'Rig 3D' ? A revolutionary technique looking for a case history

1989 ◽  
Vol 20 (2) ◽  
pp. 219
Author(s):  
B.J. Evans

Three dimensional (3D) marine seismic surveying is expensive and often a lengthy and technically difficult survey to perform. It is therefore only executed when an economically viable discovery is made. An alternative technique is offered which may be used when a marginally economic discovery is made. The technique is inexpensive compared to the conventional full 3D marine survey; it is cheaper than reconnaissance surveying and two boat operations, and provides a 3D migrated annular volume just over 3 kilometres in diameter for the approximate price of a single offset vertical seismic profile (VSP).The technique uses the exploration drilling rig as the energy source platform, the rig supply vessel as the receiver, and the site location system as the 3D navigation network. In using equipment conventionally mobilized with each drilling rig relocation, costs are substantially reduced and a larger portion of the 3D seismic exploration budget may be transferred to the engineering/drilling budget.Failure of the technique to be trialled is due to the conservatism found within the industry rather than technical considerations.

1989 ◽  
Vol 20 (2) ◽  
pp. 229
Author(s):  
S.C. Stewart ◽  
B.J. Evans

As part of an industry funded research project into the application of the technique of LOFOLD3D land seismic surveying, a four fold three dimensional seismic survey was performed in the Perth Basin at Moora, Western Australia in July 1987. The volume covered an area of four kilometres by just under two kilometres, producing a total of 23,000 common midpoint traces. The objective was to collect and process the data in such a manner that a three dimensional structural interpretation would result, which would be the same as that resulting from a conventional three dimensional survey. A cost comparison indicates that a commercial LOFOLD3D survey would reduce the cost of performing a land 3D survey to an estimated 20% of the full fold equivalent, and the technique therefore offers potential for substantial savings if it is adopted on a commercial basis.


Author(s):  
E.V. An ◽  
◽  
S.А. Istekova ◽  
Kh.M. Kassymkanova ◽  
G.K. Jangulova ◽  
...  

The article deals with the possibility of using seismic exploration in solving problems of ore geology in complex mining and geological conditions of Kazakhstan. The substantiation and characterization of geological and geophysical conditions for conducting experimental 3D seismic surveys at the deposits of the Zhilandinsky group of copper sandstones located in the Karaganda region of Central Kazakhstan are presented. The tasks are defined and the technique of conducting high-resolution 3D seismic exploration is developed, accompanied by modern processing and interpretation complexes for obtaining high-quality seismic materials for solving geological problems: studying the structural and tectonic structure of ore areas, identifying and refining ore-controlling structures, detecting and deep mapping of tectonic faults, volumetric mapping of intrusive massifs. The directions and technology of the process of modeling ore horizons and tracing them in space based on the results of a comprehensive interpretation of three-dimensional seismic exploration and geological and geophysical data, which will significantly increase the reliability coefficient of forecasting ore deposits, are indicated.


1982 ◽  
Vol 22 (1) ◽  
pp. 17
Author(s):  
J. I. Sanders ◽  
G. Steel

Two marine seismic three-dimensional (3D) surveys were carried out in the Gippsland Basin during 1980. The results of these surveys illustrate the improved structural resolution that can be obtained by 3D migration in complex areas, and also the great detail with which a structure can be defined by the dense data volume given by a 3D survey.Certain aspects of data collection and processing are particularly critical in achieving a successful 3D survey. Line spacing and depth-point spacing must be related to the maximum dips and reflection frequencies expected, and accurate navigation and streamer positioning are essential. Correct migration of the data is highly dependent on obtaining the proper migration velocities, and these are derived from the stacking velocity analysis by a form of 3D modelling.Sections and Seiscrop' horizontal time slices from the surveys demonstrate that in areas of complex three-dimensional structures, 3D seismic methods are necessary to properly image the reflection energy. The Seiscrop sections also show how the dense spatial sampling of 3D data is required to map these complex structures with adequate resolution for the most effective planning of a drilling programme.


Geophysics ◽  
1983 ◽  
Vol 48 (12) ◽  
pp. 1611-1630 ◽  
Author(s):  
Bjørn Ursin

