本文選題：吉木薩爾凹陷 + 蘆草溝組�。� 參考：《西北大學(xué)》2017年碩士論文

【摘要】：吉木薩爾凹陷位于新疆準(zhǔn)噶爾盆地東部,盆地內(nèi)部的中二疊統(tǒng)蘆草溝組分布廣泛、厚度巨大,是致密油勘探和開(kāi)發(fā)的有利層位。蘆草溝組形成于陸內(nèi)裂谷背景下還原-弱氧化的咸化湖泊環(huán)境,沉積時(shí)期受火山活動(dòng)和堿性巖漿-熱液活動(dòng)的影響,形成了一套與火山噴發(fā)和熱液活動(dòng)密切相關(guān)的特殊巖類和礦物組合。綜合考慮研究區(qū)區(qū)域構(gòu)造背景和沉積環(huán)境,在大量巖心及薄片觀察的基礎(chǔ)上,認(rèn)為蘆草溝組含油層段主要發(fā)育凝灰?guī)r、沉凝灰?guī)r、(含)凝灰質(zhì)泥晶白云巖等受巖漿-熱液活動(dòng)影響的巖石,將其統(tǒng)稱為凝灰?guī)r類。根據(jù)火山碎屑的不同,又可將凝灰?guī)r分為碳酸質(zhì)凝灰?guī)r與安山質(zhì)凝灰?guī)r。研究區(qū)凝灰?guī)r類主要由石英、長(zhǎng)石、方解石、白云石等礦物組成,少見(jiàn)巖屑組分。其中電子探針數(shù)據(jù)中長(zhǎng)石的里特曼指數(shù)均大于3.3,甚至大于9,為堿性長(zhǎng)石,表明火山碎屑來(lái)源為堿性-過(guò)堿性巖漿,霓石的發(fā)現(xiàn)佐證了這一點(diǎn)。碳酸質(zhì)凝灰?guī)r中成層發(fā)育星散狀的方解石,被紋層包繞,方解石周圍的有機(jī)質(zhì)成熟度較其它部位更高,內(nèi)部的流體包裹體呈環(huán)帶狀分布。結(jié)合熒光及陰極發(fā)光特征,判斷方解石為碳酸質(zhì)巖漿碎屑,帶來(lái)的熱量加速了周圍有機(jī)質(zhì)的成熟,并在之后熱液活動(dòng)的影響下發(fā)生加大作用,在此過(guò)程中捕獲了烴類包裹體。地球化學(xué)特征顯示,蘆草溝組安山質(zhì)凝灰?guī)r的物源主要為中酸性火山巖,與博格達(dá)南緣二疊系火山巖具有類似的稀土元素配分模式,表明二者具有親緣性。進(jìn)一步的掃描電鏡和核磁共振測(cè)試發(fā)現(xiàn),凝灰?guī)r類中原生孔隙和次生孔隙均很發(fā)育,其中又以溶孔和剩余粒間孔最為常見(jiàn),并且凝灰物質(zhì)的含量與自由流體飽和度存在正相關(guān)的關(guān)系。綜合以上特征,認(rèn)為凝灰?guī)r類既是一種優(yōu)質(zhì)的烴源巖,又具備良好的儲(chǔ)集性能,對(duì)研究區(qū)有機(jī)質(zhì)的富集和保存起到了至關(guān)重要的作用,凝灰物質(zhì)的不均勻分布是導(dǎo)致研究區(qū)致密油呈非均質(zhì)性分布的重要原因。
[Abstract]:Jimusar Sag is located in the eastern part of Junggar Basin, Xinjiang. The Lucaogou formation of the Middle Permian in the interior of the basin is widely distributed and has a huge thickness, which is a favorable horizon for the exploration and development of dense oil. The Lucaogou formation was formed in the reduction-weakly oxidized saline lacustrine environment in the context of intracontinental rift and was influenced by volcanic activity and alkaline magmatic hydrothermal activity during the sedimentary period. A set of special rock and mineral assemblages closely related to volcanic eruptions and hydrothermal activities have been formed. Considering the regional tectonic setting and sedimentary environment of the study area, based on the observation of a large number of cores and thin slices, it is considered that tuff is mainly developed in the oil-bearing formation of the Lucaogou formation. The tuffaceous mudstone dolomite, which is affected by magmatic hydrothermal activity, is called tuff. According to the difference of pyroclastic, tuff can be divided into carbonate tuff and Anshan tuff. Tuff is mainly composed of quartz, feldspar, calcite and dolomite. The Ritman exponents of feldspar in the EPMA data are all greater than 3.3 or even more than 9, which indicates that the volcanic clastic origin is alkaline-ultraalkaline magma, which is confirmed by the discovery of aegirinite. Scattered calcite is formed in layers of carbonated tuff. The maturity of organic matter around calcite is higher than that of other parts. Combined with fluorescence and cathodoluminescence characteristics, calcite is determined to be carbonaceous magmatic clastic, resulting in heat to accelerate the maturation of surrounding organic matter, and then increase the effect of hydrothermal activity, and capture hydrocarbon inclusions in the process. Geochemical characteristics show that the source of Anshan tuff in the Lucaogou formation is mainly intermediate-acid volcanic rocks and has a similar REE distribution pattern with the Permian volcanic rocks in the southern margin of Bogda indicating that they are related to each other. Further scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) measurements showed that both primary and secondary pores were well developed in tuff, among which dissolved pores and residual intergranular pores were the most common ones. And there is a positive correlation between the free fluid saturation and the content of coagulant. Combined with the above characteristics, it is considered that tuff is not only a kind of high quality source rock, but also has good reservoir performance, which plays an important role in the enrichment and preservation of organic matter in the study area. The heterogeneous distribution of tuff is an important reason for the heterogeneous distribution of dense oil in the study area.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P618.13;P587
，

本文編號(hào)：1844611