本文選題：成巖作用 + 孔隙結(jié)構(gòu)��； 參考：《西北大學(xué)》2017年碩士論文

【摘要】：頁巖氣儲層成巖作用過程、孔隙特征和孔隙演化規(guī)律的研究,能夠?yàn)榉治鲰搸r氣儲層儲集性能、探討頁巖氣賦存成藏過程和機(jī)理、預(yù)測頁巖氣“甜點(diǎn)區(qū)”提供指導(dǎo)。因此,如何準(zhǔn)確全面地剖析泥頁巖成巖作用過程、表征泥頁巖儲集層孔隙結(jié)構(gòu)特征和判斷泥頁巖孔隙空間在埋藏成巖過程中的演化規(guī)律成為儲集層研究的重要基礎(chǔ)問題。然而,目前對泥頁巖成巖作用的研究十分薄弱,頁巖氣儲層孔隙體系尚未形成統(tǒng)一的分類方案,泥頁巖納米級孔隙的表征方法也在探索之中,不同類型的孔隙在不同埋藏成巖階段的演化規(guī)律尚不明確。鄂爾多斯盆地上三疊統(tǒng)延長組長7段泥頁巖既是盆內(nèi)優(yōu)質(zhì)烴源巖,又是有利的頁巖氣儲層。本文在充分調(diào)研和總結(jié)國內(nèi)外學(xué)者研究成果的基礎(chǔ)上,針對鄂爾多斯盆地中南部延長組長7泥頁巖,采用氬離子拋光-場發(fā)射掃描電鏡觀察、氣體吸附、電子探針、X-射線衍射、鏡質(zhì)體反射率(Ro)測定和巖石熱解等多種分析測試手段,系統(tǒng)研究了長7泥頁巖巖石組合類型、礦物學(xué)和有機(jī)地球化學(xué)等特征,分析泥頁巖成巖作用類型及演化過程,明確長7泥頁巖孔隙類型及孔隙結(jié)構(gòu)特征,探討影響泥頁巖孔隙發(fā)育和演化的主要因素,總結(jié)并建立泥頁巖在埋藏成巖過程中孔隙的演化規(guī)律和模式。研究成果表明:長7泥頁巖以黏土質(zhì)泥巖和硅質(zhì)泥巖為主,其中廣泛發(fā)育粉砂質(zhì)紋層;礦物組成復(fù)雜多變,富含黏土礦物、石英和長石,碳酸鹽含量較低;有機(jī)質(zhì)含量集中分布在3%～6%之間,有機(jī)質(zhì)類型以Ⅱ型干酪根為主,有機(jī)質(zhì)的鏡質(zhì)體反射率Ro集中分布在0.8%～1.0%之間。長7泥頁巖經(jīng)歷了壓實(shí)作用、膠結(jié)作用、溶蝕作用、礦物轉(zhuǎn)化成巖作用和有機(jī)質(zhì)熱演化生烴作用共同改造,普遍進(jìn)入中成巖A期;成巖序列為黃鐵礦、菱鐵礦→方解石Ⅰ →綠泥石Ⅰ →溶蝕作用Ⅰ →自生石英Ⅰ、高嶺石→伊蒙混層→溶蝕作用Ⅱ→綠泥石Ⅱ→伊利石、自生石英Ⅱ→鐵白云石、方解石Ⅱ。長7泥頁巖孔隙類型多樣,包括粒間孔、粒內(nèi)孔、晶間孔、有機(jī)質(zhì)孔隙和裂縫孔隙,其中粒間孔隙和裂縫孔隙是最重要的孔隙類型,其它類型的孔隙相對不發(fā)育�？紫缎螒B(tài)復(fù)雜,整體上以平板狹縫形和楔形為主;孔徑分布范圍寬泛(0.1nm～1OOOOnm),孔隙度為0.5%～6.6%,中孔(2～50nm)和宏孔(50nm)是孔隙度的主要貢獻(xiàn)者。巖相類型、成巖作用、有機(jī)質(zhì)熱演化生烴作用和構(gòu)造作用是影響研究區(qū)長7泥頁巖孔隙發(fā)育及演化的四個(gè)主控因素,巖相是控制孔隙發(fā)育和演化的先決條件,并影響著埋深過程中熱演化生烴作用、成巖作用的演化過程。成巖作用、熱演化生烴作用、構(gòu)造作用相互影響、共同控制著埋藏過程中泥頁巖孔隙的發(fā)育和演化。長7段泥頁巖基質(zhì)孔隙的演化具有一定的規(guī)律性:埋深1000m的淺埋藏條件下,為孔隙度急劇降低階段;埋深在1000～2000m條件下,為孔隙度降低速率相對緩慢階段;持續(xù)下降的最大埋深至后期抬升至現(xiàn)今埋深,孔隙度緩慢降低-基本保持穩(wěn)定。
[Abstract]:The study on the diagenesis, pore characteristics and pore evolution of shale gas reservoirs can be used to analyze the reservoir performance of shale gas reservoirs, to explore the accumulation process and mechanism of shale gas accumulation, and to predict the "dessert zone" of shale gas. Therefore, how to accurately and comprehensively analyze the process of shale formation and characterization of shale reservoir pores. The structural characteristics and the evolution of shale pore space in the process of buried diagenesis have become an important basic problem in the study of the reservoir. However, at present, the study of shale formation is very weak. The pore system of shale gas reservoirs has not yet formed a unified classification scheme, and the characterization method of the shale nanoscale pores is also being explored. The evolution law of different types of pores in different buried diagenesis is not clear. The 7 section of Yanchang group Chang Group Chang of the upper three series of Ordos Basin is not only the high quality hydrocarbon source rock in the basin, but also a favorable shale gas reservoir. Lengthening the group 7 shale, using argon ion polishing and field emission scanning electron