Geological information and the inversion of seismic data

2005 ◽  
pp. 113-121
Author(s):  
Christophe Barnes ◽  
Marwan Charara ◽  
Albert Tarantola
Keyword(s):  
Seismic Data ◽  
Geological Information

Lithospheric structure in northwestern Canada from Lithoprobe seismic refraction and related studies: a synthesis

2005 ◽  
Vol 42 (6) ◽  
pp. 1277-1293 ◽  
Author(s):  
Ron M Clowes ◽  
Philip TC Hammer ◽  
Gabriela Fernández-Viejo ◽  
J Kim Welford
Keyword(s):  
Seismic Data ◽  
Seismic Refraction ◽  
Velocity Model ◽  
Wide Angle ◽  
Slave Craton ◽  
Reflection Data ◽  
Western Cordillera ◽  
Thermal Constraints ◽  
Geological Information ◽  
Tectonic Boundaries

The SNORCLE refraction – wide-angle reflection (R/WAR) experiment, SNORE'97, included four individual lines along the three transect corridors. A combination of SNORE'97 results with those from earlier studies permits generation of a 2000 km long lithospheric velocity model that extends from the Archean Slave craton to the present Pacific basin. Using this model and coincident near-vertical incidence (NVI) reflection data and geological information, an interpreted cross section that exemplifies 4 Ga of lithospheric development is generated. The velocity structural models correlate well with the reflection sections and provide additional structural, compositional, and thermal constraints. Geological structures and some faults are defined in the upper crust. At a larger scale, the seismic data identify a variety of orogenic styles ranging from thin- to thick-skinned accretion in the Cordillera and crustal-scale tectonic wedging associated with both Paleoproterozoic and Mesozoic collisions. Models of Poisson's ratio support the NVI interpretation that a thick wedge of cratonic metasediments underlies the eastern accreted Cordilleran terranes. Despite the variety of ages, orogenic styles, and tectono-magmatic deformations that are spanned by the seismic corridors, the Moho remains remarkably flat and shallow (33–36 km) across the majority of the transect. Significant variations only occur at major tectonic boundaries. Laterally variable crustal velocities are consistently slower beneath the Cordillera than beneath the cratonic crust. This is consistent with the high temperatures (800–900 °C) required by the slow upper mantle velocities (7.8–7.9 km/s) observed beneath much of the Cordillera. Heterogeneity of the lithospheric mantle is indicated by wide-angle reflections below the Precambrian domains and the western Cordillera.

Crustal structure and early Tertiary extensional tectonics of the Omineca belt at 51°N latitude, southern Canadian Cordillera

1996 ◽  
Vol 33 (12) ◽  
pp. 1596-1611 ◽  
Author(s):  
Bradford J. Johnson ◽  
Richard L. Brown
Keyword(s):  
Seismic Data ◽  
Shear Zones ◽  
Core Complex ◽  
Crustal Rocks ◽  
Early Tertiary ◽  
Geological Information ◽  
Extensional Strain ◽  
Palinspastic Restoration ◽  
Metamorphic Core ◽  
Normal Sense

A crustal cross section through the Omineca belt at the latitude of the Trans-Canada Highway has been drawn to satisfy available surface geological information and Lithoprobe seismic data from this part of the Cordilleran hinterland. Palinspastic restoration of Tertiary normal-sense shear zones leads to the conclusion that the Omineca belt at latitude 51°N was extended in the Eocene by approximately 45 km, 20–25% of the width of the belt. It is shown that the Okanagan–Eagle River fault, which defines the western margin of the Shuswap metamorphic core complex, is likely to have accommodated approximately 30 km of displacement. Restoration of this fault and of 15 km displacement on the Columbia River fault (eastern margin of the Shuswap complex) juxtaposes upper-crustal rocks with similar stratigraphic, structural, and metamorphic characteristics and indicates that the crust was over 50 km thick prior to Eocene extension. Comparison of the crustal geometry in the present and restored sections suggests that extensional strain was partitioned such that the upper crust was most highly attenuated above the central Shuswap complex, whereas the lower crust was most greatly stretched beneath the Intermontane and western Omineca belts.

