高精度三维地震技术及其在松辽盆地北部扶余油层砂体刻画中的应用

松辽盆地北部大庆长垣及其两侧扶余油层是大庆油田致密油勘探的重点领域。为了精确刻画扶余油层致密油“甜点”,经过探索形成了高精度三维地震勘探技术。以小面元、高密度、宽方位、单井小药量激发、单只高灵敏度检波器接收为采集特点,以最大限度提高地震资料分辨率为原则,以单砂体准确刻画为核心目标,全面提高了三维地震勘探精度。研究结果表明:地震资料频带由常规的4~63Hz提高到4~90Hz,扶余油层3m以上单砂体的预测精度约80%,满足了扶余油层致密油“甜点”刻画需求。高精度三维地震技术全面应用于松辽盆地北部,为大庆油田扶余油层致密油勘探提供了技术支持。

High-precision 3D seismic techniques and their application in the sandbody characterization of Fuyu oil reservoirs in North Songliao Basin

Fuyu oil layers in Daqing Placanticline and its both sides in North Songliao Basin are the major fields of tight oil exploration in Daqing Oilfield. In order to finely characterize the “sweet spot” in Fuyu tight oil, after researching, the high-precision 3D seismic exploring technique has been developed. Taking the small bin, high density, wide azimuth, single-well small charge excitation, single high-sensitivity geophone receiving as the acquisition characteristics, and enhancing maximally the seismic data resolution as the principle, accurately characterizing the single sandbody as the core goal,the 3D seismic exploration resolution was improved in an all-round way. The study results show that the frequency bandwidth of the seismic data has been increased from 4-63 Hz to 4-90 Hz, the predicted accuracy of the single sandbody above 3 m in Fuyu oil layers is about 80%, basically meet the requirement of characterizing Fuyu tight oil “sweet spot”. High-precision 3D seismic technique has been fully applied in Northern Songliao Basin, which has laid the technical support for Fuyu tight oil exploration in Daqing Oilfield.