宽方位地震技术与隐蔽油气藏勘探

宽方位地震技术即是横向接收单元尺寸与纵向接收单元尺寸之比大于0.5时的三维地震采集、处理技术。由于宽方位地震技术的方位角分布全、炮检距从小到大分布均匀,因此,宽方位地震资料中蕴含着更为丰富的信息,有助于识别微幅构造、小断层和高角度裂缝。介绍了济阳坳陷罗42地区、商741地区和准噶尔盆地中部Ⅰ区块庄1井区宽方位地震采集处理技术,并对比分析了利用宽方位地震资料预测泥页岩裂缝油气藏和火成岩裂缝系统发育带以及在庄1井区描述砂体的效果。分析认为,宽方位地震技术在研究具有各向异性特点、非均质性强的地质目标体时效果明显,但对于地质目标体为砂岩体和各向异性特点不突出的储层预测,宽方位地震资料在对砂岩体的识别能力和对物性参数的反演精度等方面并无明显优势。

Wide azimuth seismic technique and subtle hydrocarbon reservoir exploration

Wide azimuth seismic is a kind of 3-D seismic data acquisition-processing technique with the ratio between transverse and longitudinal receiver unit larger than 0.5.Wide azimuth seismic is characterized by whole distribution of azimuth angle and even distribution of offset.Thus wide azimuth seismic data contains more information,which is helpful for identifying micro-relief structure,small faults and high-angle fractures.We introduced the wide azimuth seismic acquisition and processing examples in Luo42 area and Shang741 area of Jiyang Depression,and Zhuang1 well area in central Junggar Basin.Moreover,wide azimuth seismic data was applied for predicting shale fractured reservoir and igneous rock fracture development belt,as well as characterizing the sand bodies in Zhuang1 well area.Results indicate that wide azimuth seismic is effective for the geologic bodies with anisotropy and strong heterogeneity,but there is no advantage for identifying sand bodies and inversing physical properties by using wide azimuth seismic data when the geologic target of reservoir prediction is sand bodies and the reservoirs without strong anisotropy.