Unlocking ultra-high-density seismic for CCUS applications by combining nimble nodes and agile source technologies

2022 ◽  
Vol 41 (1) ◽  
pp. 27-33
Author(s):  
Amine Ourabah ◽  
Allan Chatenay
Keyword(s):  
Carbon Capture ◽  
Oil And Gas ◽  
Test Site ◽  
High Density ◽  
Seismic Survey ◽  
Surface Model ◽  
Near Surface ◽  
Seismic Surveys ◽  
Time Migration ◽  
Trace Density

In the quest for denser, nimbler, and lower-cost seismic surveys, the industry is seeing a revolution in the miniaturization of seismic equipment, with autonomous nodes approaching the size of a geophone and sources becoming portable by crews on foot. This has created a paradigm shift in the way seismic is acquired in difficult terrains, making zero-environmental-footprint surveys a reality while reducing cost and health, safety, and environmental risk. The simplification of survey operation and the new entry price of seismic surveys unlocked by these technologies are already benefiting industries beyond oil and gas exploration. High trace density seismic has become accessible to industries playing a key role in the net-zero era, such as geothermal and carbon capture, utilization, and storage (CCUS), to which a good understanding of the subsurface geology is crucial to their success. We describe these benefits as observed during an ultra-high-density seismic survey acquired in June 2020 through a partnership between STRYDE, Explor, and Carbon Management Canada over the Containment and Monitoring Institute site. The smallest and lightest source and receiver equipment in the industry were used to achieve a trace density of 257 million traces/km2 over this test site dedicated to CCUS studies. We discuss the operational efficiency of the seismic acquisition, innovative techniques for data transfer and surveying, and preliminary results of the seismic data processing with a focus on the near-surface model and fast-track time migration.

Tailored acquisition and processing providing an enhanced subsurface image of the basin architecture, Exmouth Sub-basin, North West Shelf, Australia

2019 ◽  
Vol 59 (2) ◽  
pp. 886
Author(s):  
Alexander Karvelas ◽  
Bee Jik Lim ◽  
Lianping Zhang ◽  
Haryo Trihutomo ◽  
Oliver Schenk ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Model Building ◽  
Waveform Inversion ◽  
Hydrocarbon Exploration ◽  
Surface Velocity ◽  
Seismic Survey ◽  
Image Point ◽  
Surface Model ◽  
Near Surface ◽  
North West

Hydrocarbon exploration has resulted in the discovery of a variety of oil and gas accumulations mainly in Upper Jurassic and Lower Cretaceous intervals. However, the distribution of the different petroleum system elements including Jurassic and Triassic intervals is poorly determined, but required for improved understanding of the complex charge history, as indicated by the variety of hydrocarbon types encountered in the basin. The new WesternGeco multiclient 3D seismic survey extends to the edges of the basin to give a comprehensive picture. Raw hydrophone data were delivered from the vessel as acquisition progressed to begin the near-surface model building. The model building consisted of two major stages: first, using full waveform inversion (FWI) to derive the near-surface velocity field; and, second, common image point (CIP) tomography to update the deeper section beyond the FWI illumination zone. As illustrated herein, various stages of processing and imaging provided a cleaner and crisper dataset across the record length, allowing (1) detailed picking of the events within the entire Mesozoic (Cretaceous–Triassic) section allowing key events to be interpreted and correlated across the area and (2) accurate investigation of the complexity of different aged fault networks and their relationships across the full Exmouth Sub-basin for the first time. In summary, this survey provides a detailed insight into the deeper basin architecture of the Exmouth Sub-basin. The seamless volume imaged to depth allows accurate mapping which is critical to unravel the complex evolutionary history in a basin with proven and significant remaining hydrocarbon potential.

scholarly journals ADAPTATION OF THE METHOD OF CHROMATOGRAPHIC ANALYSIS OF GASOLINE TO ACHIEVE PURPOSES OF GEOCHEMICAL PROSPECTING FOR OIL AND GAS

2019 ◽  
pp. 16-23
Author(s):  
A. R. Kurchikov ◽  
R. I. Timshanov ◽  
E. A. Ustimenko
Keyword(s):  
Chromatographic Analysis ◽  
Oil And Gas ◽  
Seismic Survey ◽  
Near Surface ◽  
Petroleum Potential ◽  
Geological Interpretation ◽  
Gasoline Hydrocarbons ◽  
Snow Water ◽  
Individual Hydrocarbons ◽  
Background Content