scholarly journals SOUTH NATUNA BASIN RECONFIGURATION BASED ON RECENT SEISMIC AND GRAVITY SURVEYS

2019 ◽  
Vol 42 (2) ◽  
pp. 65-71
Author(s):  
Tatang Padmawidjaja ◽  
Yusuf Iskandar ◽  
Andy Setyo Wibowo ◽  
Eko Budi Lelono
Keyword(s):  
Seismic Data ◽  
Gravity Data ◽  
Sedimentary Rocks ◽  
Geological Structure ◽  
Seismic Survey ◽  
Seismic Region ◽  
Seismic Line ◽  
Geological Information ◽  
Survey Results ◽  
Basin Area

The Geological Survey Center has conducted a seismic survey in the southern Natuna Sea region to obtain geological information below relating to the potential energy resources of the area. The area research is located in the western part and outside the Singkawang Basin area (BG, 2008), which is separated by a Metamorf ridge. 2D seismic survey results show 3 different rock units, namely shallow marine sedimentary rocks, tertiary sedimentary rocks and pre-Tertiary sedimentary rocks, with pre-Tertiary sediment depths of less than 2000 ms. Interpretation of seismic data shows the pattern of graben structures that form sub-basins. strong refl ectors seen in seismic record can distinguish pre-rift, syn-rift and post-rift deposits. There are 2 wells, namely Datuk 1X and Ambu 1X. Datuk 1X has a depth of 1187 meters, and The Ambu 1X has a depth of 880 meters that is crossed by a seismic line. Both drilling has obtained Tertiary aged sandstone that covers pre-Tertiary bedrock.Gravity anomaly data in the seismic region shows anomaly values between 10 to 54 mgal which form the anomaly ridge and basinThe ridge anomaly extends as an anticline, while the anomaly basin also rises to form a syncline. Sincline and anticline trending southwest - southeast, with widening and narrowing patterns.Based on its geological model, the depth of the sediment is relatively shallow between 1500 to 2000 meters. While the integration between seismic, gravity and geomagnetic data shows the discovery of new basins that have never been described before.Finally, the integration of seismic and gravity data succeed discovers a new basin which has never been delineated before. In addition, it shows the continuity of the regional geological structure spanning from the studied area to the West Natuna Basin which is well known to be rich in hydrocarbon potential.

scholarly journals High-Resolution Seismic Data Deconvolution by A0 Algorithm

Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 497
Author(s):  
Fedor Krasnov ◽  
Alexander Butorin
Keyword(s):  
Inverse Problem ◽  
Seismic Data ◽  
Synthetic Data ◽  
Real Data ◽  
Resolving Power ◽  
New Information ◽  
Geological Information ◽  
The Matrix ◽  
Complex Models ◽  
Practical Development

Sparse spikes deconvolution is one of the oldest inverse problems, which is a stylized version of recovery in seismic imaging. The goal of sparse spike deconvolution is to recover an approximation of a given noisy measurement T = W ∗ r + W 0 . Since the convolution destroys many low and high frequencies, this requires some prior information to regularize the inverse problem. In this paper, the authors continue to study the problem of searching for positions and amplitudes of the reflection coefficients of the medium (SP&ARCM). In previous research, the authors proposed a practical algorithm for solving the inverse problem of obtaining geological information from the seismic trace, which was named A 0 . In the current paper, the authors improved the method of the A 0 algorithm and applied it to the real (non-synthetic) data. Firstly, the authors considered the matrix approach and Differential Evolution approach to the SP&ARCM problem and showed that their efficiency is limited in the case. Secondly, the authors showed that the course to improve the A 0 lays in the direction of optimization with sequential regularization. The authors presented calculations for the accuracy of the A 0 for that case and experimental results of the convergence. The authors also considered different initialization parameters of the optimization process from the point of the acceleration of the convergence. Finally, the authors carried out successful approbation of the algorithm A 0 on synthetic and real data. Further practical development of the algorithm A 0 will be aimed at increasing the robustness of its operation, as well as in application in more complex models of real seismic data. The practical value of the research is to increase the resolving power of the wave field by reducing the contribution of interference, which gives new information for seismic-geological modeling.

