| In SN gas field, there is obvious anisotropy in the Permian of Shanxizu Formation. Conventional logging can’t accurately reflect the anisotropy of formation and result in contradiction of conventional logging interpretation and oil testing results at times. In order to analyze the causes of the formation of anisotropic, determine the formation maximum and minimum horizontal stress orientation, judge the level of development, azimuth and effectiveness of reservoir fracture, this article combined the features of geological structure in the work section, mainly used dipole shear wave logging data and combined with FMI imaging logging data of South of Jiangsu reservoir anisotropy to carry out the key analysis and research emphatically in five aspects:①Analyzing the main factors that influence the quality of dipole shear wave logging data.②Analysis the waveform data preprocessing method of DSI logging data.③Research the extraction technology of fast wave transit time and high precision three.④Research the separation of Fast and slow shear wave time and extraction of time difference.⑤Research of the reservoir anisotropy analysis and application in SN gas field. And obtained the following results and understanding:(1) Dipole shear wave logging data can be easily affected by the phase shift, frequency, cycle skip, noise interference, spacing and the distance, so it must be researched for the methods of data decoding, waveform gain control, wave filtering and waveform normalization in the aspect of theory. Summarized a set of waveform pretreatment method that can effectively improve the signal to noise ratio.(2) In order to improve the precision of wave arrival time, it must be extracting three wave slowness fast and effectively. Built a set of extract methods of S-P slowness with high accuracy that the quality is controllable. Compare to the results that extract from GeoFrame software, the curve shape is a high degree of coincidence and amplitude is closed.(3) It can be seen that the analysis method can greatly reduce the calculation error of anisotropy inversion. Formed a set of models that can determine the size and orientation of the anisotropy effectively. By the research on the extraction, separation and wave time difference of fast slow shear. The studies indicate that anisotropy coefficient is strong in SN block of Shanxi Formation, the range of anisotropy coefficient is from11%to16%.(4) Obtained size and orientation of the anisotropy through the program compiled, analyzing reservoir formation fracture and in-situ stress anisotropy for SN gas field with FMI imaging data. The range of maximum horizontal stress orientation in work area formation is N85°E. Reservoir fracture azimuth is nearly east-west, and Angle of fracture trend and the maximum horizontal principal stress direction is less than45°, it will be beneficial to crack open and form cracks effectively. (5) Compared to rock mechanics test results, it is practical that using rock mechanics parameters of anisotropic model calculates TIV strata vertical and horizontal young’s modulus and poisson’s ratio. Therefore, determined a set of rock mechanics models of elastic modulus and the parameters based on3D anisotropy.Through a series of theoretical research, the software of data processing and analysis and reservoir, formed a set of methods with good applicability and technology based on DSI logging data, it consists of extracting three wave slowness, determining size and azimuth of anisotropic and evaluating formation orientation of he maximum and minimum horizontal stress, and judging the level of development, azimuth and the effectiveness of the reservoir fracture. |
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