Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected wav...Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected waves are interfered with the dominant borehole-guided modes and there are only eight receiving channels per shot available for stacking. In this paper, we apply an equivalent offset migration method based on wave scattering theory to process the acoustic reflection imaging log data from both numerical modeling and recorded field data. The result shows that, compared with the routine post-stack depth migration method, the equivalent offset migration method results in higher stack fold and is more effective for near-borehole structural imaging with low SNR acoustic reflection log data.展开更多
In oil and gas exploitation,cluster well technology can significantly reduce costs and improve efficiency.An effective adjacent well detection method can greatly reduce the risk of collision between adjacent wells.Thi...In oil and gas exploitation,cluster well technology can significantly reduce costs and improve efficiency.An effective adjacent well detection method can greatly reduce the risk of collision between adjacent wells.This study proposes a method to invert the 3D trajectory of an adjacent well using a scattered P-wave obtained by borehole azimuthal acoustic reflection imaging.After obtaining the scattered P-wave from the raw data of the target well using the wave field separation technology,the waveform data in an imaging profile can be obtained by the downhole acoustic directional reception technology.Migration imaging technology is then used to obtain the image of the formation in the imaging profile.Subsequently,by analyzing the images of the formation in the imaging profile of the different azimuths,the well spacing and azimuth of the target well can be determined.Finally,the 3D trajectory of the target well can be obtained by solving the inversion equation.This method was validated by processing the field data from a deviated well in a deep formation.The comparison of the inversion and actual trajectories of the target well demonstrated that the maximum deviation of the inversion trajectory is 0.9 m in the north-south direction,0.78 m in the east-west direction,1.45 m in the well spacing,and 2.48°in the azimuth.The field data inversion result demonstrated that the method can effectively use the azimuth reflection acoustic data to invert the 3D trajectory of an adjacent well,which indicates that the borehole azimuthal acoustic reflection imaging technology has great potential within the context of adjacent well detection.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.50674098)the 863 Program (Grant No.2006AA06Z207 & 2006AA06Z213)the 973 Program (Grant No.2007CB209601)
文摘Borehole acoustic reflection logging can provide high resolution images of nearborehole geological structure. However, the conventional seismic migration and imaging methods are not effective because the reflected waves are interfered with the dominant borehole-guided modes and there are only eight receiving channels per shot available for stacking. In this paper, we apply an equivalent offset migration method based on wave scattering theory to process the acoustic reflection imaging log data from both numerical modeling and recorded field data. The result shows that, compared with the routine post-stack depth migration method, the equivalent offset migration method results in higher stack fold and is more effective for near-borehole structural imaging with low SNR acoustic reflection log data.
基金supported by the National Natural Science Foundation of China(grant numbers 12274465,42174218)the Strategic Cooperation Technology Projects of CNPC and CUPB(grant numberZLZX2020-02).
文摘In oil and gas exploitation,cluster well technology can significantly reduce costs and improve efficiency.An effective adjacent well detection method can greatly reduce the risk of collision between adjacent wells.This study proposes a method to invert the 3D trajectory of an adjacent well using a scattered P-wave obtained by borehole azimuthal acoustic reflection imaging.After obtaining the scattered P-wave from the raw data of the target well using the wave field separation technology,the waveform data in an imaging profile can be obtained by the downhole acoustic directional reception technology.Migration imaging technology is then used to obtain the image of the formation in the imaging profile.Subsequently,by analyzing the images of the formation in the imaging profile of the different azimuths,the well spacing and azimuth of the target well can be determined.Finally,the 3D trajectory of the target well can be obtained by solving the inversion equation.This method was validated by processing the field data from a deviated well in a deep formation.The comparison of the inversion and actual trajectories of the target well demonstrated that the maximum deviation of the inversion trajectory is 0.9 m in the north-south direction,0.78 m in the east-west direction,1.45 m in the well spacing,and 2.48°in the azimuth.The field data inversion result demonstrated that the method can effectively use the azimuth reflection acoustic data to invert the 3D trajectory of an adjacent well,which indicates that the borehole azimuthal acoustic reflection imaging technology has great potential within the context of adjacent well detection.
