WO2018145487A1 - 一种测量海水中声波速度的方法 - Google Patents

一种测量海水中声波速度的方法 Download PDF

Info

Publication number
WO2018145487A1
WO2018145487A1 PCT/CN2017/107567 CN2017107567W WO2018145487A1 WO 2018145487 A1 WO2018145487 A1 WO 2018145487A1 CN 2017107567 W CN2017107567 W CN 2017107567W WO 2018145487 A1 WO2018145487 A1 WO 2018145487A1
Authority
WO
WIPO (PCT)
Prior art keywords
velocity
seawater
wave
speed
seismic data
Prior art date
Application number
PCT/CN2017/107567
Other languages
English (en)
French (fr)
Inventor
宋建国
张庭荣
王征
陈继宗
Original Assignee
中国石油大学(华东)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 中国石油大学(华东) filed Critical 中国石油大学(华东)
Publication of WO2018145487A1 publication Critical patent/WO2018145487A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H5/00—Measuring propagation velocity of ultrasonic, sonic or infrasonic waves, e.g. of pressure waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V1/00—Seismology; Seismic or acoustic prospecting or detecting
    • G01V1/38—Seismology; Seismic or acoustic prospecting or detecting specially adapted for water-covered areas
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V2210/00—Details of seismic processing or analysis
    • G01V2210/60—Analysis
    • G01V2210/63—Seismic attributes, e.g. amplitude, polarity, instant phase

