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passive margin basins. AAPG Memoir 48
Book reviews which may stimulate reaction in some readers of 'for what?'. Chapters on 'Putting it altogether', which summarises what the party chief of a land crew should be doing and 'Communications', which discusses the flow of information between field geophysicist, processor and interpreter, provide useful advice and an aide-memoir to the practising geophysicist in seismic acquisition and an insight into the job for the rest of us.
This is not a book which anyone with a serious interest in seismic data acquisition should ignore. Before commencing the design of a seismic survey, many would find it valuable to consult Pritchett's opinion on the subject, and this book may provide them with some useful advice on what might be done if problems arise.
G. Westbrook
University of Birmingham, UK
Cores and Core Logging for Geologists G. A. Blackbourn Whittles Publishing Services; 1990; Price: £19.95 This book is a welcome addition to a rather limited literature on coring methods and data interpretation, particularly the section on soft-sediment coring. It gives broader considerations to other engineeering disciplines and is not limited to the oil industry. It is an excellent guide for the trained geologist to apply his/her knowledge and experience to the description of rock sequences recovered by coring. It concentrates on aspects central to coring for all disciplines. The review of drilling and coring methods sets the scene for the techniques of 'core boring'. There is a very good general introduction to electric wireline logging; however, more emphasis could be given on the use of M W D logs for selecting core points and the use of high resolution tools and borehole scanners to interpret the position of conventional core relative to the borehole. Core handling techniques are well reviewed. In the section on heat-sealing techniques for preservation, it is well noted that cling film exudes volatile plasticizers which affect geochemical analysis and the wettability of the core. The reader should be aware that the use of impermeable membranes in conjunction with heat-sealing techniques provide efficient and cost-effective core preservation. Core logging is particularly well presented with the appropriate emphasis placed on a systematic, careful approach. The definite advantage to using a standard format and abbreviations is that it is more easily understood by others familiar with the same standard; it allows a reference for recent graduates, especially those working in a less structured environment and augments major operators' formats. The core analysis and testing overview provides a good, concise review of analytical core-testing procedures. Further mention could be made of the use of Cat-Scan techniques to
determine where plugs should be taken from a core. The discussion on core interpretation is particularly useful as it stresses how important it is to record initial interpretations before they are forgotten. The difficult question of the best techniques to preserve and store a slabbed core is dealt with adequately. Sublimation of a frozen core, however, is a problem that can easily be solved by periodically spraying the core with a saline solution. On the important question of depth, there is a particularly good discussion in various sections relating to driller's depth, log depth and true vertical depth. In addition, the book provides good cross-references within the text to sections relating to a particular subject. Additional emphasis on computer-assisted logging would be welcome, particularly in that it forms a base for which other interpretations and data may be added. This book addresses the most critical factors in cores and corelogging, namely drilling and rigsite selection and recovery techniques, on-site depth determination, depth marking, orientation and handling of cores, initial field description, preservation storage and shipping preparations. The sections on core analysis and testing techniques, interpretation and preparation of final logs complete the book. Cores and Core Logging for Geologists provides excellent coverage on methodology with emphasis on operational geology. It supplements the learning of core logging 'on the job' and should provide an excellent standard reference for the geoscientist.
R. E. Jantzen
BP Exploration, London, UK
Divergent/Passive Margin Basins. AAPG Memoir 48 J. D. Edwards and P. A. Santogrossi (Eds) AAPG; Tulsa; 1990; ISBN: 0 89181 326 8; 252pp; Price: $102.00 (hardcover); $62.00 (AAPG Members) During 1984, the A A P G initiated the publication of a series of five volumes dealing with five classes of basins. Memoir 48, dealing with divergent/passive margin basins is the first to be published: others will review cratonic basins, active margin basins, foreland basins and foldbelts, and rift basins. The purpose of the series is to provide explorationists with a broadly comparable base of data and concepts to improve their forecasts through analogue techniques. Basins were consciously selected for review in the volume as maturely explored model types. Four chapters comprising the bulk of Memoir 48 review the Campos Basin (Brazil), part of the north-west shelf of Australia, the basins onshore and offshore Gabon and finally the Niger Delta; there are also brief introductory, summary and conclusions chapters written by the editors.
