鄂尔多斯盆地演武地区侏罗系延安组延7段沉积相及储层特征研究

发布时间：2018-03-14 21:36

本文选题：鄂尔多斯盆地　切入点：延7油层组　出处：《长江大学》2017年硕士论文　论文类型：学位论文

【摘要】：鄂尔多斯盆地位于中国中西部地区,是一个多旋回复合型盆地,蕴藏着十分充足的油气资源,为中国第二大沉积盆地。本文研究地区为鄂尔多斯盆地演武地区,研究区位于鄂尔多斯盆地的西南部,其构造上位于伊陕斜坡西侧的南端并处于天环坳陷的南部,构造形态整体上表现为东西高,南北低的地势,构造较为简单,局部地区发育多个近东西向的低幅鼻状构造和穹隆构造,断层不发育,基底无大型的隆起,继承性发育特征明显。近些年来对鄂尔多斯盆地西南部地区的勘探开发,发现该地区侏罗系延安组具有较为可观的油气资源。现在基于对侏罗系试采井区井点的研究和认识上,对于演武地区的总体认识还比较薄弱,演武支河谷两侧地层划分与对比还需要进行精细比对,延安组的砂体在横纵向上的变化规律还需要细致刻画,对于储集层和油藏的参数特征的研究还有待进一步深化。伴随着油气需求的剧增,供应压力逐渐增加,但随着勘探进程的不断深入,勘探难度越来越大。此次论文研究较为全面的研究了演武地区侏罗系延安组延7油层组的地层分布特征、沉积体系特征、沉积微相类型、砂体形态展布以及储层特征,为后期进一步研究工区成藏主控因素和分析油气富集规律建立坚实的理论基础。本文以鄂尔多斯盆地演武支河谷地区侏罗系延安组延7油层组为研究对象,系统运用地质学理论基础,以岩心资料、测录井资料、部分钻井资料为依托,并进行薄片、粒度、扫描电镜、微量元素等多项分析化验测试,对研究区延7油层组进行综合性研究。运用标志层法、地层等厚法、沉积旋回法等理论,对沿7油层组进行精细地层划分与对比,详细分析了延7油层组地层分布关系、地层厚度以及岩电关系等规律,项目中通过地层研究建立了演武支河谷地区前侏罗系古地貌模型;根据岩心观察、测录井资料以及分析化验资料,对延7油层组进行了沉积体系划分、沉积微相识别、砂体平面展布以及储层特征的研究。本次论文对研究区内470口井进行小层的划分与对比,建立了20条地层对比剖面,其中顺物源方向5条,垂直物源方向6条。对比结果表明,研究区地层连续性较好,地层厚度稳定,延7油层组顶部煤层发育,稳定发育1-2套厚度约为10m左右的煤层,底部同样发育较稳定的煤层。根据旋回特征和地层等厚原则可将延7油层组划分为延71段和延72段,延71段厚度约为15-25m延72段厚度约为20-35m。研究区延7油层组为河流三角洲沉积体系,本文观点认为该地区辫状河三角洲沉积体系,主要为三角洲平原亚相,发育有分流河道、河间洼地、天然堤、沼泽等沉积微相,建立了延7油层组沉积期沉积模式。延7油层组沉积期主要以分流河道中的砂体沉积为主,砂体呈条带状分布,顺物源方向由南西-北东向延伸。砂体岩性较粗,以细砂岩、粗-中砂岩为主,发育有槽状交错层理、板状交错层理、块状层理。研究表明演武支河谷地区延7油层组为低-中渗透储层,孔隙结构以中-粗喉为主,总体物性较好,岩性主要以岩屑质长石砂岩为主,其次是长石质岩屑砂岩,其中石英总量为62.59%,长石总量为19.66%,岩屑总量为17.75%。延7油层组平均孔隙度为14.55%,平均渗透率为23.12×10-3μm2。物性由上至下呈递减的变化趋势。
[Abstract]:Erdos basin is located in the central and western regions China, is a multi cycle composite basin, there are abundant oil and gas resources, as Chinese second sedimentary basin. This study area for Erdos basin in the study area is located in the Ordos Yanwu area, the southwest part of the basin, its structure is located on the west side of the southern Yishan slope and in the days of the ring the southern part of the depression, structure of the overall performance of things, North and south is low, the structure is relatively simple, the development of a nearly East-West low amplitude nose structure and dome structure in local area, the faults are not developed, no large basement uplift, developed distinctive characteristics. In recent years of exploration and development in Southwest China part of Erdos basin, found the Jurassic Yanan group has considerable oil and gas resources. Based on the present study and understanding of the Jurassic testing well well point area, for demonstration The overall area is still relatively weak, Yanwu Branch Valley on both sides of the stratigraphic division and comparison also requires fine alignment, the sand body of Yanan group in the horizontal and vertical changes require detailed characterization, for the study of characteristics of reservoir and reservoir to be further deepened. Along with the oil and gas supply demand growth. The pressure gradually increased, but with the deepening of the process of exploration, exploration is more and more difficult. This paper researched Yanwu area Jurassic Yanan group delay 7 reservoir strata distribution, sedimentary characteristics, sedimentary microfacies, sand body distribution