Definitions

  • the invention relates to a method for measuring the propagation speed of sound waves in seawater, and particularly relates to a method for obtaining sound wave propagation speed in seawater by using marine seismic exploration data, and belongs to the technical field of marine exploration.
  • the streamer In marine seismic exploration, the streamer is generally used for seismic data acquisition.
  • the streamer is placed at a certain depth below the sea surface, and the detector is arranged at a certain interval along the streamer to receive the seismic wave field. If the depths of all the detectors are equal, The horizontal cable is collected; if the depth of each detector is different, the cable is collected. In order to avoid the influence of waves and the like on the seismic wave field, the depth of the detector is generally not less than 5 m.
  • the longitudinal wave can only propagate in the fluid and the transverse wave cannot be propagated, the seismic wave propagates in the form of sound waves in the seawater.
  • the speed of seismic waves in seawater is the speed of sound waves in seawater.
  • Seismic waves can be thought of as plane waves propagating in different directions.
  • seismic waves can be divided into primary waves and virtual reflections.
  • One wave refers to the seismic wave propagating from below the cable to the receiving point.
  • the virtual reflection refers to the seismic wave that propagates to the sea surface and is reflected down to the receiving point. .
  • Acoustic velocity in seawater is a very important physical quantity and has important applications in marine exploration. Its size is affected by temperature, salinity and pressure (water depth), and it changes with space location and time. Acoustic velocity in seawater in marine oil and gas exploration is one of the key parameters for marine seismic data processing.
  • the echo sounder is therefore an important driving force for accurate measurement of seawater sound velocity, and this need is particularly acute for accurate target distance data in sonar applications.
  • the sound velocity measurement method in seawater generally adopts two methods: one is direct measurement method and the other is indirect measurement method.
  • the device generally used in the direct measurement method is a "sonic instrument", that is, usually fixed by using a transceiving transducer The speed of sound is measured within the distance, while the water depth is measured with a pressure sensor and a temperature compensation device.
  • a pressure sensor and a temperature compensation device According to different methods of obtaining the speed of sound, it is usually divided into ring ring method, standing wave interference method, pulse superposition method and phase method.
  • the indirect measurement rule is to measure the temperature, salinity and depth of seawater by hydrological instruments, such as temperature and depth gauges, and then use these environmental measurements to calculate the sound velocity and then calculate the sound velocity profile.
  • the object of the invention is a method for measuring the velocity of sound waves in seawater, which is directly calculated and acquired based on seismic data collected by marine horizontal cables or inclined cables, and has the characteristics of high measurement efficiency, true and accurate results, time and labor saving, low cost and the like.
  • the technical solution adopted by the present invention to achieve the above object is a method for measuring the acoustic wave velocity in seawater, which is characterized by directly calculating the marine seismic exploration data, and the specific steps are as follows:
  • the first step is to construct a plane wave model of the relationship between the primary wave in seawater and the corresponding sea level virtual reflection;
  • s(t) is the sample value of seismic data at time t;
  • h is the vertical height of the seismic wave receiving point from the sea level
  • ⁇ is the angle between the plane wave and the vertical direction
  • ⁇ is the time when the virtual reflection arrives at the receiving point later than the primary wave
  • V w is a variable indicating the sound wave speed setting value
  • a third step the calculated different directions of a superimposed wave energy value E and the ordinate as the ghost, the value corresponding to the speed of sound as abscissa, plotted as curve E with speed V w, which changes maxima of the curve corresponding to the set value is the acoustic wave velocity measured by the seawater acoustic velocity V w.
  • the above method for measuring the acoustic wave velocity in seawater is characterized in that
  • l is the distance between the phase plane of the virtual reflection and the first wave, and satisfies the following formula (1):
  • the above method for measuring the acoustic wave velocity in seawater is characterized in that the second step is performed by a computer, and the calculation flow is as follows:
  • equation (3) to calculate the energy E is superimposed at different speeds, and stores the value E, and Vw, for the curve plotted with the speed V w of E;
  • step (4) determining whether V w is greater than Ve, and if so, according to the E and V w values stored in step (4), using the superimposed energy E value as the ordinate and the corresponding acoustic velocity value V w as the abscissa, drawing Curve of E as a function of speed V w ;
  • the maximum value point of the variation curve is found, and the velocity V w corresponding to the maximum value point is the acoustic wave velocity V w in the seawater.
  • the seismic data described above is acquired based on a marine horizontal cable or a diagonal cable.
  • the technical effect directly brought by the above technical solutions is to construct a plane wave model between the primary wave in the seawater and the corresponding sea surface virtual reflection; establish the time difference relationship between the primary wave and the virtual reflection (the time difference relationship and the cable depth, the acoustic wave velocity in the seawater) Correlation); constructing the relationship between the superimposed energy of the primary wave and the virtual reflection and the acoustic wave velocity in the seawater; and designing a speed scan based on the rule that "the speed at which the superimposed energy is the strongest is the true seawater acoustic velocity" The method of acoustic velocity in seawater.
