Integrated Workflow To Tackle Heterogeneous Karst Dominated Reservoirs: Kharyaga Example (Russian)
- V. Neillo (Total SA) | L. Pauget (Total SA) | C. Neumann (Total SA)
- Document ID
- Society of Petroleum Engineers
- SPE Russian Oil and Gas Exploration & Production Technical Conference and Exhibition, 14-16 October, Moscow, Russia
- Publication Date
- Document Type
- Conference Paper
- 2014. Society of Petroleum Engineers
- 1 in the last 30 days
- 91 since 2007
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The pdf file of this paper is in Russian.
Kharyaga Upper Devonian oil reservoir, developed through water injection, is part of a highly heterogeneous carbonate platform. Three sedimentary domains can be identified from South to North: a microbial reef-flat, back-barrier grainy shoals and a non-reservoir lagoon. Static and dynamic data gathered since production start-up revealed that the barrier is extensively fractured and karstified and shows a dual permeability behavior. Understanding the distribution of the dual medium is key to successful development of such a complex reservoir.
To capture the relative weight on the flow network of each type of heterogeneity, a new workflow to characterize the dual medium has been developed, including the following steps: karst facies identification from cores and borehole images, comparison of the karst facies over a detailed flow analysis including detailed PLT interpretation; analysis of the facies spatial distribution using various diagenetic scenarios. As a result a new integrated vision of the reservoir and flow system has been consolidated and 3 main emersions followed by a hydrothermal phase have been identified. Each individual emersion generated a complex karst system composed of several components linked to the paleo-topography.
Representing properly such a heterogeneous system was coped with by iterating in order to match the dynamic data. A two-stage modeling workflow was used: (1) fast iteration process using a dedicated stochastic tool which generates karst conduits, constrained by infiltration zone, paleo-water-table and paleo-topography; (2) once the right inputs are captured, the forward modeling workflow simulated the process of dissolution and generated at very fine scale a more complex and more consistent system.
Finally, this work allowed to model different representations of this complex reservoir capturing the range of remaining subsurface uncertainties and consistent with the integrated interpretation of static and dynamic data. It allows to highlight and evaluate quantitatively the stakes of current and potential new development.
|File Size||8 MB||Number of Pages||12|