and reservoir characteristics, for the later further research into the work area the main control factors of reservoir and analysis of oil and gas enrichment law to establish a solid theoretical foundation. In this paper, Erdos basin Valley Branch Yanwu Yan 7 oil-bearing formation of Jurassic system in Yanan as research object, The system used geology theory, with core data, logging data, drilling data as the basis, and sheet size, scanning electron microscope, trace elements and other analysis laboratory tests, comprehensive study of Yan 7 reservoir group. The use of the logo layer, the thickness of strata, sedimentary cycle theory etc. and the fine stratigraphic classification and correlation along the 7 formation, a detailed analysis of the Yan 7 oil-bearing strata, strata thickness and rock electricity relation law, through the formation of a valley before Yanwu Jurassic palaeogeomorphology model project; according to the core observation, logging data and analysis data of the Yan 7 oil-bearing was divided into sedimentary system, sedimentary facies identification, Study on sand body distribution and reservoir characteristics. This paper dividing and comparing the small layer on the 470 wells in the study area, set up 20 Profile comparison, which source direction along vertical direction of source 5, 6. The comparison results show that the strata in the study area has good continuity, thickness of the strata is stable, the Yan 7 oil-bearing top coal development, stable development of 1-2 sets of thickness is about 10m of the coal seam is also relatively stable. According to the development of the bottom cycle the characteristics and principle of the thickness of strata can be divided into Yin Yan 7 reservoir group 71 and Yan 72, Yan 71 section thickness of about 15-25m thickness of about 72 Yan Yan 7 reservoir group 20-35m. study area for River delta depositional system, this view is that the Braided River Delta sedimentary system in the area, mainly for delta plain subfacies developed distributary channel, natural levee, interchannl-depression, swamp sedimentary microfacies, sedimentary model is established. 7 formation sedimentary period. The Yan 7 oil-bearing sedimentary sandbody mainly in the distributary channel, sand body was strip shape, smooth material The source direction from SW-NE direction. Lithologic coarse to fine sandstone, coarse sandstone in development, trough cross bedding, tabular cross bedding, massive bedding. Research shows that the Branch Valley Yanwu Yan 7 reservoir group in low permeability reservoir, the pore structure mainly consists of - throat, overall good physical property and lithology mainly lithic feldspar sandstone, followed by feldspathic lithic sandstone, quartz feldspar which amount to 62.59%, a total of 19.66%, the total 17.75%. of cuttings Yan 7 oil-bearing average porosity is 14.55% and the average permeability is the change trend of 23.12 * 10-3 m2. were decreasing from top to bottom.

【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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