  • the above technical solution can obtain true and accurate acoustic wave velocity in seawater without any additional observation, and the obtained acoustic wave velocity in seawater is the velocity at the time of seismic data acquisition. This speed is more suitable for the processing of seismic data, and can also be used for general seawater velocity measurement purposes.
  • the present invention has the advantages of high measurement efficiency, time saving, labor saving, and cost saving as compared with the prior art.
  • Figure 1 is a plane wave model of the relationship between a primary wave and the corresponding sea surface virtual reflection
  • Figure 3 shows the acoustic velocity model in the ocean
  • Figure 4 is a synthetic seismic record of the velocity model of Figure 3, with a water depth of 20 m at the receiving point;
  • Figure 5 is a curve of superimposed energy as a function of speed, the speed range is 1200m / s to 2100m / s, an energy is calculated every 20m / s, the extreme point is 1500m / s;
  • Figure 6 shows an actual ocean seismic data with a receiving point depth of 20 m
  • Fig. 7 is a graph showing the superposition energy of the data shown in Fig. 6 as a function of speed, wherein the speed range is 1200 m/s to the data 2100 m/s, and an energy is calculated every 20 m/s, and the extreme point is 1480 m/s.
  • Figure 1 shows the plane wave model of the relationship between the primary wave in seawater and the corresponding sea surface virtual reflection.
  • 5 is the sea level
  • 4 is the receiving cable
  • 1 is any receiving point on the receiving cable
  • the distance of the receiving point from the sea level is h (h is not less than 5m);
  • the mirror point 2 of the receiving point 1 with respect to the sea level is above the sea level, and the vertical distance from the sea level is also h;
  • the primary wave is reflected at sea level to form a virtual reflection 7 .
  • the length of the ray 7 propagating downward from the sea level to the receiving point 1 is equal to the length of the ray 11 from the sea level up to the mirror point, and the first wave first arrives at the receiving point, and then the corresponding virtual reflection reaches the receiving point.
  • the time at which the ghost reflection reaches the receiving point is equivalent to the time at which the primary wave continues to propagate at the seawater sonic velocity to the mirror point 2.
  • the number 6 indicates the distance of multi-phase propagation of the virtual reflection and other phase planes; one earthquake 3 has four seismic wavelet waveforms representing two sets of primary waves and their corresponding virtual reflections, and the number 9 indicates that the primary waves correspond to them.
  • the distance 6 of the multi-phase of the virtual reflection and other multi-propagation is:
  • h is the depth at which the receiving point is at the sea surface
  • ⁇ is the angle between the plane wave and the vertical direction.
  • V w is the velocity of the acoustic wave in seawater
  • ⁇ is the time at which the virtual reflection arrives at the receiving point one time later.
  • the virtual reflection is the reflection of a wave at sea level, the reflection coefficient of the sea level is "-1". Therefore, the virtual reflection has the same shape and opposite polarity as the corresponding primary wave.
  • the primary wave is subtracted from the corresponding virtual reflection, and the value becomes twice the primary wave (negative negative negative). From the energy point of view, the energy of the subtracted signal (the sum of the squares of the sample values) is a primary wave. Four times the energy.
  • the seismic data is composed of a primary wave and a corresponding virtual reflection. Based on the relationship between the primary wave and the virtual reflection, the energy calculation formula of the subtraction signal is proposed.
  • s(t) is the sample value of the seismic data at time t.
  • the squared term in formula (3) is the squared value after subtracting the virtual reflection (negative negative positive) sample, and the squared value becomes twice the value of one wave sample.
  • the virtual reflection enhances the primary wave energy. Under ideal conditions, it is four times.
  • the superposition energy E is calculated according to the formula (3), and E reaches a maximum value when the speed is the value of the acoustic wave velocity in the seawater, and is a small value when the velocity is too large or too small;
  • FIG. 2 is a flow chart of the energy curve calculation of the present invention. As shown in Figure 2, the energy curve calculation process is as follows:
  • step (6) determining whether V w is greater than Ve, and if so, retaining the superimposed energy E value calculated in step (4) according to the E and V w values stored in step (4), and using the superimposed energy E value as the ordinate Taking the corresponding acoustic velocity value V w as the abscissa, plot the curve of E with the velocity V w ;
  • the acoustic wave propagation velocity is about 1500 m/s, and in the formation below seawater, the acoustic wave propagation velocity is about 2500 m/s.
  • the velocity corresponding to the maximum point is determined to be 1500 m/s, which is consistent with the acoustic velocity (1500 m/s) in the seawater in the model shown in Fig. 3.
  • This value is very close to the acoustic velocity of the sea area provided by CNOOC Tianjin Branch after the measurement of the sea area by the sonar in the sea area of 1490 m / s.
  • the method for measuring the acoustic wave velocity in seawater of the present invention can completely replace the on-site measurement method of the instrument. Therefore, it is more convenient and quicker, saves time and effort, and can greatly improve measurement efficiency and save on-site measurement costs.