microscopy, gas adsorption, electron probe, X- ray diffraction, vitrinite reflectance (Ro) and rock pyrolysis, and other analysis and testing methods, the characteristics of rock assemblage, mineralogical and organic geochemistry of long 7 shale are systematically studied, and the diagenesis of shale is analyzed. The type and evolution process, clear the pore type and pore structure characteristics of long 7 shale, discuss the main factors that affect the pore development and evolution of shale, summarize and establish the evolution law and model of pore in the process of shale in the process of buried diagenesis. The research results show that the long 7 shale is mainly clay mudstone and siliceous mudstone. The mineral texture is complex and changeable, the content of clay minerals, quartz and feldspar is low, the content of organic matter is concentrated between 3% and 6%, the type of organic matter is dominated by type II kerogen, and the vitrinite reflectance Ro of organic matter is concentrated between 0.8% and 1%. 7 shale has undergone compaction and cementation. Dissolution, transformation of minerals into rock and organic matter thermal evolution and hydrocarbon generation, generally entered the A stage of the middle diagenesis; the diagenetic sequence is pyrite, siderite, calcite I to chlorite I to corrosion I to self authigenic quartz I, kaolinite to immont, corrosion II, chlorite II to illite, and authigenic Shi Ying The pore types of the long 7 shale are varied, including intergranular pores, intragranular pores, intergranular pores, organic pores and fissure pores, among which intergranular pores and fissure pores are the most important pore types, and other types of pores are relatively undeveloped. The wide range (0.1nm to 1OOOOnm), porosity of 0.5% to 6.6%, mesopore (2 ~ 50nm) and macropore (50nm) are the main contributors to porosity. The lithofacies type, diagenesis, hydrocarbon generation and tectonic action of organic matter are four main controlling factors affecting the pore development and evolution of the study area 7 shale, and the lithofacies are the control of pore development and evolution. The precondition of chemical evolution has a certain regularity in the evolution of shale pores in the long 7 segments of the shale. The evolution of the pore space in the long 7 segments of shale has a certain regularity: shallow depth of the buried depth of the shale. Under the conditions of burial, the porosity is sharply reduced, and the depth of the buried depth is relatively slow under the condition of 1000 to 2000m, and the maximum depth of continuous descent is raised to the present depth, and the porosity slows down slowly - basically stable.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P618.13
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本文編號：1935202