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- Volume 36, Issue 1, 2018
First Break - Volume 36, Issue 1, 2018
Volume 36, Issue 1, 2018
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An experimental aeromagnetic survey using a rubidium vapor magnetometer attached to the rotary-wings unmanned aerial vehicle
Authors Boris Sterligov, Sergey Cherkasov, Dmitry Kapshtan and Victoria KurmaevaAbstractAn unmanned aircraft system (UAS) for aeromagnetic surveying has been developed on the platform of Geoscan-401 rotary-wings unmanned aerial vehicle. The UAS includes a light rubidium vapor magnetometer (RVM) and an additional differential GPS placed on a loop attached to the copter’s body by 50-meter cable. In operation mode, the aerodynamic design of the loop keeps it in a horizontal position. To define the metrological characteristics of the RVM, a series of tests were conducted using the commercially available magnetometers and a calibration test station. On September 2016, two experimental aeromagnetic surveys with the UAS were conducted over an area of 0.7 sq. km located 30 km northward of Saint Petersburg, Russia. Approximately 32 km of survey lines were flown in two flights of 40 minutes each. During the first flight - Survey 1, the UAS was kept at 30 m above the ground surface (altitude 150–165 m), and second - Survey 2 one went at a constant altitude of 160 m (25–40 m above the surface). The variations from the nominal altitude were approximately ± 2 m. The deviation from the line path reaches 10 m for the flights of southward direction because of southwest wind during the survey.
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Nodal land seismic acquisition: The next generation
Authors Tim Dean, John Tulett and Richard BarnwellAbstractWithin the last two years six new land seismic nodal acquisition systems have been launched, a pace unmatched even during the oil boom of the late 2000s/early 2010s. Any acquisition system that utilizes recording instrumentation that does not incorporate cables is often referred to as a nodal system. Some instruments, however, are beginning to blur what initially appears to be a clear boundary. For example, the U-Node system from Seismic Instruments utilizes a node that records data from up to 24 different channels that can then be stored locally or transmitted via Wi-Fi to a central system. The reduction in cabling, which is usually cited as the core advantage of nodal recording, is therefore limited to the backbone connecting the central recording system to the field recording units. In this paper we will concentrate on nodes that are designed to record data from a single point and are thus typically limited to six or fewer channels.
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Confidence in data recorded with land seismic recorders
Authors Nicolas Tellier and Steve WilcoxAbstractSeismic contractors and their clients constantly strive to increase the productivity of land seismic acquisition projects, and this combined with a trend for denser receiver geometries is resulting in much larger volumes of data being acquired on a daily basis. This has created a challenge for the checking of data consistency and its suitability for imaging, and has led to new approaches to in-field quality control.
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In-field QC of a land node seismic system
AbstractThe land node (also called wireless or cableless) seismic acquisition revolution hit North America in 2008–2009 and very quickly proved to be a technical and economic success. The rationale for the choice to use wireless rather than cable systems has been presented in numerous publications and venues (e.g., Caldwell, 2010; Mougenot et al., 2014; Munoz et al., 2015; Uribe et al., 2016; Yates et al., 2016; Dean et al., 2018), so suffice it to say that increased productivity, reduced costs, comparable or better data quality, and reduced health, safety, and environmental (HSE) risks have catalyzed its acceptance by the industry, particularly in North America, but also in Europe. Furthermore, the wireless systems are evolving to address what some have perceived as the inherent weaknesses of these systems: the inability to provide sufficient information in real-time about the status of the live spread of receiver stations, and to deliver in real-time substantial amounts of seismic data. It has taken longer for wireless systems to make significant inroads in other places in the world outside of North America, but that has been in the process of changing over the last few years. One place in particular where that has been changing is South America. In a geographic area where seismic activity has not been that strong over the last 5–6 years, at least 23 seismic surveys (9 2D and 14 3D) have been acquired since the beginning of 2011 using wireless acquisition systems. This paper describes how quality checking (QC) during acquisition operations was accomplished for a node system (Geospace GSX) used to acquire two 3D surveys by SAExploration for Hocol in Colombia in 2016 and 2017.