Landscapes

  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Oceanography (AREA)
  • Geology (AREA)
  • Remote Sensing (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geophysics (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

一种测量海水中声波速度的方法，利用基于海洋水平缆或斜缆采集得到的海洋地震勘探数据直接计算得出。通过先构建海水中一次波和相应的海平面虚反射之间关系的平面波模型；然后，提取若干道地震数据，对每一道海洋地震数据，分别按公式计算出不同方向来的一次波与虚反射的叠加能量E，依据绘制出的E随速度V W的变化曲线的极大值点所对应的速度确定出海水中声波速度V w。直接利用海洋地震勘探的数据，不需要额外的观测，即可获得真实准确的海水中声波速度，测量效率高，省时、省力、省费用；并且，由于所获得的海水中声波速度就是地震数据采集时的速度，因而，更适合于地震数据的处理中使用。

Description

一种测量海水中声波速度的方法 技术领域
本发明涉及一种测量海水中声波传播速度的方法，具体涉及一种利用海洋地震勘探数据获取海水中声波传播速度的方法，属于海洋勘探技术领域。
背景技术
海洋地震勘探中，一般采用拖缆进行地震数据采集，拖缆在海水面下一定的深度上，沿着拖缆以一定的间隔布设检波器接收地震波场，若所有检波器的深度是相等的，则为水平缆采集；若各检波器的深度不同，则为斜缆采集，为了避开海浪等对地震波场的影响，检波器的深度一般不小于5m。
由于流体中只能传播纵波，不能传播波横波，因此地震波在海水中是以声波形式传播的。海水中地震波的速度就是海水中声波的速度。
地震波可以看成是不同方向传播的平面波。海洋地震勘探中，可以把地震波分为一次波和虚反射，其中一次波是指从电缆下方传播到接收点的地震波，虚反射指的是地震波传播到海水水面被反射向下到达接收点的地震波。
海水中声波速度是一个非常重要的物理量，在海洋勘探中有着重要的用途，其大小受到温度、盐度和压强(水深)的影响，随着空间位置和时间不断变化。在海洋油气勘探中海水中声波速度是海洋地震资料处理的关键参数之一。
如何精确求取声波在海水中的传播速度是一个重要的研究课题。
早在1827年，法国数学家Sturm和瑞士物理学家Colladon在日内瓦湖进行过水中声速测量的试验，并得到了极为正确的淡水声速。在上世纪初，水中声速值的精确测量为水声的实际应用奠定了扎实的基础：人们在灯塔上安装好潜水钟和雾号，根据在船上测量钟声在水中传播和雾号声在空气中传播的时间间隔测量航船与灯塔间的距离。从量纲上考虑，将声在海水中传播的时间转换为距离时都必须是精确的声速值。不同时间在同一海域，回声测深仪性能会由于“午后效应”的影响而发生变化，所谓“午后效应”，即回声测距设备，每到下午性能就下降的现象。由于太阳辐射，深表层水温于下午升高，形成负梯度型声速分布，使声波向下折射，因此上午能够探测到的目标，午却因声波折射而处于声波阴影区之中，信号显著减弱，甚至完全消失。回声测深仪因此成为精确测量海水声速的重要推动原因，而这种需要对于声纳应用中获得精确的目标距离数据显得尤为突出。
现有技术中，海水中的声速测量方法一般采取两种方式：一种是直接测量法，另一种是间接测量法。其中，直接测量法一般使用的设备为“声速仪”，即通常利用收发换能器在固定 距离内测量声速，同时以压力传感器及温度补偿装置测量水深。根据获取声速的方法不同，通常情况下又分为环鸣法、驻波干涉法、脉冲叠加法以及相位法等。
间接测量法则是通过水文仪器，如温盐深仪等来测量海水的温度、盐度和深度，再利用这些环境测量与声速的经验公式，进而通过计算达到声速剖面。
以上所描述的目前国内的海水中声速的测量方法在很大程度上都依赖于对海洋环境要素的变化规律的掌握。但是，大自然的变化万千，随着时间的不同以及各种细微的变化，各项参数都各有不同。
对于海洋地震勘探来说，如何寻求一种能够测量地震数据采集时海水中声波速度方法非常重要，可以更加精确地提供地震资料处理所需要的还是声速信息，提高地震资料处理的精度和效果。
发明内容
本发明的目的是一种测量海水中声波速度的方法，其基于海洋水平缆或斜缆采集的地震数据直接计算获取，具有测量效率高、结果真实、准确，省时省力、成本低等特点。
