摘要
断层的垂向运移能力是源上复杂断裂带油气勘探的关键。针对断层垂向运移能力的评价问题,基于油气泵吸式运移原理,结合环渤中凹陷区新近系油田勘探实践,提出了构造形变体的概念,将研究对象由以往的单一断层面转变为三维的活动断裂体,建立了构造形变体的定量计算方法。研究认为:①成藏期断裂活动造成的间歇式应力释放是油气垂向快速高效运移的动力,构造形变体能够更加客观地表征断裂带的整体活动强度,进而科学地表征油气的垂向运移能力;②构造形变体包含释放体积与波及体积两大关键参数,二者与油气的垂向运移能力均具有正相关关系,释放体积和波及体积越大,油气的垂向运移能力越强;③构造形变体控制着凹陷区油气的垂向运移,从不同层面控制了油气富集区、富集带与富集块的分布。构造形变体体积的非均一性形成了多个泵吸汇烃单元,进而控制了应力释放区和油气富集区;泵吸单元构造形变的体积越大,浅层油气的富集程度越高。在同一泵吸单元,形变中心控制着油气优势富集带的分布。断裂带内的局部强构造形变控制着油气的优势充注点,进而形成油气富集断块。构造形变体概念的提出为泵吸机制下油气的垂向运移能力评价提供了理论依据,有助于高效指导渤海海域一批大型新近系油田的发现与评价,对成熟区勘探的再认识和再挖潜具有重要指导意义,在洼陷区复杂断裂带勘探中具有广阔的应用前景。
Vertical migration ability of faults is the key to hydrocarbon exploration in complex fault zones.This paper focuses on the problem of how to evaluate the vertical migration.Based on the theory of pumping-driven hydrocarbon migration in combination with exploration practices of Neogene oilfield in circum-Bozhong sag,the paper proposes a concept of structural deformation unit,and the three-dimensional active fault system,instead of a single fault plane,is taken as the research object.Moreover,the quantitative calculation method of structural deformation unit is also established.The research results are as follows.(1)The intermittent stress release caused by fault activity during the accumulation period due to strong Neotectonic movement provide the power for the rapid and efficient vertical hydrocarbon migration.By comparison,the tectonic deformation unit can more objectively represent the overall activity intensity of fault zone,and further scientifically characterize the vertical hydrocarbon migration ability.(2)Structural deformation unit has two key parameters,i.e.,released and involved volume,and both have a positive correlation with the vertical hydrocarbon migration efficiency.The larger the released and involved volume,the stronger the vertical hydrocarbon migration efficiency.(3)Structural deformation unit controls the vertical hydrocarbon migration in the sag,further controlling the distribution of hydrocarbon enrichment regions,zones and blocks from different aspects.The volume heterogeneity of structural deformation unit results in the formation of multiple pumping-driven hydrocarbon accumulation units,which control the stress release zone and hydrocarbon accumulation zone.The larger the structural deformation unit in a pumping element,the higher the hydrocarbon enrichment in shallow strata.In the same pumping element,the distribution of the dominant hydrocarbon enrichment zones is controlled by the tectonic deformation center.The predominant hydrocarbon charging positions are controlled by the regional strong tectonic deformation,thus forming the fault blocks of hydrocarbon enrichment.The concept of structural deformation unit provides a theoretical basis and a new idea for the quantitative evaluation of vertical hydrocarbon migration under the pumping mechanism,which is helpful to efficiently guide the discovery and evaluation of a batch of Neogene oilfields.It is of great guiding significance in re-understanding the hydrocarbon exploration and re-tapping the potential in mature exploration area,and has a wide application prospect in the exploitation of complex fault zones in subsag.
作者
吕丁友
黄振
杨海风
张宏国
高雁飞
宿雯
李龙
LüDingyou;Huang Zhen;Yang Haifeng;Zhang Hongguo;Gao Yanfei;Su Wen;LiLong(Tianjin Branch,CNOOC China Limited,Tianjin 300452,China)
出处
《石油学报》
EI
CAS
CSCD
北大核心
2022年第8期1078-1088,共11页
Acta Petrolei Sinica
基金
中海石油(中国)有限公司“七年行动计划”重大科技专项“渤海油田上产4000万吨新领域勘探关键技术”(CNOOC-KJ135ZDXM 36TJ08TJ)资助。
关键词
晚期成藏
构造形变体
油气垂向运移
定量表征
油气勘探
late accumulation
tectonic deformation unit
vertical hydrocarbon migration
quantitative characterization
hydrocarbon exploration