Geochemical survey is commonly applied during geological exploration to predict petroleum potential of large areas and to estimate the content of traps identified by the results of seismic survey. C1-C6 hydrocarbon concentrations in samples of surface and subsurface air, soil, snow, water, etc. are used as predictive indicators. At the exploration stage the capabilities of geochemical methods can be significantly expanded by comparing the content of gasoline hydrocarbons in samples of formation fluids and in samples of near-surface sediments. The method of chromatographic analysis of gasolines Chromatec Gazolin has been adapted for sample analysis. The taken measures to increase the sensitivity allowed us to register individual hydrocarbons C1-C10 in concentrations up to 0,01 ppb, which is obviously lower than their background content in the oil prospect areas. The revealed patterns are used in the geological interpretation of geochemical distributions based on theoretical ideas about the subvertical migration of hydrocarbons from the reservoir to the surface.

3‐D tomographic static correction

Geophysics ◽  
2002 ◽  
Vol 67 (4) ◽  
pp. 1275-1285 ◽  
Author(s):  
Xu Chang ◽  
Yike Liu ◽  
Hui Wang ◽  
Fuzhong Li ◽  
Jing Chen
Keyword(s):  
Computation Time ◽  
Matrix Decomposition ◽  
Velocity Model ◽  
Seismic Survey ◽  
Surface Model ◽  
Low Velocity ◽  
Near Surface ◽  
Model Inversion ◽  
Static Corrections ◽  
Refracted Waves

A 3‐D tomographic inversion approach based on a surface‐consistent model for static corrections is presented in this paper. Direct, reflected, and refracted waves are used simultaneously to update the near‐surface model. We analyze the characteristics of the first‐break traveltime in complicated low‐velocity layers. To improve the accuracy for the velocity model, the various first‐break times from direct, reflected, and refracted waves are considered for model inversion. A fractal algorithm which overcomes the error caused by wavelet shape differences is applied to pick first breaks. It also overcomes the leg jump of refractions. The method can pick a large number of first breaks automatically. The raypaths and traveltimes are calculated with a 3‐D ray tracer that does not increase computation time for complicated geological models. Our method can determine the raypath associated with minimum traveltimes regardless of wave mode (direct, refracted, or reflected). We use a least‐squares approach in conjunction with a matrix decomposition to reconstruct a 3‐D velocity model from the actual first‐break times obtained from 3‐D data. Finally, long‐ and short‐wavelength static corrections are calculated concurrently, based on the reconstructed velocity profile. The method can be applied to wide‐line profiles, crooked lines, and 2‐D and 3‐D seismic survey geometries. The results applied to a real 3‐D data example indicate that the 3‐D tomographic static corrections are effective for field data.

What Will Be Next? After a Decade of Exploration Activities Towards Giant Discovery in Indonesia

2020 ◽  
Author(s):  
J. Wiratno
Keyword(s):  
Oil And Gas ◽  
Task Force ◽  
Seismic Survey ◽  
Seismic Surveys ◽  
The Road ◽  
Eastern Indonesia ◽  
The North ◽  
Road Map ◽  
The Republic ◽  
The Government

Exploration activities in a decade we're going toward making a significant contribution to the discovery of oil and gas reserves or resources in Indonesia. The success of exploration activities is a joint result of several parties including the government and Cooperation Contract Contractors under SKK Migas control. The Special Task Force for Upstream Oil and Gas Business Activities (SKK Migas) continues to take various initiatives to find giant discoveries or significant oil and gas reserves. In the road map of exploration activities, a total of around 805 wells and 127,411 km of 2D seismic surveys and 64,513 km2 of 3D seismic surveys have been carried out to search for giant discoveries over the past decade. Exploration drilling activities were mostly carried out in the Western area of Indonesia with a total of 358 wells, followed by the Kalimantan area with planned drilling of 258 wells. Then as many as 195 wells were drilled in Java and Eastern Indonesia with 115 wells. Most seismic survey activities were carried out in eastern Indonesia with a total area surveyed along 60,928 km and an area of 25,470 km2, Kalimantan 24,475 km and an area of 15,287 km2, Java along 22,4455 km and 7,969 km2, the southern Sumatra area 6,708 km and an area of 6,708 km and 4,696 km2 and the survey in the North Sumatra and Natuna area is 12,854 km and 11,091 km2. Besides, various policies have been issued to intensify exploration activities in particular to maintain the Republic of Indonesia's National Energy Security in the eyes of the World.

