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Dec 2, 2013 - Gao Xiao-Wei, Chen Shi-Bo, Chen Jian-Bing, Zheng Qin-Hong, Yang Hai. Chin. Phys. B . 2012, 21(6): 064301. Full Text: PDF (402KB).
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Dear authors, Thank you very much for your contribution to Chinese Physics B. Your paper has been published in Chinese Physics B, 2014, Vol.23, No.1. Attached is the PDF offprint of your published article, which will be convenient and helpful for your communication with peers and coworkers. Readers can download your published article through our website http://www.iop.org/cpb or http://cpb.iphy.ac.cn What follows is a list of related articles published recently in Chinese Physics B.

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Acoustic scattering from a submerged cylindrical shell coated with locally resonant acoustic metamaterials

Li Li, Wen Ji-Hong, Cai Li, Zhao Hong-Gang, Wen Xi-Sen Chin. Phys. B . 2013, 22(1): 014301. Full Text:

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Point defect states of a hollow cylinder in two-dimensional phononic crystal

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Chin. Phys. B Vol. 23, No. 1 (2014) 014301

Seismoelectric waves in a borehole excited by an external explosive source∗ Zhou Jiu-Guang(周久光)a)b) , Cui Zhi-Wen(崔志文)a)† , L¨u Wei-Guo(吕伟国)a) , Zhang Yu-Jun(张玉君)a) , and Wang Ke-Xie(王克协)a) a) College of Physics, Jilin University, Changchun 130012, China b) School of Basic Medical, Beihua University, Jilin 132001, China (Received 24 January 2013; revised manuscript received 27 March 2013; published 2 December 2013)

The conversion of energy between seismic and electromagnetic wave fields has been described by Pride’s coupled equations in porous media. In this paper, the seismoelectric field excited by the explosive point source located at the outside of the borehole is studied. The scattering fields inside and outside a borehole are analyzed and deduced under the boundary conditions at the interface between fluid and porous media. The influences of the distance of the point source, multipole components of the eccentric explosive source, and the receiving position along the axis of vertical borehole, on the converted waves inside the borehole are all investigated. When the distance from the acoustic source to the axis of a borehole is far enough, the longitudinal and coseismic longitudinal wave packets dominate the acoustic and electric field, respectively. The three components of both electric field and magnetic field can be detected, and the radial electric field is mainly excited and converted by the dipole component. Owing to the existence of borehole, the electric fields and magnetic fields in the borehole are azimuthal. The distance from the point where the maximum amplitude of the axial components of electric field is recorded, to the origin of coordinate indicates the horizontal distance from the explosive source to the axis of vertical borehole.

Keywords: poroelastic wave, borehole, scattering field, explosive source PACS: 43.20.+g, 91.60.Lj, 91.30.–f

DOI: 10.1088/1674-1056/23/1/014301

1. Introduction Grain surfaces in contact with an electrolyte adsorb a chemically bound surface charge that is balanced by mobile counter ions in a thin fluid layer surrounding the grains. The ensemble of bound and mobile charge layers is referred to as the electric double layer. [1] Thus, a seismic wave that travels through a porous medium induces the pore fluid motion. The fluid motion with respect to the charge bound to the grain surface transports the mobile counter ions in the double layer and generates an electric wave current on the scale of the wavelength. In brief, the seismoelectric effect is the coupling between the elastic wave fields and the electromagnetic fields in the range of seismic frequencies. For a fluid-saturated porous medium, we can distinguish two kinds of seismoelectric effects. (1) Inside a homogeneous porous medium, a coseismic electric field is coupled to a seismic wave and therefore propagates with seismic wave velocity. [2] The coseismic magnetic fields associated with a Stoneley wave [3] and a shear wave have been measured. [4,5] (2) At an interface between two distinct porous media, a seismic wave induces a radiating electromagnetic (EM) wave that can be received synchronously at multilocations. [2,6] These effects have been verified experimentally

in the laboratory [7–10] and in the field. [11–17] Seismoelectric imaging can combine the high-spatialresolution seismic data with the sensitivities of electrical method to fluid content, connectivity, and composition. Seismoelectric investigations have been made to image the subsurface, and also to locate potential oil and gas reservoirs. [18] Especially the method of acoustoelectric well logging in porous media has been proposed to detect deep target formation. There have been many numerical simulations [19–23] and experiments [3,7,8,24–27] on the seismoelectric effect that the acoustic source located inside a borehole, especially the non-axisymmetric acousto-electric field excited by an eccentric acoustic source in the borehole, was considered by Cui et al. [23] In the above case, the incident field was the only acoustic wave field excited by an acoustic source located in the borehole. In order to survey cross borehole, several well-known experiments were performed by Zhu and Toks¨oz, [9] and Araji et al. [28] proposed a cross-hole imaging approach (for obtaining compact volumetric current source distributions) based on seismoelectric conversions. [28] In such a case, the seismoelectric coupling effect between the incident acoustic wave field and the shooting borehole needs to be considered. Moreover, Gao and Hu [29] studied the properties of seismoelectromagnetic waves radiated by a double couple in the porous for-

∗ Project

supported by the National Natural Science Foundation of China (Grant Nos. 40974067, 11134011, and 41004044), the State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLOA201108), and the Scientific Forefront and Interdisciplinary Innovation Project of Jilin University, China. † Corresponding author. E-mail: [email protected] © 2014 Chinese Physical Society and IOP Publishing Ltd http://iopscience.iop.org/cpb   http://cpb.iphy.ac.cn

014301-1

Chin. Phys. B Vol. 23, No. 1 (2014) 014301 mation, and they also [30] investigated the surface electromagnetic wavefields generated by a finite fault. To the best of our knowledge, an insightful understanding of acoustoelectric field characteristics which are excited and converted by the acoustic source outside the borehole, is lacking at present. In the present paper, we will focus on the non-axisymmetric acoustic-electric field excited by an eccentric acoustic source outside of the borehole. We theoretically formulate and numerically simulate the seismoelectric field in a fluid-filled borehole. The full waveforms of acoustic waves and electromagnetic waves propagating in the borehole are simulated and investigated.

