Tag: Réservoir

Sedimentological control on the diagenesis and reservoir quality of tidal sandstones of the Upper Cape Hay Formation (Permian, Bonaparte Basin, Australia)

The deep siliciclastic reservoir (>3500 m) of the Upper Cape Hay Formation of the Bonaparte Basin (Petrel gas field, Petrel sub-basin, Permian) exhibits wide heterogeneity in porosity (2–26%) and permeability (0.001–2500 mD). To investigate this variability, 42 samples were taken from five wells drilled through this formation. Six facies were identified from core descriptions and microscopic study of the sandstones. These facies are typical of a tide-dominated estuary, and include (1) mud flat, (2) sand flat, (3) top of tidal sand bar, (4) middle of tidal sand bar, (5) bottom of tidal sand bar, and (6) outer estuary facies. The paragenetic sequence comprises the emplacement of early aggregates of ferrous clay mineral precursors, mechanical compaction, recrystallization of those ferrous clay mineral precursors to Fe-rich chlorite and crystallization of Fe-rich chlorite forming coatings around detrital grains, chemical compaction, development of quartz overgrowth, feldspar alteration, crystallization of dickite and illite-rich illite/smectite (I-S) mixed layers, and ferrous calcite cementation. The middle and top of the tidal bars generally exhibit the highest porosity (Φ > 10%) and permeability values (k > 1 mD). Feldspar alteration released silica and aluminium into the reservoir promoting the development of dickite and illite-rich I/S mixed layers, which tended to destroy porosity and permeability, as calcite cements and quartz overgrowths. Diagenetic chlorite coatings around detrital grains are restricted to the sand bar facies deposited at the end of the last third-order transgressive systems tract of the Cape Hay Formation. The formation and conservation of ferrous clay precursors seems to be possible in an estuarine environment where seawater and fresh water are mixed and tidal sand bars are formed. These ferrous clay precursors recrystallized to Fe-rich chlorite coating after mechanical compaction. These coatings inhibited quartz cementation and prove to be the key parameter behind good reservoir qualities.

Link

Saïag, J., Brigaud, B., Portier, E., Desaubliaux, G., Bucherie, A., Miska, S., Pagel, M., 2016. Sedimentological control on the diagenesis and reservoir quality of tidal sandstones of the Upper Cape Hay Formation (Permian, Bonaparte Basin, Australia). Marine and Petroleum Geology. 77, 597-624

Permanent link to this article: http://hebergement.u-psud.fr/reliefetbassin/index.php/archive/sedimentological-control-on-the-diagenesis-and-reservoir-quality-of-tidal-sandstones-of-the-upper-cape-hay-formation-permian-bonaparte-basin-australia/

New article to Marine and Petroleum Geology

The article “Characterization and origin of permeability-porosity heterogeneity in shallow-marine carbonates : from core scale to 3D reservoir dimension (Middle Jurassic, Paris Basin, France)” by Benjamin Brigaud Benoit Vincent, Christophe Durlet, Jean-François Deconinck Emmanuel Jobard, Niel Pickard, Beatrice and Philippe Yven Landrein is ready for publication to Marine and Petroleum Geology.

Permanent link to this article: http://hebergement.u-psud.fr/reliefetbassin/index.php/archive/new-article-to-marine-and-petroleum-geology/