scholarly journals MARINE SEISMIC SURVEYS— A STUDY OF ENVIRONMENTAL IMPLICATIONS

2000 ◽  
Vol 40 (1) ◽  
pp. 692 ◽  
Author(s):  
R.D. McCauley ◽  
J. Fewtrell ◽  
A.J. Duncan ◽  
C. Jenner ◽  
M-N. Jenner ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Seismic Source ◽  
Signal Propagation ◽  
Seismic Survey ◽  
Humpback Whales ◽  
Experimental Program ◽  
3D Seismic ◽  
Environmental Implications ◽  
Alarm Response ◽  
Air Gun

An experimental program was run by the Centre for Marine Science and Technology of Curtin University between March 1996 and October 1999 to study the environmental implications of offshore seismic survey noise. This work was initiated and sponsored by the Australian Petroleum Production and Exploration Association. The program:characterised air gun signal measurements; modelled air gun array sources and horizontal air gun signal propagation;developed an 'exposure model' to predict the scale of potential biological effects for a given seismic survey over its duration;made observations of humpback whales traversing a 3D seismic survey;carried out experiments of approaching humpback whales with a single operating air gun;carried out trials with an air gun approaching a cage containing sea turtles, fishes or squid; andmodelled the response of fish hearing systems to airgun signals.The generalised response of migrating humpback whales to a 3D seismic vessel was to take some avoidance manoeuvre at >4 km then to allow the seismic vessel to pass no closer than 3 km. Humpback pods containing cows which were involved in resting behaviour in key habitat types, as opposed to migrating animals, were more sensitive and showed an avoidance response estimated at 7−12 km from a large seismic source. Male humpbacks were attracted to a single operating air gun due to what was believed the similarity of an air gun signal and a whale breaching event (leaping clear of the water and slamming back in). Based on the response of captive animals to an approaching single air gun and scaling these results, indicated sea turtles displayed a general 'alarm' response at an estimated 2 km range from an operating seismic vessel and behaviour indicative of avoidance estimated at 1 km. Similar trials with captive fishes showed a generic fish 'alarm' response of swimming faster, swimming to the bottom, tightening school structure, or all three, at an estimated 2−5 km from a seismic source. Modelling the fish ear predicted that at ranges

scholarly journals Seismic reflection imaging of a geothermal aquifer in an urban setting

Geophysics ◽  
1998 ◽  
Vol 63 (4) ◽  
pp. 1285-1294 ◽  
Author(s):  
Lee Liberty
Keyword(s):  
Seismic Reflection ◽  
Seismic Source ◽  
Urban Setting ◽  
Seismic Survey ◽  
Quality Data ◽  
Signal Quality ◽  
Fracture Permeability ◽  
Air Gun ◽  
Explosive Source ◽  
Geothermal Aquifer

A seismic reflection survey that was conducted in downtown Boise, Idaho, to help city planners site a new well for injection of spent geothermal water illustrates some methods to safely and successfully employ a seismic reflection survey in an urban setting. The objective of the seismic survey was to estimate the depth and continuity of a basalt and rhyolite volcanic sequence. Well siting was based on geothermal aquifer depth, location of interpreted faults, projected thermal impact of injection on existing wells, surface pipe extension costs, and public land availability. Seismic acquisition tests and careful processing were used to ensure high‐quality data while minimizing the potential for damage along city streets. A video camera placed in a sewer and a blast vibration monitor were used to confirm that energy from the seismic source (a 75-in3 land air gun) did not damage nearby buildings, street surfaces, or buried utilities along the survey lines. Walkaway seismic tests were also used to compare signal quality of the air‐gun source to an explosive source for imaging targets up to 800 m depth. These tests show less signal bandwidth from the air‐gun source compared to the buried explosive source, but the air‐gun signal quality was adequate to meet imaging objectives. Seismic reflection results show that the top of this rhyolite/basalt sequence dips (∼8–11°) southwest away from the Boise foothills at depths of 200 to 800 m. Seismic methods enabled interpretation of aquifer depths along the profiles and located fault zones where injected water may encounter fracture permeability and optimally benefit the existing producing system. The acquisition and processing techniques used to locate the Boise injection well may succeed for other hydrogeologic and environmental studies in urban settings.

