松辽盆地烃源岩形成环境与页岩油地质评价研究

发布时间：2018-01-19 19:01

  本文关键词： 松辽盆地 海侵事件 热模拟实验 矿物组合 页岩油 气体吸附　出处：《中国科学院广州地球化学研究所》2017年博士论文　论文类型：学位论文

【摘要】：页岩气已逐渐成为全球非常规资源勘探与开发的热点之一,然而页岩油的研究仍处于起步阶段。页岩油属于源储一体的原地成藏油,其形成机制、演化、富集及古环境条件等领域是重要的研究内容。本论文以松辽盆地青山口组(K2qn)和嫩江组(K2n)泥页岩(样品来自钻井和剖面)为对象;通过有机地球化学、封闭体系的热模拟、矿物组分及气体吸附等手段,研究了两套烃源岩的形成环境、成烃演化机制、泥页岩的物性特征、页岩油富集的地质条件及页岩油勘探目标。主要取得以下成果:(1)在松辽盆地晚白垩纪烃源岩中检测到含量呈周期性变化的C30海相甾烷,表明该沉积时期经历多期次海侵事件:嫩江组一段下部(K2n1)和嫩江组二段下部(K2n2)的C30甾烷含量较高,暗示较大范围的海侵事件,这也是水体呈现间歇性缺氧及分层的重要原因;青山口组二段下部(K2qn2)存在一次快速且强烈的海侵事件,但是该时期水体分层受外来物质输入、微生物作用及气候的共同控制;青山口组一段(K2qn1)以相对稳定的半深湖到深湖相沉积环境为特征。海侵事件使得K2n1下部水体盐度较高,K2n2水体以淡水、半咸水到咸水环境为主,而K2qn2时期水体盐度介于上述两段之间。(2)通过黄金管封闭体系,建立两套重要烃源岩的生烃演化模型,得到页岩油气富集及演化阶段:当Easy%Ro低于0.68%时,属于无效或者低效生油阶段;当Easy%Ro介于0.68~1.18%时,属于油主要生成阶段,而且1.18~1.76%范围内轻质油较为丰富;当Easy%Ro介于1.18~2.25%时,代表主要的湿气或者凝析油阶段;当Easy%Ro超过2.25%时,热裂解产物以干气为主。因此,得知K2qn烃源岩已进入晚期生油,而K2n仍处在早期到中期生油阶段,在适当的排烃范围内,松辽盆地泥页岩具有一定的页岩油潜力;对于轻烃而言,K2qn泥页岩已经进入其生成的早期到晚期之间,具有一定的开发潜能,而K2qn泥页岩轻烃生成还处于早期阶段,不利于轻质油的勘探开发。在生油窗范围内,K2qn和K2n两套泥页岩中干酪根热解残渣碳同位素及沥青质碳同位素随着成熟度增加逐渐变重,且这些碳同位素值之间具有很好的相关性;基于页岩油自生自储的特征,因此可以利用干酪根和沥青质的碳同位素来判识页岩油的演化及富集。(3)分析本文的研究对象,青山口组一段和嫩江组一、二段的下部为最好的烃源岩,青山口组二段下部次之,青山口组一段上部和嫩江组一段上部泥岩有机质丰度较差;青山口组一段、青山口组二段下部和嫩江组一、二段的下部泥页岩有机质类型以I/II型为主,嫩江组一段上部以III型为主;青山口组一段泥页岩成熟度较高,滞留油中烃类含量较高,是非常规资源勘探与开发的主要靶区。(4)K2qn和K2n两套泥页岩的粘土矿物组合形式存在差异;K2qn泥页岩中含有大量的伊利石及有序的伊/蒙混层,而K2n泥页岩以丰富的蒙脱石或者无序的伊/蒙混层为主,但是两者粘土矿物平均含量均介于40~50%之间。松辽盆地泥页岩中脆性矿物含量较高,尤其含有丰富的石英,满足工业压裂。(5)残留油(S1)与吸附油(SP)的差值法是判断泥页岩中是否存在可动页岩油的重要方法。S1-SP、含油饱和度及产油率三个参数共同显示,当H14井深超过2065m时,K2qn1泥页岩富含可动页岩油,且这些泥页岩连续分布,具有一定工业价值。这些结果建议松辽盆地青山口组一段泥页岩具有一定的页岩油潜力。(6)松辽盆地泥页岩及其干酪根的氮气气体吸附/脱附实验显示:比表面积:嫩江组泥页岩及夹层干酪根青山口组泥页岩;孔体积:干酪根嫩江组泥页岩及夹层青山口组泥页岩;平均孔径:干酪根青山口组泥页岩嫩江组泥页岩及夹层。(7)K2qn1泥页岩中不同纳米孔隙中有机质含量及其组成受排烃效率的控制,具体表现为:微孔、介孔及大孔分别与TOC或残留烃(重质烷烃和芳烃)呈现不相关、负相关及正相关的关系;排烃过程主要反映介孔中残留有机质的释放。目前大多数松辽盆地泥页岩处于或早于生油高峰,在一定的成熟度范围内生成的烃类物质抑制孔结构发育;伊/蒙混层对松辽盆地泥页岩比表面积的发育具有贡献。
[Abstract]:Shale gas has gradually become one of the hot global unconventional resource exploration and development of shale oil, however, is still in its infancy. Oil shale belongs to one of the in situ source reservoir reservoir oil and its formation mechanism, evolution, enrichment and palaeoenvironmental conditions and other fields is an important research content. The castle of Songliao basin port group (K2qn) and Nenjiang group (K2n) (shale samples from drilling and profile) as the object; through the organic geochemistry, thermal simulation of closed system, mineral components and gas adsorption means, the formation environment of two sets of source rock, hydrocarbon formation mechanism, physical characteristics of mud the geological conditions of shale, shale oil accumulation and shale oil exploration target. Main research results are as follows: (1) in the Songliao Basin in the late Cretaceous source rocks in the detected content with the periodic variation of the marine C30 steranes, shows that the deposition period experienced many times of transgression Nenjiang: group A (K2n1) and the lower part of the lower Nenjiang group of two (K2n2) of C30 sterane is higher, suggesting a larger range of transgression, which is also an important reason for water hypoxia and intermittent stratification; Qingshankou Formation in the lower part of the two member (K2qn2) has a rapid and strong transgression. But the period of stratified by external inputs, jointly control the microorganisms and the climate; the first section of Qingshankou Formation (K2qn1) to the relative stability of the semi deep lake to deep lacustrine environment features. Transgressive events make K2n1 lower water high salinity, K2n2 water to freshwater, brackish to saline environment, and K2qn2 period of water salinity between the two sections. (2) closed system through the gold tube, hydrocarbon generation and evolution model of two sets of important hydrocarbon source rocks, shale oil and gas enrichment and get evolution stages: when the Easy%Ro is lower than 0.68%, which belongs to the invalid or inefficient students The oil phase; when the Easy%Ro is 