發(fā)布時(shí)間：2018-02-24 15:05

  本文關(guān)鍵詞： 孔喉分布 微觀結(jié)構(gòu) 致密成因 致密時(shí)間 成藏時(shí)間 富縣 鄂爾多斯盆地　出處：《西北大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：鄂爾多斯盆地富縣區(qū)域三疊系延長組長8地層為三角洲前緣沉積,多發(fā)育粉-細(xì)砂巖,儲(chǔ)層物性極差。以前人的定義為依據(jù),富縣地區(qū)絕大部分長8儲(chǔ)層可歸類為致密儲(chǔ)層。致密儲(chǔ)層的孔隙結(jié)構(gòu)非常復(fù)雜,儲(chǔ)層的微觀結(jié)構(gòu)在控制油氣富集方面起著重要的作用。本文通過場發(fā)射掃描電鏡、高壓壓汞、CT、核磁共振與鑄體薄片等多種研究方法對富縣地區(qū)三疊系延長組長8致密砂巖儲(chǔ)層微觀孔喉特征、致密成因、致密砂巖儲(chǔ)層致密史與成藏史耦合關(guān)系、長8致密砂巖油富集規(guī)律等進(jìn)行研究,取得了以下新認(rèn)識(shí):長8儲(chǔ)層孔隙度和滲透率的平均值分別為8.59%、0.42×10-3μm2,歸類為特低孔-特低滲類型。高壓壓汞、場發(fā)射掃描電鏡、CT、核磁共振等分析方法統(tǒng)計(jì)表明長8儲(chǔ)層平均孔隙半徑及喉道半徑分別為1.2μm和O.Iμm,隸屬細(xì)孔-微細(xì)喉儲(chǔ)層;長8致密砂巖儲(chǔ)層發(fā)育孔隙結(jié)構(gòu)可劃分為三類,其中I類和II類孔隙結(jié)構(gòu)對致密油富集貢獻(xiàn)最大。成巖作用對長8致密砂巖儲(chǔ)層有重要的影響,壓實(shí)作用造成的孔隙度減少比例平均62.35%;膠結(jié)作用主導(dǎo)的孔隙度減少比例平均23.84%;溶蝕作用增孔率平均6.56%。壓實(shí)作用是儲(chǔ)層致密的主要成因,儲(chǔ)層中的碳酸鹽、綠泥石膜、伊利石以及云母等填隙物加劇了儲(chǔ)層致密。綜合力學(xué)平衡與巖心實(shí)驗(yàn)分析方法,得到富縣長8致密儲(chǔ)層的上限:孔隙度≤11.2%,滲透率≤0.55×10-3μm2,臨界孔喉半徑≤0.6μm。利用力學(xué)方法、錄井分析法、有效孔喉法得到長8致密砂巖儲(chǔ)層油氣充注下限:孔隙度多4.5%,滲透率≥0.04×10-3μm2,源儲(chǔ)界面的儲(chǔ)層孔喉直徑≥15.77nm,儲(chǔ)層內(nèi)部的孔喉直徑≥24nm。根據(jù)埋藏史和孔隙度演化歷史分析,長8致密砂巖儲(chǔ)層致密化時(shí)間從中侏羅世末(157Ma)開始,到早白堊世早期(128Ma)完全致密。包裹體觀察及測溫結(jié)果表明長8致密砂巖油藏有兩次油氣充注,地質(zhì)年代分別為97Ma至103Ma,和112Ma至121Ma左右,對應(yīng)早白堊世末-中期。說明長8致密油藏的致密時(shí)間早于成藏時(shí)間。根據(jù)烴源巖與儲(chǔ)層配置關(guān)系及長8含油層分布特征分析發(fā)現(xiàn)長8致密砂巖油的分布受烴源巖展布及儲(chǔ)層的控制,儲(chǔ)層含油特征受物性及孔隙結(jié)構(gòu)控制。
[Abstract]:In Fuxian, Ordos Basin, Yanchang formation of Yanchang formation in Fuxian County, Ordos Basin, is composed of delta front sediments, mostly siltstone and fine sandstone, and the reservoir physical properties are extremely poor. Most Chang 8 reservoirs in Fuxian area can be classified as dense reservoirs. The pore structure of dense reservoirs is very complex, and the microstructure of reservoirs plays an important role in controlling oil and gas enrichment. Various research methods, such as high pressure mercury injection, nuclear magnetic resonance (NMR) and casting thin slice, are used to study the microcosmic pore throat characteristics, dense origin, tight history of tight sandstone reservoir and the coupling relationship between the history of dense sandstone reservoir and the history of reservoir formation in the Triassic Yanchang Chang 8 tight sandstone reservoir in Fuxian area. The enrichment law of Chang 8 tight sandstone oil has been studied, and the following new understandings have been obtained: the average porosity and permeability of Chang 8 reservoir are 8.59 ~ 0.42 脳 10 ~ (-3) 渭 m ~ (2), respectively, which are classified as the type of ultra-low porosity and ultra-low permeability. Field emission scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) analysis show that the average pore radius and throat radius of Chang 8 reservoir are 1.2 渭 m and O. I 渭 m, respectively, which belong to micropore and microlarynx reservoir, and the pore structure of Chang 8 tight sandstone reservoir can be divided into three categories. The types I and II pore structures contribute most to the enrichment of dense oil, and diagenesis has an important effect on the tight sandstone reservoir of Chang 8. The porosity reduction caused by compaction averaged 62.35%; the proportion of porosity decrease led by cementation was 23.84; the average porosity increased by dissolution was 6.56.The compaction was the main cause of formation compaction, the carbonate and chlorite film in the reservoir, The porosity of Fuxian 8 tight reservoir is obtained by comprehensive mechanical balance and core experiment analysis method: porosity 鈮，

本文編號(hào)：1530688