INOVA Geophysical Equipment Ltd

Fengcheng, China

INOVA Geophysical Equipment Ltd

Fengcheng, China
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Wei Z.,INOVA Geophysical Equipment Ltd | Phillips T.F.,Dawson Geophysical Company
SEG Technical Program Expanded Abstracts | Year: 2013

Vibroseis has become the most widely used method in land data acquisition. When the vibrator baseplate is coupled with the ground, the ground seen by the baseplate is captured and becomes a part of source. Many researchers have developed methods to estimate this captured ground mass system. However, no one gives a quantified geometry of this captured ground mass system. This paper provides a theoretical study using a finite element analysis model to quantify this captured ground mass system. Meanwhile, through the finite element analysis model, the ground roll is visualized. © 2013 SEG.


Wei Z.,INOVA Geophysical Equipment Ltd
SEG Technical Program Expanded Abstracts | Year: 2015

Seismic vibrators are the preferred sources for land seismic surveys. Acquiring broadband seismic data using Vibroseis techniques has become more and more a routine practice. There are many parts of world with diverse terrain that encompassed heavily wooded areas, vineyards, orchards, crop lands, and mountainous regions. It is realized that a lighter and more agile vibrator would provide enough accessibility with minimal impact to the environment. However, with lighter vibrators producing a measurable broadband force signal becomes very challenge. To increase the force amplitude from a lighter vibrator, an improved design of vibrator mechanical and hydraulic system is required. This paper attempts to address this problem with a newly designed broadband lighter vibrator (UniVib 2). Experimental results show that with this new generation broadband lighter vibrator the vibrator ground force at low frequencies is significantly improved. The force in 200 Hz bandwidth is significantly increased. Moreover, the stability at very high frequencies is enhanced. © 2015 SEG.


Wei Z.,INOVA Geophysical Equipment Ltd
SEG Technical Program Expanded Abstracts | Year: 2015

Extending the Vibroseis data bandwidth towards low frequencies (below 5 Hz) can be very beneficial for land seismic exploration. However, with most conventional vibrators physical limitations in vibrator mechanical and hydraulic systems limit the ground-force output at low frequencies. To push the frequency into lower range (< 5 Hz), the vibrator output force must be significantly increased. This requires an improved design of vibrator mechanical and hydraulic system. This paper attempts to present a newly designed low frequency vibrator. Experimental results show with this new generation low frequency vibrator the vibrator ground force at low frequencies is significantly improved. Downhole results at the depth of 7500 ft (2288 m) demonstrate that this new generation low frequency vibrator can produce a measurable force-energy from 0.5 Hz to 131 Hz (8 octaves). © 2015 SEG.


Wei Z.,INOVA Geophysical Equipment Ltd. | Phillips T.F.,INOVA Geophysical Equipment Ltd.
75th EAGE Conference and Exhibition Incorporating SPE EUROPEC 2013 | Year: 2013

Extending the frequency bandwidth towards low frequencies using the Vibroseis method has gained a lot of attenation recently. The source (vibrators) becomes one of the obtacles in the success of recording low frequency seismic signals. How do we increase the vibrator ground force at low frequencies (< 10 Hz)? Can the vibrator control electronics effectively supress harmonic distortion at low frequencies? This paper attempts to provide a fresh look at these questions.


Wei Z.,INOVA Geophysical Equipment Ltd | Phillips T.F.,INOVA Geophysical Equipment Ltd
Geophysics | Year: 2013

Acquiring low-frequency seismic data using Vibroseis techniques has gained attention in recent years. Successful application of low-frequency Vibroseis acquisition requires evaluating each element of the data acquisition system and ensuring that each part of the system contributes to the success of the method. We focus on generating low frequencies with Vibroseis sources rather than recording and preserving them. To generate the low-frequency signals using seismic vibrators, it is better to know (1) the hydraulic and mechanical system of the vibrator; (2) the design of a low-frequency sweep that can deliver the vibrator ground force maximally; and (3) the vibrator control system that can minimize the harmonic distortion of the vibrator ground force output at low frequencies. Field tests show that hydraulic pump flow is not a limiting factor for the generation of the low frequencies for most modern seismic vibrators. In addition, with harmonic distortion reduction control, the vibrator performance at low frequencies is improved. © 2013 Society of Exploration Geophysicists.


