Biological memoirs最新文献

{"title":"Chapter 7 Exploration implications","authors":"A. Wilson","doi":"10.1144/M53.7","DOIUrl":"https://doi.org/10.1144/M53.7","url":null,"abstract":"Abstract Exploration of the Jurassic hydrocarbon system in the Arabian Intrashelf Basin area is in a mature state. Given the scale of the present day anticlinal structures and the adjacent synclines, all of the supergiant conventional fields trapped in huge anticlines have already been discovered. The theme throughout this Memoir has been to present the evolution of the self-contained Callovian–Tithonian Arabian Intrashelf Basin hydrocarbon system. Its size, c. 1200 × 450 km, is greater than that of the UK, larger than the Black Sea and almost as large as Turkey or the area of Texas and New Mexico in the USA. It is geologically much simpler than these regions, both in the exceptionally remarkable continuity of facies within the sequences that developed and filled the intrashelf basin and its relative tectonic simplicity, including up to the present day. The cross-sections, facies maps, depositional profiles and other data and interpretations presented in this Memoir have documented this remarkable continuity. The source rock interval is well-defined everywhere it occurs and is mature; enough oil has been generated and migrated so that every sealed trap with reservoir facies will have oil. Around and within the basin, shallow water ramp facies in each sequence are in the reservoir facies and the early-formed porosity has been preserved. The carbonate seals and, even more so, the evaporite seals are remarkably laterally continuous. Therefore the big issue in future exploration is finding a sealed trap with potential reserves large enough to be worth drilling when compared to known reserves and estimates of future production. This chapter discusses some possibilities for stratigraphic traps and unconventional plays. Potential plays have been and/or can be identified, but finding them in the present day structural setting is likely to be very difficult.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"59 1","pages":"187 - 196"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74387825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chapter 1 Introduction to the Jurassic Arabian Intrashelf Basin","authors":"A. Wilson","doi":"10.1144/M53.1","DOIUrl":"https://doi.org/10.1144/M53.1","url":null,"abstract":"Abstract The Jurassic Arabian Intrashelf Basin provides the setting for the world's greatest conventional oil reserves, including the world's largest oilfield, the supergiant Ghawar field. The stratigraphic interval corresponding to the development and infill of the Arabian Intrashelf Basin is from the uppermost Dhruma Formation to the top of the Hith Anhydrite Formation, spanning the late Bathonian–early Callovian to Tithonian. Many areas of the intrashelf basin have been well described in recent years and the stratigraphic succession has been defined in sequence concepts, but the regional development of the intrashelf basin has not been well synthesized. This Memoir builds on published data to give a regional interpretation of the geological evolution of the Arabian Intrashelf Basin. This introductory chapter reviews some of the earlier work, summarizes the key events and elements in the geological history of the Arabian Intrashelf Basin and gives a brief review of the history of petroleum exploration in this region. It is intended to serve as an extended abstract to introduce the general setting and summarize the contents of this Memoir, including some of the proposed revisions of depositional models, correlations and the sequence nomenclature, providing a context for considering and evaluating each subsequent chapter. The themes summarized in this chapter are documented and discussed in much greater detail in the subsequent chapters of this Memoir.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"5 1","pages":"1 - 19"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89725346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chapter 8 Summary and conclusions","authors":"A. Wilson","doi":"10.1144/M53.8","DOIUrl":"https://doi.org/10.1144/M53.8","url":null,"abstract":"Abstract This chapter summarizes the main conclusions in this Memoir. Included is a comparison of the Arabian Intrashelf Basin events to the Haq (2017) revision of the Jurassic sea level curve. One conclusion is that the Mid- to Late Jurassic Arabian Intrashelf Basin, with its stable tectonic setting during deposition, extensive present-day outcrops and subsurface well and seismic control, may be an ideal place to evaluate global changes during its time span. The last part of this chapter lists and discusses topics and questions raised within this Memoir which warrant further evaluation.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"107 1","pages":"197 - 205"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75579024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About this title - The Middle and Late Jurassic Intrashelf Basin of the Eastern Arabian Peninsula","authors":"A. Wilson","doi":"10.1144/M53","DOIUrl":"https://doi.org/10.1144/M53","url":null,"abstract":"This Memoir provides a thorough regional synthesis of the geology of the rimmed Arabian Intrashelf Basin, reconciling differing interpretations of lithostratigraphy, sequence stratigraphy and biostratigraphy. Variation of energy levels and facies due to its setting in the SE palaeotradewind belt are described. The intrashelf basin formed during rising sea level as a single rimmed carbonate intrashelf basin. A possible global cooling phase resulted in a lowstand which restricted the basin, resulting in petrographically unique carbonate source rock facies dominated by cyanobacterial deposition. Two subsequent third-order carbonate sequences largely filled the basin. Eustatic change concomitant with uplift of the Tethys shelf resulted in alternation of carbonates and evaporites (gypsum-anhydrite) across the region. The end result was a sealed intrashelf basin which preserved early formed porosity and confined generated hydrocarbons within the intrashelf basin facies.