Stappen High-Bjørnøya tectono-sedimentary element, Barents Sea

2021 ◽  
pp. M57-2016-24
Author(s):  
F. Tsikalas ◽  
O. A. Blaich ◽  
J. I. Faleide ◽  
S. Olaussen
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Barents Sea ◽  
Seismic Reflection Data ◽  
Structural Inheritance ◽  
Reflection Data ◽  
Geological Information ◽  
Northern Portion ◽  
Early Cenozoic ◽  
Shallow Platform

AbstractThe Stappen High-Bjørnøya tectono-sedimentary element (TSE) is located in the western Barents Shelf and is one of the prominent tectonic elements in the area. The Stappen High comprises a shallow platform, and Bjørnøya forms its highest point with exposed outcrops. Modern seismic reflection data of improved quality in the southern part of the TSE and vintage seismic data in the northern portion are utilised. Together with updated geological information at Bjørnøya, the study provides insights into the Palaeozoic to early Cenozoic evolution of the Stappen High-Bjørnøya TSE. In this context, we discuss structural inheritance, the rift development, and we account for confirmed and potential hydrocarbon systems and plays.

Prestack Bayesian statistical inversion constrained by reflection features

Geophysics ◽  
2020 ◽  
pp. 1-98
Author(s):  
Bo Yu ◽  
Hui Zhou ◽  
Lingqian Wang ◽  
Wenling Liu
Keyword(s):  
Seismic Data ◽  
Field Data ◽  
Posterior Probability ◽  
Probability Distributions ◽  
Seismic Profile ◽  
Inversion Method ◽  
Reflection Coefficients ◽  
Geological Structures ◽  
Practical Applications ◽  
Geological Information

Bayesian statistical inversion can integrate diverse datasets to infer the posterior probability distributions of subsurface elastic properties. However, certain existing methods may suffer from two issues in practical applications, namely spatial discontinuities and the uncertainty caused by the low-quality seismic traces. These limitations are evident in prestack statistical inversion since some traces in prestack angle gathers may be missing or low-quality. We propose a prestack Bayesian statistical inversion method constrained by reflection features to alleviate these issues. Based on a Bayesian linearized inversion framework, the proposed inversion approach is implemented by integrating the prestack seismic data with reflection features. The reflection features are captured from the poststack seismic profile, and they represent the relationships of the reflection coefficients between different traces. By utilizing the proposed approach, we are able to achieve superior inversion results and to evaluate inversion uncertainty simultaneously even with the low-quality prestack seismic data. The results of the synthetic and field data tests confirm the theoretical and practical effects of the reflection features on improving inversion continuity and accuracy and reducing inversion uncertainty. Moreover, this work gives a novel way to integrate the information of geological structures in statistical inversion methods. Other geological information, which can be linearized accurately or approximately, can be utilized in this manner.

RECENT DISCOVERIES IN THE PYRENEES MEMBER, EXMOUTH SUB-BASIN: A NEW OIL PLAY FAIRWAY

2005 ◽  
Vol 45 (1) ◽  
pp. 233 ◽  
Author(s):  
J.P. Scibiorski ◽  
M. Micenko ◽  
D. Lockhart
Keyword(s):  
Seismic Data ◽  
Joint Venture ◽  
Depositional Environments ◽  
3D Seismic ◽  
High Quality ◽  
Gas Field ◽  
Geological Information ◽  
Key Factor ◽  
Complex Structural ◽  
3D Seismic Data