Without doubt, the outstanding paper in the memoir is that by Guardado, Gamboa and Lucchesi on the prolific Campos Basin of Brazil, where recently discovered fields in deep water are in the super-giant class. To date relatively little easily accessible information has been published on the Campos Basin, and on these grounds alone this paper is a welcome addition to the literature of petroleum geoscience. However, this well written and lavishly illustrated paper (colour foldouts of seismic sections and colour photos of cores abound) also presents a fully integrated view of the hydrocarbon habitat of the Campos Basin based on modern concepts of sequence stratigraphy and basin evolution. The basin as a whole is first reviewed in terms of its sequence stratigraphy and the overall sequence and structural style illustrated by two key regional seismic lines. The
Marine and Petroleum Geology, 1991, Vol 8, August 371
Book reviews lithostratigraphy is placed in a sequence concept with palaeogeographic maps being used to illustrate lithostratigraphic variation and key issues such as reservoir and source distribution; well logs and core micrographs document the key reservoirs in each sequence and provide closer definition of depositional environments. The thermal history of the basin is addressed using a McKenzie stretching model. Source rock distribution is discussed in detail; the oils recovered in the Campos Basin are sourced entirely from the non-marine Lago di Feia source rock (synrift). Although originally overlain by salt, the soils have charged overlying reservoirs of various types ranging in age from Cretaceous to Miocene through gaps in the salt created by salt withdrawal. Representative oil fields in the Campos Basin are described in detail and illustrated with both seismic and well sections. There is also a brief discussion of the Marlim Field (8.2 billion bbl) reservoired in Miocene turbidites, illustrated by a spectacular seismic section. The step out to this successful deep water structural-stratigraphic play owes much to the recognition of the turbidite play in shallower water depths. The closely similar offshore and onshore basins of Gabon are described in a well written article by Teisserenc and Villemin. This paper also uses sequences to discuss the hydrocarbon habitat of the Gabon. Unlike Campos, however, the onshore and offshore basins show greater structural segmentation and synrift non-marine facies comprise non-marine sediments rather than volcanics. The successful play systems are discussed in terms of the influence of structure on reservoir distribution as well as source rock distribution and maturity. Seismic sections are used to illustrate both seismic facies and structural style. Although Cretaceous turbidites (notably in the Anguille Formation) are recognized as a play, the authors note the potential of a Tertiary turbidite play by analogy with the Campos. Unlike Campos, however, source rocks in the synrift (non-marine) as well as the post-rift contribute to the hydrocarbon charge in the basin. That new plays still remain to be found, is shown by a recent, reportedly major, discovery onshore Gabon. The two remaining review papers in the volume deal with the Niger delta and the north-west shelf of Australia. In basin development as well as hydrocarbon habitat, they bear no obvious linkage to each other or to the South Atlantic basins of the first five chapters. The chapter on the Niger Delta is an excellent summary of work published many years previously by Evamy and Whiteman, updated with a very useful regional seismic line that illustrates structural styles, and a discussion of source rock distribution in the Niger Delta. The writers identify the source rock as deltaic (marginal marine-lacustrine) but do not offer any conclusion as to its overall distribution and richness in the Niger Delta depocentre. As noted above, the paper draws heavily on a previously published account by Evamy et al. In this work, the progressive localization of
depocentres in an aggrading system by growth faults was recognized, as was the basinward younging of the growth systems. This principle will be familiar to many Gulf of Mexico geologists. However, the analysis (as is noted by the authors) predates the more modern approach used by Galloway and is capable of refinement in terms of the principles of sequence analysis. The fourth paper in the memoir deals with the north-west shelf of Australia and is a disappointment compared to the quality of the other three papers. The author does, however, comment in a footnote that the paper was written in 1985, submitted as long ago as 1986, and that it has been superseded by later published work (presumably this refers to the important new oil discoveries in the Vulcan and Dampier Sub-basins). Despite these caveats, only one highly reduced regional seismic section is shown in the paper; the fields and their reservoir are not described at all. Readers may question the interpretation of the boundary scarp of the Rankin Platform (c. 1.5 seconds relief) as an erosional unconformity. Inevitably, the reader is left with the impression that the paper has been based on internal company reports written in the 1970s. A particular weakness is the lack of a clear linkage between the sequence stratigraphy and the tectonic stratigraphic evolution of the Dampier Basin; in this context very little mention is made of the diachronous rift-drift history of the west margin of Australia. Recognizing that this region is a major gas province (and potentially an oil province), the paper does not adequately describe the hydrocarbon habitat of west and north-west Australia. A reviewer is also expected to recommend who should buy the book. In this case, I warmly recommend that the book is well worth the purchase price of $68.00 to A A P G members ($102.00 for non-members). This is because the four papers (despite the faults in one) offer a very useful synthesis. However, one might question how the editors can justify the publication of papers with so many analogues to the Gulf of Mexico without a chapter on the Gulf (or indeed other successful basins). In a valiant attempt to pull the analogies together, the editors have tried to synthesise the four chapters and make many references to the Atlantic margin of North America (a chapter on the Grand Banks would have been useful). However, in future volumes, it would be useful to analyse failure as much as success. The series is a very good concept but a set of four volumes may not be enough. It may well be worthwhile expanding the series into a succession of parts, set to a common analytical theme (regional to field specific) to include a wider range of successful as well as failed basins.
