The middle jurassic brent group of the northern north sea presents a mature and highly productive reservoir play fairway where a combination of effective facies analysis and depositional sequence stratigraphy offers real potential to optimize exploitation. The stratigraphy and main facies of the brent group in the oseberg. Accounts of the geology of individual brent group fields are not included, as these are. The problem can be as simple as a recorrelation to explain pressure miscommunication between wells, or as complex as predicting the distribution of sweet spots within an unconventional mixed carbonatesiliciclastic succession. Facies variability within a mixed carbonatesiliciclastic. Abstract not available bibtex entry for this abstract preferred format for this abstract see preferences. Classic brent stratigraphy tarbert ness etive rannoch broom mid ness shale upper brent lower brent. Petrographic evaluation of the middle jurassic sandstones.
Sequence stratigraphy as a concrete stratigraphic discipline abstract sequence stratigraphy is a stratigraphic discipline in which stratigraphic surfaces that represent changes in depositional trend are used for correlation and for defining specific types of sequence stratigraphic units. Geology, sequence stratigraphy, and oil and gas assessment of. The ones marked may be different from the article in the profile. Nov 12, 20 despite a number of publications dealing with the sequence stratigraphy of the brent group, regional interpretation remains less than straightforward. The structural and stratigraphic evolution of the north sea rift system is described, from the onset of prerift thermal uplift in the aalenian to the failure of the rift system caused by the transfer of extension out onto the atlantic margin during the neocomian.
Controls on the distribution, geometry, connectivity and orientation of sandbodies within the reservoir have been assessed via the application of highresolution sequence stratigraphic methods to an integrated dataset comprising. The stratigraphy of the great valley sequence has been the subject of much work, but problems, particularly nomenclatural, remain. The sequence part of the name refers to cyclic sedimentary deposits. Petrographic evaluation of the middle jurassic sandstones of the brent group, north sea a petrographic study of the ness, etive and rannoch formations. Paleogeographic reconstruction of facies belts at precise moments in time is the goal of the sequence stratigrapher. The broom formation overlies a basal brent sequence boundary and is a lowstand to transgressive systems tract tidalestuarine complex.
Sequence stratigraphy is concerned with the largescale, threedimensional arrangement of sedimentary strata, and the major factors that influence their geometries such as sealevel change, contemporaneous fault movements, basin subsidence and sediment supply cf. Sequence stratigraphy of source and reservoir rocks in the. High and low resolution sequence stratigraphy in lithological. In western newfoundland, a cambrian to ordovician sequence of shale and carbonates cow head group is preserved in several allochthonous thrust sheets humber arm allochthon that represent a transect across the continental slope james and stevens, 1986. Controls on facies architecture in the brent group. Nevertheless, the sequence stratigraphic significance of certain facies is sometimes overlooked, and an overview of facies interpretations is a helpful foundation for describing brent architecture and sequence stratigraphy. Trajectory analysis of the lower brent group jurassic, northern north sea.
The bottom three represent facies contacts developed within systems tracts. L sequence stratigraphy and palaeogeography of the middle jurassic brent and vestland deltaic systems, northern north sea. Bibtex entry for this abstract preferred format for this abstract see preferences find similar. A sequence stratigraphic framework was erected for the clinton group by brett and others. This surface marks the most landward position of the shoreline within a sequence, and typically, the deepest water facies within a sequence. Use of palynofacies characterization in sanddominated. Pdf sequence stratigraphy and palaeogeography of the. This paper was part of the sequence stratigraphy research project at the university of bergen, norway, and is a product of studies on the architecture. This cited by count includes citations to the following articles in scholar. Xujiaweizi rift lower cretaceous yingcheng group volcanic. Sedimentary tectonics of the jurassic sedimentary sequence in the northern viking rift graben. Pdf sequence stratigraphy and palaeogeography of the middle.
Detailed stratigraphy and facies analysis of the paleoproterozoic athabasca group along the shea creek. Sequence stratigraphy of the lower jurassic dunlin group. Controls on the distribution, geometry, connectivity and orientation of sandbodies within the reservoir have been assessed via the application of highresolution sequence stratigraphic methods to an integrated dataset comprising core. Posamentier exxon production research company houston, texas and p. Pdf the depositional history of the brent delta system can be analysed. Vail riceuniversity, houston, texas it is important to establish the fundamental concepts of sequence stratigraphy and to define terminology critical for the communication of these concepts. Stratigraphic framework for the lower cretaceous upper. Sequence stratigraphy and palaeogeography of the middle jurassic brent and vestland deltaic systems, n orthern north sea erik fjellanger, tina r. We have focused on the upper permian and uppermost triassic jurassic successions where the presence of source and reservoir rocks are well documented from previous studies.
