Nigeria: Its Petroleum Geology, Resources and Potential

Volume 1 Nigeria: Its Petroleum Geology, Resources and Potential Volume 1 Arthur Whiteman

Professor of Geology, Petroleum Exploration Studies, University of Aberdeen, Scotland

Graham & Trotman First published in 1982 by

Graham & Trotman Ltd Sterling House 66 Wilton Road London SWI V 1DE

ISBN-13: 978-94-009-7363-3 e-ISBN-13: 978-94-009-7361-9 DOl: 10.1007/978-94-009-7361-9

This production is protected by international copyright law. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photocopying or otherwise, without the prior permission of the publishers.

Typeset in Great Britain by Input Typesetting Ltd, London SW19 8DR CONTENTS

Volume 1

1. Introduction 1 2. Stratigraphy 11 2.1 General Geology and Basin Summaries 11 2.2. Basement Complex 14 2.3. Jurassic Igneous Complexes 20 2.4 Cretaceous System 26

2.4.1. General 26 2.4.2. Southern Nigeria including Anambra Platform, Abakaliki Trough and Calabar Flank: 31 Pre-Santonian Lower and Upper Cretaceous Formations 2.4.2.1. Lower Cretaceous Formations 31 2.4.2.1.1. General; 2.4.2.1.2. Asu River Group 2.4.2.2. Upper Cretaceous rocks Pre-Santonian Southern Nigeria 36 2.4.2.2.1. Geueral; 2.4.2.2.2. Odukpaui Formatiml; 2.4.2.2.3. Kealia Saudstone; 2.4.2.2.4. Man~re Formation; 2.4.2.2.5. Eze-Aku Shale Group including its relatiollShips with the Ameseri Sandstolle, Agala Salldstone and Konsisha River Group; 2.4.2.2.6. Awgu Shale and Agbani Sandstone; 2.4.2.2.7. Umuna-1, Annua-1 and Ikono-1 Volcanics; 2.4.2.3. Hydrocarbon prospects Southern Nigeria including Anambra Platform, Abakaliki 44 Trough and Calabar Flank: Pre-Santonian Lower and Upper Cretaceous Formations. 2.4.2.3.1. Pre-Santonian prospects, Anambra Platform; 2.4.2.3.2. Pre-Santonian prospects, Abakaliki Trough; 2.4.2.3.3. Pre-Santonian prospects; Calabar Flank and Hinge Line 2.4.3. Lower and Upper Benue Trough: Pre-Santonian Lower and Upper Cretaceous 49 Formations 2.4.3.1. General definition and subdivision of the Benue Trough 49 2.4.3.2. Lower Cretaceous Formations, Lower and Upper Benu~ Trough 53 2.4.3.2.1. Asu River Group; 2.4.3.2.2. Awe Formation; 2.4.3.2.3. Bima Sandstone 2.4.3.3. Upper Cretaceous Pre-Santonian Formations Lower and Upper Benue Trough 55 2.4.3.3.1. General; 2.4.3.3.2. Awe Formation; 2.4.3.3.3. Keana Formation; 2.4.3.3.4. Eze-Aku For• mation; 2.4.3.3.5. Awgu Formation; 2.4.3.3.6. Bima Sandstone; 2.4.3.3.7. Yolde Formatiml; 2.4.3.3.8. Dukul Formation; 2.4.3.3.9. Jessu Formation; 2.4.3.3.10. Sekule Formation; 2.4.3.3.11. Numanha Shales; 2.4.3.3.12. Lamja Sandstone; 2.4.3.3.13. Pindiga Formation; 2.4.3.3.14. Gulalli Formation 2.4.4. Gongola Trough, Bornu Basin and Yola Trough Upper Cretaceous Pre-Santonian 60 Formations 2.4.4.1. General 60 2.4.4.2. Upper Cretaceous Pre-Santonian Formation, Gongola Trough, Bornu Basin and Yola 63 Troughs 2.4.4.2.1. Gongila Formation; 2.4.4.2.2. Fika Shales; 2.4.4.2.3. Bima- Yola Formation 2.4.4.3. Hydrocarbon Prospects of the Lower and Upper Benue, Gongola and Yola Troughs and 63 the Nigerian Section of the Bornu Basin Pre-Santonian Lower and Upper Cretaceous Formations