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"301 1","pages":"NP - NP"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76267491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chapter 3 Lithostratigraphy and depositional characteristics, age dating and sequence stratigraphy","authors":"A. Wilson","doi":"10.1144/M53.3","DOIUrl":"https://doi.org/10.1144/M53.3","url":null,"abstract":"Abstract This chapter reviews the lithostratigraphy, biostratigraphy, age dating and sequence stratigraphy of the Arabian Intrashelf Basin to document the basic data used in the interpretations in this Memoir. The factors important to understanding these topics are discussed, including the typical facies, general depositional models, the effects of dolomitization, well log characteristics and the problems with obtaining precise age dates. Comments are included to show the interpretations preferred in this Memoir.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"1 1","pages":"37 - 94"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90806888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chapter 2 Structural development of the Arabian Intrashelf Basin region","authors":"A. Wilson","doi":"10.1144/M53.2","DOIUrl":"https://doi.org/10.1144/M53.2","url":null,"abstract":"Abstract This chapter summarizes the tectonic events that have affected the region of the Arabian Intrashelf Basin and the development of the intrashelf basin. Precambrian–Infracambrian fault systems provided a structural framework, which was later reactivated during the Late Paleozoic. Further development along the structural trends continued in the Triassic and Early Jurassic with the development of an Early Jurassic tectonically controlled intrashelf basin. The accommodation space was filled with Dhruma Formation carbonates by the early Bathonian, resulting in a broad and fairly flat platform. A crucial factor is how suppressed tectonism was during the Mid- and Late Jurassic. The intrashelf basin developed on the broad, tectonically stable Tethyan passive margin continental shelf 200--300 km distant from the Tethyan outer shelf edge. During the Mid- and Late Jurassic, this tectonic stability provided the foundation for a broad, stable Tethyan continental shelf region at least 1000 × 1200 km in area, far removed from siliciclastic sources, within which the huge Arabian Intrashelf Basin formed and the sequences of carbonate rocks and evaporites that created the Jurassic hydrocarbon system were deposited. Tectonism during the Mid- to Late Jurassic evolution of the Arabian Intrashelf Basin initially included only moderate subsidence. There was subtle uplift along some of the structural trends in the Late Jurassic and uplift and westwards structural tilt along the Tethys oceanic margin. Relatively stable tectonism continued after the Jurassic and was a major factor in the accumulation of the vast reserves of Jurassic sourced oil. Tectonic stability prevented major faulting and structural compartmentalization of the basin features, which provided large areas for hydrocarbon migration as the large and broad anticlines developed into the huge structural traps. The lack of major faulting limited the movement of burial fluids, preserving the early formed porosity and the regionally extensive seals. The present day structures primarily developed from the Late Cretaceous to Miocene as the Tethys Ocean closed.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"62 1","pages":"21 - 35"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91177159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chapter 5 Interpretation of the origin and evolution of the Arabian Intrashelf Basin and the development of the Dhruma Atash, Tuwaiq and Hanifa sequences","authors":"A. Wilson","doi":"10.1144/M53.5","DOIUrl":"https://doi.org/10.1144/M53.5","url":null,"abstract":"Abstract This is the first of two chapters in which the data presented in the first four chapters of this Memoir are reviewed and interpreted. A summary cross-section across the basin from the Saudi outcrop to Abu Dhabi and the Tethyan margin is used to summarize the regional setting and sequences as interpreted in this Memoir. The key points illustrated by the summary cross-section are stated and discussed in the first part of this chapter. Two different interpretations for the eastern margin of the intrashelf basin are reviewed. In the first of these interpretations, the margin with the deeper waters of the Tethys Ocean shelf is adjacent to the intrashelf basin rim in Abu Dhabi, whereas in the second, preferred in this Memoir, a broad, shallow Tethyan shelf platform (200–300 km wide) extends from the intrashelf basin rim to the Tethys continental shelf edge. The implications of Late Jurassic exposure and erosion on the adjacent Tethyan shelf are discussed. The development of the Arabian Intrashelf Basin during the Callovian–late Oxfordian (the Tuwaiq Mountain Formation, the source rock and the Hanifa intervals and associated sequences) is interpreted and discussed with illustrations, including step-by-step facies maps. The interpretation integrates depositional, eustatic and tectonic factors in the evolution of the intrashelf basin. The interpretation in this Memoir is that the Arabian Intrashelf Basin began with isostatic and extensional subsidence on top of a broad Dhruma Atash Member platform, which had largely filled the accommodation space up to the wave base and to near sea-level. It developed fully into an intrashelf basin during the deposition of the Callovian Tuwaiq sequence, with rising sea-levels coincident with a productive shallow water carbonate factory resulting in a rim of shallow water carbonate. An end-Callovian to early Oxfordian lowstand terminated the Tuwaiq sequence on the basin rim. During the lowstand, restricted conditions in the basin deposited the rich Lower Hanifa source rock as a lowstand systems tract. As more normal conditions returned in a subsequent sequence, the source rock facies graded upwards into Hanifa reservoir facies, which partially filled the basin. Hanifa progradation was terminated by another lowstand during which a subaqueous gypsum/anhydrite marker bed was deposited in at least part of the remnant basin. Earlier interpretations of these sequences are also discussed.