An amplitude-based multiazimuthal approach to mapping fractures using P-wave 3D seismic data

Geophysics ◽  
2004 ◽  
Vol 69 (3) ◽  
pp. 690-698 ◽  
Author(s):  
Mu Luo ◽  
Brian J. Evans
Keyword(s):  
Physical Model ◽  
Seismic Data ◽  
Single Layer ◽  
P Wave ◽  
Data Sets ◽  
Test Results ◽  
Amplitude Versus Offset ◽  
Sorting Process ◽  
Seismic Reflections ◽  
3D Seismic Data

We have tested an amplitude-based multiazimuthal approach for mapping fractures which requires only a simple azimuth-offset sorting process. By displaying the amplitudes of all traces collected within a superbin, the method predicts fractures by mapping P-wave amplitude variations, in which a lineation within the map indicates the presence and the orientation of fractures within the superbin. Test results using physical model and field data sets suggest that the amplitude-based multiazimuthal approach could help to determine the presence of multiple fracture sets in a single layer, which may be expressed through subtle variations in P-wave multiazimuthal seismic reflections. Our experiments with a physical model containing manmade vertical fractures suggest that transmission effects could be one of the dominant factors which control azimuthal amplitude versus offset (AVO) behavior. The technique described in this paper can operate on any 3D P-wave seismic data with wide azimuth and offset distributions.

Extensive, Gas-charged Quaternary Sand Accumulations of the Northern North Sea and North Sea Fan

2020 ◽  
Author(s):  
Benjamin Bellwald ◽  
Sverre Planke ◽  
Sunil Vadakkepuliyambatta ◽  
Stefan Buenz ◽  
Christine Batchelor ◽  
...  
Keyword(s):  
North Sea ◽  
Seismic Data ◽  
Data Sets ◽  
3D Seismic ◽  
Fine Grained ◽  
The North ◽  
Northern North Sea ◽  
Well Data ◽  
Sea Fan ◽  
3D Seismic Data

<p>Sediments deposited by marine-based ice sheets are dominantly fine-grained glacial muds, which are commonly known for their sealing properties for migrating fluids. However, the Peon and Aviat hydrocarbon discoveries in the North Sea show that coarse-grained glacial sands can occur over large areas in formerly glaciated continental shelves. In this study, we use conventional and high-resolution 2D and 3D seismic data combined with well information to present new models for large-scale fluid accumulations within the shallow subsurface of the Norwegian Continental Shelf. The data include 48,000 km<sup>2</sup> of high-quality 3D seismic data and 150 km<sup>2</sup> of high-resolution P-Cable 3D seismic data, with a vertical resolution of 2 m and a horizontal resolution of 6 to 10 m in these data sets. We conducted horizon picking, gridding and attribute extractions as well as seismic geomorphological interpretation, and integrated the results obtained from the seismic interpretation with existing well data.</p><p>The thicknesses of the Quaternary deposits vary from hundreds of meters of subglacial till in the Northern North Sea to several kilometers of glacigenic sediments in the North Sea Fan. Gas-charged, sandy accumulations are characterized by phase-reserved reflections with anomalously high amplitudes in the seismic data as well as density and velocity decreases in the well data. Extensive (>10 km<sup>2</sup>) Quaternary sand accumulations within this package include (i) glacial sands in an ice-marginal outwash fan, sealed by stiff glacial tills deposited by repeated glaciations (the Peon discovery in the Northern North Sea), (ii) sandy channel-levee systems sealed by fine-grained mud within sequences of glacigenic debris flows, formed during shelf-edge glaciations, (iii) fine-grained glacimarine sands of contouritic origin sealed by gas hydrates, and (iv) remobilized oozes above large evacuation craters and sealed by megaslides and glacial muds. The development of the Fennoscandian Ice Sheet resulted in a rich variety of depositional environments with frequently changing types and patterns of glacial sedimentation. Extensive new 3D seismic data sets are crucial to correctly interpret glacial processes and to analyze the grain sizes of the related deposits. Furthermore, these data sets allow the identification of localized extensive fluid accumulations within the Quaternary succession and distinguish stratigraphic levels favorable for fluid accumulations from layers acting as fluid barriers.</p>

scholarly journals Physical modeling of the Bazhenov formation in combination with CSEM and seismic methods

