DEPOSITIONAL SEQUENCE MODEL FOR THE POST-BARROW GROUP NEOCOMIAN SUCCESSION, BARROW AND EXMOUTH SUB-BASINS, WESTERN AUSTRALIA

1993 ◽  
Vol 33 (1) ◽  
pp. 151
Author(s):  
Peter A. Arditto
Keyword(s):  
Seismic Data ◽  
Sensu Stricto ◽  
Well Log ◽  
Depositional Sequence ◽  
Sequence Stratigraphic ◽  
Exmouth Plateau ◽  
Stratigraphic Analysis ◽  
Cast Doubt ◽  
Well Data ◽  
Stratigraphic Nomenclature

Structural traps at the top 'Barrow Group' are the most successful oil exploration targets in the Barrow/Exmouth Sub-basins. However, a reinterpretation of recent exploration activities undertaken by BHP Petroleum Pty Ltd, combined with regional investigations on the Exmouth Plateau, has cast doubt on the validity of accepted stratigraphic nomenclature for the Neocomian succession. A more geologically rational subdivision of the upper part of the Neocomian succession into two discrete sequence stratigraphic units is proposed.Key seismic data from the Exmouth Plateau, tied into wells with good age control, have enabled precise recognition of the Intra-Valanginian Unconformity within the currently-defined Barrow Group. The Barrow Group (sensu stricto) is redefined in this paper as the Barrow Megasequence (restricted to a Berriasian age succession), comprising a rapid progradational phase, which was abruptly terminated by the Intra-Valanginian event.Local erosion of the Barrow Megasequence along the Novara Arch through an Early Valanginian uplift, during the ensuing Valanginian regional transgression, contributed to the development of a parasitic clastic wedge, previously referred to as the Upper Barrow Delta on the Exmouth Plateau and here named the Zeepaard Sequence, with a nominated section in Zeepaard-1. The Zeepaard sequence is terminated by a Top Valanginian unconformity, upon which a final deltaic clastic pulse was deposited as the Birdrong Sequence. Each successive clastic wedge had a more limited development, with the basinward progradation terminating well short of the underlying stratigraphic unit. The Birdrong Sequence was terminated by an Intra-Hauterivian unconformity upon which the highly glauconitic, thin, Mardie Greensand Member of the Muderong Sequence was developed.The Zeepaard Sequence and overlying Birdrong Sequence can be characterised using both seismic and well log character. Well data in particular has enabled detailed stratigraphic mapping of the Birdrong Sequence which is thin and generally not seismically resolvable across the Barrow Sub-basin. This paper presents a detailed sequence stratigraphic analysis of the Birdrong Sequence using well log data.

Application of Seismic Sequence Stratigraphy for Delineating Mishrif Prospects in Western Onshore, Abu Dhabi, UAE

2021 ◽  
Author(s):  
Subrata Chakraborty ◽  
Monica Maria Mihai ◽  
Nacera Maache ◽  
Gabriela Salomia ◽  
Abdulla Al Blooshi ◽  
...  
Keyword(s):  
Abu Dhabi ◽  
Seismic Sequence ◽  
Large Area ◽  
Oil Accumulation ◽  
Sequence Stratigraphic ◽  
Stratigraphic Analysis ◽  
Seismic Sequence Stratigraphy ◽  
Well Data ◽  
Seismic Reflectors ◽  
Sweet Spots