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"63 1","pages":"113 - 157"},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81402301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Acorn and Beechnut fields, Blocks 29/8a(S), 29/8b, 29/9a(S) and 29/9b, UK North Sea","authors":"F. Hagen, J. Gluyas, G. Goffey","doi":"10.1144/M52-2018-31","DOIUrl":"https://doi.org/10.1144/M52-2018-31","url":null,"abstract":"Abstract Unocal discovered the Acorn South Field with wells 29/8b-2 and 29/8b-2s in 1983. The well and its side-track found a small accumulation of oil in Upper Jurassic, Fulmar Formation sandstones in an inter-pod setting. Well 29/8b-3 drilled two years later on what was thought to be the same structure found Acorn North, a larger accumulation of oil in a Triassic Skagerrak Formation reservoir on the crest of a Triassic pod. Premier discovered the Beechnut Field two years later, well 29/9b-2 finding oil in the Fulmar and Skagerrak formations in a faulted, inter-pod setting. Both Acorn and Beechnut are deep, high-pressure and high-temperature fields with complex reservoir stratigraphy due to halokinesis during sedimentation and post-depositional structuration. The Skagerrak Formation reservoir in Acorn North is appreciably poorer than similar-age reservoirs further north whilst the Fulmar Formation in Beechnut is relatively poorly developed. Acorn's mid-case oil in place is 90 MMbbl in the Skagerrak Formation and 13 MMbbl in the Fulmar Formation and, for Beechnut, is 15 MMbbl in the Fulmar Formation. Neither field has been developed. Limiting factors include the resource size, variable reservoir development (Beechnut), modest reservoir quality (Acorn North), compartmentalization concerns and development costs.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"29 1","pages":"349 - 359"},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73636971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Goldeneye Field, Blocks 14/29a and 20/4b, UK North Sea","authors":"N. Stewart, J. Marshall","doi":"10.1144/M52-2018-32","DOIUrl":"https://doi.org/10.1144/M52-2018-32","url":null,"abstract":"Abstract The Goldeneye gas-condensate field lies in the Moray Firth Basin in the UK Continental Shelf (UKCS) approximately 100 km off the NE coast of Scotland. The field was discovered in 1996 as a normally pressured accumulation with estimated gas-initially-in-place (GIIP) of 810 bcf with a thin oil rim in the Lower Cretaceous Captain Sandstone Member in a three-way, dip-closed structure. Field development included five production wells, with first gas achieved in 2004. Goldeneye was steadily produced under moderate aquifer support until cessation of production (COP) in 2010 following water breakthrough at the wells. Over its lifetime Goldeneye has produced 568 bcf of gas and 23 MMbbl of condensate. Around the time of COP, the UK Carbon Capture and Storage Commercialisation Competition was announced, and Goldeneye was evaluated as a candidate. The removal of significant volumes of hydrocarbons through production left remaining capacity that could be refilled without reservoir pressure significantly exceeding virgin conditions. However, following withdrawal of funding from the UK Government in 2015, the project was put on hold. Since then additional subsurface work has been conducted to support the successful abandonment of the development wells, which had previously been suspended since 2010.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"7 1","pages":"755 - 766"},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80141324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Rhyl Field, Block 113/27b, UK East Irish Sea","authors":"J. A. Patroni Zavala, M. Taylor, C. Tiltman, N. Sime","doi":"10.1144/M52-2018-84","DOIUrl":"https://doi.org/10.1144/M52-2018-84","url":null,"abstract":"Abstract The Rhyl Field is located in the offshore East Irish Sea Basin, approximately 30 km to the west of Barrow-in-Furness. Rhyl is one of the producing gas fields forming the Morecambe Hub development, operated by Spirit Energy. The Rhyl reservoir is the Ormskirk Sandstone Formation of Triassic age which regionally comprises four depositional facies types: aeolian, fluvial, sandflat and playa. The depositional system provides excellent reservoir properties that are impacted by a diagenetic history of authigenic illitization and quartz overgrowths. The northern boundary of the field is located underneath the Fleetwood Dyke Complex, resulting in significant imaging and depth-conversion uncertainty. This has been addressed by dyke mapping and manual depth corrections to seismic processing. The trapping mechanism at the southern boundary of the field is also unclear; the dip-closed structural spill point as mapped at the southern boundary appears shallower than the log-derived gas–water contact. Rhyl gas contains a significant inert content: 37% CO2 and 7% N2. The field's production rate has been limited to approximately 40 MMscfgd by the CO2 processing limit of the onshore gas terminal. Material balance studies have yielded a satisfactory understanding of connected gas in place, recoverable reserves and dynamic field behaviour.","PeriodicalId":84271,"journal":{"name":"Biological memoirs","volume":"36 1","pages":"334 - 345"},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79237834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}