2021 ◽  
Vol 266 ◽  
pp. 07003
Author(s):  
V.V. Ananyev ◽  
G.S. Grigoryev ◽  
G.D. Gorelik
Keyword(s):  
Physical Model ◽  
Seismic Data ◽  
Physical Modeling ◽  
3D Seismic ◽  
Target Interval ◽  
Elastic Parameters ◽  
Bazhenov Formation ◽  
Testing Algorithms ◽  
Electrical Prospecting ◽  
3D Seismic Data

To predict the properties of the Bazhenov formation and to identify the areas in which oil deposits are localized the use of electrical prospecting methods is promising. The main goal of the current research is to evaluate the effectiveness of using Controlled Source Electro Magnetics (CSEM) exploration for the area forecast of the properties of the Bazhenov formation. The main objectives of physical modeling in this research are: Creation of an isotropic physical model corresponding to the electrical and elastic parameters of the section of the studied area, and performing 3D modeling on it with survey parameters that reproduce real seismic and CSEM surveys To convince that the contrast of the elastic properties and the ratio of the resistivity of the target interval of the Bazhenov formation and overlying rocks in the created physical model corresponds to the real petrophysical characteristics of the section of the studied area; Obtaining initial data for testing algorithms for synchronous inversion of seismic + electric and testing various approaches to processing and interpretation of CSEM and 3D seismic data.

Investigation of fluid effects on seismic responses through a physical modeling experiment

2020 ◽  
pp. 1-38
Author(s):  
Chao Xu ◽  
Pinbo Ding ◽  
Bangrang Di ◽  
Jianxin Wei
Keyword(s):  
Seismic Data ◽  
Physical Modeling ◽  
Seismic Velocity ◽  
Water Saturation ◽  
P Wave ◽  
Seismic Velocities ◽  
Seismic Responses ◽  
Modeling Experiment ◽  
Seismic Reflections ◽  
Tight Rocks

We investigated fluid effects on seismic responses using seismic data from a physical modeling experiment. Eight cubic samples with cavities quantitatively filled with air, oil, and water and sixteen non-fluid samples were set within a physical model. Both pre-stack and post-stack seismic responses of the samples were analyzed to quantitatively investigate the fluid effect on the seismic response. It was indicated that fluids could cause detectable changes in both pre-stack and post-stack seismic responses for tight rocks. At first, fluids filled within samples caused changes in pre-stack seismic responses. Visible differences could be detected between angle gathers of the samples filled with air, oil, and water. For the base reflections, the amplitudes at large angles of the air-filled and oil-filed samples are obviously stronger than those of the water-filled sample. In addition, the presence of fluids within samples led to significant changes in post-stack seismic reflections. For samples with similar P-wave impedances to the background, we found strong seismic reflections for the fluid samples and weak or even no reflections for the non-fluid samples. There was notable interference between the top and base reflections for the fluid samples while there was none for the non-fluid samples. Seismic velocities were estimated using the two-way travel times between the top and base reflections. The estimated seismic velocity gently declined with increasing water saturation until 90%. When the water saturation was more than 90%, the seismic velocity showed a steep increase.

S-S imaging with vertical-force sources

2014 ◽  
Vol 2 (2) ◽  
pp. SE29-SE38 ◽  
Author(s):  
Bob A. Hardage ◽  
Donald Wagner
Keyword(s):  
Seismic Data ◽  
P Wave ◽  
Energy Sources ◽  
Minimal Amount ◽  
Equal Weight ◽  
Vertical Force ◽  
3D Seismic ◽  
S Wave ◽  
Receiver Arrays ◽  
3D Seismic Data

We show examples of S-S images created from multicomponent seismic data generated by vertical-force sources that can be quite useful to seismic interpreters. Two source types are used: vertical vibrators and shot-hole explosives. We first discuss S-S images made from data generated by a vertical vibrator and recorded with vertical receiver arrays of 3C geophones. We next show images extracted from surface-based 3C geophones deployed around this VSP well as a 3D seismic grid. The energy sources used to generate these surface 3D seismic data were shot-hole explosives. In all data examples, we observe that each type of vertical-force source (vertical vibrator and shot-hole explosive) produces abundant direct-S energy on radial and transverse geophones. We find only minimal amounts of P-wave energy on transverse-receiver data. In contrast, radial-receiver data have significant P-wave events intermingled with radial-S events. The minimal amount of P-wave noise on transverse-receiver data makes it easier to study S-S wave physics and to create S-S images with transverse-S data. The data examples focus on transverse-S data created by vertical-force sources because interpreters will find it more convenient to process and use this S-mode. Subsequent publications will assign equal weight to radial-S and transverse-S data.

