鄂尔多斯盆地旬邑地区延长组长8油层组储层特征研究

发布时间：2018-05-11 23:03

  本文选题：鄂尔多斯盆地 + 旬邑地区　； 参考：《西北大学》2017年硕士论文

【摘要】：三叠系延长组长8油层组是鄂尔多斯盆地主力产油层系之一,但盆地南部渭北隆起北部旬邑地区长8油层组研究程度相对低,虽然前人对其进行过不同程度的研究,但较为零散,缺乏系统的研究。本文以石油地质学、储层沉积学等多学科为理论指导依据,综合各种分析测试实验,对旬邑地区长8油层组进行储层岩石学特征、微观孔喉特征、物性特征、非均质性以及成岩作用等特征的研究,归纳出影响研究区长8储层物性的关键因素,最终对目的层长8油层组进行储层分类与评价。旬邑地区长8期主要发育的沉积相类型为三角洲前缘亚相、浅湖亚相,其中主要发育两条近乎南北向展布的三角洲前缘水下分流河道,砂体分布范围稳定,纵向上砂泥互层,互层砂为长8储层特征砂体的主要类型。研究区长8储层砂岩具混源特征,主要是岩屑长石砂岩和长石岩屑砂岩,石英、长石、岩屑含量差异小,均显示较低的成分成熟度以及结构成熟度。长8储层填隙物含量平均值为18.16%,其中胶结物以碳酸盐胶结物、粘土矿物、硅质为主。孔隙度渗透率数值总体较低,储层物性较差;长8整体上表现为储层非均质性强烈,并且长82小层较长81小层非均质性更强。研究区长8储层致密,颗粒接触主要为线状、锯齿状接触。孔隙类型主要为溶蚀孔,其次为残余粒间孔,微裂隙与晶间孔则发育较少。喉道类型以缩颈型喉道为主,其次为弯片状,喉道连通性差别较大,孔喉特征总体上表现为强的结构非均质性,毛管压力以Ⅱ类为主,其次是Ⅲ类。研究区长8储层成岩阶段主要为晚成岩A期,压实压溶作用致使研究区长8储层孔隙丧失59%,碳酸盐胶结、粘土胶结以及硅质胶结则致使孔隙减少了 38%,溶蚀作用及裂缝增加储层孔隙、提高储层渗流能力,进而改善了储层物性。综合研究区长8储层各种参数特征,将目的层长8储层主要划分为五种成岩相。构造作用、沉积相、成岩相、孔喉结构特征共同影响长8储层物性,整体上长81小层较长82小层物性更好。研究区长8共发育有四类储层,其中以Ⅱ类、Ⅲ类储层为主,Ⅱ类储层物性较好,具有实际勘探开发意义,其中长81小层较长82小层Ⅱ类储层明显发育,分布范围显著增加。
[Abstract]:The Chang 8 formation of the Yanchang formation of the Triassic is one of the main oil-producing strata in the Ordos basin, but the study degree of Chang 8 oil formation in Xunyi region in the northern part of Weibei uplift in the southern part of the basin is relatively low, although the former has studied it to different degrees. But more scattered, lack of systematic research. Taking petroleum geology and reservoir sedimentology as theoretical basis and synthesizing all kinds of analysis and test experiments, this paper carries out reservoir petrological characteristics, microscopic pore throat characteristics and physical properties of Chang 8 formation in Xunyi area. Based on the study of heterogeneity and diagenesis, the key factors affecting the physical properties of Chang8 reservoir in the study area are summarized. Finally, the reservoir classification and evaluation of Chang8 reservoir group are carried out. The main sedimentary facies of Chang8 period in Xunyi area are delta front subfacies and shallow lacustrine subfacies. Among them, there are mainly two subaqueous distributary channels near the north and south delta front. The distribution range of sand body is stable, and the sand and mud interbedded longitudinally. Interbed sand is the main type of sand body in Chang 8 reservoir. The sandstone of Chang 8 reservoir in the study area has mixed source characteristics, mainly lithic feldspathic sandstone and feldspathic sandstone, quartz, feldspar, lithic debris content difference is small, all show lower compositional maturity and structure maturity. The average content of interstitial matter in Chang 8 reservoir is 18.16, in which carbonate cementation, clay mineral and siliceous are the main cement. The porosity and permeability values are lower and the reservoir physical properties are poor, and Chang 8 is characterized by strong reservoir heterogeneity and stronger heterogeneity of Chang 82 layer than long 81 layer. Chang 8 reservoir is compact, grain contact is mainly linear and serrated contact. The pore types are mainly dissolved pores, followed by residual intergranular pores, while microcracks and intergranular pores are less developed. The throat type was mainly neck-necked throat, followed by curved flake throat, and the throat connectivity was different. The pore throat was characterized by strong structural heterogeneity, capillary pressure was mainly of type 鈪，

本文编号：1876002