Study Of 3D Observation On Forward Modeling Of Collapse Column Model

collapse column is a kind of hazard geological body widely developed in the coal-bearing strata(or coal measure strata) of Late Paleozoic, and its existence causes the discontinuity of coal seam that makes the mining work tougher and the possibility of forming conductors and gas enrichment places that induce roof falling and water bursting, thus, hinder the construction of modern coal mine of high yield, high efficient and safe.Nowadays, 3-D seismic exploration is widely applied in coal exploration and is considered as the most practicable in collapse column exploration method because of its flexible construction and abundant information etc. But in practical production, the exploration precision of collapse column is always not satisfying, and the design of observation system is closely related to the exploration precision. Therefore, the optimization design of observation system is very significant to improve the exploration precision of collapse column.This article makes an induction on collapse-column geology and geophysical characteristics of Huabei coalfields, describes the causes and distribution of collapse column in detail and summarizes the wave-field and attribute characteristics as well as its Identification Methods. Then describes the design and optimization criterias of 3-D observation system in coal exploration.Finally builds typical 3-D seismic-geological models of coalfield collapse column and makes bin, illuminance and acquisition footprint analysis of observation systems. Optimization design criterias of 3-D observation system to improve the exploration precision of collapse column was summarized bydemonstrating the acquisition parameters of normal track group recording geometry, making forward modeling by ray tracing calculation and analyzing migration sections and attribute sections gained by forward modeling.By forward modeling the typical 3-D seismic-geological models of coalfield collapse column, ways to selecting acquisition parameters to improve the Exploration Precision of collapse column were summarized: normal track group recording geometry, wide orientation observation system, brick-wall observation system, oblique-cross observation system. the exploration precision gaps of collapse column between crenellated observation system and obliquecross observation system are narrow. Coverage of track group recording geometry is relatively high in single bin along coal seam depth. Mini trace intervals and linear distance, sufficient lines, relatively small maximum horizontal-vertical offset(shot to receiver distance) and rolling distance are favorable in collapse column exploration by track group recording geometry(6small and 2 large).