A comparative study of multi-scaled high-resolution seismic surveys in shallow marine environments: examples from three sites, offshore Korea

2020 ◽  
Author(s):  
Young Jun Kim ◽  
Snons Cheong ◽  
Deniz Cukur ◽  
Dong-Geun Yoo
Keyword(s):  
High Resolution ◽  
Data Processing ◽  
Seismic Data ◽  
Single Channel ◽  
Seismic Source ◽  
Seismic Survey ◽  
Minimum Length ◽  
Seismic Surveys ◽  
Air Gun ◽  
Target Depth

<p>In marine seismic surveys, various acquisition systems are used depending on the survey purpose, target depth, survey environment, and conditions. A 3D survey of oil and/or gas exploration, for instance, require large-capacity air-gun arrays and six or more streamers with a minimum length of 6 km. In contrast, a high-resolution seismic survey for the shallow-water geological research and engineering needs a small capacity source such as air-gun, sparker, and boomer, deployed with a single-channel or multi-channel (24-channel) streamers. The main purpose of our seismic survey was to investigate the Quaternary geology and stratigraphy of offshore, Korea. Because the Quaternary is the most recent geological period, our target depth was very shallow at about 50 m below the sea-bottom. We used a high-frequency seismic source including a sparker of 2,000 J capacity or a 60 in<sup>3</sup> mini GI-gun and an eight-channel streamer with a 3.125 m group interval or a single-channel streamer that included 96 elements. To compare the resolution of seismic data according to the seismic source, a boomer or sparker systems were used with the single-channel streamer on a small survey ship. The seismic data processing was performed at the Korea Institute of Geoscience and Mineral Resources (KIGAM) with ProMAX, and the data processing and resolution of each survey were compared based on their acquisition systems.</p>

THE RESPONSE OF HUMPBACK WHALES (MEGAPTERA NOVAEANGLIAE) TO OFFSHORE SEISMIC SURVEY NOISE: PRELIMINARY RESULTS OF OBSERVATIONS ABOUT A WORKING SEISMIC VESSEL AND EXPERIMENTAL EXPOSURES

1998 ◽  
Vol 38 (1) ◽  
pp. 692 ◽  
Author(s):  
R.D. McCauley ◽  
M-N. Jenner ◽  
C. Jenner ◽  
K.A. McCabe ◽  
J. Murdoch
Keyword(s):  
Seismic Survey ◽  
Humpback Whales ◽  
North West ◽  
Air Gun ◽  
Depth Contour ◽  
Migratory Path ◽  
Source Level ◽  
Exmouth Gulf ◽  
Seismic Area ◽  
East West

During October to November 1996 WMC Petroleum conducted the Robert 3D seismic survey to the northeast of North West Cape, off Exmouth Western Australia. The survey used one of two 2678 cui (44 L) air-gun arrays of source level 258 dB re 1µPa2−m p−p below the array (77 bar-m), operating every eight s for 33.4 days of continual operation. Tracklines ran east-west across the path of southerly migrating humpback whales. Before the seismic survey began aerial surveys determined that humpbacks moving through the seismic area were distributed uniformly seaward of the 20 m depth contour. Based on observations made from the operating Geco Resolution there did not appear to be any gross changes in the migratory path of humpback whales through the seismic area. Whales approaching the operating Geco Resolution began avoidance manoeuvres at 5−8 km and mostly kept a standoff range of 3−4 km. Some whales approached the vessel closer. Experiments were carried out in Exmouth Gulf where the movements and behaviour of humpback pods were monitored before, during and after an approach with a 20 cui air-gun (0.33 L) of horizontal source level 227 dB re 1µPa2−m p−p. The levels at which avoidance manoeuvres began during these trials was approximately 159 dB re 1µPa2 p−p, which is roughly equivalent to the received level of the 2678 cui array at 5 km, at 162 dB re 1µPa2 p−p. General avoidance of the 20 cui air-gun was observed at 1 km, or a level of 168 dB re 1µPa2 p−p, which was roughly equivalent to the level of the 2678 cui array at 3 km at 170 dB re 1µPa2 p−p, which was the general minimum humpback standoff range observed from this array. Whales were observed to move closer to the operating 20 cui and 2678 cui air-gun/array. It is speculated that these whales were mostly males intent on investigating or passing quickly by the appropriate air-gun/array.

scholarly journals Feeding herring schools do not react to seismic air gun surveys

2013 ◽  
Vol 70 (6) ◽  
pp. 1174-1180 ◽  
Author(s):  
Héctor Peña ◽  
Nils Olav Handegard ◽  
Egil Ona
Keyword(s):  
Swimming Speed ◽  
School Size ◽  
Response Speed ◽  
Seismic Survey ◽  
3D Seismic ◽  
Time Behaviour ◽  
Northern Norway ◽  
Air Gun ◽  
Strong Motivation ◽  
The Mean

