ABSTRACTS

SeismicdenoisingwithCEEMDandKSVDdictionarycombinedtraining.YUEYouxi1，YANGTao2，andZENGXiande3.OilGeophysicalProspecting,2019,54(4)：729-736.

Combining the complete ensemble empirical mode decomposition (CEEMD) and the K singular value decomposition (KSVD) dictionary algorithm，a seismic denoising is proposed in this paper.A signal with random noise is decomposed by CEEMD into a series of inherent modal functions (IMF) of different scales.The IMF components are arranged from high to low frequency and their autocorrelation eliminates noise-dominant IMF components.Accumulated transitional components are superimposed and reconstructed by CEEMD decomposition again and noise-dominant components are removed again by the autocorrelation.The second remaining IMF components and the first remaining IMF components are superposed to get two new noisy signals which are sparsely represented by KSVD learning dictionary respectively.In the other words,sparse coefficients reconstruct denoised signals.Finally，two sparse denoising signals are reconstructed.Experimental results show that the proposed algorithm can better remove noise than conventional methods such as F-X，wavelet threshold，and KSVD.

Keywords：complete ensemble empirical mode decomposition (CEEMD)，K singular value decomposition (KSVD) learning dictionary，sparse representation，autocorrelation，random noise

1.School of Geosciences，China University of Petroleum (East China)，Qingdao，Shandong 266580，China

Sparse-spikedeconvolutionbasedonadaptivestepFISTAalgorithm.PANShulin1，YANKe2，LILingyun3,JIANGCongyuan4，andSHILinguang3.OilGeophysicalProspecting,2019,54(4)：737-743.

The optimal internal gradient stepLcan be searched by linear methods in the fast iterative shrinkage-thresholding algorithm (FISTA).But the stepLcan only be increased，which seriously affects the convergence of FISTA algorithm.In this paper，a sparse-spike deconvolution based on adaptive step FISTA algorithm is proposed.On the basis of FISTA algorithm，the stepLis reduced appropriately before each iteration，and then the stepLis found by a linear search to achieve the adaptive adjustment ofL.In order to realize the algorithm theoretical converge，the auxiliary sequence of the conventional FISTA algorithm is modified by combining two consecutiveL.Finally，the algorithm is converged.Theoretical model and field data tests show that the proposed method has better convergence and better anti-noise ability than the conventional FISTA algorithm，and obtain ideal inversion results of different signal-to-noise ratio data.

Keywords： sparse-spike deconvolution，fast iterative shrinkage-thresholding algorithm (FISTA)，linear search，adaptive step algorithm，convergence

1.School of Earth Science and Technology，Southwest Petroleum University，Chengdu，Sichuan 610500，China

2.Southwest Oil & Gas Field Company，PetroChina，Chengdu，Sichuan 610051，China

3.Research Institute of Geophysics，Shengli Oilfield Branch Co.，SINOPEC，Dongying，Shandong 257000，China

4.Department of Electrical and Electronic Engineering，Sichuan Vocational and Technical College，Suining，Sichuan 629000，China

SeismicrandomnoiseadaptivesuppressionbasedontheShearlettransform.TONGSiyou1,2,GAOHang1，LIURui1，andCHENXueguo3.OilGeophysicalProspecting,2019,54(4)：744-750.

Conventional thresholding methods use a unified threshold for all the transform domain coefficients.However for Shearlet transform，signals and noises in all the scales and directions are different，so a global hard threshold has some limits.Aiming at these limits，a random noise suppression is proposed with improved adaptive threshold functions.On the basis of local threshold，the Bayesian threshold is improved to form an adaptive threshold function suitable for the Shearlet transform.A relation between the signal-to-noise ratio (SNR) and threshold functions is built.Different SNRs have different weighting coefficients to adaptively calculate different thresholds.So seismic signals are preserved and the denoising is greatly improved.Tests on model and real data show that the proposed method can effectively suppress random noise and highlight weak signals.

Keywords：Shearlet transform，random noise，multi-scale geometric analysis，signal-to-noise ratio (SNR)，adaptive threshold function

1.Key Laboratory of Submarine Geosciences and Prospecting Techniques，Ministry of Education，Qingdao，Shandong 266100，China

2.Laboratory for Marine Mineral Resources，Qingdao National Laboratory for Marine Science and Technology，Qingdao，Shandong 266061，China

3.Shengli Oilfield Branch Co.，SINOPEC，Dongying，Shandong 257100，China

Seawaterdepthinversionbasedonsegmenteddatacross-bispectrum.GAOShaowu1，QIANZhongping1，SUNPengyuan1，FANGYunfeng1，LIJianfeng1，andZHANYi1.OilGeophysicalProspecting,2019,54(4)：751-756.

