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Two ideas inherent in Kozeny-Carman are important for later developments: the dependence of k on a power of porosity and on the inverse square of surface area. The various forms ofEq. 1 have been used as a starting point for predicting permeability from well log data by assuming that residual water saturation is proportional to specific surface area, Σ.
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)
Explains commonly used standard and quick-look log analysis techniques. Demonstrates the interpretation of LWD and wireline logs to determine the shale volume, lithology, porosity, and fluid saturation. Presents well log interpretation techniques suitable for both individual well analysis and field studies.
Static Modelling and Fault Seal Analysis of the Migrant Rollover Structure, Sable Subbasin, Offshore Nova Scotia, Canada
Martyns-Yellowe, K. T. (Basin and Reservoir Lab, Department of Earth and Environmental Sciences, Dalhousie University) | Richards, F. W. (Basin and Reservoir Lab, Department of Earth and Environmental Sciences, Dalhousie University) | Watson, N. (Atlantic Petrophysics Limited, Nova Scotia) | Wach, G. D. (Basin and Reservoir Lab, Department of Earth and Environmental Sciences, Dalhousie University)
Abstract Crestal faulting can lead to breach of trap integrity and leakage. The Migrant structure is an example of a potentially breached trap due to fault leakage and juxtaposition. In this paper we use 3D geocellular modeling, populated with new interpretation of input parameters, including shale volume, to examine the possible mechanism for leakage (crestal faulting). A fault plane profile (Allan diagram) was constructed, which can be taken a further step into dynamic modelling and simulation (not presented in this study). Located in the Sable Sub-basin, the Migrant structure is a fault controlled, four-way dip anticlinal closure, which formed as one of a series of related structures during rift basin extension, sediment loading and salt mobilization in the Cretaceous. Genetically related rollover structures (e.g., the Distal Thebaud Field) in a similar structural and stratigraphic setting have proved viable as a commercial trap. The Migrant N-20 well was drilled to test for hydrocarbons trapped in Late Jurassic to Early Cretaceous deltaic and fluvial-deltaic reservoirs in the structure. The well encountered gas from a deep sand reservoir during drill stem testing (DST 2) with a reported flow rate of 10 million standard cubic feet per day. However, over the duration of the test, an associated decline in flow rate and pressure depletion was observed, which led the operators to consider the target reservoir as non-commercial. In this paper we present a re-appraisal to assess why this trap failed by integrating well data (logs, checkshot and pressure) and 3D seismic to produce a static model demonstrating the trapping mechanism in the Migrant Structure. Initial observation of the 3D seismic shows shallow crestal faults while preliminary observation of well logs from the Migrant N-20 well suggests a diminishing sand/shale ratio from the shallow to deep sections of the trap. This study of the Migrant Structure contributes to the understanding of the relationship between reservoir and seal thicknesses relative to fault displacement and its role in subsurface fluid trapping or cross-fault leakage, through upward and outward displacement (stair-stepping) between reservoirs of different ages across a given fault. The paper shows how data integration and workflows have been combined effectively and is an important contribution for risk assessment in the Sable Subbasin. The proposed model can be applied in other basins including the similar salt cored basins like those offshore Brazil.
- North America > Canada > Nova Scotia > North Atlantic Ocean (0.88)
- North America > Canada > Newfoundland and Labrador > Newfoundland > North Atlantic Ocean (0.28)
- Phanerozoic > Mesozoic > Jurassic > Upper Jurassic (0.48)
- Phanerozoic > Mesozoic > Cretaceous > Lower Cretaceous (0.48)
- Geology > Structural Geology > Tectonics (1.00)
- Geology > Structural Geology > Fault (1.00)
- Geology > Sedimentary Geology > Depositional Environment (1.00)
- (4 more...)
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Processing (0.93)
- (3 more...)
- Oceania > New Zealand > East Coast Basin > PEP 38348 (0.99)
- North America > Canada > Saskatchewan > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Nova Scotia > Scotian Slope > Missisauga Formation (0.99)
- (18 more...)
- Reservoir Description and Dynamics > Storage Reservoir Engineering > CO2 capture and sequestration (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Sedimentology (1.00)
- (5 more...)
Abstract The geology toolkit that is used to reveal faults and fractures is much wider than before. This is due to 3D and 4D views in exploratory statistics programs and to the availability of user-friendly GIS software. These tools allow us to visualize a multitude of parameters that will be briefly explored here. A review of many geologic and nongeologic parameters led to evidence of fault locking and alternate fault activity. It also resulted in new structural models for the Western Canadian Sedimentary Basin (WCSB). The presented data sets include earthquakes, drilling, production, well data, aeromagnetic data, and more. Various integrated approaches reveal well-defined fault patterns that are typical of a strike-slip regime and the existence of previously unrecognized detachments that are important for hydrocarbon exploration. Some of the new geometries and associated mechanisms are illustrated here with outcrop analogues and present-day cross sections, maps, and 3D views. Only the most recent of the two identified strike-slip regimes is covered in this paper. Some emphasis is given to the recognition of detachments at various scales. Among these is the importance of megadetachments displacing the sedimentary cover by up to 16 km with respect to the aeromag. Hence, there is a need for reconstruction before making conclusions. The WCSB has a lot more to offer to explorers who understand faults, fractures, and migration paths. Integrating many types of information in map or 3D views offers new tools to identify and characterize faults.
- North America > Canada > Saskatchewan (1.00)
- North America > Canada > Northwest Territories (1.00)
- North America > Canada > Manitoba (1.00)
- (2 more...)
- Phanerozoic > Mesozoic (0.69)
- Phanerozoic > Paleozoic (0.68)
- Phanerozoic > Cenozoic > Paleogene (0.46)
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (1.00)
- Geology > Structural Geology > Fault (1.00)
- Geology > Rock Type > Sedimentary Rock (1.00)
- Geophysics > Seismic Surveying (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Magnetic Surveying > Magnetic Acquisition > Airborne Magnetic Acquisition (0.91)
- North America > Canada > Saskatchewan > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Northwest Territories > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Manitoba > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- (39 more...)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Faults and fracture characterization (1.00)
- (2 more...)