Abstract In Abu Dhabi, the Mishrif Formation is developed in the eastern and western parts conformably above the Shilaif Formation and forms several commercial discoveries. The present study was carried out to understand the development of the Mishrif Formation over a large area in western onshore Abu Dhabi and to identify possible Mishrif sweet spots as future drilling locations. To achieve this objective, seismic mapping of various reflectors below, above, and within the Mishrif Formation was attempted. From drilled wells all the available wireline data and cores were studied. Detailed seismic sequence stratigraphic analysis was carried out to understand the evolution of the Mishrif Formation and places where the good porosity-permeability development and oil accumulation might have happened. The seismic characters of the Mishrif Formation in dry and successful wells were studied and were calibrated with well data. The Mishrif Formation was deposited during Late Cretaceous Cenomanian time. In the study area it has a gross thickness ranging from 532 to 1,269 ft as derived from the drilled wells; the thickness rapidly decreases eastward toward the shelf edge and approaching the Shilaif basin. The Mishrif was divided into three third-order sequences based on core observations from seven wells and log signatures from 25 wells. The bottom-most sequence Mishrif 1.0 was identified is the thickest unit but was also found dry. The next identified sequence Mishrif 2.0 was also dry. The next and the uppermost sequence identified as Mishrif 3.0 shows a thickness from 123 to 328 ft. All the tested oil-bearing intervals lie within this sequence. This sequence was further subdivided into three fourth-order sequences based on log and core signatures; namely, Mishrif 3.1, 3.2, and 3.3. In six selected seismic lines of 181 Line Km (LKM) cutting across the depositional axis, seismic sequence stratigraphic analysis was carried out. In those sections all the visible seismic reflectors were picked using a stratigraphic interpretation software. Reflector groups were made to identify lowstand systems tract, transgressive systems tract, maximum flooding surface, and highstand systems tract by tying with the observations of log and core at the wells and by seismic signature. Wheeler diagrams were generated in all these six sections to understand the lateral disposition of these events and locales of their development. Based on stratigraphic analysis, a zone with likely grainy porous facies development was identified in Mishrif 3.0. Paleotopography at the top of Mishrif was reconstructed to help delineate areas where sea-level fall generated leaching-related sweet spots. Analysis of measured permeability data identified the presence of local permeability baffles affecting the reservoir quality and hydrocarbon accumulation. This study helped to identify several drilling locations based on a generic understanding of the Mishrif Formation. Such stratigraphic techniques can be successfully applied in similar carbonate reservoirs to identify the prospect areas.

THE FORTESCUE FIELD - NEW OIL IN THE GIPPSLAND BASIN

1980 ◽  
Vol 20 (1) ◽  
pp. 130
Author(s):  
R.C.N. Thornton ◽  
B.J. Burns ◽  
A.K. Khurana ◽  
A.J. Rigg
Keyword(s):  
Seismic Data ◽  
Sufficient Information ◽  
Well Log ◽  
Geochemical Analysis ◽  
Water Contact ◽  
Pricing Policy ◽  
Stratigraphic Analysis ◽  
Oil Water ◽  
Oil Pricing ◽  
Gippsland Basin

The Fortescue-1 well drilled in the Gippsland Basin in June 1978 was a dry hole. However, results of detailed stratigraphic analysis together with seismic data provided sufficient information to predict the possible occurrence of a stratigraphic trap on the flank of the giant Halibut structure.Three months later the West Halibut-1 well encountered oil in the Latrobe Group 16 m below that depth carried as the original oil-water contact for the Halibut field. Following wireline testing in both the water and oil-bearing sandstone units, two separate pressure systems were recognised in the well. Three additional wells, Fortescue-2, 3 and 4, were drilled to define further the limits of the field, the complex stratigraphy and the hydrocarbon contacts.Integration of detailed well log correlations, stratigraphic interpretations and seismic data indicated that the Fortescue reservoirs were a discrete set of units stratigraphically younger and separated from those of Halibut and Cobia Fields. Analysis of pressures confirmed the presence of two separate pressure systems, proving none of the Fortescue reservoirs were being produced from the Halibut platform. Geochemical analysis of oils from both accumulations supported the above results, with indications that no mixing of oils had occurred.Because the Fortescue Field is interpreted as a hydrocarbon accumulation which is completely separated from both Halibut and Cobia Fields, and was not discovered prior to September 17, 1975, it qualified as "new oil" under the Federal Government's existing crude oil pricing policy. In late 1979, the Federal Government notified Esso/BHP that oil produced from the Fortescue Field would be classified as “new oil”.