Sedimentology and sequence stratigraphy of the middle. Viking group, which is situated above the prolific brent group. North sea, but also the brent group broom, rannoch, etive and tarbert formations of the northern north sea. Walton 1996 was the first to apply sequence stratigraphic concepts to cherokee group strata, concluding that numerous sequences exist. Differential subsidence in the ness formation foreninger ved uio. Northern front range foothills, colorado by karl m.
Differential subsidence in the ness formation bajocian. Role of forced regression in controlling brent group. Idealized succession of lowstand, transgressive, and highstand sequence. Fenton sequence stratigraphic analyses of the lower jurassic dunlin group of the north viking graben provides a consistent basinwide framework for a better understanding of the sedimentary facies distributions. Establishment of a magnetostratigraphic framework for sequence stratigraphic modelling of the fluvial reservoirs in the lunde formation 251 c. The brent group is the top of the prerift sequence of the. Figure 2 therefore provides a tabulated and graphical summary of the principal facies relevant to the study area. Xujiaweizi rift lower cretaceous yingcheng group volcanic sequence stratigraphic features 437 traditional sequence stratigraphy is difficult to find and compare. Marine flooding surface separating the underlying transgressive systems tract from the overlying highstand systems tract. These facies are grouped into six spatially recurring facies associations. Alongside 3d seismic, longreach horizontal drilling and the application of plate tectonics to exploration, sequence stratigraphy has been one of the greatest scientific advances within the petroleum geology industry of the last 50 years. The regional development of the middle jurassic brent group northern north sea has been studied within a sequence stratigraphic framework, and four depositional sequences exxonian have been.
Middle jurassic magnetopolarity stratigraphy of a wellcore from the brent group, north sea. Lundschien the distal sandstone pinchout of the mesa verda group, san juan basin and its relevance for sandstone prediction of the brent. Exploration play analysis from a sequence stratigraphic. Through examination of the scaling relations of faults and the use of seismic stratigraphic techniques, we demonstrate how the temporal and spatial evolution of the fault population in a halfgraben basin can be accurately reconstructed. Jul 01, 2003 the brent group reservoir in the strathspey field, uk north sea comprises shallow marine, marginal marine and nonmarine strata of variable reservoir character. Building blocks of the sequence stratigraphic framework fundamental principles a sequence stratigraphic framework may consist of three dif. Sequence boundary fill pup22s1 mid ness shale bay mudstone 200 ft. Synsedimentary tectonics of the jurassic sedimentary. Application of highresolution sequence stratigraphy to northwest hutton field, northern north sea.
Sequence stratigraphy, sea level change and palaeoenvironments via chemostratigraphy. Appraising a late middle aged brent group field reservoir learnings after nearly 20 years of pelican field production. The subzone comprises relatively coarsegrained and pebbly sandstones deposited as a series of subtidal channels and associated sublittoral sheet and shoalmargin sequences. Review and computer modelling of the brent group stratigraphy. The geometries and so stacking patterns of uncemented carbonates and clastics. In this context, we present a regional, highresolution sequence stratigraphic framework for the brent group, uk north sea based on extensive sedimentological reinterpretation of core and wirelinelog data, combined with palynostratigraphy and published literature.
Sequence stratigraphy and palaeogeography of the middle. Implications for management of a mature brent group field 1. Formation and overlying brent group are marked by sharp breaks in the welllog curves, as are the. Pdf the regional development of the middle jurassic brent group northern north sea has been studied within a sequence stratigraphic framework, and. Sequence stratigraphy deals with genetically related sedimentary strata bounded by unconformities. Advances in sequence stratigraphy and the development of depositional models have helped explain the. Sequence stratigraphy and palaeogeography of the middle jurassic. Sedimentology and sequence stratigraphy of the thistle field.
The lowest sequence in the athabasca group, the shea creek sequence. Also worthy perhaps of mention is the separate large reservoir underneath the brent group where oil and gas are present in the statfjord group sandstones of latest triassic age. Role of forced regression in controlling brent group reservoir. This online guide is primarily aimed at the application of sequence stratigraphy to outcrops. The brent group reservoir in the strathspey field, uk north sea comprises shallow marine, marginal marine and nonmarine strata of variable reservoir character. A biostratigraphic, strontium isotopic and lithostratigraphic study of the upper part of hordaland group and lower part of nordland group in well 3472, 34712 and 347r1 h from the tordis field in the tampen area northern north sea. A basinwide sequence stratigraphy for the middle jurassic has been developed, comprising two tectonostratigraphic units j20, aalenianlate bajocian and j30. The ness formation bajocian consists of the alluvial distributary plain deposits of the middle jurassic brent delta. Stratigraphy is the geologic knowledge about the processes by which sedimentary deposits form and how those deposits change through time and space on the earths surface. The basin bounded by the 62 km long strathspey brent statfjord fault array is located on the western. The mesaverde group in the san juan basin was deposited on the western shelf of the epicontinental cretaceous.