v CONTENTS

2.4.4.3.1, General; 2.4.4.3.2, 's,'lJrcc Rocks; 2.4.4.3.3, Reservoir Rocks; 2.4.4.3.4, Specific Prospects ill Lower Be/we Trough; 2,4,4,3,5,\!'Clitic Prospects ill Upper Benue Trough; 2.4,4.3,6, Prospects ill the GOllgola and Yola Troughs 2.4.5. Sokoto "Basin" or Embayment "Ji,erian Section of lullemmeden Basin Upper Creta• 67 ceous Pre-Santonian Formations 2.4.5.1. General 67 2.4.5.2. Upper Cretaceous Formations Sokoto Embayment 73 2.4,5.2,1, Gundumi Formation; 2,4,5,2.2.1110 Formatioll; 2,4,5,2.3. Petroleum Prospects oJthe Gundumi alld IlIo Formations 2.4.6. Post Santonian Upper Cretaceous Formations 74 2.4.6.1. Southern Nigeria including Anambra Basin, Abakaliki Fold Belt, Afikpo Syncline and 74 Calabar Flank 2.4.6,1,1, Nkporo Shale; 2.4,6,1,2, Owelli Salldstone; 2,4,6,1.3. Otobi Sandstone; 2.4.6.1.4, Enugu Shales; 2.4.6,1,5, Mamu Formatioll (Lower Coal Measures); 2,4.6.1.6, Ajali Sandstolle; 2.4.6.1.7, Nsukka Formatioll (Upper Coal Measures); 2.4,6.1,8, Lafia Formatioll; 2.4.6.1.9. Gombe Salldstone 2.4.6.2. Bida Basin and adjacent areas Upper Cretaceous Post Santonian Formations 82 2.4,6.2,1, General; 2,4,6.2.2, Nupe Group; 2,4,6,2,3, Bida Sandstone Formation; 2.4,6.2.4,Sakpe Ironstolle Formation; 2.4,6,2.5, Ellagi Siltstolle Formatioll; 2.4.6.2.6. Batati Ironstone Formation; 2,4.6,2,7, Lokoja Sandstone; 2.4,6,2,8, Patti Formation; 2.4.6.2,9, Oolitic Ironstones Agbaja Plateau; 2,4.6.2, to, Correiati0l1 of Lokoja Salldstones and Patti Formations with the Nupe Group and the Late Cretaceous Sequerlce of the Anambra Basin, Northwest Flank 2.4.6.3. Hydrocarbon Prospects of the Post Santonian Upper Cretaceous Rocks of the Anambra 86 Basin, Abakaliki Fold Belt, Afikpo Syncline, Calabar Flank and Benue Depression and Flanking Basins. 2.4,6,3,1. General; 2.4,6,3,2, ,4nambra Basin Prospects; 2.4,6,3,3. Calabar Flank Prospects; 2.4,6,3.4, Other Basins 2.4.6.4. lullemmeden Basin, Sokoto Area Upper Cretaceous Post Santonian Formations 89 2,4,6,4,1, GfIleral and Rima Group; 2,4,6.4.2, Taloka Formation; 2.4,6.4.3, Dukumaje Formation; 2.4,6.4,4, Wunw Formation; 2.4,6.4,5, Conditions oj Deposition oj Rima Group and General Palaeogeography 2.4.6.5. Hydrocarbon prospects of the Post Santonian Upper Cretaceous rocks on the Nigerian 95 Section of the Iullemmeden Basin 2.4.6.6. Dahomey Miogeocline, Western Nigeria and Benin Flank: Upper Cretaceous Post San• 95 tonian Rocks 2.4.6,6,1, General; 2.4,6,6.2, Abeokuta Formation 2.4.6.7. Hydrocarbon Prospects Dahomey Miogeocline, Nigerian Section Post Santonian Upper 97 Cretaceous Hocks