The seawater depth is a basis for OBC dual-sensor data summing.A seawater depth inversion method based on segmented data cross-bispectrum is proposed in combination with the time series higher-order statistics.First the auto-bispectrum and cross bispectrum of up-going and down-going wave field data are calculated from the segmented OBC data.Then the coherent cross-bispectrum and cross-correlation spectrum are calculated.Finally，the seawater depth is calculated and used for the OBC data summing.The OBC dual-sensor segmented data computation utilizes fully stacking characteristics，which increases the suppression of Gauss random noise.Cross-bispectrum and coherent cross-bispectrum of the higher-order statistics have the advantages of suppressing Gauss and non-Gauss colored noise.Real OBC data seawater depths calculated by the proposed method match very well with measured seawater depths.These inversed seawater depths are used to dual-sensor data summing，and a good suppression of seawater reverberation is achieved，which lays a solid foundation for the subsequent velocity model building and migration.

Keywords：seawater depth，ocean bottom cable (OBC)，dual-sensor data summing，data segmentation，cross-bispectrum

1.Research & Development Centre，BGP Inc.，CNPC，Zhuozhou，Hebei 072750，China

Seismicrandomnoiseattenuationbasedonvariationalmodedecomposition.FANGJiangxiong1,2,WENZhiping2，GUHuaqi3,LIUJun2，andZHANGHua2.OilGeophysicalProspecting,2019,54(4)：757-767.

The empirical mode decomposition (EMD) method usually has heavy computational burdens and low resolution in recursive iterative sifting process.To deal with these problems a globally adaptive variational mode decomposition (VMD) method in the frequency domain is proposed.Different from the EMD recursive iterative sifting mode，the VMD decomposition process can be transformed to solving the optimization problem of the variational functional，which is constrained with the minimum sum of the estimated bandwidth of each band-limited intrinsic mode function (BIMF) component.By introducing an augmented Lagrange function to build the unconstrained term，the alternate direction method of multipliers (ADMM) is used to seek the optimal solution of the variational functional to achieve the signal decomposition.During the iterative process，the center frequency and bandwidth of each component are constantly updated，all BIMF components are obtained at one time with higher time efficiency than EMD.Each modal component has band-limited characteristics in the frequency spectrum to achieve high resolution and adaptive splitting of the signal band.Finally，tests on theoretical model and field data show that the proposed VMD method has not only excellent noise-attenuation and amplitude-preservation performances，but also high computational efficiency，which can meet the processing requirements of high-dimensional and massive seismic data.

Keywords：seismic random noise attenuation，empiri-cal mode decomposition (EMD)，variational mode decomposition (VMD)，computational efficiency

1.Nuclear Technology Application Engineering Research Center，Ministry of Education，East China University of Technology，Nanchang，Jiangxi 330013，China

2.School of Geophysics and Measurement-control Technology，East China University of Technology，Nanchang，Jiangxi 330013，China

3.Jiangxi Fundamental Geographic Information Center，Nanchang，Jiangxi 330209，China

Anefficientrefractionstaticsmethodformassiveseismicdata.XIAOYongxin1,YANGHaishen1,CUIShitian1,XULijun1,ZHAOWeiwei1,andMAJie1.OilGeophysicalProspecting,2019,54(4)：768-774.

The refraction statics has become a very mature and stable approach after years of development and improvement.This paper puts forward an efficient refraction statics method with a set of strategies for nowadays massive seismic data based on the theory of refraction statics.A first-break fast invocation is achieved with an efficient management method；the refraction velocity parallel calculation is realized with the aperture-constraint method which reduces greatly data search time；and the delay time fast calculation is accomplished with the optimization of iteration algorithms.Model data tests show that the proposed method achieves a much higher calculation efficiency of refraction statics on the premise of ensuring the calculation accuracy.For real data tests，the proposed method realizes a calculation efficiency 200～360 times faster than that of a commercial software in the condition of the same hardware and the same data volume.

Keywords： refraction static corrections，refraction velocity，delay time，aperture constraints

1.Acquisition Technique Center，BGP Inc.，CNPC，Zhuozhou，Hebei 072751，China

Sub-basaltseismicimaginginsoutheasternGreenland，Arctic.WUQilin1,LIUQuanwen1,FANGZhongyu2，ZHANGWen3,LIUJinpeng2，andZHANGZhizhong2.OilGeophysicalProspecting,2019,54(4)：775-781.