The Role of Legacy Seismic in Enhancing the Image in the Current Seismic Data – Abu Dhabi: Case Study

2021 ◽  
Author(s):  
Ramy Elasrag ◽  
Thuraya Al Ghafri ◽  
Faaeza Al Katheer ◽  
Yousuf Al-Aufi ◽  
Ivica Mihaljevic ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Survey ◽  
Surface Model ◽  
Noise Attenuation ◽  
Near Surface ◽  
Velocity Models ◽  
Multiple Attenuation ◽  
Seismic Image ◽  
Seismic Acquisition

Abstract Acquiring surface seismic data can be challenging in areas of intense human activities, due to presence of infrastructures (roads, houses, rigs), often leaving large gaps in the fold of coverage that can span over several kilometers. Modern interpolation algorithms can interpolate up to a certain extent, but quality of reconstructed seismic data diminishes as the acquisition gap increases. This is where vintage seismic acquisition can aid processing and imaging, especially if previous acquisition did not face the same surface obstacles. In this paper we will present how the legacy seismic survey has helped to fill in the data gaps of the new acquisition and produced improved seismic image. The new acquisition survey is part of the Mega 3D onshore effort undertaken by ADNOC, characterized by dense shot and receiver spacing with focus on full azimuth and broadband. Due to surface infrastructures, data could not be completely acquired leaving sizable gap in the target area. However, a legacy seismic acquisition undertaken in 2014 had access to such gap zones, as infrastructures were not present at the time. Legacy seismic data has been previously processed and imaged, however simple post-imaging merge would not be adequate as two datasets were processed using different workflows and imaging was done using different velocity models. In order to synchronize the two datasets, we have processed them in parallel. Data matching and merging were done before regularization. It has been regularized to radial geometry using 5D Matching Pursuit with Fourier Interpolation (MPFI). This has provided 12 well sampled azimuth sectors that went through surface consistent processing, multiple attenuation, and residual noise attenuation. Near surface model was built using data-driven image-based static (DIBS) while reflection tomography was used to build the anisotropic velocity model. Imaging was done using Pre-Stack Kirchhoff Depth Migration. Processing legacy survey from the beginning has helped to improve signal to noise ratio which assisted with data merging to not degrade the quality of the end image. Building one near surface model allowed both datasets to match well in time domain. Bringing datasets to the same level was an important condition before matching and merging. Amplitude and phase analysis have shown that both surveys are aligned quite well with minimal difference. Only the portion of the legacy survey that covers the gap was used in the regularization, allowing MPFI to reconstruct missing data. Regularized data went through surface multiple attenuation and further noise attenuation as preconditioning for migration. Final image that is created using both datasets has allowed target to be imaged better.

PETROLEUM POTENTIAL OF THE GREAT SOUTH BASIN, NEW ZEALAND—NEW SEISMIC DATA IMPROVES IMAGING

2007 ◽  
Vol 47 (1) ◽  
pp. 145 ◽  
Author(s):  
C. Uruski ◽  
C. Kennedy ◽  
T. Harrison ◽  
G. Maslen ◽  
R.A. Cook ◽  
...  
Keyword(s):  
New Zealand ◽  
Seismic Data ◽  
Oil And Gas ◽  
Petroleum Industry ◽  
Source Rocks ◽  
Seismic Survey ◽  
Recording Time ◽  
Petroleum Potential ◽  
South Basin ◽  
Time Migration

