Improving imaging and repeatability on land using virtual source redatuming with shallow buried receivers

Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. Q15-Q26 ◽  
Author(s):  
Dmitry Alexandrov ◽  
Andrey Bakulin ◽  
Roy Burnstad ◽  
Boris Kashtan
Keyword(s):  
Seismic Data ◽  
Near Field ◽  
Time Lapse ◽  
Elastic Model ◽  
Virtual Source ◽  
Field Zone ◽  
Near Surface ◽  
Actual Field ◽  
Different Sources

Time-lapse surface seismic monitoring typically suffers from different sources of nonrepeatability related to acquisition imperfections as well as due to complexity of the subsurface. Placing sources and receivers below the surface can improve seismic data repeatability. However, it is not always possible to bury a large number of sources, and therefore the next best option is monitoring with surface sources and buried sensors. We have discovered that redatuming of surface sources to the shallow buried receivers produced a reliable image of target reflectors despite the fact that receivers were placed in the near-field zone of the source. We redatumed data with the virtual source method using crosscorrelation of the measured wavefields. We found that redatuming also reduced nonrepeatability of seismic data associated with changes in acquisition geometry, variable source coupling, and daily/seasonal variations in the near surface. We developed these results with a synthetic case study using a realistic 1D elastic model with a free surface and acquisition geometry from an actual field experiment conducted in Saudi Arabia.

Estimating picking errors in near‐surface seismic data to enable their time‐lapse interpretation of hydrosystems

2018 ◽  
Vol 16 (6) ◽  
pp. 613-625 ◽  
Author(s):  
M. Dangeard ◽  
L. Bodet ◽  
S. Pasquet ◽  
J. Thiesson ◽  
R. Guérin ◽  
...  
Keyword(s):  
Seismic Data ◽  
Time Lapse ◽  
Near Surface

Time-Lapse Seismic for Reservoir Management: Case Studies From Offshore Niger Delta, Nigeria

2016 ◽  
Vol 19 (03) ◽  
pp. 391-402
Author(s):  
Sunday Amoyedo ◽  
Emmanuel Ekut ◽  
Rasaki Salami ◽  
Liliana Goncalves-Ferreira ◽  
Pascal Desegaulx
Keyword(s):  
Case Studies ◽  
Niger Delta ◽  
Reservoir Management ◽  
Time Lapse ◽  
Seismic Survey ◽  
Elastic Model ◽  
Field Development ◽  
4D Seismic ◽  
The Impact

Summary This paper presents case studies focused on the interpretation and integration of seismic reservoir monitoring from several fields in conventional offshore and deepwater Niger Delta. The fields are characterized by different geological settings and development-maturity stages. We show different applications varying from qualitative to quantitative use of time-lapse (4D) seismic information. In the first case study, which is in shallow water, the field has specific reservoir-development challenges, simple geology, and is in phased development. On this field, 4D seismic, which was acquired several years ago, is characterized by poor seismic repeatability. Nevertheless, we show that because of improvements from seismic reprocessing, 4D seismic makes qualitative contributions to the ongoing field development. In the second case study, the field is characterized by complex geological settings. The 4D seismic is affected by overburden with strong lateral variations in velocity and steeply dipping structure (up to 40°). Prestack-depth-imaging (PSDM) 4D seismic is used in a more-qualitative manner to monitor gas injection, validate the geologic/reservoir models, optimize infill injector placement, and consequently, enhance field-development economics. The third case study presents a deep offshore field characterized by a complex depositional system for some reservoirs. In this example, good 4D-seismic repeatability (sum of source- and receiver-placement differences between surveys, dS+dR) is achieved, leading to an increased quantitative use of 4D monitoring for the assessment of sand/sand communication, mapping of oil/water (OWC) front, pressure evolution, and dynamic calibration of petro-elastic model (PEM), and also as a seismic-based production-logging tool. In addition, 4D seismic is used to update seismic interpretation, provide a better understanding of internal architecture of the reservoirs units, and, thereby, yield a more-robust reservoir model. The 4D seismic in this field is a key tool for field-development optimization and reservoir management. The last case study illustrates the need for seismic-feasibility studies to detect 4D responses related to production. In addition to assessing the impact of the field environment on the 4D- seismic signal, these studies also help in choosing the optimum seismic-survey type, design, and acquisition parameters. These studies would possibly lead to the adoption of new technologies such as broad-band streamer or nodes acquisition in the near future.

