利用“两宽一高”地震资料预测深层储层

Predicting deep reservoirs with "2W1H" seismic data

塔东古城低凸起奥陶系埋深大于6000m,主要储层为白云岩和灰岩,属于典型的深层—超深层勘探领域。超深层地震资料的品质受采集、衰减和处理等因素影响,储层预测一般难以达到预期结果。为此,以宽方位资料为基础,确立了"两宽一高"资料解释思路,基于地震资料的宽频带和方位信息,系统地开展了塔东古城低凸起深层岩溶储层岩性预测、方位优选及优势方位含气性检测。为了提高研究区储层预测精度,确定有利勘探区带,利用宽频带资料预测白云岩的分布,利用优势方位数据体检测储层的含油气性。研究结果表明:根据宽频带资料振幅与频率(AVF)的关系预测储层的效果明显优于叠前反演;宽方位资料存在一定的油气响应优势方位,在该方位各向异性影响小,油气响应特征更明显,能更好地预测深层油气有利分布区。

The Ordovician reservoirs at deeper than 6000 m in the Gucheng low uplift in the eastern Tarim Basin are dolomite and limestone,which are taken as the typical deep to ultra-deep exploration targets.The quality of ultra-deep seismic data is affected by seismic acquisition,attenuation and processing,so that it is difficult to get expected results of reservoir prediction.In this study,based on the data with wide azimuth,the interpretation workflow for"2W1H"data was proposed,and then based on the information of broadband and azimuth,lithology prediction,zonal optimization and gas identification by dominant zones of deep karst reservoirs were carried out in the Gucheng low uplift.In order to improve the accuracy of reservoir prediction and determine the favorable exploration area in the study area,the distribution of dolomite was predicted by using the broadband of the seismic data,and the gas potential of the reservoir was detected by using the dominant azimuth of the seismic data.The results show that reservoir prediction based on the relationship between amplitude and frequency(AVF)is better than that of prestack seismic inversion.The wide azimuth seismic data has certain dominant azimuth of hydrocarbon response,and the anisotropy at such azimuth is less,and the hydrocarbon response characteristics are more obvious.This can better predict the distribution of favorable deep gas reservoirs.