P‐wave anisotropy from azimuthal velocity and AVO using wide‐azimuth 3D seismic data

2004 ◽  
Author(s):  
Ahmed M. Al‐Marzoug ◽  
Fernando A. Neves ◽  
Jung J. Kim ◽  
Edgardo L. Nebrija
Keyword(s):  
Seismic Data ◽  
Azimuthal Velocity ◽  
P Wave ◽  
3D Seismic ◽  
3D Seismic Data

Monitoring CO2saturation using time-lapse amplitude versus offset analysis of 3D seismic data from the Ketzin CO2storage pilot site, Germany

2018 ◽  
Vol 66 (8) ◽  
pp. 1568-1585
Author(s):  
Monika Ivandic ◽  
Peter Bergmann ◽  
Juliane Kummerow ◽  
Fei Huang ◽  
Christopher Juhlin ◽  
...  
Keyword(s):  
Seismic Data ◽  
Time Lapse ◽  
3D Seismic ◽  
Pilot Site ◽  
Amplitude Versus Offset ◽  
3D Seismic Data ◽  
Amplitude Versus

A comparison of streamer and OBC seismic data at Beryl Alpha field, U. K. North Sea

Geophysics ◽  
2007 ◽  
Vol 72 (3) ◽  
pp. B69-B80 ◽  
Author(s):  
Jonathan Stewart ◽  
Andrew Shatilo ◽  
Charlie Jing ◽  
Tommie Rape ◽  
Richard Duren ◽  
...  
Keyword(s):  
North Sea ◽  
Seismic Data ◽  
Signal To Noise Ratio ◽  
Vertical Component ◽  
Hard Water ◽  
Detailed Comparison ◽  
P Wave ◽  
Data Sets ◽  
Ocean Bottom ◽  
Streamer Data

Compressional P-wave ocean-bottom-cable (OBC) seismic data from the Beryl Alpha field in the U. K. North Sea provide a superior image of the subsurface compared to heritage streamer seismic data. To determine the reason for the superiority of OBC data, the results of a detailed comparison of these OBC and streamer data sets are compared. The streamer and OBC data sets are reprocessed using a strategy that attempts to isolate the roles of processing, fold, azimuth, PZ combination, and hydrophone and geophone data have on the improved OBC image. The vertical component of the geophone (OBC Z) provides the major contribution to the improved OBC image. The imaged OBC Z datacontain fewer multiples and have a higher signal-to-noise ratio than the streamer. The OBC data have a lower level of multiple contamination because of the contribution from the OBC Z component, together with an effective suppression of receiver-side water-column reverberations as a result of the combination of the OBC hydrophone and geophone traces (PZ combination). The increased fold and wider azimuths of OBC data improve the OBC image slightly. Wider azimuths improve fault imaging, especially for faults oriented obliquely to the inline and crossline directions. The particular conditions at Beryl Alpha field that make the OBC survey successful are the relatively hard water bottom and the presence of multiples that are difficult to remove from streamer data using standard demultiple techniques.

Inversion and interpretation of a 3D seismic data set from the Ouachita Mountains, Oklahoma

Geophysics ◽  
2009 ◽  
Vol 74 (2) ◽  
pp. B37-B45 ◽  
Author(s):  
Abuduwali Aibaidula ◽  
George McMechan
Keyword(s):  
Seismic Data ◽  
Acoustic Impedance ◽  
3D Visualization ◽  
Wave Impedance ◽  
P Wave ◽  
3D Seismic ◽  
S Wave ◽  
Ouachita Mountains ◽  
Data Set ◽  
3D Seismic Data

Acoustic impedance inversion (AI) and simultaneous angle-dependent inversion (SADI) of a 3D seismic data set characterize reservoirs of Mississippian Morrowan age in the triangle zone of the frontal Ouachita Mountains, Oklahoma. Acoustic impedance of the near-angle seismic data images the 3D spatial distributions of Wapanucka limestone and Cromwell sandstone. Lamé [Formula: see text] ([Formula: see text] and [Formula: see text]) and [Formula: see text] sections are derived from the P-wave and S-wave impedance ([Formula: see text] and [Formula: see text]) sections produced by the SADI. Lithology is identified from the gamma logs and [Formula: see text]. The [Formula: see text], [Formula: see text], and [Formula: see text] are interpreted in terms of a hydrocarbon distribution pattern. The [Formula: see text] is used to identify high [Formula: see text] regions that are consistent with high sand/shale ratio. The estimated impedances and derived Lamé parameter sections are consistent with the interpretation that parts of the Wapanucka limestone and Cromwell sandstone contain potential gas reservoirs in fault-bounded compartments. The Cromwell sandstone contains the main inferred reservoirs; the two largest of these are each [Formula: see text] in pore volume. The inversion results also explain the observed low production in previous wells because those did not sample the best compartments. We propose a single new well location that would penetrate both reservoirs; 3D visualization facilitates this recommendation.