本发明为实现上述目的所采用的技术方案是，一种测量海水中声波速度的方法，其特征在于，利用海洋地震勘探数据直接计算得出，具体步骤如下：
第一步，构建海水中一次波和相应的海平面虚反射之间关系的平面波模型；
第二步，提取若干道地震数据，对每一道海洋地震数据，分别按下式(3)计算出不同方向来的一次波与虚反射的叠加能量E：
Figure PCTCN2017107567-appb-000001
上式(3)中：
s(t)为地震数据在t时刻的样点值；
h为地震波接收点距离海平面的垂直高度；
α为平面波与竖直方向的夹角；
τ为虚反射比一次波晚到达接收点时间；
Vw为变量，表示声波速度设定值；
第三步，将计算出的不同方向来的一次波与虚反射的叠加能量E数值作为纵坐标、以与其对应的声波速度数值作为横坐标，绘制成E随速度Vw的变化曲线，该变化曲线的极大值点所对应的声波速度设定值即为测量出的海水中声波速度Vw。
优选为，上述的测量海水中声波速度的方法，其特征在于，
Figure PCTCN2017107567-appb-000002
上式(2)中：
l为虚反射等相位面比一次波多传播的距离，满足下式(1)：
l＝2hcosα  (1)。
进一步优选，上述的测量海水中声波速度的方法，其特征在于，第二步由计算机执行，计算流程如下：
(1)、提取一道地震数据；
(2)、从地震数据道头中提取地震波接收点的深度h；
(3)、设定表示平面波方向的角度α范围、初始速度Vs、速度增量Δv和终止速度Ve；
(4)、用公式(3)计算出不同速度下的叠加能量E，并保存E和Vw数值，用于绘制E随速度Vw的变化曲线；
(5)、设定速度增加量Vw＝Vw+Δv；
(6)、判断Vw是否大于Ve，若是，则根据步骤(4)保存的E与Vw数值，以叠加能量E数值作为纵坐标、以与其对应的声波速度数值Vw作为横坐标，绘制E随速度Vw的变化曲线；
若否，则返回步骤(4)；
(7)、当E随速度Vw的变化曲线绘制完成后，找出变化曲线的极大值点，该极大值点所对应的速度Vw，即为海水中声波速度Vw。进一步优选，上述地震数据是基于海洋水平缆或斜缆采集得到的。
上述技术方案直接带来的技术效果是，通过构建海水中一次波和相应的海面虚反射之间的平面波模型；建立一次波与虚反射的时差关系(该时差关系与电缆深度、海水中声波速度相关)；构建一次波与虚反射的叠加能量与海水中声波速度的计算关系式；并基于“使叠加能量最强的速度就是真正的海水声波速度”的规则设计了一种通过速度扫描来确定海水中声波速度的方法。
上述技术方案通过直接利用海洋地震勘探的数据，不需要任何额外的观测，即可获得真实准确的海水中声波速度，并且，所获得的海水中声波速度就是地震数据采集时的速度。该速度更适合于地震数据的处理中使用，同时也能用于一般的海水速度测量目的。
即，本发明相对于现有技术，具有测量效率高，省时、省力、省费用等有益效果。
附图说明
图1为一次波和相应的海面虚反射之间关系的平面波模型；
图2为本发明的能量曲线计算流程图；
图3为海洋中声波速度模型；
图4为图3所速度模型的一道合成地震记录，接收点水深20m；
图5为叠加能量随速度变化的曲线，速度范围为1200m/s到2100m/s，每隔20m/s计算一个能量，极值点在1500m/s；
图6为一道实际的海洋地震数据，接收点深度为20m；
图7为图6所示数据的叠加能量随速度变化的曲线，其中，速度范围为1200m/s到资料2100m/s，每隔20m/s计算一个能量，极值点在1480m/s。
附图标记说明：
1、接收点，2、镜像点，3、一道地震记录，4、接收电缆，5、海平面，6、虚反射等相位面多传播的距离，7、虚反射，8、一次波，9、时差，10、平面波的等相位面，11、虚反射从海平面到镜像点的射线。
具体实施方式
下面结合附图，对本发明进行详细说明。
图1为海水中一次波和相应的海面虚反射之间关系的平面波模型。
如图1所示，图中5为海平面，4为接收电缆，1为接收电缆上的任意一个接收点，该接收点距海平面的距离为h(h不小于5m)；
接收点1相对于海平面的镜像点2，位于海平面之上，距海平面的垂直距离也为h；
8为两组来自不同方向的一次平面波，简称一次波，其中一组以α角入射到海平面的一次波等相位面10；
一次波在海平面被反射，形成虚反射7。
