Data Processing And Interpretation Of Marine Controlled Source Electromagnetic Survey

In recent years, the Marine electromagnetic exploration in Marine oil and gasexploration technology plays an important role. From1970s to today, the Marineelectromagnetic technology has experienced a tortuous development process in recentyears, the Marine electromagnetic exploration in Marine oil and gas explorationtechnology plays an important role. The university of California at the Scrippsinstitute and university of California at Berkeley in the Marine electromagneticresearch aspects of the research, makes the Marine electromagnetic detectiontechnology has achieved iconic progress and put it into the practical application stage.At present, the marine electromagnetic detection method mainly USES the seafloormagnetotellurics method(MT) and marine controlled source electromagneticdetection(CSEM). Because of Marine electromagnetic exploration technology cangain not only the accuracy of the submarine structure also can improve the successrate of drilling, greatly reduce the risk of ocean exploration, this mainly displays inthe ocean of controlled source electromagnetic detection, the detection method in thebottom of the sea to see if there is oil and gas layer at the same time, also candetermine whether the trap and the boundary of oil and gas layer and contains oil andgas, which is superior to seismic exploration technology, in light of the advantages, inthe EAGE and SEG annual meeting every year, about the theme of the controlledsource electromagnetic exploration has become the hot spot of attention. FusedMarine controlled source electromagnetic detection technology in the offshore oil andgas exploration technology has become a necessary process of oil and gas exploration.This article mainly relying on national project, in the sea of controlled sourceelectromagnetic detection basic principle on the basis of the detected signal processing and interpretation. Main completed the following work:（1）Research related to marine controlled source electromagnetic detectionliterature, the basic principles of marine controlled source electromagnetic detection,describe the shallow water drag construction methods and deep-sea fixed constructionmethods both marine controlled source electromagnetic detection work;（2）Respectively, through the introduction of the transmitter and receiverequipment, analysis of marine controlled source electromagnetic signal acquisition;（3）The basic theoretical knowledge of the electromagnetic field, according toMaxwell’s equations and boundary conditions are derived in the frequency domainMaxwell’s equations and horizontal electric dipole source electromagnetic fieldstrength;（4）A few examples of marine controlled source electromagnetic signaltransmitted waveform, square wave signal used on the subject;（5）Analysis to the received signal of marine controlled source electromagneticdetection, mainly through the propagation path of the received signal is studied,combined with the analysis of the seawater characteristics for the noise encountered inthe detection process;（6）In data processing, according to the elliptically polarized derived formula,using matlab software programming, using wavelet transform modulus maximamethod of signal noise removal, find the air wave suppressed, and a few of them themethod formula derivation, spectral analysis, normalization, geometry, and full3Dposition correction processing method, at the same time get the related data andgraphics;（7）Introduced the data interpretation methods commonly used in the marinecontrolled source electromagnetic detection, electromagnetic field amplitude versusoffset from the curve obtained by the one-dimensional forward MVO graph, the curveclearly expressed considerable of submarine high impedance Oil layer; and theestablishment of a single-layer high impedance oil and gas layer model, matlabsoftware in conjunction with the programming model, to draw high resistance oil andgas layer thickness MVO maximum relations;（8）Being supplied through the investigation of practical examples, in order toreally understanding marine controlled source electromagnetic detection technology.