Volcanic basalts are widely distributed in JMY area of southeastern Greenland,Arctic.It is often compromised in sub-basalt imaging.Numerical simulation results show that low frequency is useful for geometrical characteristics and physical properties of the Mesozoic sediments,which are covered by Eocene and Oligocene basalt.The ana-lysis results are used to guide the processing of broadband seismic data and protect low frequencies signal of deeper reflectors.It is noticeable that the data quality of deep data is improved by broad-band recording through ghost elimination.The results provide a more relieable interpretation,which reveal the thickness and distribution of Mesozoic sediments source,is conducive to the hydrocarbon exploration.

Keywords：acoustic wave equation，forward modeling，broadband，Arctic，basalt， sub-basalt imaging

1.College of Petroleum Engineering，Guangdong University of Petrochemical Technology，Maoming，Guangdong 525000，China

2.Tepu，GEO-COSL，CNOOC，Zhanjiang，Guangdong 524057，China

3.CNOOC International Limited，Beijing 100027，China

CommonreflectionsurfacestackbasedonparametersearchingbyPSO.SUNXiaodong1,2,JIAYanrui1，LIZhenchun1,andSONGYu.OilGeophysicalProspecting,2019,54(4)：782-786.

The common reflection surface (CRS) is based on the theory of the Fresnel zone，the signal-to-noise ratio (SNR) can be maximized while maintaining the resolution.CRS stack effect depends on the wavefield kinematic parameters.Therefore，the search for these parameters is particularly important.If using point-by-point calculation or violent search to find the best parameters，the calculation is too difficult to be achieved.Some local optimization algorithms can significantly reduce the amount of computation，but its effectiveness is limited by initial parameters.This thesis attempts to use particle swarm optimization (PSO) to achieve the search of 2D CRS parameters.So the efficiency of CRS parameter search is improved and the calculation time is greatly shortened.Tests on model and real data verify the validity of the proposed method.

Keywords：common reflection surface (CRS)，Fresnel zone，signal-to-noise ratio (SNR)，particle swarm optimization (PSO)

1.School of Geosciences，China University of Petroleum (East China)，Qingdao，Shandong 266580，China

2.Laboratory for Marine Mineral Resource，Qing-dao National Laboratory for Marine Science and Technology，Qingdao，Shandong 266071，China

Undulatingseasurfaceinfluenceonreflectionseismicresponses.MENGXiangyu1,SUNJianguo1,WEIPuli1,andXUZeshuang1.OilGeophysicalProspecting,2019,54(4)：787-795.

In order to truly simulate undulating sea surface influence on reflection seismic responses，a moderate calm sea surface undulation model (2m wave height) is built with the wave spectrum calculation model proposed by Wen Shengchang et al.Considering both accuracy and computational efficiency，we use the unequal distance difference scheme based on the ghost point extrapolation.Through the numerical simulation of simple layered model and Marmousi model，the following conclusions are obtained：①The ghost wave and the primary reflection interferes irregularly under the influence of the undulating sea surface，resulting in different reflection seismic responses；②The phenomenon of “jitter” of seismic reflection from the undulating sea surface occurs at all times，and is related to the undulating shape of the sea surface；③Due to uneven illuminations of secondary reflection and irregular interferences of primary reflection，an uneven spatial distribution of seismic reflection energy affects greatly travel time，waveform，amplitude，spectrum，phase and bandwidth of direct and reflected waves，and causes a series of practical problems，such as poor ghost suppression，low signal-to-noise ratio，low resolution and local inversion non-convergence.

Keywords：wave spectrum，undulating sea surface，ghost point extrapolation，unequal distance difference

1.College of GeoExploration Sciences and Technology，Jilin University，Changchun，Jilin 130026，China

Asourcefastsweepingmethodforsolvingellipticallyanisotropiceikonalequation.CUINingcheng1,2,HUANGGuangnan1,2,LIHongxing1,2,ZHANGHua1,2,ZHANGXiaofeng1,2,andXIAOKun1，2.OilGeophy-sicalProspecting,2019,54(4)：796-804.

The seismic traveltime calculation is an important part of ray tracing，tomography，and seismic migration.Conventional traveltime fast sweeping methods scan directly the global computational domain without considering the scanning validity.In a real calculation，the scanning without the source point is invalid due to the lack of source information and cannot calculate right traveltime.In this paper，a source fast sweeping method is proposed，which moves the starting point of scanning to the source without invalid scanning，and improves the calculation efficiency.The source fast sweeping method in elliptical anisotropy medium is realized based on the factored eikonal equations and upwind difference scheme.Numerical simulation results show that the proposed source fast sweeping method obtains the same results as conventional methods，but it achieves higher calculation efficiency.