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The state of land seismic
By Doug CriceAbstractIt has been said that when the oil and gas industry catches a cold, geophysical contractors get the flu, and the equipment manufacturers get pneumonia. This metaphor describes the leveraged financial impact of the periodic collapses in the price of oil. The oil companies cut back on exploration, and the contractors reduce the number of active crews. Surplus equipment is warehoused and the contractors stop buying hardware altogether. Why buy gear when you have it on the shelf?
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Surface seismic for structural imaging and reservoir characterization
Authors Anastasia Poole and Phillip BilsbyAbstractIn the current challenging oil and gas environment it is now more important than ever to maximize return on investment. At a time when projects can face time and budget constraints, and the number of wells required to access both unconventional and conventional resources increases, improvements in the accuracy of seismic information can create significant value during the decision-making process.
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The low-frequency seismic vibrator: design and experimental verification
Authors Zhouhong Wei, Jason Criss, Andy Bull, Fuhe Liang and Yongsheng WuAbstractExtending the Vibroseis acquisition bandwidth towards low frequencies has become an increasing trend in land seismic exploration. It is clear that adding low-frequency content to seismic data can be beneficial to enabling waveform inversion for velocity model determination or refinement, improving the resolution of seismic data and obtaining structural information of deeper reservoirs. These geophysical benefits have been highlighted by many authors, for example Baeten et al. (2013) and Mahrooqi et al. (2012). However, using the Vibroseis method to acquire low frequency seismic data becomes very challenging. Owing to mechanical and hydraulic limitations, most conventional seismic vibrators cannot produce sufficient low-frequency force for transmission of seismic energy into deep ground below 10 Hz. Because of this fact many sweep design techniques aimed at enhancing the Vibroseis low-frequency contents have been developed (Bagaini 2006, 2008; Sallas 2010; Baeten 2011). These low frequency sweeps can enable conventional vibrators to shake as close as possible to their low-frequency mechanical limitations. Unfortunately, this approach requires a lower drive level and hence a slower sweep rate resulting in a longer sweep length. Therefore, the generation of extra low-frequency bandwidth with low frequency sweep methods usually has an impact on productivity.
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The future of land exploration: brute force and ignorance, or adherence to the science?
By Bob HeathAbstractIt is difficult to ignore claims, brought on by the continuing relatively low price of oil, that the business of land seismic surveying is stuck in the doldrums. Those in the know assure us that until oil returns to $100 or more, such operations will be too expensive to undertake routinely while these same ‘experts’ believe hardware development and manufacture will never be significantly profitable again. As one who has written and spoken extensively on this subject for decades, sadly I have to agree that the bien pensants may for once have a point, or part of one anyway. I do not see that land equipment and exploration can expect a bright future if oil continues to hover around its current price. However, this is only if land seismic carries on in the way it has been doing. If we make some overdue technological changes and adhere better to the science, the future is bright and potentially very profitable. With much of the necessary new technology in or starting to move out of incubators, an investment less than the cost of acquiring a medium-sized survey could be all it takes. Therefore, the prospect of low cost oil actually presents significant commercial opportunities to someone.
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Volumes & issues
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Volume 42 (2024)
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Volume 41 (2023)
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Volume 40 (2022)
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Volume 39 (2021)
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Volume 38 (2020)
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Volume 37 (2019)
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Volume 36 (2018)
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Volume 35 (2017)
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Volume 34 (2016)
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Volume 33 (2015)
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Volume 32 (2014)
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Volume 31 (2013)
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Volume 30 (2012)
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Volume 29 (2011)
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Volume 28 (2010)
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Volume 27 (2009)
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Volume 26 (2008)
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Volume 25 (2007)
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Volume 24 (2006)
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Volume 23 (2005)
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Volume 22 (2004)
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Volume 21 (2003)
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Volume 20 (2002)
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Volume 19 (2001)
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Volume 18 (2000)
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Volume 17 (1999)
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Volume 16 (1998)
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Volume 15 (1997)
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Volume 14 (1996)
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Volume 13 (1995)
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Volume 12 (1994)
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Volume 11 (1993)
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Volume 10 (1992)
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Volume 9 (1991)
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Volume 8 (1990)
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Volume 7 (1989)
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Volume 6 (1988)
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Volume 5 (1987)
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Volume 4 (1986)
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Volume 3 (1985)
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Volume 2 (1984)
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Volume 1 (1983)