共查询到18条相似文献，搜索用时 500 毫秒
1.
数字检波器在地震勘探中的应用效果 总被引：2，自引：0，他引：2
随着地震勘探精度的要求和发展,对地震仪器和检波器的要求也不断提高,只有接收到来自地下的有效反射信号,尤其是深层的高频弱反射信号,才能通过室内处理达到提高勘探精度的目的。数字检波器具有直接输出数字、高保真矢量场、感应器倾斜校正等特点,其动态范围与目前最先进的地震仪器相匹配,对来自地下的地震波没有改造,真实地记录了地震波的特性。针对数字检波器的特性进行了系统试验,通过试验效果分析认为:在信噪比方面,单个数字检波器与单个普通检波器无明显的差别,但单个数字检波器的信噪比明显低于多个普通检波器组合的信噪比;在能量方面,单个数字检波器的能量相当于多个普通检波器组合的能量;在频率方面,教字检波器比普通检波器的频带宽,可以预测,数字检波器将广泛地应用于高分辨率地震勘探中。 相似文献
2.
地震检波器是实现把机械振动转换为电信号的传感器,不同检波器具有不同的相位特性和频率特性。从检波器的振动理论方程着手,分析了地震资料反射品质与检波器特性的关系。结合地质任务和技术指标要求,在相同采集因素条件下,执行特定的试验内容,考核了不同检波器类型及其性能,对资料进行了有益的处理方法尝试,获得实用而有意义的结论。在目的层较浅的探区,试验数据表明采用自然频率较低的检波器和特殊的低截处理方法同样能够实现高分辨率的地震勘探效果。 相似文献
3.
4.
本文概述了检波器的发展过程，从理论上论述了检波器特性与地震信号的关系。通过对ＣＪ－１检波器的特性分析和与其它种类检波器的对比，并结合实际应用，指出了使用ＣＪ－１检波器压制干扰，提高分辨率的有效途径。 相似文献
5.
6.
7.
以胜利油田为例,地震勘探工作经过几十年的实践,经历了二维单次覆盖技术、二维多次覆盖技术、三维地震、高精度三维地震等发展阶段。“九五”以来,胜利油田主要勘探目标转向复杂断裂带、潜山构造、地层岩性等隐蔽油气藏,地表条件由简单地区转向复杂地区,勘探深度由浅中层向中深层延伸,探区由济阳探区向外围、新疆、合肥、东北等新区拓展。为适应勘探目标的变化,胜利物探开发和发展了高精度三维地震勘探技术、山地地震勘探技术、沙漠戈壁地震勘探技术、平原复杂地表地震勘探技术、滩浅海地震勘探技术等有胜利物探特色的技术系列。随着油气勘探程度的提高,勘探对象主要转向了地层、岩性等隐蔽油藏及深海油气藏,因而,地震勘探也要随之发展,时延地震技术、全波场地震技术、深海地震勘探技术等技术将成为胜利物探的发展方向。 相似文献
8.
9.
在滩浅海地震勘探中,由于海水深度和潮流的变化,在水面上按照预定位置沉放的检波器,在海底不可能放置在预定的位置。为此,利用基准网平差初至波定位方法对海底检波器位置进行了准确的二次定位,并对初至波二次定位和声波二次定位进行了比较分析。基准网平差初至波定位方法在KD-1滩浅海地区高精度地震勘探应用中取得了良好的效果。 相似文献
10.
11.
Duennebier F.K. Harris D.W. Jolly J. Babinec J. Copson D. Stiffel K. 《Oceanic Engineering, IEEE Journal of》2002,27(2):212-217
The Hawaii-2 Observatory seismic system is currently transmitting high-quality seismic data from the ocean floor in the central NE Pacific Ocean through Hawaii to the IRIS Data Management Center. The system includes broad-band seismic, geophone, acoustic, and ocean current sensors. The seismic sensors are buried about 0.4 m below the ocean floor to improve coupling to the ocean bottom and to reduce noise levels. The system can be remotely calibrated, leveled and locked, and gains can be changed on command from shore. Data are temporarily stored in the seismic package for retransmission as needed to correct for transmission problems and to prevent loss of data. Data generated are valuable for studies of the Earth's structure and the dynamics of earthquakes 相似文献
12.
First arrival compressional wave signals from an airgun source, as detected by a variety of seismometers in a shallow bay, are remarkably uniform. However, minor variations in wavelet appearance imply some combination of the instrument response and coupling to the bottom. Signal spectra show typically a spectral peak at 12 Hz and an envelope very similar to that expected from an airgun source. Those instruments with a decoupled geophone package have spectra most like the theoretical spectrum but spectra for the other instruments are not significantly different. Little variation exists in spectra between tripod-mounted and inverted-pendulum OBS configurations for the low amplitude P-waves observed here. The signal source is the principal influence on the resulting spectra rather than OBS configuration or bottom coupling. 相似文献
13.
