extensively used for classifying different rock types based on geological properties and flow dynamics at pore level. These flow units imitate similar attributes of the whole reservoir system having the same geological and petrophysical parameters that consistently influence fluid flow in a reservoir [1 - 4]. Geologist describes flow units as geological flow units or lithofacies according to their similar diagenetic and depositional overprint using analysis of core samples and core description [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