Keywords：source fast sweeping，traveltime calculation，factored eikonal equation，anisotropic

1.State Key Laboratory of Nuclear Resources and Environment，East China University of Technology，Nanchang，Jiangxi 330013，China

2.Department of Geophysics，School of Geophysics and Measurement-control Technology,East China University of Technology，Nanchang，Jiangxi 330013，China

Adata-drivencontrolled-beammigrationmethod.LYUKaokao1,XUJixiang1,ZHANGCai1,LILinggao1,andSUNXiping1.OilGeophysicalProspecting,2019,54(4)：805-813.

The ray-based beam migration is a flexible，efficient and relatively accurate prestack depth imaging approach，which can resolve steep-dip structures and image multiple arrivals.The Gaussian beam migration projects all the reflection events into the subsurface along the traveltime isochrones，indicating that it will migrate all the events in theτ-pdomain，which leads to huge calculations，and migration noise and artifacts.As an improvement for Gaussian beam migration，controlled beam migrations use only selected events.But most controlled beam migrations just use the instantaneous slowness information at receivers，neglecting the slowness information at sources.In this paper，in order to make full use of the slowness information both at sources and receivers，we propose a data-driven controlled beam migration.First local slant stacks of common-receiver gathers and common-shot gathers are carried out，the slowness information at sources and receivers are extracted with the coherence analysis.Then a migration quality control factor is designed to choose events.Finally，the selected events are imaged.Compared with the conventional Gaussian beam migration，the data-driven controlled beam migration can better suppress migration noise and artifacts，and achieve better imaging of low signal-to-noise ratio data.Model and field data tests prove the feasibility，validity，and applicability of the proposed method.

Keywords：ray-based beam migration，controlled-beam migration，common-shot gather，common-receiver gather，local slant stack，τ-pdomain

1.Research Institute of Petroleum Exploration & Development，CNPC，Beijing 100083，China

Generalizedscreenpropagatormigrationbasedonparticleswarmoptimizationandamplitude-preservedimagingconditions.HERun1,YANGWuyang1,WANGEnli1,WEIXinjian1,XIEChunhui1,andYANGuoliang1.OilGeophysicalProspecting,2019,54(4)：814-825.

For identifying more and more complex structures，conventional one-way wave migrations are obviously inadequate in terms of imaging accuracy and amplitude preservation.To solve this problem we propose in this paper a generalized screen propagator migration based on particle swarm optimization and amplitude-preserved imaging conditions.First，on the basis of conventional amplitude-preserved acoustic wave equation，a particle swarm optimization is used to perform the global optimal coefficients of vertical wave number expansion in the generalized screen propagator，and to improve its imaging accuracy for steep dip strata.Then a Gaussian-window function optimization is used to optimize deconvolution imaging conditions to ensure both the amplitude preservation and the calculation stability.Model trials and seismic data applications show that the proposed migration can not only improve the complex structure imaging，but also reduce the amplitude attenuation in strata.

Keywords：generalized screen propagator，particle swarm optimization，Gaussian-window function，Taylor series，amplitude preservation

1.Northwest Branch，Research Institute of Petroleum Exploration & Development，PetroChina，Lanzhou，Gansu 730020，China

Hydraulic-fracturingshear-tensilemicroseismicfocalmechanismmomenttensorinversion.TANGJie1,2，WENLei1,2,LICong1,2,andQIRuixuan1，2.OilGeophysicalProspecting,2019,54(4)：826-835.

Due to limited receivers，small monitoring angles，and a single measure direction in a well，focal positioning and focal mechanism analyses based on microseismic monitoring signals in wells are not accurate enough.So a hydraulic-fracturing focal mechanism calculation with P-wave first-motion amplitude inversion is proposed.The moment tensor inversion uses P-wave and S-wave particle motion equations in uniform elastic medium to calculate Green’s functions.Based on tests of the proposed method on model data，the following understanding is obtained：①Isotropic (ISO) components are not sensitive to errors compared with compensated linear vector dipole (CLVD) components when using the full moment tensor inversion.This is because ISO components are linear functions of moment tensor eigenvalues when the moment tensor is decomposed，but CLVD components are nonlinear functions；②The acquisition geometry is very important for inversion results of non-double-coupled (non-DC) components.An appropriate acquisition geometry increases the credibility of seismic moment tensor DC and non-DC component analysis；③The geometric distribution and the type of rupture mechanism can be observed from radiation patterns.Radiation patterns of different focal types have some differences.The limited focal sphere coverage will bring multiple solutions to the inversion.

