鄂尔多斯盆地吴起—志丹地区延长组长7段页岩气形成条件研究

发布时间：2018-01-17 03:12

  本文关键词：鄂尔多斯盆地吴起—志丹地区延长组长7段页岩气形成条件研究　出处：《西北大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 泥页岩微孔 页岩气 形成条件 延长组长7段 吴起-志丹地区

【摘要】：鄂尔多斯盆地具有丰富的油气资源,盆地延长组长7段发育于湖盆鼎盛时期。吴起-志丹地区作为本次研究区,其长7沉积期处于湖盆中心,为了明确研究区长7段页岩气形成条件,本论文在收集大量地质、测井、分析化验等资料及现场岩心观察的基础上,对采集样品进行了烃源岩、储层物性等方面的分析测试,其中包括薄片鉴定、有机地化测试、孔渗分析、X衍射分析、场发射扫描电镜观察、含气性分析。对吴起-志丹地区长7段页岩气形成条件进行了深入研究,取得了以下新认识:研究区长7时期以深湖相为主,泥页岩厚度达90m,分布连续稳定。TOC含量高,介于2.01%-12.03%之间。利用多元回归分析法建立了吴起-志丹地区的TOC测井解释模型,拟合效果较好,应用该模型能够较为准确评价研究区有机质丰度的平面变化。有机质以II型为主,成熟度较高,Ro介于0.7%-1.2%之间,热解峰温主要分布于440-460℃之间。研究表明吴起-志丹地区长7段泥页岩段有机质丰度高,厚度大,且热演化达到生油气阶段,具有形成页岩气的物质条件。研究区泥页岩矿物组成主要为石英和黏土矿物。石英含量平均为31.11%,黏土矿物含量平均为28.98%,主要由绿泥石、伊利石和伊蒙混层组成。泥页岩脆性指数分布于0.53-0.75之间,孔隙度平均为2.82%,渗透率平均为0.028×10-3μm2。场发射扫描电镜等分析表明研究区泥页岩微孔类型主要以粒间孔和晶间孔为主,有机质孔发育差。孔径主要分布于30-300nm,以中孔-宏孔为主,微孔基本不发育。页岩喉道半径分布在10.79nm-190nm,主要分布在15nm-30nm之间,为纳米级孔喉,页岩储层孔渗条件较差。通过气测数据可知研究区含气量分布区间为2.6m3/t-5.5m3/t,大于页岩气开发标准的下限值。研究发现泥页岩含气量受泥岩厚度、TOC、石英和黏土矿物含量等多种因素的影响。根据泥页岩的烃源岩生气潜力、储集特征,结合实测泥页岩含气情况制定了适合研究区的页岩气评价标准,预测了长7段页岩气有利勘探区。
[Abstract]:Ordos basin has abundant oil and gas resources, the basin member 7 of Yanchang formation developed in the heyday of the basin. In Wuqi - Zhidan area as the study area, the long period in 7 sedimentary basin center, in order to clear the research section of Chang 7 shale gas formation conditions, this paper collected a large number of geological, well logging, based on experiment data and field observation of cores, the collected samples of source rock, reservoir analysis and other aspects, including thin section identification, organic geochemical test, porosity and permeability analysis, X diffraction, field emission scanning electron microscopy observation, analysis of gas. On the Zhidan area of Chang 7 shale gas formation conditions are studied deeply, has made the following research: new understanding of Chang 7 period in deep lake facies, mud shale thickness of 90m, the distribution of continuous and stable content of.TOC is high, the range of 2.01%-12.03%. By using multiple regression analysis method The Wuqi and Zhidan area TOC logging interpretation model, the fitting effect is good, the application of the model can be more accurate evaluation of district level changes the abundance of organic matter. The organic matter is mainly of II type, high maturity, Ro between 0.7%-1.2% and pyrolysis peak temperature between 440-460 DEG C is mainly distributed in the Zhidan area. The results show that Wuqi long the 7 section of mud shale with high organic matter abundance, thickness, and thermal evolution of hydrocarbon generation at the gas phase, with the formation of shale gas material conditions. Study area of shale mineral is mainly composed of quartz and clay minerals. Quartz content was 31.11%, the average content of clay minerals is 28.98%, mainly composed of chlorite, illite and illite layer. The shale brittleness index distribution between 0.53-0.75, the average porosity is 2.82%, the average permeability is 0.028 x 10-3 scanning electron microscopy m2. field shows that the shale pore type in the study area, the main To and intergranular pores, organic matter pores. The aperture is mainly distributed in the 30-300nm, with a hole in the macro pore, micropore no development. Shale distribution of throat radius in 10.79nm-190nm, mainly in 15nm-30nm, nano pore throat, a poor permeability shale reservoir pore. Test data showed that the study area gas distribution range of 2.6m3/t-5.5m3/t by gas, shale gas development is greater than the standard limit value. The study found that the shale gas content by mudstone thickness, TOC, a variety of factors such as quartz and clay mineral content. According to the shale source rocks potential, reservoir characteristics, combined with the measured shale the gas to develop shale gas evaluation standards suitable for the study area, the prediction of Chang 7 shale gas favorable exploration area.

【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13
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本文编号：1436044