【摘要】：直羅油田位于鄂爾多斯盆地內(nèi)部的陜北斜坡構(gòu)造單元上,前期的勘探開發(fā)表明該區(qū)延長組儲層物性差,油氣分布主要受沉積相帶、成巖作用、儲層物性等因素控制。針對這一狀況,本文以沉積巖石學(xué)、儲層地質(zhì)學(xué)、石油地質(zhì)學(xué)、地球物理測井等相關(guān)理論為指導(dǎo),結(jié)合多元統(tǒng)計學(xué)的研究方法,以目前先進的實驗測試手段為依托,應(yīng)用地質(zhì)露頭、鉆井、測井等資料,采取宏觀與微觀相結(jié)合的研究方法,對直羅油田西北部延長組長2儲層特征進行詳細(xì)研究。綜合研究認(rèn)為區(qū)域構(gòu)造較為平緩,有一些低緩的鼻狀隆起,地層厚度較為穩(wěn)定,變化不大。區(qū)內(nèi)物源主要來自北東方向,各時期的河道都具有北東-南西向展布的特征,長2以三角洲前緣沉積為主,沉積亞相類型主要有水下分流河道,分流河道側(cè)翼,分流間灣等,長21,長22小層砂體最為發(fā)育,長23在研究區(qū)鉆遇率低,且以泥質(zhì)分流間灣為主。長2儲層砂巖主要為巖屑長石砂巖和長石砂巖,碎屑組成主要為石英、長石、巖屑、云母等,填隙物組分總體含量比較高,膠結(jié)物以綠泥石膜為主。砂巖的成分成熟度比較低,結(jié)構(gòu)成熟度達(dá)到中等,分選比較好,磨圓主要為次棱角狀。砂巖碎屑顆粒之間主要為點-線接觸,膠結(jié)類型以孔隙式膠結(jié)為主。儲層多發(fā)育殘余粒間孔隙、粒間溶孔、粒內(nèi)溶孔。長2孔隙度平均為12.57%,滲透率平均為2.50×10-3μm2。本次選用Q型因子分析和聚類分析的多元統(tǒng)計學(xué)方法進行儲層分類與評價,這種定量的儲層評價方法與以往定性的儲層評價方法相比,從客觀數(shù)據(jù)出發(fā),有效避免了主觀因素的干擾,每一個評價因子都附有權(quán)重系數(shù),同時給出了綜合因子得分公式,即儲層評價模型,對研究區(qū)有很好的適用性。分類結(jié)果將研究區(qū)長2儲層劃分為3類:Ⅰ類(好儲層)、Ⅱ類(中等儲層)、Ⅲ類(無效儲層)。綜合來看,Ⅰ類,Ⅲ類儲層在研究區(qū)發(fā)育較少,僅在長2儲層個別地區(qū)發(fā)育,Ⅱ類儲層在研究區(qū)內(nèi)分布最為廣泛。
[Abstract]:Zhiluo Oilfield is located in the structural unit of northern Shaanxi slope in Ordos Basin. The early exploration and development show that the reservoir physical property of Yanchang formation in this area is poor, and the distribution of oil and gas is mainly controlled by sedimentary facies zone, diagenesis, reservoir physical property and so on. In view of this situation, based on the relevant theories of sedimentary petrology, reservoir geology, petroleum geology, geophysical logging and so on, combined with the research methods of multivariate statistics, this paper relies on the advanced experimental testing methods. Based on the geological outcrop, drilling and logging data, the characteristics of Yanchang 2 reservoir in northwestern Zhiluo Oilfield are studied in detail by combining macroscopic and microcosmic research methods. It is considered that the regional structure is relatively smooth, there are some low slow rhinoid uplift, the formation thickness is relatively stable, and the change is not obvious. The source of material in this area mainly comes from the north to east direction, and the channel in each period has the characteristics of NE-NW distribution, Chang 2 is dominated by delta front sedimentation, the sedimentary subfacies are mainly subaqueous distributary channel, distributary channel flank, distributary bay and so on. The sand body of Chang 21 and Chang 22 is the most developed, and Chang 23 has a low drilling rate in the study area, and is dominated by muddy distributary bay. The sandstone of Chang 2 reservoir is mainly lithic feldspar sandstone and feldspar sandstone, and the clastic composition is mainly quartz, feldspar, lithic debris, mica, etc. The composition maturity of sandstone is low, the structure maturity is medium, the sorting is better, and the grinding circle is mainly sub-angled. The sandstone clastic grains are mainly point-line contact, and the type of cementation is pore cementation. The reservoir develops residual intergranular pores, intergranular dissolved pores, and intragranular dissolved pores. The average porosity of Chang 2 is 12.57 and the average permeability is 2.50 脳 10 ~ (-3) 渭 m ~ (2). The multivariate statistical method of Q type factor analysis and cluster analysis is used for reservoir classification and evaluation. This quantitative reservoir evaluation method is compared with the previous qualitative reservoir evaluation method, starting from the objective data. It can avoid the interference of subjective factors effectively, and each evaluation factor has weight coefficient. At the same time, the comprehensive factor score formula, that is, reservoir evaluation model, is given, which has good applicability to the study area. According to the classification results, Chang2 reservoir in the study area can be divided into three categories: class 鈪，

本文編號：2306857