摘要
安徽巢湖-含山地区位于下扬子陆块北西部,下古生界富有机质泥页岩分布面积广、沉积厚度大,是页岩气勘探的有利区域。但因该区构造复杂,深部地质情况不明,造成页岩气勘探尚未取得重要发现。为了查明区内下古生界地层页岩气资源潜力,实施了巢湖-含山页岩气二维地震勘探。在对激发接收等关键采集参数实验比较后认为采用“宽线、高覆盖、长排列、小道距”的采集方式,可以增强深层的弱反射信息,有效改善采集单炮的品质。室内处理采用GeoEast软件,应用“菲涅带层析反演静校正、保真叠前去噪、子波一致性处理、沿层交互速度分析、克希霍夫叠前时间偏移”等一系列处理技术,有效提高地震资料的信噪比和成像精度。应用上述采集、处理方法技术组合,所获得地震剖面主要目标层波组特征清晰,识别出下古生界下志留统—上奥陶统泥页岩与灰岩岩性分界面,以及晚印支期以来本区主要三期性质不同的构造改造变形,为研究本区页岩气地质条件提供了技术支撑。
The Chaohu-Hanshan area of Anhui Province is located in the northwest of the lower Yangtze landmass, where the lower Paleozoic organic-rich shale has a wide distribution area and a large sedimentary thickness, favorable to shale gas explorat ion. However, due to the complex s t ructure and unknown deep geological conditions, shale gas exploration has not made important discoveries. In order to find out the resource potential of shale gas in the lower Paleozoic strata in the area, two-dimensional seismic exploration of the Chaohu-Hanshan shale gas was carried out. After experimental comparison of key acquisition parameters such as of shooting and receiving, it is concluded that the acquisition method of “wide spacing lines, high coverage, long arrangement and small group interval” can enhance the weak reflection information in the deep layer and effectively improve the quality of single-shot acquisition. GeoEast software was adopted for indoor processing, and a series of processing technologies, such as “Fresnel zone tomography inversion static correction, fidelity pre-stack denoising, wavelet consistency processing, along-layer interaction velocity analysis, Kirchhoff pre-stack time migration”, were applied to effectively improve the signal-to-noise ratio and imaging accuracy of seismic data. Application of the combined methods and techniques mentioned above for acquisition and processing brought seismic profiles of main target layers showing clear wave group characteristics, from which we can identify the lithologic interface between mud shale and limestone for the lower Silurian-upper Ordovician of lower Paleozoic, and three tectonic reworking deformations of different natures since the late Indosinian period, providing technical support for study of geological conditions of shale gas in this area.
作者
殷启春
郑红军
蒲可瑜
李凤霞
YIN Qi-chun;ZHENG Hong-jun;PU Ke-yu;LI Feng-xia(Nanjing Geological Survey Center, China Geological Survey, Nanjing, Jiangsu 210016,China;North China Geophysical Exploration Department, Oriental Geophysical Corporation, Renqiu, Hebei 062520,China;Dagang Branch, Oriental GeophysicalCorporation, Dagang, Tianjin 300280,China)
出处
《安徽地质》
2019年第1期49-54,共6页
Geology of Anhui
基金
中央财政二级项目:苏皖地区页岩气地质调查(DD20190083)资助
关键词
下扬子陆块
构造复杂区
页岩气
二维地震采集处理解释一体化
Lower Yangtze Land Mass
Structurally Complex Area
Shale Gas
Integration of 2D SeismicAcquisition
Processing and Interpretation