2.5. Cenozoic Erathem in Nigeria 99 2.5.1. General 99 2.5.2. lullemmeden Basin, Sokoto Section, Northern Nigeria Cenzoic Formations 100 2.5.2.1. General 100 2.5.2.2. Gwandu Formation 102 2.5.2.3. Gamba Formation 102 2.5.2.4. Kalambaina Formation 102 2.5.2.5. Dange Formation 102 2.5.2.6. Hydrocarbon Prospects of the Cenozoic Gwandu Formation and Sokoto Group of the 104 Nigerian Section of the Iullemmeden Basin. 2.5.3. Bornu Basin and adjacent Southern Chad Basin Cenozoic Formations 104 2.5.3.1. General 104 2.5.3.2. Kerri-Kerri Formation 104 2.5.3.3. Jos Sediments 104 2.5.3.4. Chad Formation 104 2.5.4. Dahomey Miogeocline, Western Nigeria Cenozoic Formations 104 2.5.4.1. General 104 2.5.4.2. Imo Shale 106 2.5.4.3. Ewekoro Formation 108 2.5.4.4. Ameki Formation 108 2.5.4.5. Oshoshun Formation 109 2.5.4.6. Illaro Formation 109 2.5.4.7. Ijebu Formation 110 2.5.4.8. Ogwashi-Asaba Formation 110

VI CONTENT~

2.5.4.9. Benin Formation (surface) 110 2.5.5. Niger Delta complex Cenozoic Formations 110 2.5.5.1. General 110 2.5.5.2. Benin Formation (subsurface) 114 2.5.5.3. Afam Clay Member (subsurface) 120 2.5.5.4. Agbada Formation (subsurface) 120 2.5.5.5. Akata Formation (subsurface) 129 2.5.5.6. Imo Shale Formations (surface) 131 2.5.5.7. Ameki Formation (surface) 132 2.5.5.8. Ogwashi-Asaba Formation (surface) 133 2.5.5.9. Benin Formation (surface) 138 2.5.5.10. Agbada (surface) and Akata (subsea) formations 138 2.5.5.11. Formations and environments of the Late Quaternary Niger Delta 139 2.5,5.11.1. Upper Flood Plain Environment and Deposits; 2.5.5.11.2. Lower Floodplain Environment and Deposits; 2.5.5.11.3. Mangrove Swamp 'Environment and Deposits; 2.5.5.11.4. Beach Environment and Deposits; 2.5.5.11.5. Ri!'er Mouth bar Environment and Deposits; 2.5.5.11.6. Deltaftont Platform Environment and Deposits; 2.5.5.11.7. Pro-Delta Slope Deposits; 2.5.5.11.8. Opm Shelf En!'ironmmt and Deposits; 2.5.5.11.9. Older Sands 2.5.5.12 Present day Niger Delta and Niger-Benue drainage system: Basic Environmental Data 145 2.5.5.12.1. General; 2.5.5.12.2. Niger-Benue Sedimmts; 2.5.5.12.3. Distributive Agents, River Flows; 2.5.5.12.4. Distributive AgCl1ts, Tidal Flows; 2.5.5.12.5. Distributive Agmts; Wind-Wave Currmts; 2.5.5.12.6. Distributive Agents.' Longshore drift and the Niger Delta Submarine Canyons 2.5.5.13. Size, shape, etc. of the Niger Delta Complex and the Present Day System 163

