Fracture Characterization and Diagenesis in the Clipper Field, Sole Pit Basin, Southern North Sea
| Autor: | J.F. Brint, R.C.M.W. Franssen, A. Beecham, T.J. Sleeswijk Visser |
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| Rok vydání: | 1993 |
| Předmět: |
geography
geography.geographical_feature_category Anhydrite Dolomite Geochemistry Energy Engineering and Power Technology Geology Cataclastic rock Sedimentary basin Petroleum reservoir Diagenesis Paleontology chemistry.chemical_compound Fuel Technology chemistry Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Carbonate Sedimentary rock |
| Zdroj: | AAPG Bulletin. 77 |
| ISSN: | 0149-1423 |
| DOI: | 10.1306/bdff801a-1718-11d7-8645000102c1865d |
| Popis: | The Clipper field in the Sole Pit basin produces from tight Leman sandstones of the Rotliegende Group (Lower Permian). The reservoir consists of aeolian sediments. Gas production comes from open natural fractures and dune slipface sands with highly variable rates. The effects of fractures and diagenesis on reservoir quality were investigated. Three fracture networks have been observed in two highly deviated cored wells. Fault-related fractures occur close to, and parallel with, seismically mapped faults. Fold-related fractures occur as two sets of conjugate fractures, with the local maximum compressive stresses ([sigma][sub 1]) trending northeast-southwest and northwest-southeast, respectively. The dominant fracture types are cataclastic and dilational shear fractures. The cataclastic shear fractures were reopened and both fracture types are partially filled by silica, carbonate, and anhydrite cements. The main cement types within the sandstone matrix include dolomite, silica, anhydrite, illite, and ferroan carbonates. Early carbonate cements precipitated during initial burial from a mixture of Rotliegende groundwater and marine pore-fluids from the higher temperatures from Zechstein-derived pore fluids. Pore-filling and fracture-related ferroan carbonate and silica cement precipitated between temperatures of 100-150[degrees]C from isotopically evolved pore fluid. Integration of these data with the burial history and regional geological data reveal that the fault-related fracturesmore » formed during the formation of the Sole Pit rift basin in the Middle to Late Jurassic. The fold-related fractures formed during the Late Cretaceous inversion. The open fractures that contribute to production are associated with the inversion-related deformation. Modeling of these fracture networks, calibrated against available well data, can be used to define areas with high shear fracture density and assist development of fields in the Sole Pit basin.« less |
| Databáze: | OpenAIRE |
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