Keywords：microseismic，focal mechanism inversion，isotropic (ISO)，compensated linear vector dipole (CLVD)，non-double-coupled (non-DC)，full moment tensor，deviatoric moment tensor

1.School of Geosciences，China University of Petroleum (East China)，Qingdao，Shandong 266580，China

2.Laboratory for Marine Mineral Resources，Qingdao National Laboratory for Marine Science and Technology，Qingdao，Shandong 266071，China

Frequencydispersionandattenuationofporousrockswithpennyshapedfractures.ZHANGFanchang1,SANGKaiheng1,andLUYawei1.OilGeophysicalProspecting,2019,54(4)：836-843.

Conventional integral methods usually have the singularity problem in solving frequency-dependent elastic modulus of penny shaped fractures，and can only obtain a single normal frequency-dependent modulus.In order to quickly and accurately perform numerical simulation of the penny shaped fracture，based on the Gauss-Lobatto discrete integral，a new approach is proposed.First the second Fredholm integral equation is transformed into a discrete integral in a finite interval.Then，the solving the zero-limit of far field multiple scatter equation and the discrete integral procedure are unified with the high-order approximation.To obtain the frequency-dependent elastic tensor，analytic elastic moduli equations at the high and low frequency limits are respectively obtained with the anisotropic Gassmann equation，the linear slip theory，and the Hudson crack model.Based on the analysis of phase velocity and viscoelastic reflection coefficient，the following understanding are obtained：A.The greater the fracture denty is，the graeter the attenuated peak amplitude is；B.The attenuated peak amplitude has lower frequency when the fracture size or the fluid viscosity becomes greater；C.The incident velocity and attenuation in the vertical direction have greater change than that in the horizontal direction；D.The reflection coefficient of gas-bearing media is significantly larger than that of oil-bearing or water-bearing media.

Keywords： penny shaped fracture，discrete integral，anisotropic Gassmann equation，linear slip theory，Hudson crack model

1.School of Geosciences，China University of Petroleum (East China)，Qingdao，Shandong 266580，China

5Dseismicdataregularizationandapplicationinfracturecharacterization.WANGXia1,LIFeng1,ZHANGYanqing1,HANBing1,QIANLiping1,andZHUDouxing1.OilGeophysicalProspecting,2019,54(4)：844-852.

5D seismic data usually refer to snail gathers generated from a wide-azimuth，broadband and high-density acquisition after the azimuth-preserved migration.5D seismic data contains azimuth information.Therefore，it can be used to better solve underground anisotropic problems.How to excavate potential geological information in the 5D data is a new challenge for interpreters.This paper proposes a 5D seismic data visualization approach with 5D data regularization in the offset-azimuth domain.On this basis，a 3D offset vector gather (OVG) display in cylindrical coordinates is achieved，the common offset gather，the common azimuthal gather and gather slice can be displayed and extracted easily.Based on the 5D seismic data visualization，an azimuth statistics method is presented to compute anisotropy intensity and draw rose diagrams.This method can describe multiple fractures，but conventional ellipse-fitting method cannot，and the fracture interpretation is improved.

Keyword：offset-azimuth domain，rectangle-data regularization，gather visualization，azimuth statistics method，fracture characterization，anisotropic intensity

1.Geological Research Center，GRI，BGP Inc.，CNPC，Zhuozhou，Hebei 072751，China

Hydrocarbondetectionwithfluid-mobilityandtime-frequencyphasefusion.ZHANGShengqiang1，ZHANGZhijun1,TANHuihuang1,andGUOJun1.OilGeophysicalProspecting,2019,54(4)：853-859.

Hydrocarbon detection methods based on only amplitude and frequency information have serious multi-solution problems.Therefore，we propose a hydrocarbon detection approach with fluid mobility and time-frequency phase fusion based on sparse inversion complex spectral decomposition，which introduces the phase information to supplement the amplitude and frequency information.So this method can make full use of dynamic characteristics to detect oil and gas，and reduce multi-solutions and uncertainty of hydrocarbon detection.The proposed hydrocarbon detection approach is applied to synthetic and real data.The processing results show that the proposed approach achieves high resolution and good indications of hydrocarbon-bearing reservoirs and reduces multi-solutions and uncertainty of hydrocarbon detection，which demonstrates a bright application prospect.

Keywords：sparse inversion complex spectral decomposition，hydrocarbon detection，fusion，time-frequency phase spectrum，fluid mobility，high resolution

1.Tianjin Branch，CNOOC Ltd.，Tianjin 300459，China

Faultidentificationwithshort-timeFouriertransformfrequency-decomposedcoherenceimprovedbysynchronousextrusion.YANHaitao1,ZHOUHuai-lai1,2,NiuCong3,WuNanke1,andZHOUJian1.OilGeophysicalProspecting,2019,54(4)：860-866.