D. G. Roberts BP Exp/orat/on, Houston, TX, USA
Classic Petroleum Provinces J. Brooks (Ed) Geological Society Special Publication No. 50; Geological Society Publishing House; 1990; ISBN 0 903317 48 6. Price: £89 (£39 to Fellows) Classic Petroleum Provinces has been assembled in the belief that there is much oil and gas still to be found and produced in mature provinces, a point of view reiterated by BP (Oil and Gas Journal, Aug 20 1990, p. 56) who estimate that North Sea reserves discovered but not yet produced amount to 10 billion bbl, a total equivalent to cumulative production to the end of 1989. Jim Brooks' main hope in publishing the volume was to inform everyone of some of the main advances in petroleum geology and exploration. As one would expect there are some fine review papers in this volume - - good all-round classical petroleum geology.
372
There are authoritative accounts on Venezuela, Ecuador, the Gulf Coast, Permian Basin and Compos Basin inter alia. Of particular note is the paper on the Russian Pre-Cambrian oil pools. There are also papers on areas not yet classic provinces. Of these, some, such as Yemen, may emerge sooner than others, such as Pakistan. Brooks himself tabulates 18 giant oil provinces, although the volume includes papers from only 10 of them: Mexico, Sirte-Libya, California, Sumatra and the Sahara are all missing. A few papers seem out of place, particularly part of a PhD thesis dealing with an individual field, and a detailed
Marine and Petroleum Geology, 1991, Vol 8, August
This is not a book which anyone with a serious interest in seismic data acquisition should ignore. Before commencing the design of a seismic survey, many would find it valuable to consult Pritchett's opinion on the subject, and this book may provide them with some useful advice on what might be done if problems arise.
G. Westbrook
University of Birmingham, UK
Cores and Core Logging for Geologists G. A. Blackbourn Whittles Publishing Services; 1990; Price: £19.95 This book is a welcome addition to a rather limited literature on coring methods and data interpretation, particularly the section on soft-sediment coring. It gives broader considerations to other engineeering disciplines and is not limited to the oil industry. It is an excellent guide for the trained geologist to apply his/her knowledge and experience to the description of rock sequences recovered by coring. It concentrates on aspects central to coring for all disciplines. The review of drilling and coring methods sets the scene for the techniques of 'core boring'. There is a very good general introduction to electric wireline logging; however, more emphasis could be given on the use of M W D logs for selecting core points and the use of high resolution tools and borehole scanners to interpret the position of conventional core relative to the borehole. Core handling techniques are well reviewed. In the section on heat-sealing techniques for preservation, it is well noted that cling film exudes volatile plasticizers which affect geochemical analysis and the wettability of the core. The reader should be aware that the use of impermeable membranes in conjunction with heat-sealing techniques provide efficient and cost-effective core preservation. Core logging is particularly well presented with the appropriate emphasis placed on a systematic, careful approach. The definite advantage to using a standard format and abbreviations is that it is more easily understood by others familiar with the same standard; it allows a reference for recent graduates, especially those working in a less structured environment and augments major operators' formats. The core analysis and testing overview provides a good, concise review of analytical core-testing procedures. Further mention could be made of the use of Cat-Scan techniques to
determine where plugs should be taken from a core. The discussion on core interpretation is particularly useful as it stresses how important it is to record initial interpretations before they are forgotten. The difficult question of the best techniques to preserve and store a slabbed core is dealt with adequately. Sublimation of a frozen core, however, is a problem that can easily be solved by periodically spraying the core with a saline solution. On the important question of depth, there is a particularly good discussion in various sections relating to driller's depth, log depth and true vertical depth. In addition, the book provides good cross-references within the text to sections relating to a particular subject. Additional emphasis on computer-assisted logging would be welcome, particularly in that it forms a base for which other interpretations and data may be added. This book addresses the most critical factors in cores and corelogging, namely drilling and rigsite selection and recovery techniques, on-site depth determination, depth marking, orientation and handling of cores, initial field description, preservation storage and shipping preparations. The sections on core analysis and testing techniques, interpretation and preparation of final logs complete the book. Cores and Core Logging for Geologists provides excellent coverage on methodology with emphasis on operational geology. It supplements the learning of core logging 'on the job' and should provide an excellent standard reference for the geoscientist.
