高青断裂带多藏共存机制研究

【作者】 徐亮；

【导师】 张哨楠；

【作者基本信息】 成都理工大学 ， 矿产普查与勘探， 2007， 博士

【摘要】 高青大断层是一条长期继承性活动的基底大断层，为一级铲式正断层，是东营凹陷与青城凸起的分界断层，它的发展和演化控制着青城凸起和博兴注陷的形成和演化，对油气聚集起着重要作用；尤其是沿着高青断裂带依次分布了油藏、甲烷气藏和二氧化碳气藏，这三种类型的藏共存在断裂带上并具有相对独立的特征。通过断裂封堵性研究、油源对比、气藏成因分析、不整合和连通砂岩在成藏过程中的作用以及多藏共存规律等方面对于这种特殊的成藏现象开展了系统的研究，取得了以下成果：在系统研究断层纵向、侧向封堵性机理的基础上，分析了高青大断裂具有幕式输导特征。断裂带兼具正断和扭动性质，以高17块油藏为例，通过断层两侧岩性的配置关系分析了高青断裂带的侧向封堵性。通过油源对比，说明高青油田油源主要来自博兴洼陷沙四段烃源岩；烃类气的地化指标反映为油型气，且都不同程度遭受生物降解。非烃类气层中碳同位素特征说明是无机成因，而且是岩浆—幔源成因。He、N₂也来自地幔。在高青断裂带的油气聚集成藏过程中，不整合面与连通砂体都起到了重要的配合作用，不整合面既是运移的通道，同时其上的泥岩起到了封堵的作用，砂体是油气斜侧向运移的主要通道，从而形成了地层不整合油气藏、断块油气藏、岩性油气藏、复合油气藏等不同类型的油气藏。高青断裂带具有多期、复式成藏的特点，油气富集区沿高青断裂带两侧呈带状分布，各含油气层系具有明显的分区性。断层、砂体、不整合对油气分布的控制作用，其中高青断裂带是油气分布的主控因素。油藏的油源是洼陷内烃源岩，烃类气藏属于油型气，二氧化碳气藏是深部物质上涌引发上地幔活动，导致深部挥发分及活动组分向上运移随岩浆入侵和断裂活动，在断裂带附近的各类圈闭为气体聚集的有利场所。同时花501气藏中含He，N₂和CO₂气为主的非烃气与油型CH₄气分层聚集，表明至少有两期成藏。更多还原

【Abstract】 GaoQing big fault which has been regarded as a bounding fault of DongYing sag and QingCheng uplift, is a long term inheritable actival big fault of basement, whose evolution controls the formation and evolution of QingCheng uplift and BoXing sag, and also has profound effection on hydrocarbon accumulation; Especially these reservoirs of three kind（oil reservoir、methane reservoir and carbon dioxide gas pool） ,which distribute along the GaoQing fault zone, coexist within the fault zone and each has it’s unique character. According to the research of the factors during reservoir formation （fault seal research、oil-source correlation、Genetic Analysis Gas Pool、Unconformity research） and many aspects such as rule of multi-reservoirs coexistence etc, we have conducted systematic research on this special phenomenon of reservoir formation, and reached following results:At the base of fault’s vertical and crossrange blockage theory, it regards that GaoQing big fault has obvious character of episodic transporting, it also a fault with character of both normal faults and torquing. Taking Gao 17 oil reservoir for example, the research has analysised the crossrange blockage of GaoQing zone fault belt, according to the lithological ordonnance in two sides of fault.By oil-source correlation, it is clear that the Qinggao oil field’s main oil-source comes from source rock of S4 section of BoXing sag; The geochemical index of hydrocarbon gas inflects it has the character of petroliferous gas and has suffered from different extent of biology degradation. The character of carbon isotopes in nonhydrocarbon gas layer has proved its inorganic origin, mainly of magma-mantle cause. He、N₂ have also come from mantle.In the process of oil-gas accumulation in Gao-qing fracture belt, unconformity surface and connected sand body make an important chrous. Not only fracture surface is the migration channel, but also the mudstone upon it, has plugging effect. Since the sand body is the main channel for the oil-gas’s lateral migration, accordingly many reservoirs of different types has formed such as : unconformity oil-gas pool, fault block oil-gas pool, lithological oil-gas pool, composite pool and so on.Reservoir formation of Gaoqing fractural belt has character of multi-periods、multi-accumulation, the enriching sections distribute along the bilateral of GaoQing fault. Each layer that contains oil-gas has obvious regionalization. Fault、sand body、unconformity has controlled the distribution of oil-gas and GaoQing fault is the main control factor among them. The oil source of oil reservoir is the hydrocarbon source rock of sag; hydrocarbon gas reservoir is regarded as petroliferous gas; Dioxide carbon reservoir is formed mainly by the movement of upper mantle caused by the emerge of deep part material: the deep part volatile matter and actival compound made up-migration with magma intrusion and fractural movement, then trapped within multi-traps located at the structural belt. At the same time, the non-hydrocarbon gas in Hua 501 gas reservoir which mainly contains He、N₂ and CO₂,and CH₄ petroliferous gas assembled separately, this mean that there were at least two period for reservoir formation.更多还原