Ironstones, condensed beds, and sequence stratigraphy of the. The prograding rannoch and etive formations of the brent group show a uniform. Dakota group in northern front range foothills, colorado. A magnetopolarity stratigraphy has been constructed by detailed palaeomagnetic investigations of a wellcore covering the middle jurassic brent group, north sea.
Accordingly, such studies 43 sequence stratigraphy of source and reservoir rocks in the upper permian and jurassic of. The regional development of the middle jurassic brent group northern north sea has been studied within a sequence stratigraphic framework, and four. Sedimentology and sequence stratigraphy of the middleupper jurassic krossfjord and fensfjord formations, troll field, northern. Our sequences are interpreted from a combination of lithostratigraphic, biostratigraphic and seismic stratigraphic correlation. Sequence stratigraphy and coal cycles based on accommodation trends were investigated in the coalbearing lower cretaceous mannville group in the lloydminster heavy oil field, eastern alberta. Idealized succession of lowstand, transgressive, and highstand sequence sets.
Sequence stratigraphy material for this chapter are mainly from the following articles. Middle jurassic magnetopolarity stratigraphy of a wellcore. The components of the creaming curve refer to systems tract or sequence set, depending upon the size and scale of the play being considered. The tectono stratigraphic evolution of the northern north sea is class into three main stages. We specialize in solving geologic problems encountered in the oil and gas and mining sector. He has held positions in both academia and industry, and is a current academician in the russian academy of science. This note summarizes the results of further studies that support this lower position for the boundary. Regional to global correlations by amina mabrouk1, ian jarvis2, habib belayouni1, amanda murphy2, and richard t.
To establish the depositional setting of the sedimentary section, sequence stratigraphy uses the geometric arrangement of sedimentary fill, particularly the vertical succession of sedimentary facies geometries and their enveloping surfaces known as stacking satterns. The regional development of the middle jurassic brent group northern north sea has been studied within a sequence stratigraphic framework, and four depositional sequences exxonian have been recognized. Combined low and high resolution sequence stratigraphy can be used in largescale lithological prediction and comparison between systems situated far apart, and in detailed withinsystem predictions on a reservoir scale. Sequence stratigraphy is a working methodology that. With this paper we summarize in part, and build upon, the work published by catuneanu et al. It usually involves subdividing a sedimentary basin fill into individual sequence s of deposition hence the name, which can then be linked to changes in the two fundamental parameters of sediment supply and accommodation the amount of space available for deposition.
The implication is that in several regional stratigraphic frameworks. The connectivity and production characteristics of these sandstones can be predicted through the application of highresolution sequence stratigraphic correlation techniques. In particular, when the volcanic eruption is strong and multistage, the phase sequence changes further complicated in the horizontal and vertical. Trajectory analysis of the lower brent group jurassic.
Field work during the summer of 1993 included biostratigraphic, sedimentological and sequence strati. Such withintrend facies contacts may be marked on a sequence stratigraphic crosssection only after the sequence stratigraphic framework has been constructed. The north of the brent province differs from classically studied southern areas in being dominated by marginalmarine deltafront facies. Waage a shorter contribution to general geology geological survey professional paper 274b a revised subdivision and terminology for the dakota group and local details of its stratigraphy united states government printing office, washington. Idealized creaming curve from a sequence stratigraphic perspective.
As a result, none of the examples deal with topics related specifically to cores, well logs, or most significantly, seismic. Sequence stratigraphy as a sequence stratigraphy as a. Practical sequence stratigraphy was originally published as a fifteenpart series in the canadian society of petroleum geologists monthly magazine, the reservoir, between may 2008 and september 2009. In the late 1970s, seismic data was interpreted stratigraphically to define packages of strata hundreds of meters thick that were deposited between sea level cycles that lasted 0. Published online by the canadian society of petroleum. This has allowed a chronostratigraphical subdivision of the ravenscar group and enabled regional correlation of the constituent formations with coeval sediments of similar facies of the north viking graben brent group and offshore midnorway fangst group. Sequence stratigraphy american association of petroleum.
Tectonostratigraphic evolution of the brage fault zone. Ashton embry for his work in making this series possible. Dunlin group and represents a separate depositional phase to the main brent progradational shorefacedeltaic sequence. The study area is in a low accommodation setting on the cratonic margin of the western canada sedimentary basin. Sequence stratigraphy is a methodology that employs stratal stacking patterns and key bounding surfaces to erect a framework allowing depositional facies to mapped and interpreted paleogeographically. Trajectory analysis of the brent group jurassic, northern north sea. The north of the brent province differs from classically studied southern areas in being dominated by marginalmarine deltafront. Dunlin group sequence stratigraphy in the northern north sea. Even though the physical dimensions of the outcrop might be fairly.78 1058 935 86 46 155 808 1078 1645 870 596 502 1581 1032 1168 745 629 1079 1237 1414 708 921 311 130 443 597 1215 877 728 1272