本文選題：五峰-龍馬溪組 + 頁巖巖相��； 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：頁巖巖相的劃分方式有按沉積構(gòu)造劃分,按礦物組成劃分以及結(jié)合沉積構(gòu)造和礦物組成劃分三種方式。本文選取按沉積構(gòu)造來劃分頁巖巖相。頁巖沉積構(gòu)造中又以紋層最為容易識別和分類。所以本文選取從四川盆地東緣巫溪1井,焦石壩地區(qū)的X井和Y井,以及秀山溶溪地表剖面3處剖面的五峰-龍馬溪組頁巖樣品進(jìn)行顯微鏡觀察分析,觀察到塊狀頁巖、平行紋層頁巖、不平行紋層頁巖3類主要的頁巖巖相,以及斑狀紋層頁巖、透鏡狀紋層頁巖和粒序紋層頁巖這幾種分布不太廣泛的頁巖巖相。薄片下觀察到,塊狀頁巖的紋層最不明顯,平行紋層頁巖的紋層細(xì)長而平直,不平行紋層頁巖的紋層則粗壯且相互呈低角度相交。紋層中主要礦物為石英、白云母、長石、方解石、白云石等脆性礦物,周圍基質(zhì)中則以黏土礦物占多數(shù)。五峰-龍馬溪組頁巖3種主要的頁巖巖相在礦物組成上有明顯的區(qū)別。按照塊狀頁巖、平行紋層頁巖以及不平行紋層的頁巖的順序,平均石英含量依次降低,分別為61%、50%、32%,平均黏土礦物含量依次升高25.8%、29.1%、53.2%。石英含量與TOC呈正相關(guān),黏土礦物含量與TOC呈負(fù)相關(guān)。就礦物組分來說,塊狀頁巖和平行紋層頁巖的頁巖氣儲集物性要優(yōu)于不平行紋層頁巖。掃描電鏡可以觀察到紋層的細(xì)微特征,礦物的定向排列尤為明顯。四川盆地東緣五峰-龍馬溪組頁巖主要發(fā)育粒間格架孔、黏土片間孔、粒緣孔、莓球狀黃鐵礦粒內(nèi)晶間孔、黏土粒內(nèi)孔、成巖溶孔、有機(jī)質(zhì)孔以及微裂縫8類微觀孔隙。雖然五峰-龍馬溪組頁巖不同頁巖巖相所經(jīng)歷的成巖后生作用差別不是太大,演化程度也差不多。但其初始沉積條件的不同導(dǎo)致了他們的微孔分布特征有一定的差別。有機(jī)質(zhì)孔和莓球狀黃鐵礦粒內(nèi)晶間孔在塊狀頁巖中最為發(fā)育,而不平行紋層頁巖中粒間格架孔和黏土片間孔更占優(yōu)勢。就有機(jī)質(zhì)類型而言,3類主要頁巖巖相的有機(jī)質(zhì)主要屬于腐泥型(I)到腐殖-腐泥型(II1)。TOC的含量為塊狀頁巖高于平行紋層頁巖高于不平行紋層頁巖。三條剖面所有樣品統(tǒng)計顯示,塊狀頁巖TOC為3.7%,平行紋層頁巖TOC為3.4%,不平行紋層TOC則只有1.1%。四川盆地東緣五峰-龍馬溪組頁巖樣品的主微量數(shù)據(jù)顯示,3類主要頁巖巖相的脆性程度都與TOC呈正相關(guān)。微量數(shù)據(jù)顯示,塊狀頁巖和平行紋層頁巖的水體環(huán)境主要為缺氧到貧氧,而不平行紋層頁巖的水體環(huán)境主要為貧氧到氧化。不平行紋層頁巖所反映的水動力環(huán)境要強(qiáng)于塊狀頁巖和平行紋層頁巖。3種主要巖相所反映的海水古鹽度均為微咸水,但塊狀頁巖和平行紋層頁巖所代表的古水深是明顯大于不平行紋層頁巖的。塊狀頁巖代表了一種穩(wěn)定的沉積環(huán)境,沉積速率可快可慢,可以形成于水下峽谷或者陸棚上水體較深的區(qū)域這些沉積速率高的地方,也可以形成于水體相對安靜,沉積速率低,懸浮作用沉積的地區(qū),關(guān)鍵是沒有明顯的沉積間斷。筆者認(rèn)為頁巖中紋層的出現(xiàn)代表了一種與河流周期性洪水有關(guān)(間歇性的懸浮沉積)的環(huán)境,平行紋層頁巖代表了這種季節(jié)性(或周期性)洪水不太猛烈的環(huán)境,使得洪水期沉積的層和非洪水期沉積沉積層界限明顯平直,侵蝕作用較輕。不平行紋層頁巖的紋層較平行紋層的粗,可能反映了更加劇烈的周期性洪水。洪水帶來的沉積物明顯受到了底流、波浪或潮汐的改造。至于橫向上三條剖面/井所反映的主要巖相分布的差異,可能與剖面在陸棚中的位置有關(guān)。因為較高的TOC,石英含量以及大量發(fā)育的有機(jī)質(zhì)孔,塊狀頁巖和平行紋層頁巖對于頁巖氣勘探開發(fā)的意義明顯大于不平行紋層頁巖。
[Abstract]:There are three ways of dividing shale facies according to the sedimentary structure, dividing according to mineral composition and dividing the sedimentary structure and mineral composition. This paper selects the sedimentary structure to divide the shale facies. In the shale sedimentary structure, the striate layer is most easily identified and classified. So this paper selects Wuxi 1 well from the eastern margin of the Sichuan basin and the coke stone. The X and Y wells in the dam area and the five peak of the 3 section of the surface section of the Xiushan dissolve Creek section are observed and analyzed by microscope, and the 3 major shale facies, such as massive shale, parallel laminar shale, and non parallel shales, have been observed, as well as the porphyritic shale, transparent and granular shale and grain sequence shale. Too extensive shale facies. Under thin slices, the lamina of the massive shale is the least obvious, the lamina of the parallel shales is slender and straight, the layers of the non parallel shales are strong and intersected with each other. The main minerals in the striate are quartz, muscovite, feldspar, calcite, dolomite, and other brittle minerals, and clay in the surrounding matrix. The mineral composition of the 3 major shale facies in the five peak - Long Ma Creek formation shale is distinctly different in the mineral composition. The average quartz content, in order of massive shale, parallel layer shale and non parallel shales, decreased in turn, 61%, 50%, 32% respectively, and the average clay mineral content increased by 25.8%, 29.1%, and 53.2%. quartz content in turn. There is a positive correlation with TOC, and the clay mineral content is negatively correlated with the TOC. As for the mineral components, the shale gas reservoir properties of the massive shale and the parallel shales are superior to those of the non parallel shales. The fine characteristics of