鹤岗矿区巨厚砾石等复杂条件下三维地震勘探技术应用

Application of 3D Seismic Prospecting under Hugely Thick Gravels etc Complex Conditions in Hegang Mining Area

鹤岗矿区深层煤地层地震地质条件非常复杂,而且近地表有一套巨厚砾石层、浅层煤存在多层采空区,对地震波下传能量具有很强的屏蔽作用。为此,采用可控震源“两宽一高”地震采集技术,及基于菲涅尔带的层析反演静校正、OVT域偏移处理技术与地震几何体属性解释技术等,有效克服了鹤岗矿区近地表巨厚砾石、多层采空区对地震波能量屏蔽的问题,解决了深层多套近距离煤层地震资料信噪比低的问题。此次勘探解释煤层落差≥5m的断层88条、采空非垮塌区面积0.76km 2,采空垮塌区面积0.85km 2,其结果与地质精查吻合率>90%;圈定了采空区和透水高风险区域,为工作面布局和矿井生产避开高风险区域,预防透水事故发生提供了准确的地质资料;另外定性预测了矿区内的瓦斯/煤层气。

Seismic-geological condition of deep coal-bearing strata is very complex in the Hegang mining area.Near surface has a set of hugely thick gravels layer,while multilayer gob areas existed in shallow coal seams,all of these have strong shielding effects on seismic wave energy down-going transmission.Therefore,the vibroseis“wide azimuth,wide band and high density”seismic data acquisition technology,tomographic inversion statics based on Fresnel zone,OVT domain migration processing technology and seismic geometry attribute interpretation technology etc have been used to effectively overcome near surface hugely thick gravels,multilayer gob areas seismic wave energy shielding issues,as well as deep multi-set close interval coal seams seismic data low SNR issue in Hegang mining area.During the prospecting has interpreted 88 faults with throw≥5m,without collapsed worked out area 0.76km 2,collapsed worked out area 0.85km;coincidence rate with results from geological detail exploration>90%.The prospecting has also delineated gob area and perviousness high risk areas as working faces layout and mine production should be avoided areas;provided accurate geological data to prevent flooding accident;in addition,qualitatively predicted mining area gas/CBM.