Extended source and receiver arrays have proved to be an effective tool for improving the data quality in marine seismic exploration. The extended arrays may be implemented in the field, or in a computer by the summation of traces with a common receiver coordinate or a common source coordinate, respectively. A tilted source or receiver array may be used to enhance reflectors with a specific dip. A tilted source array can be implemented in the field by delaying the pulses at the source subarrays, or in the computer by time‐shifting the traces before implementing the long source array. A tilted receiver array can approximately be implemented in the computer by time‐shifting the traces before implementing the long receiver array. In areas with complex geologic structure, the data can be corrected for normal moveout prior to implementing the extended arrays. The theoretical response of reflected waves from dipping reflectors for different extended array filters is given. Vertical and horizontal stacking constitute a spatial filter which is similar to an extended array filter. Vertical stacking with linear time shifts between the traces can be used to enhance reflectors with a specific dip. The theoretical response of reflected waves from dipping reflectors for different vertical and horizontal stacking filter is given. In order to discriminate against coherent noise travelling in the cross‐line direction, areal arrays must be used. The theoretical responses of three‐dimensional spatial filters are derived in the appendices. These responses are based on quadratic traveltime approximations for reflections in inhomogeneous layered media. A data example is presented which demonstrates the practical use of extended array filters, both implemented in the field and in the computer. From this example and others have come the following conclusions. In areas with strong coherent noise, a field‐implemented extended source array gives a signal‐to‐coherent noise improvement which cannot be obtained in data processing. In other areas, computer implementation of the extended arrays gives signal‐to‐coherent noise improvement as effectively as a field‐implemented extended source array. In such cases, the extended array filters should be implemented in the computer due to greater flexibility in testing on data and to the possibility of producing different stacked sections. Noise reduction is done more effectively by extended array filtering than by vertical and horizontal stacking prior to CDP stacking (weighted or unweighted full‐fold horizontal stacking).


2021 ◽  
Vol 11 (11) ◽  
pp. 5156
Author(s):  
Abd Al-Salam Al-Masgari ◽  
Mohamed Elsaadany ◽  
Numair A. Siddiqui ◽  
Abdul Halim Abdul Latiff ◽  
Azli Abu Bakar ◽  
...  

This study identified the Pleistocene depositional succession of the group (A) (marine, estuarine, and fluvial depositional systems) of the Melor and Inas fields in the central Malay Basin from the seafloor to approximately −507 ms (522 m). During the last few years, hydrocarbon exploration in Malay Basin has moved to focus on stratigraphic traps, specifically those that existed with channel sands. These traps motivate carrying out this research to image and locate these kinds of traps. It can be difficult to determine if closely spaced-out channels and channel belts exist within several seismic sequences in map-view with proper seismic sequence geomorphic elements and stratigraphic surfaces seismic cross lines, or probably reinforce the auto-cyclic aggregational stacking of the avulsing rivers precisely. This analysis overcomes this challenge by combining well-log with three-dimensional (3D) seismic data to resolve the deposition stratigraphic discontinuities’ considerable resolution. Three-dimensional (3D) seismic volume and high-resolution two-dimensional (2D) seismic sections with several wells were utilized. A high-resolution seismic sequence stratigraphy framework of three main seismic sequences (3rd order), four Parasequences sets (4th order), and seven Parasequences (5th order) have been established. The time slice images at consecutive two-way times display single meandering channels ranging in width from 170 to 900 m. Moreover, other geomorphological elements have been perfectly imaged, elements such as interfluves, incised valleys, chute cutoff, point bars, and extinction surfaces, providing proof of rapid growth and transformation of deposits. The high-resolution 2D sections with Cosine of Phase seismic attributes have facilitated identifying the reflection terminations against the stratigraphic amplitude. Several continuous and discontinuous channels, fluvial point bars, and marine sediments through the sequence stratigraphic framework have been addressed. The whole series reveals that almost all fluvial systems lay in the valleys at each depositional sequence’s bottom bars. The degradational stacking patterns are characterized by the fluvial channels with no evidence of fluvial aggradation. Moreover, the aggradation stage is restricted to marine sedimentation incursions. The 3D description of these deposits permits distinguishing seismic facies of the abandoned mud channel and the sand point bar deposits. The continuous meandering channel, which is filled by muddy deposits, may function as horizontal muddy barriers or baffles that might isolate the reservoir body into separate storage containers. The 3rd, 4th, and 5th orders of the seismic sequences were established for the studied succession. The essential geomorphological elements have been imaged utilizing several seismic attributes.


2014 ◽  
Author(s):  
Wang Yuhua ◽  
Liu Zhenkuan ◽  
Jiang Hongliang

1999 ◽  
Vol 18 (1) ◽  
pp. 36-38 ◽  
Author(s):  
D.D. Sternlicht

2020 ◽  
pp. 11-18
Author(s):  
A.S. Hasanov ◽  
◽  
◽  

Khidirly-Bandovan structures have been studied through geological mapping, structural exploration drilling, geophysical methods (gravimetric, magnetic, electrical, seismic exploration methods) since the 1930s. Small amount of oil from different wells in the upper part of Productive Series (PS) and huge amount of gas fountain from Middle Absheron sediments have been obtained. As the interest to these areas had not decreased, the geophysical surveys continued during further years. Seismic exploration surveys were executed in Bandovan structure via Common Depth Point (CDP) method in 2004, refracted ray method and gravimetric exploration complex in 2006 and 3D seismic exploration works and gravimetric investigations with “Scintrex CG-5 Autograv” devices in 2016, correspondingly. In the result of analysis of distribution characteristics for local gravimetric anomalies, as well as 3D descriptions of new gravimetric data, up-to-date logs on tectonic state of Khidirly-Bandovan structure have been obtained and as the new oil-gas exploration objects, the west and south-west wings of these structures highlighted.


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