the layers can be observed by the scanning electron microscope, and the directional arrangement of the minerals is particularly obvious. The five peaks of the eastern margin of the Sichuan basin and the shale of the long Ma Xi formation are mainly in the shale. There are 8 kinds of micropores in the granular pore, clay interslice hole, grain margin hole, intergranular pore of raspberry globular pyrite, inner pore of clay particle, karst hole, organic pore and micro fissure. Although the difference of the diagenesis of different shale facies in the five peaks of the long Ma Creek shale is not too big and the evolution degree is similar. There are some differences in the distribution characteristics of their micropores. The intergranular pores in the granular shale are the most developed in the organic pore and the raspberry spheroidal pyrite in the bulk shale, while the grain intergrate holes and the clay interlamellar pores in the non parallel laminar shale are dominant. As for the organic matter, the organic matter of the 3 main types of main shale facies belongs mainly to the humic type. (I) the content of humic and humic mud type (II1).TOC is higher than that of parallel shales higher than that of non parallel shales. All samples of three sections show that massive shale TOC is 3.7%, parallel layer shale is TOC 3.4%, and the non parallel layer TOC is only the main trace data of the five peak of the eastern margin of the Sichuan basin, the east margin of the long Ma Creek formation shale. The brittleness of the 3 main types of shale facies is positively correlated with the TOC. The trace data shows that the water environment of the massive shale and the parallel shales is mainly from oxygen to oxygen poor, while the water environment in the non parallel shales is mainly poor oxygen to oxidation. The hydrodynamic environment reflected by the non parallel shales is stronger than the massive shale and parallel. The paleo salinity of the.3 major lithofacies reflected in the shales is micro brackish water, but the ancient water depth represented by the massive shale and the parallel shales is obviously larger than that of the non parallel shales. The massive shale represents a stable sedimentary environment, and the deposition rate can be quickly slow and can be formed in underwater canyons or on the shelf of the continental shelf. The region with high deposition rate can also be formed in areas with relatively quiet water body, low deposition rate, and sedimentation in the area of suspension. The key is that there is no obvious depositional discontinuity. The occurrence of the striate in the shale represents a environment associated with the periodic flood of rivers (intermittent suspended sediments), and the parallel shale is represented. This seasonal (or periodic) flood is not very violent, which makes the boundary between the sedimentary layers and the non deluge sedimentary layers clear and the erosion is lighter. The roughness of the grain layers of the non parallel laminar shale may reflect a more intense periodic flood. The sediment brought by the flood is obviously underflow. The difference in the main facies distribution reflected by three cross sections / wells in the transverse direction may be related to the position of the section in the shelf. Because of the high TOC, quartz content and a large number of developed organic pores, the significance of the massive shale and parallel shales is obviously greater than that of the non parallel lines. Layer shale.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P618.13

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 唐躍剛,任德貽;煤中黃鐵礦的成因研究[J];地質(zhì)論評;1996年01期

2 梁狄剛;郭彤樓;陳建平;邊立曾;趙U，

本文編號：1911907