虚反射7从海平面向下传播到达接收点1的射线的长度与虚反射从海平面向上到镜像点的射线11的长度是相等的一次波先到达接收点，然后对应的虚反射到达接收点。
虚反射到达接收点的时间等同于一次波以海水声波速度继续传播到达镜像点2的时间。
图1中，数字6表示的是虚反射等相位面多传播的距离；一道地震3上面有四个地震子波波形，代表两组一次波及其对应的虚反射，数字9表示一次波与其对应的虚反射到达接收点的旅行时之差τ。
如图1所示，虚反射等相位面多传播的距离6(虚反射等相位面比一次波多传播的距离)为：
l＝2hcosα  (1)
式(1)中，h为接收点在海面一下的深度，α为平面波与竖直方向的夹角。
根据如图1所示的海水中一次波和相应的海面虚反射之间关系的平面波模型，建立一次波与虚反射的时差关系为：
Figure PCTCN2017107567-appb-000003
式中Vw为海水中声波的速度，τ为虚反射比一次晚到达接收点时间。
由于虚反射是一次波在海平面上的反射，海平面的反射系数为“-1”。因此，虚反射与对应的一次波相比，形状相同、极性相反。一次波与对应的虚反射相减，数值变为一次波的两倍(负负得正)，从能量的角度来看，相减后信号的能量(样点数值的平方和)则是一次波能量的四倍。
地震数据是由一次波与相应的虚反射组成的，根据一次波与虚反射的关系提出相减信号的能量计算公式。
考虑到虚反射与一次波存在时差τ，根据上式(1)和上式(2)把不同方向α来的一次波减去虚反射后平方求和，提出下式所示的相减信号叠加能量公式：
Figure PCTCN2017107567-appb-000004
上式(3)中，s(t)为地震数据在t时刻的样点值。
在速度正确时，公式(3)中的平方项是一次波减去虚反射(负负得正)样点后数值、成为一次波样点数值两倍后的平方，虚反射加强了一次波能量，理想条件下是四倍。
在速度与海水速度不一致时计算的时间延迟τ与实际情况不符合，公式(3)中的平方项不再是一次波减去对应的虚反射，而是一次波减去一个随机的样点数值后的平方，能量得不到显著加强。
因此，根据公式(3)计算叠加能量E，在速度取值为海水中声波速度时E达到极大值，在速度偏大或偏小时E为较小的数值；
对一道海洋地震数据，用公式(3)计算不同速度下的叠加能量E，得到E随速度Vw的变化曲线，极值点对应的速度就是海水中声波速度。
图2为本发明的能量曲线计算流程图。如图2所示，能量曲线计算流程如下：
(1)、提取一道如图4所示的20m深接收点合成地震记录，如图3所示，其速度模型的合成地震道包含一次波和虚反射；
(2)、从地震数据道头中提取地震波接收点的深度h；
(3)、设定表示平面波方向的角度α范围、初始速度Vs、速度增量Δv和终止速度Ve；
(4)、用公式(3)计算出不同速度下的叠加能量E，并保存E和Vw数值，用于绘制E随速度Vw的变化曲线；
(5)、设定速度增加量Vw＝Vw+Δv；
(6)、判断Vw是否大于Ve，若是，则根据步骤(4)保存的E与Vw数值保留步骤(4) 计算出的叠加能量E数值，并，以该叠加能量E数值作为纵坐标、以与其对应的声波速度数值Vw作为横坐标，绘制E随速度Vw的变化曲线；
若否，则返回步骤(4)；
(7)、当E随速度Vw的变化曲线绘制完成后，找出变化曲线的极大值点，该极大值点所对应的速度Vw，即为海水中声波速度Vw。图3为海洋中声波速度模型。
如图3所示，在1000米深的海水中，声波传播速度约为1500m/s，海水以下的地层中，声波的传播速度约2500m/s。
如图5所示，确定极大值点对应的速度为1500m/s，与图3所示模型中海水中声波速度(1500m/s)一致。
该数值与图3中海水中声波速度完全吻合。
证明，本发明的测量海水中声波速度的方法，所获得的声波速度的结果是正确的、可靠的。
下面结合实施例，对本发明作进一步的说明。
实施例1：
(1)取某海洋地震勘探数据一道，如图6所示；
(2)设定角度α范围为0°-90°、初始速度Vw＝1200m/s、速度增量Δv＝20m/s和终止速度Vend＝2100m/s；
(3)用公式(3)计算E；
(4)绘制出能量E随速度Vw变化曲线，如图6所示，确定能量E随速度Vw变化曲线中极大值点对应的速度为1480m/s。
该数值与中海油服天津分公司用声纳在该海域测量后提供的该海区的声波速度1490m/s，数值非常接近。
表明：本发明的测量海水中声波速度的方法，完全可以替代仪器的现场测量方法。从而，更加方便快捷，既省时省力，有可大幅提高测量效率、节省现场测量费用。