Much of the Great South Basin is covered by a 30,000 km grid of old seismic data, dating from the 1970s. This early exploration activity resulted in drilling eight wells, one of which, Kawau–1a, was a 461 Bcf gas-condensate discovery. Three other wells had significant oil and gas shows; in particular, Toroa–1 had extensive gas shows and 300 m oil shows. Cuttings are described in the geological logs as dripping with oil. The well was never tested due to engineering difficulties, meaning that much of the bore was accidentally filled with cement while setting casing.In early 2006, Crown Minerals, New Zealand’s petroleum industry regulating body, conducted a new 2D seismic survey in a previously lightly surveyed region across the northern part of the Great South Basin. While previous surveys were generally recorded for five seconds, sometimes six, with up to a 2,500-metre-long cable, the new survey, acquired by CGG Multiwave’s Pacific Titan, employed a 6,000-metre-long streamer and recorded for eight seconds.The dataset was processed to pre-stack time migration (PreSTM) by the GNS Science group using its access to the New Zealand Supercomputer. Increasing the recording time yielded dividends by more fully imaging, for the first time, the nature of rift faulting in the basin. Previous data showed only the tops of many fault blocks. The new data show a system of listric extensional faults, presumably soling out onto a mid-crust detachment. Sedimentary reflectors are observed to seven seconds, implying a thickness of up to 6,000 m of section, probably containing source rock units. The rotated fault blocks provide focal points for large compaction structures. The new data show amplitude anomalies and other features possibly indicating hydrocarbons associated with many of these structures. The region around the Toroa–1 well was typified by anomalously low velocities, which created a vertical zone of heavily attenuated reflections, particularly on intermediate processing products. The new data also show an amplitude anomaly at the well’s total depth (TD) which gives rise to a velocity push-down.Santonian age coaly source rocks are widespread and several reservoir units are recognised. The reservoir at Kawau–1a is the extensive Kawau Sandstone, an Early Maastrichtian transgressive unit sealed by a thick carbonate-cemented mudstone. In addition to the transgressive sandstone target, the basin also contains sandy Eocene facies, and Paleogene turbidite targets may also be attractive. Closed structures are numerous and many are very large with potential to contain billion barrel oil fields or multi-Tcf gas fields.

Repeatability study of seismic source signatures

Geophysics ◽  
2001 ◽  
Vol 66 (6) ◽  
pp. 1811-1817 ◽  
Author(s):  
Bibi C. Aritman
Keyword(s):  
Phase Difference ◽  
Seismic Source ◽  
Seismic Survey ◽  
Surface Source ◽  
Near Surface ◽  
Seismic Surveys ◽  
Instantaneous Phase ◽  
Reservoir Monitoring ◽  
The Difference

This study discusses the repeatability of source signature using the instantaneous phase, as derived from the complex trace attributes. The study is part of a very large 2‐D seismic survey using sources of vibroseis and surface dynamite. The field procedure consisted of recording the production record, retaining the positions, then repeat‐recording the same shake or shot. The instantaneous phase was found to be the best measure for the difference between the first and the repeat records. In addition to the instantaneous phase, other analyses were used to evaluate changes in source signature. Results were tabulated for statistical comparisons and graded for quality. Excluding erroneous cases, the remainder of poor repeatabilities were studied. The analyses of near‐offset data seem to indicate that nonrepeatability of source signature relates mostly to changes in absorption and cohesion induced by elastic saturation at the near surface. In general, by time shifting and phase rotating the repeat record, the difference in instantaneous phase tends to diminish. The new idea of using instantaneous phase difference plots to evaluate repeatability offers improved evaluation of source signatures and can also be used to detect time‐lapsed changes in reservoir monitoring. By evaluating repeatability and avoiding elastic saturation near the surface, source signatures can be made more consistent, thus increasing the resolution of stacked data for 2‐D, 3‐D, and 4‐D seismic surveys.

South West Hub CCS Project: Lessons to be learned from the 2014 3D seismic survey

2015 ◽  
Vol 55 (2) ◽  
pp. 473
Author(s):  
Martin Burke ◽  
Dominique Van Gent
Keyword(s):  
Carbon Capture ◽  
Best Practice ◽  
Carbon Capture And Storage ◽  
Seismic Survey ◽  
3D Seismic ◽  
Seismic Surveys ◽  
Land Access ◽  
Community Attitudes ◽  
South West ◽  
Geological Information

