%0 Conference Paper %1 Goldberg2008 %A Goldberg, Karin %A Abel, Mara %A Daudt, Jose A. %A de Ros, Luiz F. %A Scherer, Claiton %A Anonymous, %B AAPG Annual Convention & Exhibition %D 2008 %K America Cenozoic Echinoidea Echinozoa Eocene Invertebrata Paleogene Peru South Tertiary clastic deltaic depositional environment environmentEchinodermata exploration fluvial lithofacies lower permeability petroleum porosity properties reservoir rocks sandstone sedimentary %T Reservoir petrofacies of the Echinocyamus Formation (Talara Basin, Peru); an approach for high-resolution reservoir characterization %V 2008 %X The Echinocyamus Formation comprises complex fluvial and deltaic reservoirs deposited during the Lower Eocene in the fore-arc Talara Basin (NW Peru). Detailed petrographic analysis with the Petroledge (super (R)) system yielded crucial information on the main controls on reservoir quality and heterogeneity. The sandstones are feldspathic litharenites, rich in andesitic volcanic rock fragments, low-grade meta-sedimentary and meta-volcanic rocks. Diagenetic constituents include smectite, calcite, albite, quartz, pseudomatrix, pyrite and titanium minerals. Zeolite and siderite occur only in fluvial sandstones. Twelve reservoir petrofacies were defined combining depositional structures, textures and primary composition with dominant diagenetic processes and products: RimsPorous, Intraclastic, Conglomeratic, Overgrowths, RimsCompacted, ZeoliteCalcite, FinePorous, PostCompCalcite, PreCompCalcite, SmectiteFilled, FineUnsorted, and FineCompacted. These petrofacies are associated in different proportions in fluvial and deltaic depositional domains. Packing is normal to tight, and deformation of ductile grains into pseudomatrix is common. Intergranular porosity averages 7.5% in fluvial and 4.6% in deltaic sandstones. Grain dissolution porosity attains up to 8% in the fluvial and 10.3% in the deltaic. Intergranular cements reduce porosity and decrease permeability in both intervals, especially in the petrofacies RimsCompacted, FinePorous, and SmectiteFilled. This effect is stronger in the fluvial interval, where smectite is the main cement controlling permeability. Fluvial reservoirs always display higher porosity and permeability than deltaic reservoirs. In the latter, delta-plain deposits are relatively better than delta-front. Reservoir petrofacies were an operational tool for understanding the heterogeneous distribution of quality within the extremely complex Echinocyamus reservoirs.

@inproceedings{Goldberg2008, abstract = {The Echinocyamus Formation comprises complex fluvial and deltaic reservoirs deposited during the Lower Eocene in the fore-arc Talara Basin (NW Peru). Detailed petrographic analysis with the Petroledge (super (R)) system yielded crucial information on the main controls on reservoir quality and heterogeneity. The sandstones are feldspathic litharenites, rich in andesitic volcanic rock fragments, low-grade meta-sedimentary and meta-volcanic rocks. Diagenetic constituents include smectite, calcite, albite, quartz, pseudomatrix, pyrite and titanium minerals. Zeolite and siderite occur only in fluvial sandstones. Twelve reservoir petrofacies were defined combining depositional structures, textures and primary composition with dominant diagenetic processes and products: RimsPorous, Intraclastic, Conglomeratic, Overgrowths, RimsCompacted, ZeoliteCalcite, FinePorous, PostCompCalcite, PreCompCalcite, SmectiteFilled, FineUnsorted, and FineCompacted. These petrofacies are associated in different proportions in fluvial and deltaic depositional domains. Packing is normal to tight, and deformation of ductile grains into pseudomatrix is common. Intergranular porosity averages 7.5% in fluvial and 4.6% in deltaic sandstones. Grain dissolution porosity attains up to 8% in the fluvial and 10.3% in the deltaic. Intergranular cements reduce porosity and decrease permeability in both intervals, especially in the petrofacies RimsCompacted, FinePorous, and SmectiteFilled. This effect is stronger in the fluvial interval, where smectite is the main cement controlling permeability. Fluvial reservoirs always display higher porosity and permeability than deltaic reservoirs. In the latter, delta-plain deposits are relatively better than delta-front. Reservoir petrofacies were an operational tool for understanding the heterogeneous distribution of quality within the extremely complex Echinocyamus reservoirs.}, added-at = {2012-09-14T22:25:01.000+0200}, author = {Goldberg, Karin and Abel, Mara and Daudt, Jose A. and de Ros, Luiz F. and Scherer, Claiton and Anonymous}, biburl = {https://www.bibsonomy.org/bibtex/225ac52efdcf595e8b775369f307d97fe/bdi}, booktitle = {AAPG Annual Convention \& Exhibition}, groups = {public}, interhash = {96db2d8bea7141fb675e91cfbeb0ab19}, intrahash = {25ac52efdcf595e8b775369f307d97fe}, keywords = {America Cenozoic Echinoidea Echinozoa Eocene Invertebrata Paleogene Peru South Tertiary clastic deltaic depositional environment environmentEchinodermata exploration fluvial lithofacies lower permeability petroleum porosity properties reservoir rocks sandstone sedimentary}, timestamp = {2012-09-17T18:17:00.000+0200}, title = {Reservoir petrofacies of the Echinocyamus Formation (Talara Basin, Peru); an approach for high-resolution reservoir characterization}, username = {bdi}, volume = 2008, year = 2008 }