Claims (4)

  1. 一种测量海水中声波速度的方法，其特征在于，利用海洋地震勘探数据直接计算得出，具体步骤如下：
    第一步，构建海水中一次波和相应的海平面虚反射之间关系的平面波模型；
    第二步，提取若干道地震数据，对每一道海洋地震数据，分别按下式(3)计算出不同方向来的一次波与虚反射的叠加能量E：
    Figure PCTCN2017107567-appb-100001
    上式(3)中：
    s(t)为地震数据在t时刻的样点值；
    h为地震波接收点距离海平面的垂直高度；
    α为平面波与竖直方向的夹角；
    τ为虚反射比一次波晚到达接收点时间；
    Vw为变量，表示声波速度设定值；
    第三步，将计算出的不同方向来的一次波与虚反射的叠加能量E数值作为纵坐标、以与其对应的声波速度数值作为横坐标，绘制成E随速度VW的变化曲线，该变化曲线的极大值点所对应的声波速度设定值即为测量出的海水中声波速度Vw。
  2. 根据权利要求1所述的测量海水中声波速度的方法，其特征在于，
    Figure PCTCN2017107567-appb-100002
    上式(2)中：
    l为虚反射等相位面比一次波多传播的距离，满足下式(1)：
    l＝2hcosα  (1)。
  3. 根据权利要求1所述的测量海水中声波速度的方法，其特征在于，第二步由计算机执行，计算流程如下：
    (1)、提取一道地震数据；
    (2)、从地震数据道头中提取地震波接收点的深度h；
    (3)、设定表示平面波方向的角度α范围、初始速度Vs、速度增量Δv和终止速度Ve；
    (4)、用公式(3)计算出不同速度下的叠加能量E，并保存E和Vw数值，用于绘制E随速度VW的变化曲线；
    (5)、设定速度增加量Vw＝Vw+Δv；
    (6)、判断Vw是否大于Ve，若是，则根据步骤(4)保存的E与Vw数值，以叠加能量E数值作为纵坐标、以与其对应的声波速度数值Vw作为横坐标，绘制E随速度VW的变化曲 线；
    若否，则返回步骤(4)；
    (7)、当E随速度VW的变化曲线绘制完成后，找出变化曲线的极大值点，该极大值点所对应的速度Vw，即为海水中声波速度Vw。
  4. 根据权利要求1至3任一所述的测量海水中声波速度的方法，其特征在于，所述地震数据是基于海洋水平缆或斜缆采集得到的。
PCT/CN2017/107567 2017-02-13 2017-10-25 一种测量海水中声波速度的方法 WO2018145487A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201710075413.X 2017-02-13
CN201710075413.XA CN106959152B (zh) 2017-02-13 2017-02-13 一种测量海水中声波速度的方法

Publications (1)

Publication Number Publication Date
WO2018145487A1 true WO2018145487A1 (zh) 2018-08-16

Family

ID=59481076

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/107567 WO2018145487A1 (zh) 2017-02-13 2017-10-25 一种测量海水中声波速度的方法

Country Status (2)