2. Model and theory 2.1. Physical model Physical model is shown in Fig. 1, a point source is located at (r0 , θ 0 , 0) outside the borehole in a cylindrical coordinate system, and the z axis is coincident with the axis of vertical borehole. Here, r0 is the distance from the point source to the axis of coordinate, θ 0 is the inclined angle, i.e., the offx-axis angle of the source. The receiving devices are located at position (rre , θ , z) inside the borehole, with rre being the distance from the receivers to the z axis, and θ being the angle of the receivers relative to the x axis. borehole

z

I

II

R

r

rre o

R

y

θ r0

x

source

θ0

Fig. 1. Physical model.

2.2. Seismoelectric waves in the saturated porous medium According to Pride’s theory, in the absence of the applied force and electric current sources, we may write the equations for the coupled electromagnetic and acoustic fields in fluid saturated porous medium as follows:

𝐵 = µ𝐻,

(1h)

𝐷 = ε𝐸.

(1i)

These governing equations are the Biot equations for porous medium acoustics along with the Maxwell equations for the electric and magnetic fields 𝐸 and 𝐻. Here, 𝜏 is the bulk stress in the porous medium, p is the pressure in the pore fluid, 𝑢 is the displacement in the solid, and 𝑤 is the relative fluid–solid motion. The symbol ρ denotes the bulk density of the porous medium. The fourth and fifth equations are in the form of Darcy law and Ohm’s law, through which acoustic and electromagnetic fields are coupled. Here, 𝐽 is the electriccurrent density; −iω𝑤 is the Darcy filtration velocity; H, C, M, and G are four moduli of isotropic porous medium; ε is the permittivity of porous medium; σ (ω) is the frequencydependent electrical conductivity of the medium; κ(ω) is the dynamic permeability; η is the fluid dynamic viscosity coefficient; L(ω) is the frequency-dependent electrokinetic coupling coefficient. The expressions for σ (ω), k(ω), and L(ω) are given in Refs. [1], [2], and [6]. We decompose basic vector fields 𝑢, 𝑤, and 𝐸 into their compressional, vertically and horizontally polarized shear components, and further express them in terms of scalar potential functions which can be found in Ref. [22].   𝑢(r) = ∑ ∇ϕ j j=pf,ps + ∑ ∇ × (χ j ez ) j=sh,te  + ∑ ∇ × ∇ × (Γj ez ) j=sv,tm , (2a)   𝑤(r) = ∑ a j ∇ϕj j=pf,ps + ∑ a j ∇ × (χ j ez ) j=sh,te  + ∑ a j ∇ × ∇ × (Γj ez ) j=sv,tm , (2b)   (r) 𝐸 = ∑ β j ∇ϕ j j=pf,ps + ∑ β j ∇ × (χ j ez ) j=sh,te  (2c) + ∑ β j ∇ × ∇ × (Γj ez ) j=sv,tm , where ϕ j is the compressional wave potential; ez is the unit vector in thez direction; χ j is the horizontal polarized shear potential; Γ j is vertically polarized shear wave potential. The expressions for α j and β j ( j = pf, ps, sh, te, sv, tm) are given in Ref. [2]. The overall seismoelectric fields outside the borehole should include the incident field produced by the acoustic source and the reflection field induced by the boundary in borehole wall. 2.2.1. Incident field in fluid-saturated porous medium

∇ × 𝐸 = iω𝐵,

(1a)

∇ × 𝐻 = iω𝐷 + 𝐽 ,

(1b)

2

∇ · 𝜏 = −ω (ρ𝑢 + ρf 𝑤),

(1c)

𝐽 = σ (ω)𝐸 + L(ω)(−∇p + ω 2 ρf 𝑢),

(1d)

2

−iω𝑤 = L𝐸 + (−∇p + ω ρf 𝑢)κ(ω)/η,

(1e)

An explosive source is assumed to be located at the point (r0 , θ 0 , 0), and it will radiate spherical wave with velocity Vpf in the infinite porous formation. Using the cylinder integral and Bessel function addition theorem, the displacement potential of a explosive point source in the frequency-axialwavenumber domain can be expressed as

T

𝜏 = (H − 2G)(∇ · 𝑢)𝐼 +C(∇ · 𝑤)𝐼 + G(∇𝑢 + ∇𝑢 ), (1f) −p=C∇ · 𝑢+M∇ · 𝑤,

(1g) 014301-2

φ (d) (r, θ , kz , ω) = −Q

F(ω) ∞ ∑ εn Kn (ηpf r0 ) 2π n=0

Chin. Phys. B Vol. 23, No. 1 (2014) 014301 × In (ηpf r) cos n(θ − θ0 ),

(3)

where F(ω) is the Fourier transform of the acoustic source function f (t); Q is the volume constant (for convenience, we set Q = 1 m3 ); ε n is Neumann’s factor (ε n = 1 for n = 0; 2 = ε n = 2 for n 6= 0); η pf is the radial wavenumber and ηpf 2 2 2 th k − ω /Vpf ; In and Kn denote the n -order modified Bessel function of first kind and that of second kind, respectively. It should be noted that for the convenience of discussion, we set θ 0 = 0 in the following content. Combining Eqs. (3), (1g), and (2), we can obtain the pore fluid pressure, the displacement of the solid 𝑢(d) , the relative velocity of fluid-solid motion 𝑤(d) , and the accompanied electric field 𝐸 (d) . However, the accompanied magnetic field 𝐻 (d) = 1/(iω µ) × 𝐸 = 0. 2.2.2. Reflection medium

field

in

fluid-saturated

porous

Outside the borehole, for the radiation conditions, the solutions of the reflection field are given by (r)

Z +∞ ∞

(r)

−∞ n=0 j=pf,ps Z +∞ ∞

(r)

−∞ n=0 j=sh,te Z +∞ ∞

ϕn (r, θ , z) = χn (r, θ , z) = Γn (r, θ , z) =

∑ ∑

Anj Kn (η j r) cos nθ e ikz z dkz , (4a)

∑ ∑

Anj Kn (η j r) sin nθ e ikz z dkz , (4b)

∑ ∑

Anj Kn (η j r) cos nθ e ikz z dkz . (4c)

