【摘要】：鄂爾多斯盆地具有豐富的低滲透油氣資源,盆地中生界三疊系延長組泥頁巖廣泛發(fā)育,其中以長7油層組底部的“張家灘頁巖”為代表的頁巖層厚度大,分布廣泛,有機碳含量高,熱演化程度適中,具備良好的頁巖氣成藏條件。本次研究從分析下寺灣地區(qū)現(xiàn)有的測井、巖心、分析化驗資料入手,結合儲層地質學、沉積學、石油地質學理論,對4口井進行巖心觀察及分析測試,開展研究區(qū)長7油層組非常規(guī)儲層有機地化特征、成巖作用、儲層物性等方面的研究,總結了研究區(qū)長7油層組非常規(guī)儲層發(fā)育的影響因素及影響非常規(guī)儲層物性的主要因素。長7油層組泥頁巖脆性礦物中石英平均含量19.8%,長石平均含量15.9%。黏土礦物含量較高且變化大,主要為伊/蒙混層和伊利石,綠泥石及高嶺石含量相對較少。有機質類型主要為Ⅱ型,有機顯微組分以鏡質組和惰性組為主,而殼質組含量相對較少。泥頁巖有機碳含量(TOC)平均值4.79%,85%以上的樣品屬于好的烴源巖。泥頁巖鏡質體反射率(Ro)平均值0.92%,表明有機質熱演化達到成熟階段。根據(jù)掃描電鏡觀察的孔隙結構特征,將泥頁樣品孔隙分為粒間孔,粒內(nèi)孔及有機組分孔3類,從孔隙成因來說主要為次生粒間孔,包括粘土礦物層間孔及少量黃鐵礦晶間孔,也含少量粒內(nèi)溶蝕孔。砂泥互層段孔隙較純泥巖孔隙明顯發(fā)育,且原生孔及次生孔均發(fā)育,一些長石顆粒被溶蝕形成粒內(nèi)溶孔,是頁巖氣運移的重要通路。有機組分發(fā)育蜂窩狀有機孔,主要是生烴有機顯微組分原始生物細胞結構孔隙,以及后期熱演化生烴過程中形成的次生孔隙,孔徑分布于1-200nm。長7油層組泥頁巖孔隙度很低,平均為2.1%,壓汞曲線呈現(xiàn)出分選差、細歪度的特征,喉道屬細微型,游離氣儲集條件較差。研究發(fā)現(xiàn),脆性礦物中,長石含量越高,孔隙度越高。黏土礦物總體含量也呈現(xiàn)出與孔隙度的正相關性。泥頁巖孔隙度與有機質含量呈負相關,說明有機質對孔隙度沒有貢獻反而有不利影響。研究認為鄂爾多斯盆地下寺灣地區(qū)延長組長7油層組非常規(guī)儲層分布廣,厚度大,生烴潛力較好,具有頁巖氣形成和勘探開發(fā)的潛力,泥頁巖儲層非均質性、粘土礦物與有機質之間關系等值得進一步研究。
[Abstract]:The Ordos Basin is rich in low permeability oil and gas resources, and shale is widely developed in the Mesozoic Triassic Yanchang formation, in which the "Zhangjiatan Shale" at the bottom of Chang 7 oil formation is characterized by large thickness and wide distribution. The organic carbon content is high, the thermal evolution is moderate, and there are good conditions for shale gas accumulation. This study begins with the analysis of existing logging, core and laboratory data in Xiusi Bay area, and combines the theories of reservoir geology, sedimentology and petroleum geology to conduct core observation and analysis and test on 4 wells. The organic geochemical characteristics, diagenesis and reservoir physical properties of unconventional reservoirs in Chang7 reservoir formation were studied. The influencing factors of unconventional reservoir development and the main factors affecting physical properties of unconventional reservoirs in Chang7 reservoir formation were summarized. The average content of quartz and feldspar are 19.8and 15.9in the shale brittle minerals of Chang 7 formation respectively. The clay mineral content is high and varied, mainly in the mixed layer and Illite, and the content of chlorite and kaolinite is relatively small. The type of organic matter is mainly type 鈪，

本文編號：2393945