Country Link
CN (1) CN106959152B (zh)
WO (1) WO2018145487A1 (zh)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106959152B (zh) * 2017-02-13 2018-06-05 中国石油大学(华东) 一种测量海水中声波速度的方法
CN108983284B (zh) * 2018-06-22 2020-03-10 中国石油大学(华东) 一种适用于海上斜缆数据的f-p域鬼波压制方法
CN109725053B (zh) * 2019-01-22 2021-03-12 中国人民解放军国防科技大学 基于高分辨率海洋再分析产品获取水声场特性数据的方法
CN114814276B (zh) * 2022-03-21 2023-08-18 汕头大学 海上风电设备运行导致周边海水垂向运动流速的计算方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4236406A (en) * 1978-12-11 1980-12-02 Conoco, Inc. Method and apparatus for sonic velocity type water cut measurement
DE3704472A1 (de) * 1987-02-13 1988-08-25 Standard Elektrik Lorenz Ag Messeinrichtung zur messung der relativgeschwindigkeit
CN101482614A (zh) * 2008-01-07 2009-07-15 格库技术有限公司 声音传播速度建模方法、装置和系统
CN102853896A (zh) * 2011-06-29 2013-01-02 瑟塞尔公司 声学节点网络中估计水下声速的方法，存储构件和装置
CN103575927A (zh) * 2012-07-26 2014-02-12 瑟塞尔公司 声节点的水速的估计方法
CN106959152A (zh) * 2017-02-13 2017-07-18 中国石油大学(华东) 一种测量海水中声波速度的方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080008037A1 (en) * 2006-07-07 2008-01-10 Welker Kenneth E Acoustic propagation velocity modeling methods, apparatus and systems
WO2010138625A1 (en) * 2009-05-27 2010-12-02 Teledyne Rd Instruments Method and system for remote sound speed measurement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4236406A (en) * 1978-12-11 1980-12-02 Conoco, Inc. Method and apparatus for sonic velocity type water cut measurement
DE3704472A1 (de) * 1987-02-13 1988-08-25 Standard Elektrik Lorenz Ag Messeinrichtung zur messung der relativgeschwindigkeit
CN101482614A (zh) * 2008-01-07 2009-07-15 格库技术有限公司 声音传播速度建模方法、装置和系统
CN102853896A (zh) * 2011-06-29 2013-01-02 瑟塞尔公司 声学节点网络中估计水下声速的方法，存储构件和装置
CN103575927A (zh) * 2012-07-26 2014-02-12 瑟塞尔公司 声节点的水速的估计方法
CN106959152A (zh) * 2017-02-13 2017-07-18 中国石油大学(华东) 一种测量海水中声波速度的方法

Also Published As

Publication number Publication date
CN106959152B (zh) 2018-06-05
CN106959152A (zh) 2017-07-18

Similar Documents

Publication Publication Date Title
US11733381B2 (en) Sound velocity profile inversion method based on inverted multi-beam echo sounder
WO2018145487A1 (zh) 一种测量海水中声波速度的方法
CN106154276B (zh) 基于海底混响和传播损失的深海海底参数反演方法
CN104820218B (zh) 一种基于频域自相关的浅海海底单参数反演方法
CN111142071B (zh) 一种结合半经验公式的单阵元匹配场爆炸声源定位方法
CN104678384B (zh) 一种波束域的声压差互相关谱分析水下目标速度估计方法
Gunn et al. Calibrated seismic imaging of eddy‐dominated warm‐water transport across the Bellingshausen Sea, Southern Ocean
CN104268848A (zh) 一种海洋内波波速监测的方法
CN101576621B (zh) 海底电缆双检地震勘探的数据处理方法及数据处理装置
CN113686964A (zh) 一种基于泄漏模态声波导特性的海冰厚度观测方法
US20130325427A1 (en) Methods and systems for computing notional source signatures from near-field measurements and modeled notional signatures
Gong et al. Combined migration velocity model-building and its application in tunnel seismic prediction
CN110780340B (zh) 一种浅海弹性软沉积层横波声速或厚度的反演方法
US10317543B2 (en) Estimation of a far field signature in a second direction from a far field signature in a first direction
CN113777654B (zh) 一种基于伴随状态法初至波走时层析的海水速度建模方法
Huang et al. Estimation of seawater movement based on reflectors from a seismic profile
CN109490962A (zh) 一种浅地层剖面非零偏移距的消除方法
CN114838808A (zh) 一种基于浅海声信道响应的打桩冲击噪声源级测量系统及方法
CN113419288A (zh) 地下掩体反演的数据探测与预处理方法
CN105891541B (zh) 基于层间相关性的adcp表层盲区流速估算方法
Mosquera et al. Salinity estimation from acoustic Doppler velocimeter measurements
US10067254B2 (en) Removal of an estimated acquisition effect from a marine survey measurement
Morozov et al. Methodical aspects of the application of acoustic doppler current profilers in the black sea
US10401515B2 (en) Estimation of water properties from seismic data
Yang et al. Enhanced mixing at the edges of mesoscale eddies observed from high‐resolution seismic data in the Western Arctic Ocean

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17895648

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17895648

Country of ref document: EP

Kind code of ref document: A1