Results of the analysis and interpretation of the records of 17 ocean bottom seismometers designed at the Shirshov Institute of Oceanology, Russian Academy of Sciences (a three-component geophone and a hydrophone), installed with an interval of 10–20 km along a profile in the transition zone from the Baltic shield to the Barents Sea basin are presented. The studies were carried out in 1995 from R/V Professor Kurentsov. An air gun with a chamber volume of 80 1 was used as the source of seismic waves with a shooting interval of 250 m. The longest range of records of deep refracted and wide-angle reflected waves (up to 300 km) was reached with the hydrophones. Two-dimensional seismic modeling allowed us to refine the earlier versions of the seismic cross section of the earth’s crust and uppermost mantle in the study region. New data confirmed that, in the central area of the Barents Sea, the “granitic-metamorphic” layer of the crust with a seismic velocity of 6.2 km/s typical of the Baltic Shield is absent. In this region, a thin consolidated crust with a seismic velocity of 6.8 km/s is covered with a thick (more than 25 km) sedimentary layer. In this layer, a local low-velocity zone probably exists, which causes a strong attenuation of the “crustal” waves. 相似文献
14.
Félix Avedik Vincent Renard Didier Buisine Jean-Yves Cornic 《Marine Geophysical Researches》1978,3(4):357-379
This paper describes a pop-up ocean bottom seismograph designed primarily for refraction surveys both on the continental shelf and in deep sea. Its development is the extension of our system based on seismic detectors located on the sea floor with radio transmission of seismic signals and used for seismic refraction studies on the continental shelf. The seismic detectors (vertical geophone or hydrophone and two orthogonally mounted horizontal geophones) are located outside of the pressure vessel on the main frame. Optionally, the seismic sensors may be decoupled from the main frame assembly. This decoupling is performed by a mobile arm positioning the separate three component sensor package on the sea floor.Contribution No. 455 of the Département Scientifique, Centre Océanologique de Bretagne. 相似文献
15.
Takao Eguchi Yukio Fujinawa Tadayoshi Matsuzaki Masaru Aoyagi 《Marine Geophysical Researches》1986,8(2):187-199
We designed a new pop-up type Ocean Bottom Seismometer (OBS) in order to study micro-earthquakes in off-shore areas. With a 57 cm O.D. sphere of high tension aluminium alloy, the OBS system, including one vertical and one horizontal geophone, can safely operate on ocean floors of up to 6000 m depth for seismic observations. The amplified seismic data and the time code are directly recorded on the four-channel cassette deck for periods of up to one month. The frequency response curve throughout the recording and play-back system is flat for the range, 1–15 Hz (–3 dB). The anchor release and the geophone clamp are operated by an acoustic command signal.So far, we have deployed our OBS's 42 times in the ocean. All of the OBS's deployed have been recovered safely. Seismic data has provided seismological evidence for a number of processes associated with tectonism along subduction zones and spreading ridges (e.g., Eguchi et al., 1986). 相似文献
16.
S. H. Johnson M. D. Cranford B. T. Brown J. E. Bowers R. E. McAllister 《Marine Geophysical Researches》1977,3(1):103-117
A compact and relatively low-cost ocean bottom seismograph has been constructed for use in marine seismic research. The instrument is deployed as a free-fall package and can record for 12.5 days. Signals from a vertical geophone, a hydrophone, and a clock are direct recorded on four channels of 6.35×10-3 m magnetic tape. A timed-release system returns the instrument to the surface. 相似文献
17.
为给寒区海域的波浪能估算提供科学依据,提出一种合理推算冰水共存海域波浪条件及波能流密度的方法,该方法将海冰模型与水动力学模型耦合模拟得到的冰浓度以线性修正函数的方式纳入波浪模型的海面摩阻风速方程中,并基于MCT (model coupling toolkit)耦合器将海冰模型、水动力学模型与波浪模型进行实时耦合。基于该方法模拟了渤海冬季寒潮大风期间的海冰以及波能流密度的演化。模拟结果表明,在2012年2月5~8日寒潮大风期间,结冰区域占到渤海总面积的1/3,约有76%的渤海海域的平均波能流密度受海冰影响减小,其中辽东湾近岸的波能流密度平均受冰影响最多减小了100%,而渤海湾和莱州湾近岸受冰影响最多分别减小了60%和50%。即使是无冰覆盖的老铁山水道,其波能流密度的最大值也受冰影响减少了14%。耦合模拟可以更为准确地对渤海冬季的波能流密度分布进行评估,为波浪能发电厂选址提供依据。 相似文献
18.
We describe recent mechanical andeelectronic modifications to the Cambridge Ocean Bottom Hydrophone system, enabling it to record in addition three geophone channels from a deployed, disposable geophone package. Examples of data from seismic refraction experiments show good correspondence between records of ground motion detected by the hydrophone and the vertical geophone. Seismic signals are undistorted by noise from instrument related sources. Clear examples of P to S conversions just below the receiver are observed. Improved recording conditions are achieved by deploying the geophones in a small pressure vessel as far away as possible from the main instrument package. 相似文献