Wei Z.,INOVA Geophysical Equipment Ltd | Phillips T.F.,INOVA Geophysical Equipment Ltd | Hall M.A.,INOVA Geophysical Equipment Ltd
Geophysics | Year: 2010

Vibrators are the most widely used sources in land seismic exploration. Successful application of vibroseis technology requires evaluating each element in the vibrator system and ensuring that each part of the system contributes to the success of the method. To obtain a high-quality image of the subsurface using the vibroseis method, it is beneficial to know: the frequency bandwidth the vibrator and its control system can deliver; the outgoing signal from the vibrator and the repeatability of the source signature; and the harmonic distortion level on the vibrator force output and the limits the vibrator is subject to. Fundamental discussions on the vibrator system that have been forgotten over time are presented. © 2010 Society of Exploration Geophysicists.


Wei Z.,INOVA Geophysical Equipment Ltd | Phillips T.F.,Dawson Geophysical
Geophysics | Year: 2013

Extending the vibroseis bandwidth toward low frequencies (below 10 Hz) can bring many benefits for land seismic exploration such as deeper signal penetration and for nearsurface inversion techniques. Due to physical limitations in vibrator mechanical and hydraulic systems, the ground force output from a vibrator at low frequencies is limited. This limited ground force output is severely distorted by harmonic distortion such that the ground force in fundamental frequencies is reduced. We focused on reducing harmonic distortion through vibrator control algorithms to improve vibrator performance at low frequencies. The purpose was to show that with only vibrator control algorithms, the fundamental ground force from a vibrator can be noticeably improved at low frequencies. In addition, we demonstrated a synthetic case using the weighted-sum ground force to simulate slip-sweep acquisition. Presumably, reducing source generated harmonic distortion can help decrease the slip time in slip-sweep operations thereby increasing productivity rates. © 2013 Society of Exploration Geophysicists.


Wei Z.,INOVA Geophysical Equipment Ltd | Hall M.A.,Geokinetics
Leading Edge (Tulsa, OK) | Year: 2011

The vibroseis method has, for half a century, achieved great success in land seismic exploration. However, some practical issues still arise that have remained theoretically unexplained. For example, on soft ground, the vibrator produces subharmonics and ultra-subharmonics in addition to main harmonics; whereas on hard ground, the vibrator generates harmonics only. Geophones on soft ground also behave abnormally while geophones on hard ground behave normally. This paper analyzes these phenomena and demonstrates that the softness of the ground's top layer is responsible for subharmonics and ultra-subharmonics. This soft ground layer causes the geophone abnormality as well. Unfortunately, quantification for this behavior has not been achieved. © 2011 Society of Exploration Geophysicists.


Wei Z.,INOVA Geophysical Equipment Ltd | Hall M.A.,Geokinetics | Phillips T.F.,INOVA Geophysical Equipment Ltd
Geophysical Prospecting | Year: 2012

The seismic vibrator has become a very important source for land data acquisition and there have been dramatic improvements in recent times in the application of the vibroseis technique. These improvements have led to much increased productivity and in many cases much denser source sampling. At the same time, the vibrator itself has seen little improvement over the last couple of decades. There are needs in a few areas where an improvement in the vibrator itself can bring benefits to the quality of the seismic data acquired. This paper describes progress in four such areas, low-frequency performance, high-frequency performance, an improved estimate of the vibrator groundforce and source signature consistency over variable ground conditions. Each of these vibrator characteristics will be discussed in turn. Meanwhile, two field test results in which the performance of two different vibrators in these four areas are compared. © 2011 European Association of Geoscientists & Engineers.


Wei Z.,INOVA Geophysical Equipment Ltd | Phillips T.F.,INOVA Geophysical Equipment Ltd
Geophysical Prospecting | Year: 2012

The vibroseis method has become the principal data acquisition method in land seismic exploration. It seems that this method has been extended to its limits as the search for energy resources continues. Many practical issues arising from field operations have remained theoretically unexplained, for example, variations in wavelet arrival time, inaccurate wavelet estimation and harmonics in the wavelet itself. The focus of this paper is the proposal of a new model, which is referred to as the vibrator-coupled ground model, to simulate the filtering effects of a complex coupling system consisting of the coupling between the baseplate and the ground as well as the coupling between the captured ground mass near the vibrator baseplate and the surrounding earth. With this vibrator-coupled ground model many of the practical issues mentioned above were reasonably addressed. Furthermore, it was demonstrated from experimental tests that both the pilot sweep and the weighted-sum groundforce, when filtered by the vibrator-coupled ground model, are proportional to the far-field particle velocity whereas the unfiltered signals are not. The harmonics on the filtered weighted-sum groundforce successfully maintain a proportional relationship with the harmonics seen in the far-field signal. © 2011 European Association of Geoscientists & Engineers.

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