时频电磁井震联合建模反演探测深部火山岩储层内幕结构: 渤海湾盆地LD地区实例研究

盆地深部火山岩储层地震受能量屏蔽影响反射杂乱，使得火山岩油气藏的勘探非常困难。针对深部火山岩储层多期叠置的复杂内幕结构，研究了最优偏移距、激发周期窗口的时频电磁采集技术和时频电磁井震联合建模反演及电性节律变化火山岩期次解释技术，有效提高了该方法的深层分辨率和对深层目标的识别能力。在渤海湾盆地LD地区的研究应用效果明显，结果揭示红星构造带沙三段火山岩喷发自下而上表现出"弱-强-强-弱-弱"的"两强三弱"的特征，发育两个火山岩喷发机构，共同控制了5个期次的火山岩储层相带分布；桃园构造带沙三段各期次火山岩喷发强度明显减弱，仅发育一个火山岩喷发机构，除期次3火山岩储层相带分布范围相对较大外，其他期次火山岩主要局限分布于火山口附近，以爆发相为主，规模明显减小。后续钻探结果证实时频电磁揭示的火山岩储层分布正确，并为该区油气大发现提供了有力支撑，为探测类似的复杂目标提供了成功范例与技术方法。 

Inversion of time-frequency electromagnetic well seismic modeling to probe the inner structure of deep volcanic reservoir: A case study of LD area in Bohai Bay Basin

The seismic reflection of volcanic reservoir in deep basin is disorderly due to the influence of energy shielding, which makes the exploration of volcanic reservoir very difficult. Aimed at the complex inner structure of deep volcanic reservoir with multi-phase superposition, the optimal offset, time-frequency electromagnetic acquisition technology of the excitation period window, time-frequency electromagnetic well seismic joint modeling inversion and electrical variation rhythm coding volcanic period interpretation technology are studied, which effectively improved the depth resolution and the recognition ability of the method. The research and application effect in LD area of Bohai Bay Basin are obvious. The results show that the volcanic eruptions of the third member of Shahejie Formation in the Red Star tectonic belt show the characteristics of "two strong three weak" of "weak-strong-strong-weak-weak" from bottom to top. Two volcanic eruption mechanisms are developed, which jointly control the distribution of volcanic reservoir facies in five periods. In Taoyuan structural belt, the volcanic eruption intensity of each stage of the third member of the Shahejie Formation is significantly weakened, and only one volcanic eruption mechanism is developed. Except for the relatively large distribution range of volcanic reservoir facies in stage 3, the volcanic rocks in other stages are mainly confined to the crater, mainly in eruption facies, and their scale is significantly reduced. The follow-up drilling results confirmed that the distribution of volcanic reservoir revealed by time-frequency electromagnetic was correct, which provided strong support for the large oil and gas discovery in this area and provided a successful example and technical methods for the detection of similar complex targets.