石油与天然气地质 ›› 2023, Vol. 44 ›› Issue (2): 247-263.doi: 10.11743/ogg20230201

• 油气地质 • 上一篇    下一篇

超薄砂岩储层预测方法研究与应用

王光付1(), 徐海1, 李发有1, 孙建芳1, 段文龙2   

  1. 1.中国石化 石油勘探开发研究院,北京 102206
    2.中国石油大学(北京) 地球物理学院,北京 102249
  • 收稿日期:2022-12-20 修回日期:2023-01-20 出版日期:2023-04-01 发布日期:2023-03-17
  • 第一作者简介:王光付(1965—),男,博士、教授级高级工程师,油气田开发。E?mail: wanggf.syky@sinopec.com
  • 基金项目:
    中国石化科技部基金项目(P20072-2)

Predication methods of ultra-thin sandstone reservoirs and their application to blocks 14 and 17 in the Andes, Ecuador

Guangfu WANG1(), Hai XU1, Fayou LI1, Jianfang SUN1, Wenlong DUAN2   

  1. 1.Petroleum Exploration and Development Research Institute,SINOPEC,Beijing 102206,China
    2.Institute of Geophysics,China University of Petroleum (Beijing),Beijing 102249,China
  • Received:2022-12-20 Revised:2023-01-20 Online:2023-04-01 Published:2023-03-17

摘要:

目前在油气勘探开发领域,针对中等埋深(2 500~3 500 m)砂岩储层预测的极限厚度一般可以达到5~10 m,而小于5 m的超薄储层准确预测仍为工业界难题。基于厄瓜多尔安第斯14和17区块不同时期采集和处理的多工区叠后地震数据,采用构造趋势面驱动叠后连片一致性处理,压制了多工区相位、能量、频率及闭合差等因素对薄层反射的干扰,降低了储层预测的多解性。基于时-频衰减高精度合成记录标定方法,消除由于地层吸收产生的时间累积误差,精确标定和解剖薄层反射特征,确定了超薄储层分辨的最低主频。基于无井驱动的“稳态变时频子波” 叠后宽频有效信号高分辨率处理技术,有效恢复了薄层弱反射系数。基于宽频地震波形约束,优化了相控非线性反演的算法与工作流程。通过上述研究,形成了一套有效的超薄砂岩储层综合预测方法和技术体系,成功地实现了埋深3 000 m、厚度2~5 m潮汐水道砂体的精准预测,新钻滚动评价井和开发井验证其预测准确率达到90 %以上。

关键词: 宽频信号重建, 相控波形反演, 构造面, 潮汐水道, 超薄层, 储层预测, 厄瓜多尔

Abstract:

The minimum sand thickness for clastic reservoirs at medium burial depth between 2 500 and 3 500 meters to be predictable with current techniques is generally no more than 5 to 10 meters, while prediction of ultra-thin reservoirs with a thickness less than 5 meters remains a tough challenge. Based on the post-stack seismic data acquired and processed at different times from blocks 14 and 17 in the Andes of Ecuador, this study uses the post-stack consistent processing method driven by the structural trend surface to suppress and eliminate the interference of phase, energy, frequency and closure error on thin-bed reflection and reduce reservoir prediction uncertainty. The time-frequency attenuation, high-precision synthetic seismogram calibration method is employed to erase the accumulative time shift caused by formation absorption, accurately calibrate and analyse reflection characteristics of thin layers, and determine the minimum predominant frequency for resolving ultra-thin reservoirs. The weak reflection coefficient of thin layers is also effectively restored by using the high-resolution processing technology on post-stack broadband signals of “steady-state time-frequency-varying wavelet” without well data driving. The algorithm and workflow of facies-controlled waveform inversion are optimized based on broadband seismic waveform constraints. A series of technologies have then been developed and applied to the blocks, from which some tidal channel sand bodies of only 2 to 5 meters thick and 3 000 meters deep were successfully mapped. The drilling results of new appraisal wells and development wells verified that a prediction accuracy of at least 90 % with the methods has been reached.

Key words: broadband signal restoration, facies-controlled waveform inversion, structural surface, tidal channel, ultra-thin bed, reservoir prediction, Ecuador

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