−∞ n=0 j=sv,tm

According to Eqs. (2) and (4), the basic vector fields 𝑢, 𝑤, and 𝐸 can be obtained. Applying them to Eq. (1), all other quantities such as stress tensor, pore fluid pressure, and magnetic vector can also be deduced. The detailed expressions of these formulations can be found in Ref. [22]. So far, outside the borehole, the total fields including the incident field and reflect field can be induced. 2.3. Acoustic and electromagnetic fields inside the borehole

2.3.2. Electromagnetic field inside the borehole When the electromagnetic field is relevant to angle, a separation variable approach is needed to deal with the components of the electric field on the radial non-homogeneous second-order partial differential equations. For convenience, we take the longitudinal component of electromagnetic field as auxiliary condition function, i.e.,  Z 1 +∞ ∞ e   E (r, θ , z) =  ∑ An In (ηe r) cos nθ e ikz z dkz ,  z 2π −∞ n=0 (6) Z  1 +∞ ∞ h  ikz z   Hz (r, θ , z) = ∑ An In (ηe r) sin nθ e dkz , 2π −∞ n=1 where ηe2 = kz2 − ke2 , ke2 = ω 2 µe εb , and εb = εf + iσf /ω, with µ e being the magnetic permeability. Substituting Eq. (6) into Maxwell’s equation, transverse field components are obtained, and detailed expressions of those formulations could be found in Ref. [22]. 2.4. Boundary condition The boundary conditions of seismoelectric waves for a cylindrical interface at the position r = a between a fluid and a fluid-saturated formation are   (ur )II + (wr )II = (Ur )I , (pf )II = (p)I , (τrr )II = (−p)I , (τrz )II = 0, (τrθ )II = 0, (Eθ )II = (Eθ )I , (7)  (Ez )II = (Ez )I , (Hθ )II = (Hθ )I , (Hz )II = (Hz )I , where subscripits I and II correspond to fluid of borehole and porous formation. The boundary equation may be written in the form of M9×9 A9×1 = B9×1 ,

(8)

where n oT pf ps sh te sv tm e h 𝐴9×1 = Am , n , An , An , An , An , An , An , An , An 𝐵9×1 = {b1 , b2 , b3 , b4 , b5 , b6 , b7 , 0, 0}T , and 𝐵9×1 corresponds to the radiation field of acoustic source in fluid-saturated porous medium. The expressions are given by

The acoustic pressure and the electromagnetic field inside the borehole are uncoupled.

b1 = {(1 + α j )Θ j [(n/r)In (η j r) + η j In+1 (η j r)]} j=pf ,

2.3.1. Acoustic pressure inside the borehole

b2 = {Θ j {[−[H − 2G +Cα j ]k2j + 2G[(n2 − n)/r2 + η 2j ]]

b2 = {k2j (−Mα j −C)[Θ j In (η j r)]} j=pf , × In (η j r) − 2G(η j /r)In+1 (η j r)}} j=pf ,

The displacement potential of borehole fluid can be written as [22] 1 Φ(r, θ , z) = 2π

Z +∞ ∞



−∞ n=0

Am n (kz , ω)In (ηf r) cos nθ

e

ikz z

b4 = { − ikz 2Θ j [(n/r)In (η j r) + η j In+1 (η j r)]} j=pf , b5 = { −Θ j [(2n(n − 1)/r2 )In (η j r)

dkz , (5)

where Am n is the transmission coefficient. The radial component of the displacement field ur (r, θ , z) and borehole fluid pressure p(r, θ , z) are obtained using ur = ∂ Φ/∂ r and p = ω 2 ρf Φ.

+ (2n/r)η j In+1 (η j r)]} j=pf , b6 = { −Θ j β j (n/r)In (η j r)} j=pf , b7 = {Θ j iβ j kz In (η j r)} j=pf , where Θ j = [εn /(2π)Kn (η j r0 ) cos nθ ] j=pf . The complex matrices M9×9 can be found in Ref. [22].

014301-3

Chin. Phys. B Vol. 23, No. 1 (2014) 014301 3. Numerical results In the space–time domain, the acoustic wave field and the electromagnetic field can be generally expressed as −∞

Ξ (r, θ , z, ω)F(ω) e

r0=0.11 m r0=0.2 m

800

dω,

(9)

where Ξ can be p, Ez , Er , Eθ , Hz , Hr , Hθ , etc. The parameters in this paper are defined as: solid bulk modulus Ks = 3.57 × 1010 Pa; frame bulk modulus Kb = 1.439 × 1010 Pa; G = 1.399 × 1010 Pa; fluid bulk modulus Kf = 0.225 × 1010 Pa; fluid viscosity η = 0.001 Pa·s; tortuosity α∞ = 3; porosity ψ = 0.21; permeability κ = 3×10−13 m2 ; salinity Cf = 0.01 mol/L. This study focuses on the acoustoelectric fields excited by the explosive point source located in the saturated porous medium. Especially for the condition that the centre frequency ( f0 ) is low and the distance (r0 ) from the acoustic source to the axis of vertical borehole is far, it is easy to obtain valid data. It may be helpful in explaining cross-seismic data and has a potential significance in the actual oil exploration. In addition, microseisms are common in rocks ranging from tight sandstones and gas shales to carbonates and even volcanic, and at depths ranging from tens of meters to more than four thousand meters. [31] Data in the literature show that, typically, microseisms associated with a cross borehole have dominant frequencies extending from 200 Hz to approximately 1 kHz. The condition of microseismic monitoring is also considered. In the first section, we discussed the effect of r0 in the case of f0 = 1 kHz. When the distance changes gradually from r0 = 0.11 m to r0 = 1 m, the received acoustic wave field and electric field are shown in Fig. 2. Figure 2(a) shows that when r0 = 0.11 m, we can find the distinct longitudinal wave packets, Stoneley wave packets, etc. In Fig. 2(b), the coseismic longitudinal wave packets, the coseismic Stoneley wave packets can also be found. With r0 increasing, Stoneley wave packets, coseismic Stoneley wave packets, and so on all become less obvious. Especially when r0 = 1 m, only the longitudinal wave packets and coseismic longitudinal wave packets can be observed in Figs. 2(a) and 2(b), respectively. One of the possible reasons for explaining the above phenomenon is that with r0 increasing, the coupling effect between acoustic wave and borehole weakens. Therefore, the acoustic and electric fields we received are mainly determined by the incident longitudinal wave. That is to say, the reflection field is very weak. The above results also confirm that the seismoelectric conversion is induced on the fluid-saturated porous medium side of the borehole, not on the borehole fluid side. [9] At the same time, in order to testify the validity of numerical full-waveform simulation method, we compare the results obtained in this paper with that using quasi-steady method proposed by Hu. Moreover, we find that there are no differences between the results from the two methods. For convenience,

