渤海海域龙口7-1火山岩潜山油气勘探发现及成藏新认识  

Discovery and new understanding of oil and gas exploration in volcanic buried hill of LK7-1 in Bohai Sea

作　　者：王昕 陈磊 高雁飞 程鑫 张蔚 王志萍 赵志平 WANG Xin;CHEN Lei;GAO Yanfei;CHENG Xin;ZHANG Wei;WANG Zhiping;ZHAO Zhiping(CNOOC China Limited,Tianjin Branch,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《中国海上油气》2025年第2期14-26,共13页China Offshore Oil and Gas

基　　金：国家自然科学基金重点支持项目“渤海海域中生界潜山火山岩相发育机制及成储机理(编号:U24B2017)”;“十三五”国家科技重大专项子课题“中国近海富烃凹陷优选与有利勘探方向预测(编号:2016ZX05024-002-006)”;中海石油(中国)有限公司“七年行动计划”重大科技专项课题“渤海油田上产4000万吨新领域勘探关键技术(编号:CNOOC-KJ135ZDXM 36TJ08TJ)”部分研究成果。

摘　　要：随着渤海潜山勘探程度提高,变质岩及碳酸盐岩潜山勘探发现难度越来越大,获得更为复杂的火山岩潜山突破势在必行。2024年在渤东低凸起钻探了LK7-A井,实现了渤海东部中生界火山岩领域性突破。利用新钻探井录井、测井及岩矿等资料,结合新采集处理三维地震数据,对龙口7-1潜山油气成藏条件展开研究。结果表明:(1)龙口7-1潜山发育顶气底油的似层状油气藏,具有高温高压、岩性岩相复杂、储层非均质性强等特点。(2)“岩性岩相-构造作用-风化淋滤”控制储层的形成。优势岩性为优质储层形成提供良好基础,强烈构造改造是优质火山岩储层形成的关键,晚期风化淋滤利于规模性优质储层形成;利用基于随机森林的深度学习孔隙度反演技术可实现火山岩储层预测。(3)“源-储-盖”超压联合控制火山岩油气的高效富集,龙口7-1中生界油气藏具有超压控制下的火山岩风化壳型成藏模式。烃源岩发育欠压实和生烃增压,超压烃源岩为渤东低凸起提供充足物质基础和运移动力;储层内发育传递型超压,超压酸性流体延缓孔喉物性的降低,为油气持续充注提供了良好通道;欠压实超压泥岩盖层为油气成藏提供了良好保存条件。龙口7-1潜山的勘探发现揭示了渤海东部中生界火山岩油气藏勘探潜力,对推动渤海广泛分布的中生界火山岩勘探具有重要指导意义。As exploration of the buried hills in the Bohai Sea intensifies,the challenge of identifying metamorphic and carbonate rock structures is increasing.Therefore,breakthroughs in the more complex volcanic buried hills structures are essential.In 2024,Well LK7-A was drilled in the Bodong low uplift,marking a significant advancement in the Mesozoic volcanic rock field in eastern Bohai Sea.Utilizing data from this new well—including well logging,measurements,and rock and mineral information—along with newly processed 3D seismic data,this study investigated the oil and gas accumulation conditions in the LK7-1 structure.The results indicate the following:①The LK7-1 buried hill is an oil and gas reservoir of a nearlayered structure,characterized by high temperature and pressure,gas at the top and oil at the bottom,complex lithology and lithofacies,and strong reservoir heterogeneity.②The formation of the reservoir is governed by“lithology and lithofacies-structural actions-weathering and leaching”.Dominant lithologies provide a solid foundation for the formation of high-quality reservoirs;intense structural modifications are crucial for developing high-quality volcanic reservoirs;late-stage weathering and leaching are favorable for the formation of large-scale high-quality reservoirs.Volcanic reservoir prediction can be achieved using porosity inversion technology based on deep learning and random forest.③The combination of overpressure in the source-reservoir-cap system controls the efficient accumulation of oil and gas in the volcanic rocks.The Mesozoic oil and gas reservoir in the LK7-1 buried hill exhibits a volcanic weathering crust accumulation model under overpressure control.Source rocks with pressurization caused by disequilibrium compaction and hydrocarbon generation provide adequate material basis and migration dynamics for the Bodong low uplift.The development of internal transferred overpressure in the reservoir,along with overpressured acidic fluids,mitigates the deterioration of pore throat pro

关 键 词：渤海海域 渤东低凸起 中生界火山岩 龙口7-1 勘探发现 优质储层 成藏模式 

分 类 号：TE122.1[石油与天然气工程—油气勘探] P744.4[天文地球—海洋科学]