Recent drilling by BHP Billiton Pty Ltd in WA-155-P(1) and WA-12-R, on behalf of its partners Apache Energy Ltd and INPEX ALPHA LTD, has resulted in the discovery of four oil fields in the southern Exmouth Sub-basin, namely Ravensworth, Crosby, Stickle and Harrison. These discoveries, together with the earlier discoveries made by West Muiron–5 and Pyrenees–2, define the Early Cretaceous Pyrenees Member play fairway.The Pyrenees Trend play was first conceived in 1999 following appraisal of the Macedon gas field (Keall, 1999), but the concept remained dormant until the integration of geological information with high quality 3D seismic data led to the recognition of hydrocarbon related seismic attributes in the postulated play fairway.Ravensworth–1 intersected a 37 m gross oil column below a 7 m gas cap in high quality Pyrenees Member sandstones beneath the regionally significant Intra- Hauterivian Unconformity. Ravensworth, located on a northeast–southwest trending fault terrace, is a complex structural-stratigraphic trap that relies on separate top, base and cross-fault seals. High quality 3D seismic data coupled with recent interpretation techniques were integral to its discovery. In particular, the quantitative interpretation of seismic amplitude populations was a key factor in decreasing exploration risk.The Ravensworth discovery was followed by successful exploration wells on the adjacent Crosby, Stickle and Harrison fault terraces. Four appraisal wells have since been drilled at the northern ends of the main discoveries.The oil in the Pyrenees Member discoveries is biodegraded, moderately viscous (8–11 cp) and heavy (18–19° API gravity). Methane-dominated gas caps were intersected in Ravensworth–1, West Muiron–5 and Pyrenees–2.The recent drilling and coring campaigns by BHP Billiton and others in the Exmouth Sub-basin have significantly advanced knowledge of the stratigraphy and depositional environments of the late Tithonian to early Berriasian Macedon, Muiron and Pyrenees Members of the lower Barrow Group. The lower Barrow Group is a third order sequence deposited rapidly in marine to fluviodeltaic environments in response to the breakup of Gondwana and the onset of active rifting along the West Australian margin.BHP Billiton and its joint venture partners are assessing the commercial viability of the Pyrenees Trend discoveries.

ADVANCES IN RISKING EXPLORATION PROSPECTS

2005 ◽  
Vol 45 (1) ◽  
pp. 143 ◽  
Author(s):  
D.C. Lowry ◽  
R.J. Suttill ◽  
R.J. Taylor
Keyword(s):  
Seismic Data ◽  
Information Needs ◽  
Column Height ◽  
Limited Data ◽  
Technical Literature ◽  
Geological Information ◽  
Level Of Knowledge ◽  
The Subject ◽  
Reserve Size ◽  
Exploration Activity

Assessment of prospect risk is a vital exploration activity, but technical literature on the subject shows few advances in methodologies in the last 20 years. Origin Energy has found that published procedures are not always adequate. Three perceived shortcomings are examined and techniques are proposed to overcome them.Cases where prospect risk is dependent on reserve size. Traditional methodologies assume the two are independent. This assumption is clearly inappropriate for, say, a prospect for which the success case value is based on the mapped closure, but which has suspect seal capacity that may limit the column height to something less than full-to-spill. A way forward is to build a variable risk array for a range of column heights and calculate the incremental risked NPV for each layer. The expected monetary value (EMV) is computed for a range of column heights based on the NPV of cumulative risked reserves;Cases where the estimation of chance of success (COS) based on traditional geological information needs to be combined with direct hydrocarbon indicators (DHIs) from seismic data. DHIs are not infallible indicators, however, and cannot be used to set the COS for elements such as charge to say 100%. Bayes’ Theorem can be used to combine the two sets of uncertain information.Cases where prospects are risked on very limited data. Traditional risking does not adequately incorporate the level of knowledge on which risk assessments are made. Inadequacies are identified in existing methodologies, but no simple and satisfactory solutions can be identified. We do suggest a way forward, however, for a related problem—testing the sensitivity of the EMV calculation for an exploration prospect for uncertainties in COS.

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