Planning and field techniques for 3D land acquisition in highly tilled and populated areas - today's results and future trends

Bertelli, L.; Mascarin, B.; Salvador, L.

doi:10.3997/1365-2397.1993002

Cited by 5 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Simulation of 3-D survey geometries enables the distribution of key parameters, such as fold, minimum and maximum offsets, and azimuth and offset distributions within single CMP bins, to be displayed and verified (Bertelli et al, 1993). In addition, unfavorable effects caused by deviations from the ideal acquisition scheme may be easily evaluated and minimized if interactive simulation tools are available.…”

Section: Presurvey Computer Designmentioning

confidence: 99%

Shallow 3-D seismic reflection surveying: Data acquisition and preliminary processing strategies

1998

View full text Add to dashboard Cite

A comprehensive strategy of 3-D seismic reflection data acquisition and processing has been used in a study of glacial sediments deposited within a Swiss mountain valley. Seismic data generated by a downhole shotgun source were recorded with single 30-Hz geophones distributed at 3 m x 3 m intervals across a 357 m x 432 m area. For most common-midpoint (CMP) bins, traces covering a full range of azimuths and source-receiver distances of -2 to -125 m were recorded. A common processing scheme was applied to the entire data set and to various subsets designed to simulate data volumes collected with lower density source and receiver patterns. Comparisons of seismic sections extracted from the processed 3-D subsets demonstrated that high-fold (>40) and densely spaced (CMP bin sizes < 3 m x 3 m) data with relatively large numbers (>6) of traces recorded at short (<20 m) source-receiver offsets were essential for obtaining clear images of the shallowest (<100 ms) reflecting horizons. Reflections rich in frequencies > 100 Hz at traveltimes of ^20 to -170 ms provided a vertical resolution of 3 to 6 m over a depth range of ^-15 to ^-150 m. The shallowest prominent reflection at 20 to 35 ms (^-15 to 27 m depth) originated from the boundary between a near-surface sequence of clays/silts and an underlying unit of heterogeneous sands/gravels.

show abstract

Section: Presurvey Computer Designmentioning

confidence: 99%

Shallow 3-D seismic reflection surveying: Data acquisition and preliminary processing strategies

1998

View full text Add to dashboard Cite

show abstract

“…An example of random geometry is described by Bertelli et al (1993), where it is applied in an area surrounding Milan, Italy. The circular geometry (coil shooting) proposed by to achieve wide-azimuth data using only a single streamer vessel can also be considered a random geometry.…”

Section: Examples Of Various Geometriesmentioning

confidence: 99%

3D Seismic Survey Design, Second edition

Vermeer¹

2012

View full text Add to dashboard Cite

3-D symmetric sampling

Vermeer

1998

GEOPHYSICS

View full text Add to dashboard Cite

Three‐dimensional seismic surveys have become accepted in the industry as a means of acquiring detailed information on the subsurface. Yet, the cost of 3-D seismic data acquisition is and will always be considerable, making it highly important to select the right 3-D acquisition geometry. Up till now, no really comprehensive theory existed to tell what constitutes a good 3-D geometry and how such a geometry can be designed. The theory of 3-D symmetric sampling proposed in this paper is intended to fill this gap and may serve as a sound basis for 3-D geometry design and analysis. Methods and theories for the design of 2-D surveys were developed in the 1980s. Anstey proposed the stack‐array approach, Ongkiehong and Askin the hands‐off acquisition technique, and Vermeer introduced symmetric sampling theory. In this paper, the theory of symmetric sampling for 2-D geometries is expanded to the most important 3-D geometries currently in use. Essential elements in 3-D symmetric sampling are the spatial properties of a geometry. Spatial aspects are important because most seismic processing programs operate in some spatial domain by combining neighboring traces into new output traces, and because it is the spatial behavior of the 3-D seismic volume that the interpreter has to translate into maps. Over time, various survey geometries have bee devised for the acquisition of 3-D seismic data. All geometries constitute some compromise with respect to full sampling of the 5-D prestack wavefield (four spatial coordinates describing shot and receiver position, and traveltime as fifth coordinate). It turns out that most geometries can be considered as a collection of 3-D subsets of the 5-D wavefield, each subset having only two varying spatial coordinates. The spatial attributes of the traces in each subset vary slowly and regularly, and this property provides spatial continuity to the 3-D survey. The spatial continuity can be exploited optimally if the subsets are properly sampled and if their extent is maximized. The 2-D symmetric sampling criteria—equal shot and receiver intervals, and equal shot and receiver patterns—apply also to 3-D symmetric sampling but have to be supplemented with additional criteria that are different for different geometries. The additional criterion for orthogonal geometry (geometry with parallel shotlines orthogonal to parallel receiver lines) is to ensure that the maximum cross‐line offset is equal to the maximum inline offset. Three‐dimensional symmetric sampling simplifies the design of 3-D acquisition geometries. A simple checklist of geophysical requirements (spatial continuity, resolution, mappability of shallow and deep objectives, and signal‐to‐noise ratio) limits the choice of survey parameters. In these consideration, offset and azimuth distributions are implicitly being taken care of. The implementation in the field requires careful planning to prevent loss of spatial continuity.

show abstract

Planning and field techniques for 3D land acquisition in highly tilled and populated areas - today's results and future trends

Cited by 5 publications

References 0 publications

Shallow 3-D seismic reflection surveying: Data acquisition and preliminary processing strategies

Shallow 3-D seismic reflection surveying: Data acquisition and preliminary processing strategies

3D Seismic Survey Design, Second edition

3-D symmetric sampling

Contact Info

Product

Resources

About