Simultaneous joint inversion of amplitude-versus-offset and controlled-source electromagnetic data by implicit representation of common parameter structure

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. ID15-ID27 ◽  
Author(s):  
Martha Lien
Keyword(s):  
Joint Inversion ◽  
P Wave ◽  
Fluid Distribution ◽  
Model Parameters ◽  
Data Sets ◽  
Controlled Source ◽  
Flow Monitoring ◽  
Fluid Saturation ◽  
Amplitude Versus Offset ◽  
Amplitude Versus

I evaluated a simultaneous joint inversion of seismic amplitude-versus-offset (AVO) and controlled-source electromagnetic (CSEM) data for fluid-flow monitoring. A new approach for structure-coupled joint inversion was presented, in which the coupling of the two data types was obtained by allowing for the direct identification of parameter structure that is shared by the different geophysical model parameters. The main idea was to use a composite parameter representation, which enables inversion with respect to the parameter magnitude and parameter structure. In the current application, parameter structure refers to transitions between dominating property values and is represented by the position and shape of the flooding front. Hence, with this approach, the position and shape of the flooding front are inverted for directly, and the coupling between the different data sets is obtained without the inclusion of an additional penalizing term in the objective function. Regularization of the inverse problem is obtained by using a flexible parameterization grid adapted to the resolution power of the available data. This approach is especially suited for problems in which the prior information is limited or highly uncertain. The solution approach is illustrated for two types of coupling: (1) identification of fluid saturation using rock-physics modeling and (2) for structure-coupled joint inversion with respect to P-wave velocity and electric conductivity. Through various synthetic examples in 2D, the proposed approach showed its efficiency for identifying the main features of the fluid distribution within the reservoir. Simultaneously inverting AVO and CSEM data was further seen to give results that were more robust with respect to certain random and more systematic (modeling) errors compared with inverting the data sets separately.

Mesozoic tectonostratigraphic evolution of the North Carnarvon Basin unlocked using regional 3D seismic

2016 ◽  
Vol 56 (2) ◽  
pp. 564
Author(s):  
Daniel Bishop ◽  
Megan Halbert ◽  
Katherine Welbourn ◽  
Ben Boterhoven ◽  
Stacey Mansfield ◽  
...  
Keyword(s):  
Seismic Data ◽  
Regional Scale ◽  
Depositional Environments ◽  
Single Channels ◽  
Data Sets ◽  
3D Seismic ◽  
The North ◽  
Basin Scale ◽  
3D Seismic Data ◽  
Carnarvon Basin

Interpretation of regional scale merged 3D seismic data sets covering the North Carnarvon Basin has for the first time enabled a detailed description of Mesozoic stratigraphic and structural features on a basin scale. Isoproportional slicing of the data enables direct interpretation of Triassic depositional environments, including contrasting low-stand and high-stand fluvial channel complexes, marginal marine clastic systems and reef complexes. Channels vary dramatically between sinuous-straight single channels within low net:gross floodplain successions, to broad channel belts within relatively high net:gross fluvial successions. The latter can be traced from the inboard part of the basin to the outer areas of the Exmouth Plateau. 3D visualisation and interpretation has demonstrated the huge variety of structural styles that are present, including basement-involved extensional faults, detached listric fault complexes, polygonal faults, and regional scale vertical strike-slip faults with flower structures. Fault trends include north–south, north–northeast to south–southwest, and northeast–southwest, with deformation events occurring mainly between the Rhaetian and Valanginian. Extensional and compressional deformation has created multiple horsts, three-way fault closures, fold belts and associated four-way anticlinal traps. Wrench tectonics may also explain pock-mark trains with the interpreted transfer of over-pressure from Triassic to Early Cretaceous levels. The use of regional scale merged 3D seismic data sets is now shedding light on tectonostratigraphic features on a basin scale that were previously unrecognised or enigmatic on 2D seismic or local 3D seismic data sets.

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