Limited by low resolution seismic data and background noise caused by stratigraphic occurrence，minor faults and fractures are very difficult to be accurately identified.To solve this issue，an approach is proposed in the paper.The high-frequency multi-resolution of short-time Fourier transform improved by synchronous extrusion decomposes seismic data volume spectrum into single-frequency data of different frequencies，and the multi-trace tilt-oriented coherence is used to cohe-rently calculate the single-frequency data volume.The proposed approach can effectively eliminate the background noise and improve seismic data resolution.The multi-trace tilt-oriented coherence can accurately characterize minor faults and fractures.This proposed approach is successfully applied to the fault identification in some work areas in the South China Sea and rather good results are achieved.

Keywords：fault identification，simultaneous-extrusion improved short-time Fourier transform，frequency-decomposed，coherence

1.College of Geophysics，Chengdu University of Technology，Chengdu，Shichuan 610059，China

2.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation，Chengdu University of Technology，Chengdu，Shichuan 610059，China

3.CNOOC Research Institute，Beijing 100028，China

Fluididentificationbasedonforwardmodeling.HEYi1,ZHUJitian1,ZHANGYingzhao1,GUOMinggang1,andWANGLijun1.OilGeophysicalProspecting,2019,54(4)：867-874，881.

Seismic reflections of the structure X in the depression D in the deep water area of the western South China Sea is characterized by bright spots with low frequency and strong amplitude of targets.So there is no reference for the hydrocarbon detection due to the lack of well data (only one dry well drilled) in the area.Therefore，a fluid identification based on forward modeling is proposed.First，target velocity and other parameters are calculated when velocity calculated by Wyllie formula based on logging data is consistent with prestack seismic velocity.Then，geological models are established by multi-point controls and a forward modeling is carried out and compared with seismic sections to achieve the fluid identification.This proposed approach is used to a new area (no or very few wells) and some significant discoveries are obtained by drilling，which shows validity and practicability of the proposed approach.

Keywords：forward modeling，fluid identification，new area (no or very few wells)，Wyllie formula

1.Petroleum Research Institute for Western Part，South China Sea，Zhanjiang Branch，CNOOC，Zhanjiang，Guangdong 524057，China

Seismogramsynthetizinginthedepth-domainwithpointspreadfunction.ZHANGJinling1,XUMeiru1，YEYueming1,WANGZhaoqi1,andWANGZong-ren1.OilGeophysicalProspecting,2019,54(4)：875-881.

Currently the prestack depth migration (PSDM) becomes the prevailing imaging technology.But the seismic data interpretation and reservoir inversion are still been carried out in the time domain due to the hardness of depth domain seismogram synthetizing.It leads complex workflows and low efficiency.To tackle this problem，we propose a depth domain seismogram synthetizing approach based on unstationary convolution with point spread function (PSF).First，the basic principle of the proposed approach is discussed and the PSF in the spatial domain is derived from the time domain wavelet.Then the depth domain seismogram synthetizing of the PSF unsteady convolution model is presented.Model and real data tests prove the feasibility and accuracy of proposed approach.

Keywords：point spread function (PSF)，seismogram，depth domain，convolution，data interpretation

1.Hangzhou Research Institute of Geology，PetroChina，Hangzhou，Zhejiang 310023，China

Time-lapseseismicinthesteamchambermonitoringofSAGD.XINKunlie1.OilGeophysicalProspecting,2019，54(4)：882-890，907.

The 4D seismic is a widely used and well-perfected technology in reservoir monitoring.In the middle to late stage of the steam assisted gravity drainage (SAGD) development in Liaohe Oilfield，the identification of steam chambers and residual oil becomes more and more difficult.To solve the problem，a time-lapse seismic monitoring project is conducted.Based on previous researches，time-lapse seismic monitoring feasibility study is carried out.Time-lapse seismic data is normalized and its attribute differences are analyzed.With seismic attribute differences，inter-beds are predicted，steam chambers and the remaining oil distribution are characterized.The proposed approach has achieved good results in the guiding SAGD dynamic adjustment and remaining oil potential.

Keywords：time-lapse seismic，steam assisted gravity drainage (SAGD)，steam chamber，remaining oil，variance analysis，root mean square amplitude

1.Heavy Oil Development Branch，Liaohe Oilfield Company，PetroChina，Panjin，Liaoning 124010，China

Strike-slipfaultdisplacementcalculationbasedonstructurephysicalsimulation.WUKui1,HEJing1，ZHANGZhongqiao1,ZHANGJiangtao1,andZHANGJinhui1.OilGeophysicalProspecting,2019,54(4)：891-900.

