复杂断块油藏地震标定研究与新认识——以大港自来屯油田为例

以大港自来屯复杂断块油田为例,对地震标定问题进行了分析与研究,总结出6个方面的有效措施,厘清了研究区复杂的井震关系,得到以下结论与认识:研究区枣Ⅴ底与Ek12之间有一稳定的反射同相轴,系复合波叠合形成,资料为正极性、枣Ⅴ底对应波谷反射;以枣32井目标区为例,利用测井相的相似与差异特征,查清了孔二段先沉积后隆起、隆起区枣Ⅴ厚度变薄的成因;采用先连续地层、后复杂地层、再斜井辅助验证的标定策略,实现了构造异常复杂区井震标定;讨论了标定的拉伸/压缩功能,建议此功能有效性当以测井相、地震相整体吻合为原则;利用密井网优势,分析了全区地震速度和测井声波时差换算速度的差异,从多井统计的角度检验了标定的正确性;将标定分为层位标定与储层标定,薄互储层的识别可尝试采用90°相移技术。研究成果对大港油田开展油藏精细描述、对其它复杂断块进行地震标定有一定的参考价值。

This study analyzes the seismic calibration of the Zilaitun complex fault block oil field,and puts forward six measures to clarify the complex well-to-seismic relationship.The following conclusions and inferences are drawn:①there is a stable reflection seismic event between the bottom of Z5 and Ek12 in the study area,which occurs because of composite wave superposition,and the bottom interface of Z5 corresponds to trough reflection with normal polarity;②taking the target area of the Zao32 well as an example,according to logging facies,the causes of the second member of the Kongdian formation depositing first and then uplifting,and the thinning of the Z5 thickness in uplifted areas are determined;③the calibration strategy of continuous and complex formations,and last inclined well verification is adopted to realize well seismic calibration in the complex structural area;④by discussing the calibration function of stretch/squeeze movement,we suggest that the validity of the function should be based on the overall coincidence of logging and seismic facies;⑤the differences between the seismic velocity and conversion velocity from AC logging are analyzed,using the advantage of the dense well networks,and calibration verification is performed using the statistics of multiple well points;and ⑥calibration can be divided into stratigraphy calibration and reservoir calibration,and the thin interbed reservoir can use the 90° phase-shifting technique.The research results can serve as a reference for fine reservoir descriptions in the Dagang oilfield,potentially enabling the seismic calibration of other complex fault blocks.

国家自然科学基金项目(42072169)和大港油田项目“自来屯开发区孔店组高精度油藏描述油藏地球物理关键技术研究”(DGYT-2020-

JS-50413)共同资助。