0.68~1.18%, which belongs to the main oil generating stage, and the range of 1.18~1.76% light oil is rich; when Easy%Ro is 1.18~2.25%, represent the main moisture or condensate phase; when Easy%Ro is more than 2.25% pyrolysis products to dry gas as the main. Therefore, K2qn that the source rock has entered advanced oil, while K2n was still in the early to mid stage of hydrocarbon generation, expulsion in the appropriate range, Songliao Basin shale has a certain potential for shale oil; light hydrocarbon, K2qn shale has entered the early to late stage, has certain development potential, and light hydrocarbon generating shale K2qn in the early stages of exploration and development, is not conducive to the light oil in the oil window. Within the range of K2qn and K2n two sets of shale kerogen pyrolysis residue carbon isotope and asphaltene carbon isotope with maturity increased gradually, and the Have a good correlation between the carbon isotope values; shale oil reservoir based on self characteristics, so we can use the carbon isotope of kerogen and asphalt to determine the evolution of knowledge and enrichment of shale oil. (3) analysis of the object of study, a group of a group of Qingshankou and Nenjiang, two lower segment as the best source rock of Qingshankou formation, the lower part of the two member of Qingshankou Formation in the upper part and the upper part of Nenjiang formation mudstone organic matter abundance is poor; 1 of Qingshankou Qingshankou formation, a group of two lower and lower Nenjiang shale organic type two segment dominated by I/II Nenjiang, a group of the top section is mainly of III type; the first section of Qingshankou Formation shale high maturity, high retention hydrocarbon content in oil, is the main target of the exploration and development of unconventional resources. (4) the clay mineral assemblage form of K2qn and K2n two sets of shale are different; K2qn in mud shale Contains a large number of ordered illite and illite / smectite mixed layer, while the K2n shale dominated by smectite rich or disordered illite / smectite mixed layer, but the average contents of the clay minerals are between 40~50%. High brittle mineral content of shale in Songliao Basin, especially rich in quartz, meet industrial fracturing. (5) residual oil (S1) and oil adsorption (SP) difference method is an important method to judge whether there is a.S1-SP in shale oil shale, oil saturation and oil production rate of three common parameters showed that when 2065m is greater than H14 deep wells, K2qn1 shale rich movable shale oil, shale and the continuous distribution of a certain industrial value. These results suggest that Qingshankou Formation of Songliao basin has a certain potential for shale oil shale. (6) nitrogen gas adsorption / shale in Songliao Basin and its kerogen desorption experiments showed that the specific surface area of Nenjiang Shale and laminated shale kerogen in Qingshankou formation; pore volume: Nenjiang formation shale and kerogen interlayer Qingshankou mudstone and shale; the average pore size: kerogen shale Qingshankou group Nenjiang shale and laminated. (7) the content of organic matter in different pores in mud shale and K2qn1 control of hydrocarbon expulsion efficiency, specific performance: microporous, mesoporous and macroporous respectively with TOC or residual hydrocarbon (heavy alkanes and aromatics) showed no correlation, negative correlation and positive correlation; hydrocarbon expulsion process mainly reflects the release of residual organic matter in mesopores. At present, most of the shale in Songliao basin or early in the peak of oil generation, inhibition of pore structure development of hydrocarbon generation in a certain maturity range; illite / smectite mixed layer of Songliao Basin shale surface area development has contributed.

【学位授予单位】：中国科学院广州地球化学研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P618.13
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本文编号：1445168