油藏精细描述技术在歧南西斜坡隐蔽油气藏勘探中的应用

THE APPLICATION OF DETAILED RESERVOIR DESCRIPTION TECHNOLOGY TO SUBTLE HYDROCARBON RESERVOIR EXPLORATION IN THE WEST SLOPE AREA OF QINAN

针对研究区隐蔽油气藏的特殊性和复杂性,依据现代油藏精细描述的基本内容和方法,提出了勘探难点,给出了解决对策。首先,以高分辨率三维地震资料为基础,运用层序地层学方法精细划分地层,准确确定描述单元;其次,采用优势频带相干处理和倾角、方位角、断棱综合检测等微小断层识别技术,精确落实薄储层内微幅隐蔽构造;最后,结合钻井、测井、试油等资料,综合地质分析,通过楔型正演模拟、井约束地震反演、地震波形分类、分频解释、属性分析与优化、全三维解释、三维可视化和模式识别等技术的综合应用,对歧南西斜坡目的层段进行了储层精细预测和描述,明确了沙三段滩坝砂及沙一段特殊岩性体的空间展布规律,圈定出不同层序内有利岩性圈闭带的分布。综合油藏精细描述结果,在歧南西斜坡部署了一批预探井,均获高产工业油气流。由此形成的隐蔽油气藏精细描述技术系列,对今后类似的油气藏勘探具有一定的借鉴和参考意义。

In view of the particularity and complexity of the subtle hydrocarbon reservoir in the west slope area of Qinan, the authors pointed out the difficulties in litho-reservoir exploration and provided the solutions according to the basic methods of the modern reservoir description. First, on the basis of improving resolution of seismic data, the strata were divided by utilizing sequence stratigraphy technique, and the object units of description were identified successfully, Second, the subtle structure features which existed in thin beds were detected accurately by applying several advanced techniques of structural interpretation, such as dominant band coherence processing and dip and azimuth angle composite detection that can identify small faults. Third, the spatial distribution regularities of bar sandbody of the 3rd Member of Shahejie Formation and special rock units of the 1st Member of Shahejie Formation were determined and the optimal litho-traps existing in different sequences in the west slope area of Qinan were delineated by various means such as drilling, logging, geological survey, oil test, integrating forward modeling （ GMAPLUS）, seismic inversion （ JASON）, classification （ Stratimagic）, Spee Dceomp （ LandMark）, attribute analysis and optimization （ MDI）, true 3D interpretation, 3D visualization （ Geo-Probe） and pattern recognition. Finally, several pre-exploratory wells were arranged in the west slope area according to the results of comprehensive reservoir description in Qinan, and all of them later produced high-yield oil and gas. The series of detailed description technologies for subtle hydrocarbon reservoir produced in this study may provide a good example for other similar hydrocarbon reservoir exploration.