【摘要】：本文綜合應(yīng)用了沉積學(xué)、儲層沉積學(xué)及石油地質(zhì)學(xué)等理論知識和方法,在前人研究的基礎(chǔ)上,通過巖芯觀察、測井資料解釋、室內(nèi)薄片觀察及掃描電鏡、壓汞測試等多種測試分析手段,對渭北地區(qū)上三疊統(tǒng)延長組長7、長6及長3油層組的沉積相和儲層特征及儲層主控因素進行了較深入的研究。研究區(qū)長7、長6及長3油層組主要為辮狀河三角洲沉積體系和湖泊體系,并進一步分為三類亞相,八種微相。區(qū)內(nèi)儲集砂體主要為三角洲前緣水下分流河道、河口壩及淺湖砂壩。水下分流河道砂體儲層物性最好,次為河口壩,水下分流間灣、淺湖泥及半深湖泥儲層物性最差。研究區(qū)長7、長6及長3油層組砂巖的結(jié)構(gòu)成熟度和成分成熟都較低,以巖屑長石砂巖、長石巖屑砂巖為主,孔隙類型主要為原生粒間孔、長石及巖屑粒內(nèi)溶孔、粒間溶孔。砂巖的分選較好,中值半徑較小,屬細孔-微喉型,略偏粗歪度。成巖作用類型主要有壓實(溶)作用、膠結(jié)作用、溶蝕作用和交代作用,研究區(qū)主要處于晚成巖A期。通過薄片觀察、掃描電鏡分析及沉積、成巖作用的研究明確提出了沉積作用是影響儲層物性好壞的基礎(chǔ),而成巖作用是控制區(qū)內(nèi)砂巖儲層原生孔隙保存和次生孔隙發(fā)育的主要因素,其中壓實(溶)作用和膠結(jié)作用是降低儲層儲集性能的重要因素,溶解作用則形成大量次生孔隙,有效地改善了砂巖儲層的物性。經(jīng)過綜合分析和評價,可將長7、長6及長3儲層分為四類,其中Ⅰ類儲層物性最好,Ⅱ類儲層物性稍差于Ⅰ類儲層,依次類推,Ⅳ類儲層物性最差。Ⅰ類、Ⅱ類儲層在建莊-四郎廟-腰坪一線發(fā)育,Ⅲ類儲層在偏橋鎮(zhèn)及其周邊發(fā)育,Ⅱ+Ⅲ類儲層存在于宜君縣以南區(qū)域。
[Abstract]:In this paper, the theory and methods of sedimentology, reservoir sedimentology and petroleum geology are synthetically applied. On the basis of previous studies, core observation, log data interpretation, laboratory sheet observation and scanning electron microscope are used. In this paper, the sedimentary facies, reservoir characteristics and main reservoir control factors of Chang 7, Chang 6 and Chang 3 reservoirs of Upper Triassic Yanchang formation in Weibei area were studied by means of mercury injection test and other testing and analysis methods. The Chang 7, Chang 6 and Chang 3 reservoirs in the study area are mainly composed of braided river delta sedimentary system and lake system, and are further divided into three subfacies and eight microfacies. The reservoir sand bodies are mainly delta front underwater distributary channel, estuarine dam and shallow lake bar. The reservoir physical properties of underwater distributary channel sand body is the best, followed by estuarine dam, underwater distributary bay, shallow lake mud and semi-deep lake mud reservoir. The structure maturity and composition maturity of sandstone of Chang 7, Chang 6 and Chang 3 oil formations in the study area are low. The main types of sandstone are lithic feldspar sandstone, feldspar lithic sandstone, primary intergranular pore, feldspar and lithic intragranular dissolved pore and intergranular dissolved pore. The separation of sandstone is better, the median radius is smaller, it belongs to fine pore-microlarynx type, slightly coarse skewness. The main types of diagenesis are compaction (dissolution), cementation, dissolution and metasomatism. Through thin slice observation, scanning electron microscope analysis, deposition and diagenesis, it is clearly pointed out that sedimentation is the basis of influencing reservoir physical properties. Diagenesis is the main factor for the preservation of primary pores and the development of secondary pores in sandstone reservoirs in the controlled area. Compaction (dissolution) and cementation are important factors to reduce reservoir performance, while dissolution forms a large number of secondary pores. The physical properties of sandstone reservoir are improved effectively. Through comprehensive analysis and evaluation, Chang 7, Chang 6 and Chang 3 reservoirs can be divided into four categories. Among them, type 鈪，

本文編號：2188236