(a)

r0=0.5 m r0=1 m

400 p/Pa



−iωt

1200

0 -400 -800 -1200 0

1.5Τ10-3

4

8 t/ms

12

r0=0.11 m r0=0.2 m r0=0.5 m r0=1 m

1.0Τ10-3 Ez/VSm-1

F(r, θ , z,t) =

Z 1 +∞

we will only show the results derived from the coupled method in this paper.

5.0Τ10-4

16

(b)

0 -5.0Τ10-4 -1.0Τ10-3 -1.5Τ10-3 0

4

8 t/ms

12

16

Fig. 2. Waveforms of (a) acoustic wave field and (b) electric field Ez with different values of r0 f0 = 1000 Hz, rre = 0.01 m, z = 15 m, and θ = 0.

Then, we pay our attention to obtain multipole acoustoelectric field in condition that r0 is large and f0 is low. The adopted parameters are: r0 = 50 m, f0 = 100 Hz, and rre = 0.01 m. Now the coupling effect between the incident waves and borehole is weak. If we do not consider the borehole, we only receive acoustic pressure p, the displacements uz and ur , and the electrical fields Ez and Er . However, duo to the existence of borehole, magnetic field Hθ can also be received inside the borehole. We can also use the magnetic information in the inverse problem as new magnetic sensors can be used in boreholes. The magnetic field is easier to invert than the electrical field as the magnetic permeability is constant and the electrical conductivity is not constant. [29] Because the eccentric explosive source can be represented as superposition of multipole acoustic source. For one thing, we distinguish the monopole, dipole, quadrupole, and hexapole from multipole sources. Here we set z = 50 m. Figure 3 shows that the received multipole acoustoelectric field in the borehole fluid is excited by the point source outside the borehole. Comparing the acoustic wave field with the electric field, if the acoustic pressure is 103 Pa, we can record the electric field on the order of 10−4 V. In Figs. 3(a)–3(d), we only observe the longitudinal wave packets obviously. The longitudinal waves are mainly excited and converted by monopole component, as shown in Figs. 3(a), 3(b), and 3(d). However, figure 3(c) shows that the longitudinal wave packets are mainly excited and converted by the dipole component in the electric field Er .

014301-4

Chin. Phys. B Vol. 23, No. 1 (2014) 014301 n/ n/ n/ n/

p/Pa

400

3 Ez/10-4 VSm-1

800 (a)

0 -400

n/ n/ n/ n/

(b)

1

-1

-800 20

40 t/ms

60

n/ n/ n/ n/

Er/10-7 VSm-1

2 (c) 1

-3 0

80

20

40 t/ms

60

0 -1

80

n/ n/ n/ n/

(d) Hθ/10-7 ASm-1

0

1

0

-1

-2 0

20

40 t/ms

60

0

80

20

40 t/ms

60

80

Fig. 3. An investigation for distinguishing (a) acoustic wave field p, (b) electric field Ez , (c) electric field Er , and (d) magnetic field Hθ at f0 = 100 Hz, rre = 0.01 m, z = 50 m, and θ = 0.

(a) 200

in electric field Ez , the amplitude of longitudinal wave packets first increases, and then decreases. Figure 5 clearly depicts the position of the maximum acoustoelectric field. The displacement potential function of a spherical wave can be described as ϕ = Q e ikR /R. Therefore, in the cylindrical coordinate system, the axial component of displacement outside the borehole can be written as s s  ω2 Qz 1 z2 z2 |uz | = 2 =Q . k2 + 2 + R R (z2 + r2 )2 Vpf2 (z2 + r2 )3

160

z/m

120 80 40 0

0

20

40 t/ms

60

80

(b) 200

z/m

150

100

50

0 0

20

40 t/ms

60

80

Fig. 4. The full wave (a) acoustic wave field and (b) electric field obtained by multichannel measurement. The number of channel is 38, and the other parameters are the same as those in Fig. 3.

Furthermore, we consider the influence of the receiving position along the axis of vertical borehole by multichannel receivers. Figure 4 shows the full wave contrast diagram of acoustoelectric field obtained by multichannel measurement. With the increase in the distance (z) from receivers to the origin of coordinate, the amplitude of longitudinal wave packets always attenuates in the acoustic pressure field p. However,

When r = z, one can obtain the maximum values of uz and Ez because the electric field Ez is accompanied by uz in the porous formation outside the borehole according to Eq. (2). It should be noted that the electric field Ez is continuous at borehole wall, and uz is not. Therefore, inside the borehole, at this moment, Ez also reaches a maximum value, and uz does not. Just as shown in Fig. 5, when z = 50 m, the amplitude of the longitudinal wave reaches its maximum value in the electric field Ez (Fig. 5(a)). However, in Fig. 5(b) the maximum value of the displacement uz is located at z = 35 m. Therefore, if we obtain the location of the maximum Ez at the borehole axis, we will be able to determine the distance from the acoustic source to the borehole axis. If we estimate the position of acoustic source, we could use the electric field Er or the displacement ur . Figure 5 shows that the amplitudes of the electric field Er and displacement ur all monotonically decrease and their maximum amplitudes occur in z = 0 plane where the receiver is just located. When z = 0, we obtain the maximum amplitudes of electric field Er

014301-5

Chin. Phys. B Vol. 23, No. 1 (2014) 014301 with different values of incident angle θ as shown in Fig. 6. It is easy to find that the electric field Er is axisymmetric and the acoustic source is just located at the axis of symmetry. 250

2.0

U/nm

200

1.6

Ur 150



1.2

100

0.8

50

0.4

0

p/103 Pa

P Uz

(a)

0 -150

-50

50

150

z/m 3.0T10-4

Ez Er Eθ

(b)

E/VSm-1

2.0T10-4

References

1.0T10-4 5.0T10-7

[1] [2] [3] [4]

3.0T10-7 1.0T10-7 -150

-50

50

150

z/m

[5]

Fig. 5. The maximum amplitudes of (a) the acoustic wave field p and the displacement u, and (b) electric field E, obtained by multichannel measurement. The parameters are the same as those in Fig. 3.

