The object-based stochastic approach in facies modelling is important in the construction of geologically consistent 3-D reservoir models and in constraining the distribution of petrophysical properties. Tortuosity factor, facies, porosity and cementation factor constitute major uncertainties in the generated 3-D static model of the Niger Delta Basin. Reservoir quality in the Dahomey Basin is mainly controlled by detrital matrix, carbonate cement, and iron oxide and iron oxyhydroxide cements.
Reservoir quality is studied using a wide range of similar techniques in both sandstones and carbonates. Sandstone and carbonate reservoir quality both benefit from the study of modern analogues and experiments, but modelling approaches are currently quite different for these two types of reservoirs. There are many common controls on sandstone and carbonate reservoir quality, but also distinct differences due primarily to mineralogy. Numerous controversies remain including the question of oil inhibition, the key control on pressure solution and geochemical flux of material to or from reservoirs. This collection of papers contains case-study-based examples of sandstone and carbonate reservoir quality prediction as well as modern analogue, outcrop analogue, modelling and advanced analytical approaches.
Carbonate cements are very common and abundant in clastic sequences. They profoundly influence the quality of hydrocarbon reservoirs and supply important information on palaeoenvironments and the chemical composition and flow patterns of fluids in sedimentary basins. Despite this importance, their distribution patterns in time and space and their geochemical evolution are not yet deeply explored and elucidated. This Special Publication contains 21 review papers and case studies on carbonate cementation in clastic sequences written by invited specialists on the subject. These papers present a wide and deep coverage that enhance our knowledge about carbonate cementation in various clastic depositional environments, tectonic settings and burial histories. The book will be of special interest to researchers, petroleum geologists and teachers and students at the postgraduate level.
Contains details on the geological units of Nigeria and the associated mineral resources. The book is divided into three parts. Part 1 discusses the geology of the crystalline rocks and their regional distribution while the sedimentary basins constitute the subject of Part 2. Part 3 takes the mineral resources of Nigeria one on one, their geological environment, mode of occurrence, localities and where possible the reserves estimation. Thereafter, an account of the previous and current mining policies (including that of petroleum) of the Nigerian government is given and goes ahead to list some specific investment opportunities in the solid minerals sector.
This book is intended as a practical handbook for those engaged in the task of analyzing the paleogeographic evolution of ancient sedimentary basins. The science of stratigraphy and sedimentology is central to such endeavors, but although several excellent textbooks on sedimentology have appeared in recent years little has been written about modern stratigraphic methods. Sedimentology textbooks tend to take a theoretical approach, building from physical and chemical theory and studies of mod ern environments. It is commonly difficult to apply this information to practical problems in ancient rocks, and very little guidance is given on methods of observation, mapping and interpretation. In this book theory is downplayed and the emphasis is on what a geologist can actually see in outcrops, well records, and cores, and what can be ob tained using geophysical techniques. A new approach is taken to stratigraphy, which attempts to explain the genesis of lithostratigraphic units and to de-emphasize the importance of formal description and nam ing. There are also sections explaining principles of facies analysis, basin mapping methods, depositional systems, and the study of basin thermal history, so important to the genesis of fuels and minerals. Lastly, an at tempt is made to tie everything together by considering basins in the con text of plate tectonics and eustatic sea level changes.
