Abstract:The Kulongshan mountainous area is rich in oil and gas resources in Jiuquan Basin. It is characterized by both complex in near-surface and overthrust subsurface structures, leading to great difficulties in subsurface accurate imaging. Conventional floating-datum-based prestack migration doesn't work well in such an area, so that problems such as insufficient static correction, inadequate adjustment of floating datum to severely undulating surface, and inaccurate shallow velocity models affecting the migration accuracy of deeper structures are presented, and the conventional method cannot satisfy the requirement for precise imaging of the overthrust structures. This paper proposes an integration strategy of static correction and depth imaging. Combining with the partitioned double-variable static correction, it can improve the accuracy of high-frequency near-surface static correction. The key technique integrates near-surface refraction inverted velocity with deep reflection inverted velocity reasonably to acquire a high-precision global velocity model, and uses pre-stack depth migration of true surface with small-scale surface smoothing parameters to enhance the deep imaging accuracy. Application of the high-precision depth modeling and imaging processing technique to raw data shows that the method can improve the imaging quality and accuracy of complex thrust structure effectively, proving the superiority and feasibility of the method for high-precision modeling and imaging in complex areas.
肖明图, 苏勤, 余国祥, 李斐, 凌越, 邵喜春. “双复杂”条件高精度建模与成像方法——以酒泉盆地窟窿山地区为例[J]. 石油地球物理勘探, 2020, 55(s1): 41-48.
XIAO Mingtu, SU Qin, YU Guoxiang, LI Fei, LING Yue, SHAO Xichun. Research on high-precision modeling and imaging with dual-complexity conditions: Taking the Kulongshan mountainous area of Jiuquan Basin as an example. Oil Geophysical Prospecting, 2020, 55(s1): 41-48.
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