scholarly journals Stratigraphic analysis and calculation of reserves in the Colorado field, MMV, Colombia

2016 ◽  
pp. 24-31
Author(s):  
Ricardo Mier-Umaña ◽  
Tania Sarith Palmera Henao ◽  
Juan Sebastian Luna-Osorio ◽  
Leidy Alexandra Delgado-Blanco
Keyword(s):  
Oil And Gas ◽  
Well Log ◽  
Stratigraphic Analysis ◽  
Original Oil In Place ◽  
Log Interpretation ◽  
Well Data ◽  
Fluvial Environments ◽  
Well Log Interpretation

Based on review of previous information and correlation of 7 lithostratigraphic sections from well data, it was possible to establish the presence of channels in fluvial environments of the Mugrosa Formation, with good lateral continuity, in the B and C zones, in the Middle Magdalena Valley Basin (VMM). The results of well log interpretation (NSP logs) indicate the presence of channel sands and proved the previous sedimentological model of the field. In the sedimentological model proposed, zones B and C (Mugrosa Formation) show a very good lateral continuity of sands. The reserve calculations of original oil in place (OOIP) and original gas in place (GOES) indicates that the largest reserves of oil and gas are located in the zone C, with reserves of 118 million bbl and 33.9 Gigas of cubic feet respectively.

THE EASTERN OTWAY BASIN WANGERRIP GROUP REVISITED USING AN INTEGRATED SEQUENCE STRATIGRAPHIC METHODOLOGY

1995 ◽  
Vol 35 (1) ◽  
pp. 372 ◽  
Author(s):  
P. A. Arditto
Keyword(s):  
Seismic Data ◽  
Well Log ◽  
Third Order ◽  
Traditional Methods ◽  
Depositional History ◽  
Sequence Stratigraphic ◽  
Reflection Seismic ◽  
Stratigraphic Subdivision ◽  
History Of ◽  
Definition Of

Recent exploration by BHP Petroleum in VIC/ P30 and VIC/P31, within the eastern Otway Basin, has contributed significantly to our understanding of the depositional history of the Paleocene to Eocene siliciclastic Wangerrip Group. The original lithostratigraphic definition of this group was based on outcrop description and subsequently applied to onshore and, more recently, offshore wells significantly basinward of the type sections. This resulted in confusing individual well lithostratigraphies which hampered traditional methods of subsurface correlation.A re-evaluation of the Wangerrip Group stratigraphy is presented based on the integration of outcrop, wireline well log, palynological and reflection seismic data. The Wangerrip Group can be divided into two distinct units based on seismic and well log character. A lower Paleocene succession rests conformably on the underlying Maastrichtian and older Sherbrook Group, and is separated from an overlying Late Paleocene to Eocene succession by a significant regional unconformity. This upper unit displays a highly progradational seismic character and is named here as the Wangerrip Megasequence.Regional seismic and well log correlation diagrams are used to illustrate a subdivision of the Wangerrip Megasequence into eight third-order sequences. This sequence stratigraphic subdivision of the Wangerrip Group is then used to construct a chronostratigraphic chart for the succession within this part of the Otway Basin.

DEPOSITIONAL SEQUENCE OF THE WITHNELL FORMATION, DAMPIER SUB-BASIN

1995 ◽  
Vol 35 (1) ◽  
pp. 296
Author(s):  
J. S. Rasidi
Keyword(s):  
Late Cretaceous ◽  
Seismic Data ◽  
Depositional Environment ◽  
Thickness Distribution ◽  
Well Logs ◽  
Hydrocarbon Potential ◽  
Depositional Sequence ◽  
Well Data ◽  
Water Depths ◽  
Reservoir Facies

