[ ETUDE PETROGRAPHIQUE ET STRUCTURALE DES SEDIMENTS ALBIENS DU BASSIN SEDIMENTAIRE COTIER DU BENIN ]
Volume 18, Issue 3, November 2016, Pages 794–807
Armand KIKI1, Christophe KAKI2, and Gérard Alfred Franck d'ALMEIDA3
1 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
2 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
3 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
In the offshore basin of Benin, some sediments of Albian age were identified. These sediments are gathered in formation named “Albian Formation”. At regionally scale, they are targeted for petroleum exploration and production. This paper aims to precise the petrographic and structural features of these sediments. Petrographic analyzes reveal the presence of two dominant facies (a main sandy facies and a shale facies which is thicker in deep offshore). Sandstones are very compact, gray to dark gray, and composed mainly of sharp and subrounded quartz grains of various sizes. Shales are massive, gray to blackish and friable to compact. Seismic sections interpretations show that Albian formation is generally continuous, of more or less constant thick and little varied lithological composition in East-West direction. In North-South direction, the formation gradually thick towards the offshore and become significantly reduced in very deep water. The formation is affected by normal and combined faults as well as by reverse faults of NE-SW and NW-SE trends. Structural traps of hydrocarbons are more present in shallow deep offshore while, in deep offshore, traps are essentially of stratigraphic type.
Author Keywords: offshore Benin, Albian formation, petrographic and structural features, facies, faults, traps.
Volume 18, Issue 3, November 2016, Pages 794–807
Armand KIKI1, Christophe KAKI2, and Gérard Alfred Franck d'ALMEIDA3
1 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
2 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
3 Départment des Sciences de la Terre, Faculté des Sciences et Techniques (FAST), Université d’Abomey-Calavi, 01 BP 4256 Cotonou, Benin
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
In the offshore basin of Benin, some sediments of Albian age were identified. These sediments are gathered in formation named “Albian Formation”. At regionally scale, they are targeted for petroleum exploration and production. This paper aims to precise the petrographic and structural features of these sediments. Petrographic analyzes reveal the presence of two dominant facies (a main sandy facies and a shale facies which is thicker in deep offshore). Sandstones are very compact, gray to dark gray, and composed mainly of sharp and subrounded quartz grains of various sizes. Shales are massive, gray to blackish and friable to compact. Seismic sections interpretations show that Albian formation is generally continuous, of more or less constant thick and little varied lithological composition in East-West direction. In North-South direction, the formation gradually thick towards the offshore and become significantly reduced in very deep water. The formation is affected by normal and combined faults as well as by reverse faults of NE-SW and NW-SE trends. Structural traps of hydrocarbons are more present in shallow deep offshore while, in deep offshore, traps are essentially of stratigraphic type.
Author Keywords: offshore Benin, Albian formation, petrographic and structural features, facies, faults, traps.
Abstract: (french)
Dans le bassin offshore du Bénin, des sédiments datés de l’Albien ont été identifiés. Ces sédiments sont regroupés en une formation appelée “Formation albienne”. A l’échelle régionale, ils sont ciblés dans le cadre de l’exploration et de la production pétrolière. Cet article vise à préciser les caractéristiques pétrographiques et structurales de ces sédiments. Les analyses pétrographiques révèlent la présence de deux faciès dominants (un principal faciès gréseux et un faciès argileux plus épais en offshore profond). Les grès sont indurés, gris à gris sombre et composés majoritairement de grains de quartz anguleux à subarrondis de tailles variées. Les argiles sont massives, grise à noirâtre et friables à compactes. L’interprétation des sections sismiques montre que la formation albienne est généralement continue, d’épaisseur à peu près constante et de composition lithologique peu variée selon la direction Est-Ouest. Selon la direction Nord-Sud, cette formation s’épaissit progressivement en direction du large avant d’être considérablement réduite en eau très profonde. Dans son ensemble, la formation est affectée par des failles normales simples et conjuguées ainsi que par des failles inverses de directions NE-SW et NW-SE. Des pièges structuraux d’hydrocarbures sont plus présents en offshore peu profond alors qu’en offshore profond, les pièges sont essentiellement de type stratigraphique.
Author Keywords: offshore du Bénin, formation albienne, caractéristiques pétrographiques et structurales, faciès, failles, pièges.
How to Cite this Article
Armand KIKI, Christophe KAKI, and Gérard Alfred Franck d'ALMEIDA, “PETROGRAPHIC AND STRUCTURAL STUDY OF ALBIAN DEPOSITS OF THE BENIN COASTAL SEDIMENTARY BASIN,” International Journal of Innovation and Applied Studies, vol. 18, no. 3, pp. 794–807, November 2016.