This paper demonstrates an example of strike-slip fault displacement calculation based on structure physical simulation.Using drilling data and seismic interpretation，a structural physical simulation of Liaozhong Sag is completed based on local faults and fault system characteristics.Three groups of fault patterns are involved，i.e.，two main parallel strike-slip faults，two main non-parallel strike-slip faults，and a single main strike-slip fault.The evolution and formation mechanism of the strike-slip faults are discussed and main strike-slip fault displacement is calculated.The following understandins are obtained：①Several geese and broom fault systems were developed in Liaozhong at the end of the LZ1 fault and upper layers of strike-slip faults，which were mainly controlled by the Oligocene right-lateral strike-slipping；②Geese and broom fault systems，and plane through fractures were formed with the increase of slip，geese and broom fault systems can be used as references for deep strike-slip fault interpretation；③Based on quantitative statistical analysis，the ratio of extension to slip is about 3：2，the strongest strike-slipping of three main faults was in the Dongying Period，and the largest slip occurred at LZ1.

Keywords：structural physical simulation，strike-slip fault，strike-slip displacement，broom fault,goose fault,Liaozhong Sag

1.Tianjin Branch，CNOOC，Tianjin 300459，China

Calibrationofdouble-emissionandsingle-receivingresonantelectromagneticwaveloggingcoilsystem.ZHAOZhizhong1,2,XINGBowen1,2,3，ZHANGChao3,LIUGuoqiang3，4，LIYanhong3,andANHui-lin3，4.OilGeophysicalProspecting,2019,54(4)：901-907.

Increasing the source distance from the recei-ver is an effective way to increase the detection depth of the electromagnetic wave resistivity logging-while-drilling tool，but in this case the received signals are seriously attenuated.In this paper，the principle of resonance is introduced into the electromagnetic wave resistivity logging-while-drilling，and a double-emission and single-receiving re-sonance coil system is used to increase the voltage amplitude of the receiving coil.The scale loop si-mulation formation conductivity is often used in laboratories to conduct research on instrument response characteristics.The calibration method for the double-emission and single-receiving resonance coil system is completely different from that of conventional open coil systems.Based on Doll geometric factor theory，the calibration ring parameter selection of the double-emission and single-receiving resonance coil system is studied，and it is found that the parameter selection should be compromised between the relative degree of stability and the scale ring resistance resolution to reduce the measurement error.An experimental platform is built and open-circuit response characteristics and resonant response characteristics of the receiving coil in a uniform layer are compared.The results show that the resonant method only increases the amplitude of the receive response without changing the amplitude ratio，which verifies the correctness of the scale ring parameter selection and the correctness of the resonance method.

Keywords：scale ring，resonant coil，double-emission and single-receiving，logging-while-drilling

1.State Key Laboratory of Reliability and Intelligence of Electrical Equipment，Hebei University of Technology，Tianjin 300130，China

2.Hebei Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability，Hebei University of Technology，Tianjin 300130，China

3.Institute of Electrical Engineering，Chinese Academy of Sciences，Beijing 100190，China

4.University of Chinese Academy of Sciences，Beijing 100049，China

Time-frequencyelectromagnetic(TFEM)method:Dataacquisitiondesign.HEZhanxiang1,2,YANGGuoshi3，CHENSiqi4,ZHAOGuo3,LIUZihao3，andGUORongwen4.OilGeophysicalProspecting,2019,54(4)：908-914.

The time-frequency electromagnetic(TFEM) method is a controlled source electromagnetic method developed for oil and gas exploration，which can detect deeply-buried targets.Based on a real geoelectric model and the noise analysis in the Area Q，the characteristics of electromagnetic anomalies caused by geological targets are analyzed by 3D modeling，and the acquisition design is comprehensively studied.A receiving system design with equal-waist trapezoidal region electrode distribution and receiving signal balance and a transmitting system optimal design for target anomaly contrast analysis are proposed.At the same time，based on the single-noise analysis of the stacking times，an excitation design method for excitation period setting and stacking time is also proposed.