R. E. Jantzen
BP Exploration, London, UK
Divergent/Passive Margin Basins. AAPG Memoir 48 J. D. Edwards and P. A. Santogrossi (Eds) AAPG; Tulsa; 1990; ISBN: 0 89181 326 8; 252pp; Price: $102.00 (hardcover); $62.00 (AAPG Members) During 1984, the A A P G initiated the publication of a series of five volumes dealing with five classes of basins. Memoir 48, dealing with divergent/passive margin basins is the first to be published: others will review cratonic basins, active margin basins, foreland basins and foldbelts, and rift basins. The purpose of the series is to provide explorationists with a broadly comparable base of data and concepts to improve their forecasts through analogue techniques. Basins were consciously selected for review in the volume as maturely explored model types. Four chapters comprising the bulk of Memoir 48 review the Campos Basin (Brazil), part of the north-west shelf of Australia, the basins onshore and offshore Gabon and finally the Niger Delta; there are also brief introductory, summary and conclusions chapters written by the editors.
Without doubt, the outstanding paper in the memoir is that by Guardado, Gamboa and Lucchesi on the prolific Campos Basin of Brazil, where recently discovered fields in deep water are in the super-giant class. To date relatively little easily accessible information has been published on the Campos Basin, and on these grounds alone this paper is a welcome addition to the literature of petroleum geoscience. However, this well written and lavishly illustrated paper (colour foldouts of seismic sections and colour photos of cores abound) also presents a fully integrated view of the hydrocarbon habitat of the Campos Basin based on modern concepts of sequence stratigraphy and basin evolution. The basin as a whole is first reviewed in terms of its sequence stratigraphy and the overall sequence and structural style illustrated by two key regional seismic lines. The
Marine and Petroleum Geology, 1991, Vol 8, August 371
Book reviews lithostratigraphy is placed in a sequence concept with palaeogeographic maps being used to illustrate lithostratigraphic variation and key issues such as reservoir and source distribution; well logs and core micrographs document the key reservoirs in each sequence and provide closer definition of depositional environments. The thermal history of the basin is addressed using a McKenzie stretching model. Source rock distribution is discussed in detail; the oils recovered in the Campos Basin are sourced entirely from the non-marine Lago di Feia source rock (synrift). Although originally overlain by salt, the soils have charged overlying reservoirs of various types ranging in age from Cretaceous to Miocene through gaps in the salt created by salt withdrawal. Representative oil fields in the Campos Basin are described in detail and illustrated with both seismic and well sections. There is also a brief discussion of the Marlim Field (8.2 billion bbl) reservoired in Miocene turbidites, illustrated by a spectacular seismic section. The step out to this successful deep water structural-stratigraphic play owes much to the recognition of the turbidite play in shallower water depths. The closely similar offshore and onshore basins of Gabon are described in a well written article by Teisserenc and Villemin. This paper also uses sequences to discuss the hydrocarbon habitat of the Gabon. Unlike Campos, however, the onshore and offshore basins show greater structural segmentation and synrift non-marine facies comprise non-marine sediments rather than volcanics. The successful play systems are discussed in terms of the influence of structure on reservoir distribution as well as source rock distribution and maturity. Seismic sections are used to illustrate both seismic facies and structural style. Although Cretaceous turbidites (notably in the Anguille Formation) are recognized as a play, the authors note the potential of a Tertiary turbidite play by analogy with the Campos. Unlike Campos, however, source rocks in the synrift (non-marine) as well as the post-rift contribute to the hydrocarbon charge in the basin. That new plays still remain to be found, is shown by a recent, reportedly major, discovery onshore Gabon. The two remaining review papers in the volume deal with the Niger delta and the north-west shelf of Australia. In basin development as well as hydrocarbon habitat, they bear no obvious linkage to each other or to the South Atlantic basins of the first five chapters. The chapter on the Niger Delta is an excellent summary of work published many years previously by Evamy and Whiteman, updated with a very useful regional seismic line that illustrates structural styles, and a discussion of source rock distribution in the Niger Delta. The writers identify the source rock as deltaic (marginal marine-lacustrine) but do not offer any conclusion as to its overall distribution and richness in the Niger Delta depocentre. As noted above, the paper draws heavily on a previously published account by Evamy et al. In this work, the progressive localization of