[6] [7] [8]

0 2.0T10-10

[9] [10] [11] [12]

30

330

1.5T10-10 1.0T10-10

300

60

[13] [14] [15] [16] [17]

5.0T10-11 0 270 0

90

5.0T10-11 1.0T10-10

borehole are azimuthal. Inside the borehole, the three components of either electric field or magnetic field can be detected, and the radial electric field is mainly excited and converted by the dipole component. The magnetic field is easier to invert than the electrical field as the magnetic permeability is constant and the electrical conductivity is not constant. When the distance from the acoustic source to the axis of a borehole is large, the longitudinal and coseismic longitudinal wave packets dominate the acoustic and electric field, respectively. According to the location of the maximum axial component of electric field which is continuous at borehole wall, we will be able to determine the distance from the acoustic source to the borehole axis. The results of this paper may be significant for the seismoelectric effect to be used in microseisms and crosshole measurements.

240

[18] [19]

120

1.5T10-10 2.0T10-10

210

[20]

150 180

[21]

Fig. 6. Maximum amplitudes of electric field Er with different values of θ when z = 0. The other parameters are the same as that in Fig. 3.

[22]

4. Conclusions In this paper, we consider the acoustic and electric fields excited by the explosive point source outside of the borehole surrounded by the saturated porous medium based on Pride’s theory. We present theoretical expressions for wave fields and analyze numerical results of the acoustic and electric fields based on both the coupled method and quasi-steady method. The algorithms in this paper to simulate seismoelectric wave propagation prove to be valid and efficient. Due to the existence of borehole, the electric fields and magnetic fields in the

[23] [24] [25] [26] [27] [28] [29] [30] [31]

014301-6

Pride S R 1994 Phys. Rev. B 50 15678 Pride S R and Haartsen M W 1996 J. Acoust. Soc. Am. 100 1301 Zhu Z Y and Toks¨oz M N 2005 Geophys. 70 F45 Bordes C, Jouniaux L, Dietrich M, Pozzi J P and Garambois S 2006 Geophys. Res. Lett. 33 L01302 Bordes C, Jouniaux L, Garambois S, Dietrich M, Pozzi J P and Gaffet S 2008 Geophys. J. Int. 174 489 Haartsen M W and Pride S R 1997 J. Geophys. Res. 102 24745 Zhu Z Y, Haartsen M W and Toks¨oz M N 1999 Geophys. 64 1349 Zhu Z Y, Haartsen M W and Toks¨oz M N 2000 J. Geophys. Res. 105 28055 Zhu Z Y and Toks¨oz M N 2003 Geophys. 68 1519 Block G I and Harris J G 2006 J. Geophys. Res. 111 B01304 Long L T and Rivers W K 1975 Geophys. 40 233 Butler K E, Russell R D, Kepic A W and Maxwell M 1996 Geophys. 61 1769 Mikhailov O V, Haartsen M W and Toks¨oz M N 1997 Geophys. 62 97 Beamish D 1999 Geophys. J. Int. 137 231 Garambois S and Dietrich M 2001 Geophys. 66 1417 Dupuis J C, Butler K E and Kepic A W 2007 Geophys. 72 A81 Haines S S, Pride S R, Klemperer S L and Biondi B 2007 Geophys. 72 G9 Revil A and Jardani A 2010 Geophys. J. Int. 180 781 Hu H S, Liu J Q, Wang H B and Wang K X 2003 Chin. J. Geophys. 46 362 Pain C C, Saunders, Worthington M H, Singer J M, Stuart-Bruges W, Mason G and Goddard A 2005 Geophys. J. Int. 160 592 Guan W, Hu H S and Chu Z T 2006 Acta Phys. Sin. 55 0267 (in Chinese) Cui Z W 2004 Theroretical and Numerical Study of Modified Biot’s Models, Acoustoelectric Well Logging and Acoustic Logging While Drilling Excited by Multipole Acoustic Sources (Ph.D thesis) (Changchun: Jilin University) (in Chinese) Cui Z W, Wang K X, Hu H S and Sun J G 2007 Chin. Phys. 16 0746 Zhu Z Y, Chi S H, Zhan X and Toks¨oz M N 2008 Commun. Comput. Phys. 3 109 Hunt C W and Wothington M H 2000 Geophys. Res. Lett. 27 1315 Mikhailov O V, Queen J H and Toks¨oz M N 2000 Geophys. 65 1098 Dupuis J C and Butler K E 2006 Geophys. Res. Lett. 33 L16301 Araji A H, Revil A, Jardani A, Minsley B J and Karaoulis M 2012 Geophys. J. Int. 188 1285 Gao Y X and Hu H S 2010 Geophys. J. Int. 181 873 Hu H S and Gao Y X 2011 J. Geophys. Res. 116 B08302 Warpinski N 2009 JPT 118537 80

Chinese Physics B Volume 23

Number 1

January 2014

TOPICAL REVIEW — Magnetism, magnetic materials, and interdisciplinary research 017702

Energy band alignment at ferroelectric/electrode interface determined by photoelectron spectroscopy Chen Feng, Wu Wen-Bin, Li Shun-Yi and Andreas Klein

018104

The basis of organic spintronics: Fabrication of organic spin valves Chen Bin-Bin, Jiang Sheng-Wei, Ding Hai-Feng, Jiang Zheng-Sheng and Wu Di RAPID COMMUNICATION

014201

Low temperature enhancement of alignment-induced spectral broadening of femtosecond laser pulses Wang Fei, Jiang Hong-Bing and Gong Qi-Huang GENERAL

010101

Single-photon modulation spectrum Liu Yan, Yu Bo, He Bo, Zhang Guo-Feng, Xiao Lian-Tuan and Jia Suo-Tang