Keywords：time-frequency electromagnetic (TFEM)，data acquisition，3D modeling，data acquisition parameter design

1.Academy for Advanced Interdisciplinary Studies，Southern University of Science and Technology，Shenzhen，Guangdong 518055，China

2.Department of Earth and Space Sciences，Sou-thern University of Science and Technology，Shen-zhen，Guangdong 518055，China

3.GME & Geochemical Surveys，BGP Inc.，CNPC，Zhuozhou，Hebei 072751，China

4.School of Geosciences and Info-Physics，Central South University，Changsha，Hunan 410083，China

Magneticsourcesingle-pointpositioningbasedonsecond-ordermagnetictensorEulerdeconvolution.LIQingzhu1,LIZhining1,ZHANGYingtang1,andFanHongbo1.OilGeophysicalProspecting,2019,54(4)：915-924.

In order to distinguish the magnetic anomaly of small-scale magnetic objects from strong geomagnetic field and improve the single-point position-ing accuracy of magnetic objects，a single-point positioning method based on second-order magnetic tensor Euler deconvolution is proposed.First the concept of the second-order tensor system and its measurement are discussed based on the planar cross magnetic gradient tensor system.Then the relationship between first-order and second-order tensor data of magnetic source and their position vectors is derived with 3D Euler deconvolution formula.Finally the invariant relationship between the eigenvectors of the tensor matrix eigenvalues and the position vector of magnetic source is derived under the magnetic dipole field，and magnetic source coordinates are calculated.Model data tests show that the proposed method can accurately locate single-point objects in a uniform strong magnetic field.Real data tests show that the proposed method achieves the small-scale magnet positioning root-mean-square error (RMSE) less than 10cm after the system error correction.

Keywords：second-order magnetic gradient tensor，single-point positioning，Euler deconvolution，error correction

1.Department of Vehicle and Electrical Engineering，The Army Engineering University of PLA，Shijiazhuang，Hebei 050003，China

Potentialfieldseparationbasedonthelowrankandsparsecharacteristics.ZHUDan1,LIUTianyou1,andLIHongwei2.OilGeophysicalProspecting,2019,54(4)：925-936.

The robust principal component analysis (RPCA) extends the single objective function optimization problem for low-dimensional signal rank minimization of principal component analysis (PCA) to the two-objective function optimization problem for low-dimensional signal rank minimization with high-dimensional signal sparse.Conventional potential field separation methods such as matched filtering usually have overfitting or underfitting problems.To solve this kind of problems，this paper analyzes the low rank structures of regional field and sparse structures of local field.The RPCA is used to the potential field separation，also makes the separation more robust.Based on synthetic model tests，the proposed method is an effective and practical spatial-domain method with weight-ing parameters easy to be valued，and it can avoid errors caused by the Fourier transform.The proposed method is used to deal with data in Weiningbeishan area，Ningxia Province.Separated local low gravity anomalies and local high magnetic anomalies match very well with known underground igneous rocks，and six potential igneous rock zones are delineated.

Keywords：robust principal component analysis (RPCA)，potential field separation，low-rank matrix，sparse matrix，exact augmented Lagrange multipliers(EALM) algorithm，Weiningbeishan Area

1.Institute of Geophysics and Geomatic，China University of Geosciences(Wuhan)，Wuhan，Hubei 430074，China

2.School of Mathematics and Physic，China University of Geosciences(Wuhan)，Wuhan 430074，China

Deepvolcanicreservoirexplorationwithjointedelectromagneticandseismicdata：anexampleofvolcanicinvestigationinLiaodongSag.XUGuifen1,2,HEZhanxiang3,4,SHIYanling1,andDONGWeibin1.OilGeophysicalProspecting,2019,54(4)：937-946.

Seismic reflections from deep volcanic strata are disorderly，which makes volcanic reservoir detection very difficult.To overcome this difficulty，a specific technical strategy is proposed in this paper.The simulated annealing constrained inversion of jointed electromagnetic and seismic data improves the resolution together with drilling data calibration and shallow model building.With lithological analysis，the electrical variation regularity of volcanic rock in the research area is revealed，and an electrical variation rhythm coding is put forward to interpret reservoirs.In the end，the multi-stage and facies distribution of volcanic rocks in the third member of Shahejie Formation are identified，and the distribution characteristics of trachyte are described，which may provide a feasible reference for the exploration of similar complex targets.

Keywords：constrained inversion of jointed electromagnetic and seismic data，volcanic，rhythm coding,Liaodong Sag

1.GME & Geochemical Surveys，BGP Inc.，CNPC，Zhuozhou，Hebei 072751，China

2.School of Electrical Engineering，Hebei University of Technology，Tianjin 300401，China

3.Academy for Advanced Interdisciplinary Stu-dies，Southern University of Science and Technology，Shenzhen，Guangdong 518055，China

4.Department of Earth and Space Sciences，Sou-thern University of Science and Technology，Shen-zheng，Guangdong 518055，China