depocentres in an aggrading system by growth faults was recognized, as was the basinward younging of the growth systems. This principle will be familiar to many Gulf of Mexico geologists. However, the analysis (as is noted by the authors) predates the more modern approach used by Galloway and is capable of refinement in terms of the principles of sequence analysis. The fourth paper in the memoir deals with the north-west shelf of Australia and is a disappointment compared to the quality of the other three papers. The author does, however, comment in a footnote that the paper was written in 1985, submitted as long ago as 1986, and that it has been superseded by later published work (presumably this refers to the important new oil discoveries in the Vulcan and Dampier Sub-basins). Despite these caveats, only one highly reduced regional seismic section is shown in the paper; the fields and their reservoir are not described at all. Readers may question the interpretation of the boundary scarp of the Rankin Platform (c. 1.5 seconds relief) as an erosional unconformity. Inevitably, the reader is left with the impression that the paper has been based on internal company reports written in the 1970s. A particular weakness is the lack of a clear linkage between the sequence stratigraphy and the tectonic stratigraphic evolution of the Dampier Basin; in this context very little mention is made of the diachronous rift-drift history of the west margin of Australia. Recognizing that this region is a major gas province (and potentially an oil province), the paper does not adequately describe the hydrocarbon habitat of west and north-west Australia. A reviewer is also expected to recommend who should buy the book. In this case, I warmly recommend that the book is well worth the purchase price of $68.00 to A A P G members ($102.00 for non-members). This is because the four papers (despite the faults in one) offer a very useful synthesis. However, one might question how the editors can justify the publication of papers with so many analogues to the Gulf of Mexico without a chapter on the Gulf (or indeed other successful basins). In a valiant attempt to pull the analogies together, the editors have tried to synthesise the four chapters and make many references to the Atlantic margin of North America (a chapter on the Grand Banks would have been useful). However, in future volumes, it would be useful to analyse failure as much as success. The series is a very good concept but a set of four volumes may not be enough. It may well be worthwhile expanding the series into a succession of parts, set to a common analytical theme (regional to field specific) to include a wider range of successful as well as failed basins.
D. G. Roberts BP Exp/orat/on, Houston, TX, USA
Classic Petroleum Provinces J. Brooks (Ed) Geological Society Special Publication No. 50; Geological Society Publishing House; 1990; ISBN 0 903317 48 6. Price: £89 (£39 to Fellows) Classic Petroleum Provinces has been assembled in the belief that there is much oil and gas still to be found and produced in mature provinces, a point of view reiterated by BP (Oil and Gas Journal, Aug 20 1990, p. 56) who estimate that North Sea reserves discovered but not yet produced amount to 10 billion bbl, a total equivalent to cumulative production to the end of 1989. Jim Brooks' main hope in publishing the volume was to inform everyone of some of the main advances in petroleum geology and exploration. As one would expect there are some fine review papers in this volume - - good all-round classical petroleum geology.
372
There are authoritative accounts on Venezuela, Ecuador, the Gulf Coast, Permian Basin and Compos Basin inter alia. Of particular note is the paper on the Russian Pre-Cambrian oil pools. There are also papers on areas not yet classic provinces. Of these, some, such as Yemen, may emerge sooner than others, such as Pakistan. Brooks himself tabulates 18 giant oil provinces, although the volume includes papers from only 10 of them: Mexico, Sirte-Libya, California, Sumatra and the Sahara are all missing. A few papers seem out of place, particularly part of a PhD thesis dealing with an individual field, and a detailed
Marine and Petroleum Geology, 1991, Vol 8, August