The Late Cretaceous Withnell Formation has attracted very little exploration attention because of the perception that it has poor hydrocarbon potential. This unfavourable perception has arisen from the fact that very little is known about its depositional environment and lithofacies and therefore, its petroleum prospectivity.A sudden fall of relative sea level occurred at the end of the Santonian, and was followed by the deposition of the siliciclastic Withnell Formation. The occurrence of a number of channels and canyons at the base of the formation, over the old shelf and slope on the southern margin of the sub-basin, supports the hypothesis that the Withnell Formation began as a lowstand systems tract. The thickness distribution of the formation and the progradation direction of seismic packages suggest a southeasterly provenance. Correlation of seismic data and well logs, and rock descriptions demonstrate the presence of units deposited during increasing water depths and subsequent highstand systems tract.Much more information, both seismic and well data, is required to establish the facies distribution within the Withnell Formation which may contain sand-prone lowstand facies such as basinfloor or slope fans. The presence of such reservoir facies would enhance the petroleum prospectivity of the Withnell Formation.

A SEQUENCE STRATIGRAPHIC DEPOSITIONAL MODEL OF NEOPROTEROZOIC STRATA, YOWALGA AREA, OFFICER BASIN,WESTERN AUSTRALIA

2000 ◽  
Vol 40 (1) ◽  
pp. 15 ◽  
Author(s):  
S.N. Apak ◽  
H.T. Moors
Keyword(s):  
Seismic Data ◽  
Sequence Stratigraphic ◽  
Petroleum Systems ◽  
Stratigraphic Analysis ◽  
Regional Correlation ◽  
Depositional Settings ◽  
Potential Reservoir ◽  
Storm Wave ◽  
Flooding Events ◽  
Stacking Patterns

Additional data and further studies have now improved geological, geophysical, and geochemical understanding of the Neoproterozoic strata of the Officer Basin. New sequence stratigraphic analysis of continuously cored drillholes (particularly Empress–1/1A), extended throughout the area with wireline log and seismic correlations, provide enhanced recognition of depositional fades and thus basin architecture. Four major flooding events and fifteen sedimentary successions, interpreted as parasequence sets by regional correlation, are recognised across the Yowalga area. These parasequence sets are traceable using seismic data, with flooding events identified on cores and logs producing regional or local reflectors with good amplitude and continuity.Sedimen tary cycles are dominantly mixed carbonates- siliciclastics with primarily progradational stacking patterns. These imply transgressive and regressive cycles in a basin with low bathymetric relief. Depositional settings range from supratidal to just below storm wave base.This interpretation improves the prediction of potential petroleum systems. An architectural model for each formation allows prediction of depositional trends including potential reservoir, source rock and seal in the Yowalga area.

Seismic depositional sequence characterization by using enhanced multi-channel variational mode decomposition

2021 ◽  
pp. 1-61
Author(s):  
Yajun Tian ◽  
Jinghuai Gao
Keyword(s):  
Seismic Data ◽  
Field Data ◽  
Scale Space ◽  
Space Representation ◽  
Variational Mode Decomposition ◽  
Depositional Sequence ◽  
Sequence Characterization ◽  
Sequence Stratigraphic ◽  
Mode Decomposition ◽  
Seismic Sequence Stratigraphy

For the seismic stratigraphy, a key issue is distinguishing the characteristics of seismic reflections generated by geological events with different scales, which in turn assists the sequence stratigraphic interpretation. The data-driven signal decomposition approaches, like variational mode decomposition (VMD) and multi-channel variational mode decomposition (MVMD), can utilize waveform similarity to decompose seismic data into several IMFs. Unfortunately, it is a hard task to define the number of IMFs. To overcome the shortcoming of the previous works, we constructed an enhanced multi-channel variational mode decomposition (EMVMD) and then proposed a workflow to decompose seismic data. We first explained the relationship between the IMFs and structures with different scales. Then, we proposed a method to set the number of IMFs by introduce the contraction operator mapping (COM) and the scale-space representation (SSR). Finally, we provided a workflow and applied it to synthetic and field data to identify seismic sequence stratigraphy boundaries. Synthetic and field data examples show that our workflow preserves lateral continuity and precisely extracts IMFs caused by depositional sequences with different geologic scales, facilitating the interpretation of subtle depositional patterns.

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