010201

Symmetries and conservation laws of one Blaszak–Marciniak four-field lattice equation Wang Xin, Chen Yong and Dong Zhong-Zhou

010202

Control of epileptiform spikes based on nonlinear unscented Kalman filter Liu Xian, Gao Qing and Li Xiao-Li

010203

Nonlocal symmetry, optimal systems, and explicit solutions of the mKdV equation Xin Xiang-Peng, Miao Qian and Chen Yong

010301

Implementation of a one-dimensional quantum walk in both position and phase spaces Qin Hao and Xue Peng

010302

Monogamy of quantum correlations in the one-dimensional anisotropic XY model Xu Shuai, Song Xue-Ke and Ye Liu

010303

Distributed wireless quantum communication networks with partially entangled pairs Yu Xu-Tao, Zhang Zai-Chen and Xu Jin

010304

Hierarchical and probabilistic quantum state sharing via a non-maximally entangled |χi state Peng Jia-Yin, Bai Ming-Qiang and Mo Zhi-Wen

010305

Quantum broadcast communication and authentication protocol with a quantum one-time pad Chang Yan, Xu Chun-Xiang, Zhang Shi-Bin and Yan Li-Li

010306

Quantum electrodynamics in a laser and the electron laser collision Zhang Qi-Ren

010307

Oscillating multidromion excitations in higher-dimensional nonlinear lattice with intersite and external on-site potentials using symbolic computation B. Srividya, L. Kavitha, R. Ravichandran and D. Gopi (Continued on the Bookbinding Inside Back Cover)

010308

Production and detection of ultracold Cs2 molecules via four-photon adiabatic passage Li Jian, Liu Yong and Cong Shu-Lin

010501

Bifurcation analysis of the logistic map via two periodic impulsive forces Jiang Hai-Bo, Li Tao, Zeng Xiao-Liang and Zhang Li-Ping

010502

Stochastic resonance for a metapopulation system driven by multiplicative and additive colored noises Wang Kang-Kang and Liu Xian-Bin

010503

Surface structures of equilibrium restricted curvature model on two fractal substrates Song Li-Jian, Tang Gang, Zhang Yong-Wei, Han Kui, Xun Zhi-Peng, Xia Hui, Hao Da-Peng and Li Yan

010504

Robust networked H∞ synchronization of nonidentical chaotic Lur’e systems Yang De-Dong

010505

Lyapunov function as potential function: A dynamical equivalence Yuan Ruo-Shi, Ma Yi-An, Yuan Bo and Ao Ping

010506

Gradient method for blind chaotic signal separation based on proliferation exponent L¨u Shan-Xiang, Wang Zhao-Shan, Hu Zhi-Hui and Feng Jiu-Chao

010507

Control schemes for synchronizing two subnetworks with weak couplings Zhang Jian-Bao, Ma Zhong-Jun and Zhang Gang

010508

Tracking of a third-order maneuvering target under an arbitrary topology Dong Li-Jing, Chai Sen-Chun and Zhang Bai-Hai

010701

Fast filtering algorithm based on vibration systems and neural information exchange and its application to micro motion robot Gao Wa, Zha Fu-Sheng, Song Bao-Yu and Li Man-Tian ATOMIC AND MOLECULAR PHYSICS

013101

Simulating electron momentum spectra of 𝑖so-C2 H2 Cl2 : A study of the core electronic structure Huang Yan-Ru and Chen Ming-Ming

013102

Effects of pressure and gas-jet thickness on the generation of attosecond pulse Li Xiao-Yong, Wang Guo-Li and Zhou Xiao-Xin

013103

Density functional theory study of Mg2 Nin (𝑛 = 1–8) clusters Zhang Jian-Ting, Li Jing and Sheng Yong

013201

Ionization energies and term energies of the ground states 1s2 2s of lithium-like systems Li Jin-Ying and Wang Zhi-Wen

013202

Theoretical study on isotope separation of an ytterbium atomic beam by laser deflection Zhou Min and Xu Xin-Ye

013301

High-resolution photoassociation spectroscopy of ultracold Cs2 long-range 0− g state: The external well potential depth Liu Wen-Liang, Wu Ji-Zhou, Ma Jie, Xiao Lian-Tuan and Jia Suo-Tang

013302

Field-free molecular orientation induced by combined femtosecond single- and dual-color laser pulses: The role of delay time and quantum interference Qin Chao-Chao, Jia Guang-Rui, Zhang Xian-Zhou, Liu Yu-Fang, Long Jin-You and Zhang Bing (Continued on the Bookbinding Inside Back Cover)

013401

Mαβ X-ray production cross sections of Pb and Bi by 9–40 keV electron impact Wu Ying, Wang Guan-Ying, Mu Qiang and Zhao Qiang

013402

Radio-frequency spectroscopy of weakly bound molecules in ultracold Fermi gas Huang Liang-Hui, Wang Peng-Jun, Fu Zheng-Kun and Zhang Jing

013601

Structure, stability and electronic properties of SrSi𝑛 (𝑛 = 1–12) clusters: Density-functional theory investigation Zhang Shuai, Qin Yi, Ma Mao-Fen, Lu Cheng and Li Gen-Quan

013701

Electrostatic surface trap for cold polar molecules on a chip Wang Qin, Li Sheng-Qiang, Hou Shun-Yong, Xia Yong, Wang Hai-Ling and Yin Jian-Ping ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS

014101

Extraordinary terahertz transmission through subwavelength spindle-like apertures in NbN film Zheng Xiao-Rui, Cheng Fei, Wu Jing-Bo, Jin Biao-Bing and Zhu Bei-Yi

014202

Third-order aberration analysis of tilted-pupil optical systems Wang Yu, Zhang Xin, Wang Ling-Jie and Wang Chao

014203

Optical properties of ytterbium-doped tandem-pumped fiber oscillator Hao Jin-Ping, Yan Ping, Xiao Qi-Rong, Li Dan and Gong Ma-Li

014204

Nonvolatile photorefractive properties in triply doped stoichiometric Mg:Fe:Mn:LiTaO3 crystals Sun Ting, Zhang Xiao-Dong, Sun Liang and Wang Rui