The South West Hub (SWH) project is Australia's first carbon capture and storage (CCS) flagship project. Managed by the WA government's Department of Mines and Petroleum (DMP), the SWH is assessing the geological properties of a proposed CO2storage site in the southwest of WA to determine its feasibility. This includes collating detailed geological information, partnering with researchers, acquiring baseline data, consulting with communities and stakeholders, and negotiating land access. Recent activities have included a 2D seismic survey in 2011, drilling of a stratigraphic well (Harvey–1) in 2012 and a comprehensive (115 km2) 3D seismic survey in 2014. A further drilling program is planned for the fourth quarter of 2014 until the first quarter of 2015. The 2014 3D seismic survey has been described as one of the most complex land-based seismic surveys conducted in Australia due to environmental factors, and competing land-use and land-access constraints. This extended abstract reviews the recent 3D seismic survey, including the development of the project's scope and procurement processes through to community engagement and implementation, and outlines how the lessons are being incorporated into the upcoming drilling program. It will also discuss legacy issues that have impacted on community attitudes and confidence, and the challenges of working with potentially hostile communities, and also demonstrate how the project adopted and adapted best practice engagement guidelines and toolkits for CCS projects to achieve successful outcomes.

Recent applications of turning-ray tomography

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE243-VE254 ◽  
Author(s):  
Xianhuai Zhu ◽  
Paul Valasek ◽  
Baishali Roy ◽  
Simon Shaw ◽  
Jack Howell ◽  
...  
Keyword(s):  
Reservoir Characterization ◽  
Velocity Model ◽  
Surface Velocity ◽  
Seismic Survey ◽  
Structural Imaging ◽  
Prestack Depth Migration ◽  
Near Surface ◽  
Depth Migration ◽  
Time Migration ◽  
Prestack Time Migration

Recent applications of 2D and 3D turning-ray tomography show that near-surface velocities are important for structural imaging and reservoir characterization. For structural imaging, we used turning-ray tomography to estimate the near-surface velocities for static corrections followed by prestack time migration and the near-surface velocities for prestack depth migration. Two-dimensional acoustic finite-difference modeling illustrates that wave-equation prestack depth migration is very sensitive to the near-surface velocities. Field data demonstrate that turning-ray tomography followed by prestack time migration helps to produce superior images in complex geologic settings. When the near-surface velocity model is integrated into a background velocity model for prestack depth migration, we find that wave propagation is very sensitive to the velocities immediately below the topography. For shallow-reservoir characterization, we developed and applied azimuthal turning-ray tomography to investigate observed apparent azimuthal-traveltime variations, using a wide-azimuth land seismic survey from a heavy-oil field at Surmont, Canada. We found that the apparent azimuthal velocity variations are not necessarily related to azimuthal anisotropy, or horizontal transverse isotropy (HTI), induced by the stress field or fractures. Near-surface heterogeneity and the acquisition footprint also could result in apparent azimuthal variations.

Imaging the near surface using velocity inversions of ultra-high-density 3D seismic data

2021 ◽  
Vol 40 (8) ◽  
pp. 584-589
Author(s):  
Tim Dean ◽  
Margarita Pavlova ◽  
Matthew Grant ◽  
Martin Bayly ◽  
Denis Sweeney ◽  
...  
Keyword(s):  
Seismic Data ◽  
Coal Industry ◽  
High Density ◽  
Rock Properties ◽  
3D Seismic ◽  
Near Surface ◽  
Seismic Surveys ◽  
Weathered Layer ◽  
History Of ◽  
The Cost

Within the coal industry, there is a rich history of the use of the surface seismic method, principally for exploration and employing sparse 2D lines for broad resource delineation and structural modeling. However, the acquisition of 3D seismic surveys adjacent to open-cut mines (from which the majority of coal is extracted) for superior resource definition ahead of their expansion has been explored only recently. Although the reflection results are extremely useful and enable the mapping of faults with sub-5 m throws, there is still interest in determining if the seismic data can be used to image both structures and rock properties in the near surface. In addition to mapping near-surface structures that have geotechnical implications, the ability to map the overburden properties (which can be quite heterogeneous) is desired. Before mining activities can take place, the overburden needs to be removed. The cost of the removal method employed is directly affected by the depth of the weathered layer and rock properties. In particular, hardness can vary significantly. In this paper, we demonstrate how high-density seismic data originally acquired for reflection processing can be processed to generate high-resolution velocity (both VS and VP) depth volumes, which enable the successful identification of shallow structures and the creation of highly detailed near-surface rock-property volumes.

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