Abstract Peña, H., Handegard, N. O. and Ona, E. 2013. Feeding herring schools do not react to seismic air gun surveys. – ICES Journal of Marine Science, 70: 1174–1180. The real-time behaviour of herring schools exposed to a full-scale 3D seismic survey off Vesterålen, northern Norway, was observed using an omnidirectional fisheries sonar. Throughout the study period, the herring swam slowly against the predominant northeast current, with a net displacement along with the current. The mean swimming speed after subtracting the drift velocities was 0.35 m s−1, and the mean response speed in the direction away from the air gun array was 0.22 m s−1. No changes were observed in swimming speed, swimming direction, or school size that could be attributed to the transmitting seismic vessel as it approached from a distance of 27 to 2 km, over a 6 h period. The unexpected lack of a response to the seismic survey was interpreted as a combination of a strong motivation for feeding, a lack of suddenness of the air gun stimulus, and an increased level of tolerance to the seismic shooting.

The shape of things to come — Development and testing of a new marine vibrator source

2019 ◽  
Vol 38 (9) ◽  
pp. 680-690 ◽  
Author(s):  
Benoît Teyssandier ◽  
John J. Sallas
Keyword(s):  
Seismic Source ◽  
Test Facility ◽  
Data Sets ◽  
Far Field ◽  
Ocean Bottom ◽  
Air Gun ◽  
Seismic Image ◽  
Field Radiation ◽  
Technical Issues ◽  
To Come

Ten years ago, CGG launched a project to develop a new concept of marine vibrator (MV) technology. We present our work, concluding with the successful acquisition of a seismic image using an ocean-bottom-node 2D survey. The expectation for MV technology is that it could reduce ocean exposure to seismic source sound, enable new acquisition solutions, and improve seismic data quality. After consideration of our objectives in terms of imaging, productivity, acoustic efficiency, and operational risk, we developed two spectrally complementary prototypes to cover the seismic bandwidth. In practice, an array composed of several MV units is needed for images of comparable quality to those produced from air-gun data sets. Because coupling to the water is invariant, MV signals tend to be repeatable. Since far-field pressure is directly proportional to piston volumetric acceleration, the far-field radiation can be well controlled through accurate piston motion control. These features allow us to shape signals to match precisely a desired spectrum while observing equipment constraints. Over the last few years, an intensive validation process was conducted at our dedicated test facility. The MV units were exposed to 2000 hours of in-sea testing with only minor technical issues.

Optimization Of A 3D Seismic Survey Onshore Abu Dhabi - From Field Tests To Final Design

2000 ◽  
Author(s):  
Abu Baker Al Jeelani ◽  
Samer Marmash ◽  
Abdul Salam Bin Ishaq ◽  
Ahmed Al-Shaikh ◽  
Eric Kleiss ◽  
...  
Keyword(s):  
Field Tests ◽  
Seismic Survey ◽  
Abu Dhabi ◽  
3D Seismic ◽  
Final Design

Exploring for stratigraphic traps in the Patchawarra Formation, Cooper Basin: an integrated seismic methodology

2018 ◽  
Vol 58 (2) ◽  
pp. 779
Author(s):  
Alexandra Bennett
Keyword(s):  
Complex Geometry ◽  
Imaging Techniques ◽  
South Australia ◽  
Seismic Interpretation ◽  
Seismic Survey ◽  
3D Seismic ◽  
Seismic Resolution ◽  
Seismic Reflectivity ◽  
Seismic Area ◽  
Cooper Basin

The Patchawarra Formation is characterised by Permian aged fluvial sediments. The conventional hydrocarbon play lies within fluvial sandstones, attributed to point bar deposits and splays, that are typically overlain by floodbank deposits of shales, mudstones and coals. The nature of the deposition of these sands has resulted in the discovery of stratigraphic traps across the Western Flank of the Cooper Basin, South Australia. Various seismic techniques are being used to search for and identify these traps. High seismic reflectivity of the coals with the low reflectivity of the relatively thin sands, often below seismic resolution, masks a reservoir response. These factors, combined with complex geometry of these reservoirs, prove a difficult play to image and interpret. Standard seismic interpretation has proven challenging when attempting to map fluvial sands. Active project examples within a 196 km2 3D seismic survey detail an evolving seismic interpretation methodology, which is being used to improve the delineation of potential stratigraphic traps. This involves an integration of seismic processing, package mapping, seismic attributes and imaging techniques. The integrated seismic interpretation methodology has proven to be a successful approach in the discovery of stratigraphic and structural-stratigraphic combination traps in parts of the Cooper Basin and is being used to extend the play northwards into the 3D seismic area discussed.

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