014205

Controllable beating signal using stored light pulse Wang Lei, Yang Qing-Yu, Wang Xiao-Xiao, Luo Meng-Xi, Fan Yun-Fei, Kang Zhi-Hui, Dai Tian-Yuan, Bi Sheng, Wang Hai-Hua, Wu Jin-Hui and Gao Jin-Yue

014206

Irradiation effect on strain sensitivity coefficient of strain sensing fiber Bragg gratings Jin Jing, Lin Song and Song Ning-Fang

014207

Experimental demonstration of single-mode fiber coupling using adaptive fiber coupler Luo Wen, Geng Chao, Wu Yun-Yun, Tan Yi, Luo Qi, Liu Hong-Mei and Li Xin-Yang

014301

Seismoelectric waves in a borehole excited by an external explosive source Zhou Jiu-Guang, Cui Zhi-Wen, L¨u Wei-Guo, Zhang Yu-Jun and Wang Ke-Xie

014701

Longitudinal and transverse structure functions in decaying nearly homogeneous and isotropic turbulence Imtiaz Ahmad, Lu Zhi-Ming and Liu Yu-Lu

014702

Dual solutions in boundary layer flow of a moving fluid over a moving permeable surface in presence of prescribed surface temperature and thermal radiation Swati Mukhopadhyay PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

015101

A growth kinetics model of rate decomposition for Si1−x Gex alloy based on dimer theory Dai Xian-Ying, Ji Yao and Hao Yue (Continued on the Bookbinding Inside Back Cover)

015201

Exploration of the Townsend regime by discharge light emission in a gas discharge device

015202

Hilal Yucel Kurt Growth rate of peeling mode in the near separatrix region of diverted tokamak plasma Shi Bing-Ren CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

016101

Quasi-homoepitaxial GaN-based blue light emitting diode on thick GaN template Li Jun-Ze, Tao Yue-Bin, Chen Zhi-Zhong, Jiang Xian-Zhe, Fu Xing-Xing, Jiang Shuang, Jiao Qian-Qian, Yu Tong-Jun and Zhang Guo-Yi

016102

Structural stability and electrical properties of AlB2 -type MnB2 under high pressure Meng Xiang-Xu, Fan Jing, Bao Kuo, Li Fang-Fei, Huang Xiao-Li, Li Yan, Tian Fu-Bo, Duan De-Fang, Jin Xi-Lian, Zhu Pin-Wen, He Zhi, Zhou Qiang, Gao Chun-Xiao, Liu Bing-Bing and Cui Tian

016103

Structural and electron charge density studies of a nonlinear optical compound 4, 4 di-methyl amino cyano biphenyl Naima Boubegra, Abdelkader Chouaih, Mokhtaria Drissi and Fodil Hamzaoui

016104

Structure of Lennard–Jones nanowires encapsulated by carbon nanotubes Wu Wen-Qian, Tian Ming-Li, Chen Hang-Yan, Yuan Qing-Hong and Sun De-Yan

016801

First-principles calculations of 5d atoms doped hexagonal-AlN sheets: Geometry, magnetic property and the influence of symmetry and symmetry-breaking on the electronic structure Zhang Zhao-Fu, Zhou Tie-Ge, Zhao Hai-Yang and Wei Xiang-Lei

016802

Kinetic Monte Carlo simulations of three-dimensional self-assembled quantum dot islands Song Xin, Feng Hao, Liu Yu-Min, Yu Zhong-Yuan and Yin Hao-Zhi

016803

Superamphiphobic, light-trapping FeSe2 particles with a micro-nano hierarchical structure obtained by an improved solvothermal method Yu Jing, Wang Hui-Jie, Shao Wei-Jia and Xu Xiao-Liang CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES

017101

Phase transition and thermodynamic properties of ThO2 : Quasi-harmonic approximation calculations and anharmonic effects Li Qiang, Yang Jun-Sheng, Huang Duo-Hui, Cao Qi-Long and Wang Fan-Hou

017102

Spin texturing in a parabolically confined quantum wire with Rashba and Dresselhaus spin–orbit interactions S. Sarıkurt, S. S¸akiro˘glu, K. Akg¨ung¨or and ˙I. S¨okmen

017103

Effects of the 3d transition metal doping on the structural, electronic, and magnetic properties of BeO nanotubes Zhang Jian-Min, Song Wan-Ting, Li Huan-Huan, Xu Ke-Wei and Ji Vincent

017104

Thickness dependence of the anomalous Hall effect in disordered face-centered cubic FePt alloy films Chen Ming, He Pan, Zhou Shi-Ming and Shi Zhong (Continued on the Bookbinding Inside Back Cover)

017201

Theoretical study of thermoelectric properties of MoS2 Guo Huai-Hong, Yang Teng, Tao Peng and Zhang Zhi-Dong

017202

Resonant tunneling through double-barrier structures on graphene Deng Wei-Yin, Zhu Rui, Xiao Yun-Chang and Deng Wen-Ji

017203

Spin and valley half metal induced by staggered potential and magnetization in silicene Wang Sa-Ke, Tian Hong-Yu, Yang Yong-Hong and Wang Jun

017301

Electronic structure and magnetic properties of substitutional transition-metal atoms in GaN nanotubes Zhang Min and Shi Jun-Jie

017302

Optical binding forces between plasmonic nanocubes: A numerical study based on discrete-dipole approximation Zhang Xiao-Ming, Xiao Jun-Jun and Zhang Qiang

017303

Time-dependent degradation of threshold voltage in AlGaN/GaN high electron mobility transistors Ma Xiao-Hua, Jiang Yuan-Qi, Wang Xin-Hua, L¨u Min, Zhang Huo, Chen Wei-Wei and Liu Xin-Yu

017304

Ab initio study of structural, electronic and optical properties of ternary CdO1−x Sex alloys using special quasi-random structures Muhammad Rashid, Fayyaz Hussain, Muhammad Imran, S. A. Ahmad and N. A. Noor

017305

Mobility limited by cluster scattering in ternary alloy quantum wires Zhang Heng, Yang Shao-Yan, Liu Gui-Peng, Wang Jian-Xia, Jin Dong-Dong, Li Hui-Jie, Liu Xiang-Lin, Zhu Qin-Sheng and Wang Zhan-Guo

