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Liu Z.,China National Petroleum Corporation | Sa L.,China National Petroleum Corporation | Dong S.,China National Petroleum Corporation | Han X.,INOVA Geophysical Equipment Ltd
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting | Year: 2013

Kernel seismic acquisition equipment is one of the key factors in geophysical exploration technology applications. The equipment development is the motive power to promote seismic exploration technology development. Some of new acquisition approaches such as high density, wide azimuth, and full wave, turn into the key technologies to solve more and more complex geology problems in oil and gas exploration. Over ten-thousand-channel acquisition systems, high-fidelity and broadband digital sensors, and new featured vibrators for high production acquisition are foundations of the technology application. This article introduces development of the kernel seismic acquisition equipment in the world and analyzes its current status in China. According to the authors, the equipment development direction will be hybrid data recording systems with wireless and wire data transmission, digital sensors, high-efficient and broadband vibrators in order to meet future geophysical development requirements in China. Source

Spiewak S.,University of Calgary | Selvakumar A.,INOVA Geophysical Equipment Ltd | Arjmand M.T.,University of Calgary | Lawrence E.,Polytec Inc.
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2010

Microsystems Technology based inertial sensors offer important advantages in low-invasive measurement of spatial motion with sub-micron accuracy. Their successful implementation hinges upon achieving very low distortion and noise at the low end of the frequency spectrum. Of particular importance is the Vibration Rectification Error (VRE) - An apparent shift in the signal bias that occurs when inertial sensors are subjected to vibration. A common approach to the reduction of VRE is assuring a highly symmetrical mechanical structure of sensors. Furthermore, a low cross-Axis sensitivity is desirable. In accelerometers these properties are achieved by employing multiple flexures supporting the seismic mass. However, this may lead to mechanical over-constraining and multiple local equilibria rather than a single global one. Multiple equilibria combined with the nonlinearity of flexures create conditions for chaotic behavior, which can greatly degrade the sensors' performance. We investigate representative architectures of high performance servo accelerometers, study the impact of over-constraining, and develop comprehensive dynamic models accounting for the presence of this condition. Given the complexity of spatial motion of the proof mass and resulting deformations in the flexures, we employ computer aided generation of constitutive, symbolic and scaleable models of the investigated sensors. We illustrate analytical investigations with numerical simulations and experimental results. Copyright © 2010 by ASME. Source

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. Source

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. Source

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. Source

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