Substituting petro-elastic model with a new proxy to assimilate time-lapse seismic data considering model errors

2021 ◽  
pp. 109970
Author(s):  
Shahram Danaei ◽  
Gilson M. Silva Neto ◽  
Denis J. Schiozer ◽  
Alessandra Davolio
Keyword(s):  
Seismic Data ◽  
Time Lapse ◽  
Elastic Model ◽  
Model Errors

scholarly journals Geochemistry and related studies of Clyde Estuary sediments

2017 ◽  
Vol 108 (2-3) ◽  
pp. 269-288 ◽  
Author(s):  
David G. Jones ◽  
Christopher H. Vane ◽  
Solveigh Lass-Evans ◽  
Simon Chenery ◽  
Bob Lister ◽  
...  
Keyword(s):  
Seismic Data ◽  
Surface Sediments ◽  
Sidescan Sonar ◽  
Near Surface ◽  
Glacial Sediments ◽  
Shallow Seismic ◽  
Limited Success ◽  
Shallow Layer ◽  
Quaternary History ◽  
Different Sources

ABSTRACTGeochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity.

Transmission-based near-surface deconvolution

Geophysics ◽  
2020 ◽  
Vol 85 (2) ◽  
pp. V169-V181 ◽  
Author(s):  
Daniele Colombo ◽  
Diego Rovetta ◽  
Ernesto Sandoval-Curiel ◽  
Apostolos Kontakis
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Complex Structure ◽  
Seismic Source ◽  
Time Lapse ◽  
Near Surface ◽  
Early Arrival ◽  
Seismic Recording ◽  
Exploration Area ◽  
Scalar Amplitude

We have developed a new framework for performing surface-consistent amplitude balancing and deconvolution of the near-surface attenuation response. Both approaches rely on the early arrival waveform of a seismic recording, which corresponds to the refracted or, more generally speaking, to the transmitted energy from a seismic source. The method adapts standard surface-consistent amplitude compensation and deconvolution to the domain of refracted/transmitted waves. A sorting domain specific for refracted energy is extended to the analysis of amplitude ratios of each trace versus a reference average trace to identify amplitude residuals that are inverted for surface consistency. The residual values are either calculated as a single scalar value for each trace or as a function of frequency to build a surface-consistent deconvolution operator. The derived operators are then applied to the data to obtain scalar amplitude balancing or amplitude balancing with spectral shaping. The derivation of the operators around the transmitted early arrival waveforms allows for deterministically decoupling the near-surface attenuation response from the remaining seismic data. The developed method is fully automatic and does not require preprocessing of the data. As such, it qualifies as a standard preprocessing tool to be applied at the early stages of seismic processing. Applications of the developed method are provided for a case in a complex, structure-controlled wadi, for a seismic time-lapse [Formula: see text] land monitoring case, and for an exploration area with high dunes and sabkhas producing large frequency-dependent anomalous amplitude responses. The new development provides an effective tool to enable better reservoir characterization and monitoring with land seismic data.

Optimising Time-Lapse Seismic Data Processing: Stage 2C of the CO2CRC Otway Project Case Study

2019 ◽  
Author(s):  
Dmitry Popik ◽  
Roman Pevzner ◽  
Stanislav Glubokovskikh ◽  
Valeriya Shulakova ◽  
Sasha Ziramov
Keyword(s):  
Data Processing ◽  
Seismic Data ◽  
Time Lapse ◽  
Seismic Data Processing ◽  
Processing Stage
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