Volume 2

3. Structure 167 3.1 General 167 3.2 Basement Complex and Jurassic Igneous Complexes 170 3.2.1. Basement Complex Structures 170 3.2.2. Jurassic Igneous Complexes 171 3.3 Structure Affecting Pre-Santonian Lower and Upper Cretaceous Formations (Onshore) 172 3.3.1. General 172 3.3.2. Abakaliki Fold Belt 173 3.3.2.1. General Structural Description 173 3.3.2.2. Age of the Abakaliki Fold Belt 176 3.3.2.3. Minor Basic and Intermediate Intrusives and Effusives, Abakaliki Fold Belt 176 3.3.2.4. Lead-Zinc Mineralization: Abakliki Fold Belt 178 3.3.3. Structure, Mamfe Embayment 179 3.3.4. Structure, Benue Fold Belt 179 3.3.4.1. General 179 3.3.4.2. Lower Benue Fold Belt 181 3.3.4.3. Upper Benue, Vola and Gongola Fold Belts 183 3.3.5. Origin of the Abakaliki-Benue Fold Belts: Largely Historical 187 3.3.6. Origin of the Abakaliki-Benue Fold Belts (this account) 216 3.3.6.1. General 216 3.3.6.2. Transpressional and Transtensional Basins: do they occur in the Abakaliki and Benue 217 Troughs? 3.3.6.3. Rift Origin of the Abakaliki-Benue-Gongola-Vola Trough Systems 217 3.3.6.4. The Dynamics of Faulting and Folding, Abakaliki-Benue Fold Belt (this account) 223

VIl CONTENTS

3.4 Structure affecting Post-Santonian Upper Cretaceous Formations 226 3.4.1. General 226 3.4.2 Anambra Basin Post-Santonian Development 227 3.4.3. Dahomey Basin Post-Santonian Development 232 3.4.4. Bida Basin? Mainly a Post-Santonian Basin 233 3.4.5. Mamfe Basin 239 3.4.6. Wase-Gombe Basin, Post-Santonian Development 240 3.4.7. Wukari-Mutum Biyu Basin, Post-Santonian Development 246 3.4.8. Bornu, Chad and Iullemmeden Basins, Post-Santonian Development 246 3.4.8.1. General 246 3.4.8.2. Bornu Basin 247 3.4.8.3. Bornu Basin: Summary of Petroleum Prospects 247 3.4.8.4. Iullemmeden Basin, Nigeria 248 3.4.9. General Note on the Structural Development of the Cameroun Zone 249 3.5. Structure Affecting Offshore Mesozoic-Cenozoic Sediments, Gulf of Guinea, the Ceno- 251 zoic Niger Delta Complex and the Cameroun Coastal Basins 3.5.1. General 251 3.5.2. Early Stages in the Structural Evolution of the Gulf of Guinea Miogeocline, ? Jurassic to 251 Late Cretaceous times 3.5.3. Later stages in the Structural Evolution of the Gulf of Guinea Miogeocline and the Niger 256 Delta Complex, Late Cretaceous-Cenozoic time 3.5.3.1. General 256 3.5.3.2. Generation of the Cenozoic Niger Delta Complex 269 3.5.3.3. Niger Delta Complex Synsedimentary structures, growth faults, mud Diapirs, etc. 276 3.5.3.3.1. General Comment and Description; 3.5.3.3.2. Origin of the Niger Delta Growth Faults and Rollovers

4. Oil and Gas occurrences Cenozoic Niger Delta Complex: Source, Reser- 306 voir, Migration and accumulation data and case histories 4.1 General 306 4.2 Case History: Bomu Field 311 4.3 Case History: Okan Field 315 4.4 Afiesere and Eriemu Fields: Reservoir and Petrophysical Data 316 5. Petroleum Production Data, Reserve Data and generalized prospects for 321 Nigeria 5.1. Production Data 321 5.2 Reserve Data 329 5.3 A Selection of Petroleum Prospects and Plays, based on published information 334

6. A Chronological Review of selected exploration and production devel- 339 opments for the Petroleum Industry in Nigeria 1908-1979 7. Concession Maps and Exploration Data 1963-1979 350 8. Selected References 376 List of Figures 382

Vlll "So geographers [geologists), in Afric maps, With savage pictures fill their gaps; And o'er uninhabitable downs Place elephants for want of towns."

Jonathan Swift On Poetry