017401

Electronic structures of halogen-doped Cu2 O based on DFT calculations Zhao Zong-Yan, Yi Juan and Zhou Da-Cheng

017501

Application of longitudinal generalized magneto-optical ellipsometry in magnetic ultrathin films Wang Xiao, Lian Jie, Zhang Fu-Jun, Gao Shang, Chen Yan-Xue, Yu Xiao-Hong, Li Ping, Wang Ying-Shun and Sun Zhao-Zong

017502

Determination of the magnetic anisotropy constant of Cu/Fe/SiO2 /Si by a magneto-optical Kerr effect susceptometer Jia Yi-Jiao, He Wei, Ye Jun, Hu Bo, Chen Zi-Yu, Gao You-Hui, Zhang Xiang-Qun, Yang Hai-Tao and Cheng Zhao-Hua

017701

Interfacial and electrical properties of HfAlO/GaSb metal-oxide-semiconductor capacitors with sulfur passivation Tan Zhen, Zhao Lian-Feng, Wang Jing and Xu Jun

017801

Numerical investigation of the enhanced unidirectional surface plasmon polaritons generator Zhang Zhi-Dong, Wang Hong-Yan, Zhang Zhong-Yue and Wang Hui

017802

Multi-band microwave metamaterial absorber based on coplanar Jerusalem crosses Wang Guo-Dong, Liu Ming-Hai, Hu Xi-Wei, Kong Ling-Hua, Cheng Li-Li and Chen Zhao-Quan

017803

Tandem white organic light-emitting diodes adopting a C60 :rubrene charge generation layer Bi Wen-Tao, Wu Xiao-Ming, Hua Yu-Lin, Sun Jin-E, Xiao Zhi-Hui, Wang Li and Yin Shou-Gen

(Continued on the Bookbinding Inside Back Cover)

017804

Vibration analysis of a new polymer quartz piezoelectric crystal sensor for detecting characteristic materials of volatility liquid Gu Yu, Li Qiang, Xu Bao-Jun and Zhao Zhe

017805

High quality above 3-µm mid-infrared InGaAsSb/AlGaInAsSb multiple-quantum well grown by molecular beam epitaxy Xing Jun-Liang, Zhang Yu, Xu Ying-Qiang, Wang Guo-Wei, Wang Juan, Xiang Wei, Ni Hai-Qiao, Ren ZhengWei, He Zhen-Hong and Niu Zhi-Chuan

017806

Spin–orbit coupling effects on the in-plane optical anisotropy of semiconductor quantum wells Yu Jin-Ling, Chen Yong-Hai, Lai Yun-Feng and Cheng Shu-Ying INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

018101

Thermal stability and high-temperature shape memory characteristics of Ti–20Zr–10Ta alloy Zheng Xiao-Hang, Sui Jie-He, Zhang Xin, Yang Zhe-Yi and Cai Wei

018102

Tunable ultra-wideband terahertz filter based on three-dimensional arrays of H-shaped plasmonic crystals Yuan Cai, Xu Shi-Lin, Yao Jian-Quan, Zhao Xiao-Lei, Cao Xiao-Long and Wu Liang

018103

First-principles investigation of chemical modification on two-dimensional iron–phthalocyanine sheet Wang Hong-Bo, Su Yan and Chen Gang

018201

Effect of metal oxide arrester on the chaotic oscillations in the voltage transformer with nonlinear core loss model using chaos theory Hamid Reza Abbasi, Ahmad Gholami, Seyyed Hamid Fathi and Ataollah Abbasi

018202

Stereodynamics in reaction O(1 D) + CH4 →OH + CH3 Sha Guang-Yan, Yuan Jiu-Chuang, Meng Chang-Gong and Chen Mao-Du

018501

Quasi-two-dimensional threshold voltage model for junctionless cylindrical surrounding gate metaloxide-semiconductor field-effect transistor with dual-material gate Li Cong, Zhuang Yi-Qi, Zhang Li and Jin Gang

018502

Enhancing light extraction of GaN-based blue light-emitting diodes by a tuned nanopillar array Chen Zhan-Xu, Ren Yuan, Xiao Guo-Hui, Li Jun-Tao, Chen Xia, Wang Xue-Hua, Jin Chong-Jun and Zhang Bai-Jun

018503

Spin pumping at the Co2 FeAl0.5 Si0.5 /Pt interface Wu Yong, Zhao Yue-Lei, Xiong Qiang, Xu Xiao-Guang, Sun Young, Zhang Shi-Qing and Jiang Yong

018504

Chemical synthesis of zinc oxide nanorods for enhanced hydrogen gas sensing Musarrat Jabeen, Muhammad Azhar Iqbal, R Vasant Kumar, Mansoor Ahmed and Muhammad Tayyeb Javed

018505

A snapback suppressed reverse-conducting IGBT with uniform temperature distribution Chen Wei-Zhong, Li Ze-Hong, Zhang Bo, Ren Min, Zhang Jin-Ping, Liu Yong and Li Zhao-Ji

018506

Electrical and dielectric properties of Al/p-Si and Al/perylene/p-Si type diodes in a wide frequency range Ahmet Kaya, Sedat Zeyrek, Sait Eren San and S¸msettin Altındal

(Continued on the Bookbinding Inside Back Cover)

018701

Position difference regularity of corresponding R-wave peaks for maternal ECG components from different abdominal points Zhang Jie-Min, Guan Qun, Tang Li-Ming, Liu Tie-Bing, Liu Hong-Xing, Huang Xiao-Lin and Si Jun-Feng

018901

A local-world evolving hypernetwork model Yang Guang-Yong and Liu Jian-Guo

018902

Output regulation for linear multi-agent systems with unmeasurable nodes Liang Hong-Jing, Zhang Hua-Guang, Wang Zhan-Shan and Wang Jun-Yi

018903

Unsupervised neural networks for solving Troesch’s problem Muhammad Asif Zahoor Raja GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS

019201

Continuity and momentum equations for moist atmospheres Ran Ling-Kun, Gao Shou-Ting and Cao Jie