Micro-pore multifractal characteristics of Benxi Formation sandstone reservoir in Gaoqiao area, Ordos Basin
-
摘要: 选取鄂尔多斯盆地高桥地区上古生界本溪组11块砂岩样品,基于岩石薄片及扫描电镜分析储层岩性特征及孔隙结构特征,引入多重分型理论,对砂岩样品核磁共振T2分布数据进行了研究,探讨了砂岩储层孔隙多重分形特征,并分析了多重分形参数与砂岩孔隙结构参数、矿物组成及砂岩物性参数之间的关系。结果表明:本溪组砂岩多为石英砂岩及岩屑石英砂岩,石英体积分数63%~85%,平均71.45%;岩屑体积分数3%~17.5%,平均10.91%,不含长石,胶结物以高岭石(φB为3%~10%,平均6.3%)及碳酸盐(φB为0~9%,平均5.65%)为主。储层孔径分布具有多重分形特征,多重分形参数Dmin-Dmax介于1.16~1.83、Dmin/Dmax介于2.73~6.92、Δα介于1.37~4.33。研究表明,f(α)-α多重分形奇异谱及q-Dq广义多重分形参数均可用于定量评价储层。多重分形参数与石英含量及岩屑含量分别呈微弱正相关及负相关关系,与填隙物含量呈明显负相关关系。多重分形参数大小与储层渗流能力密切相关,随着渗透率不断增大,多重分形参数表现为先增大、后减小的趋势,因此,并非非均质性越小,储层越好,大量晶间孔的发育可降低储层非均质性,但也会大大制约储层渗流能力。相对较大孔隙发育,且未经过强烈压实、胶结等成岩作用改造,储层非均质性较弱的储层是油气勘探的有利区域。Abstract: Eleven sandstone samples from Benxi Formation of Upper Paleozoic in Gaoqiao area of Ordos Basin were selected.The lithological characteristics and pore structure characteristics of the reservoir were analyzed based on rock slices and scanning electron microscopy.The distribution data of nuclear magnetic resonance T2 of sandstone samples were studied by using multifractal theory.The pore multifractal characteristics of sandstone reservoir are discussed, and the relationship between multifractal parameters and pore structure parameters, mineral composition and physical properties of sandstone is analyzed.The results show that the sandstones of Benxi Formation are mostly quartz sandstones and lithic quartz sandstones, and the skeleton grains are mainly quartz (63%-85%, with an average of 71.45%)and lithic debris(3%-17.5%, with an average of 10.91%), without feldspar.The cements are mainly kaolinite(3%-10%, with an average of 6.3%) and carbonate cements(0-9%, with an average of 5.65%).The pore size distribution of sandstone reservoir shows obvious multifractal characteristics.The multifractal parameters, Dmin-Dmax, Dmin/Dmax and Δα is between 1.16-1.83, 2.73-6.92 and 1.37-4.33 respectively.Research shows that both α-f(α) multifractal singular spectrum and q-D(q) generalized multifractal parameters can be used to quantitatively characterize the heterogeneity of pore distribution of sandstone reservoirs.The multifractal parameters have weak positive correlation and negative correlation with quartz content and rock debris content respectively, and have obvious negative correlation with cements content.The multifractal parameters are closely related to the permeability of reservoir.With the permeability increasing, the multifractal parameters show the trend of increasing first and then decreasing.Therefore, it is not that the smaller the heterogeneity is, the better the reservoir is.The development of a large number of intercrystalline pores can reduce the heterogeneity of the reservoir, but also greatly restricts the permeability of the reservoir.Relatively large pores are developed and have not undergone strong compaction, cementation and other diagenetic transformation.Reservoirs with weak heterogeneity are favorable areas for oil and gas exploration.
-
Key words:
- multifractal /
- pore structure /
- sandstone reservoir /
- Benxi Formation /
- Ordos Basin
-
表 1 研究区本溪组砂岩储层岩石学特征
Table 1. Petrological characteristics of Benxi Formation sandstone reservoir in the study area
样号 层位 深度h/m 岩性 碎屑颗粒φB/% 填隙物φB/% 石英 长石 岩屑 高岭石 伊利石 碳酸盐 黄铁矿 其他 1# 晋祠 3 651.5 岩屑石英砂岩 71 0 10.0 9.0 2.0 4.0 2.5 1.5 2# 晋祠 3 652.7 岩屑石英砂岩 69 0 10.5 10.0 1.5 3.0 2.0 4.0 3# 晋祠 3 381.0 石英砂岩 81 0 4.0 4.5 2.0 7.0 1.0 0.5 4# 晋祠 3 383.3 岩屑石英砂岩 73 0 13.5 6.5 0.5 3.0 2.0 1.5 5# 晋祠 3 385.7 岩屑石英砂岩 64 0 13.0 4.0 4.0 9.0 4.0 2.0 6# 晋祠 3 386.2 岩屑石英砂岩 67 0 15.5 3.0 2.0 8.0 4.5 0 7# 畔沟 3 539.9 岩屑石英砂岩 63 0 16.5 8.0 4.0 6.0 1.0 1.5 8# 畔沟 3 541.0 岩屑石英砂岩 68 0 12.5 7.5 2.5 7.5 1.5 0.5 9# 畔沟 3 540.1 岩屑石英砂岩 63 0 17.5 5.5 3.5 9.0 0.5 1.0 10# 晋祠 3 028.6 石英砂岩 85 0 3.0 5.0 0 0 0 7.0 11# 晋祠 3 027.6 石英砂岩 82 0 4.0 7.0 0 0 0 7.0 表 2 储层物性及核磁共振分析结果
Table 2. Reservoir physical properties and nuclear magnetic resonance analysis results
样品号 φ气/% k气/10-3 μm2 岩性 φ水/% φ核磁/% T2截止值/ms 束缚水饱和度/% 可动水饱和度/% 1# 4.08 1.177 5 岩屑石英砂岩 3.92 3.84 10.40 41.92 58.08 2# 6.55 1.017 3 岩屑石英砂岩 3.75 3.56 2.98 42.91 57.09 3# 4.04 0.025 9 石英砂岩 4.54 4.49 53.23 72.45 27.55 4# 6.57 0.313 6 岩屑石英砂岩 7.15 7.02 64.85 42.94 57.06 5# 3.50 0.116 9 岩屑石英砂岩 3.25 2.84 4.82 27.96 72.04 6# 3.58 0.286 4 岩屑石英砂岩 3.38 3.26 16.01 50.98 49.02 7# 3.20 0.100 7 岩屑石英砂岩 3.24 2.86 7.79 71.19 28.81 8# 5.41 0.387 1 岩屑石英砂岩 5.74 5.46 8.39 64.36 35.64 9# 2.80 0.111 6 岩屑石英砂岩 2.62 2.50 4.64 63.28 36.72 10# 7.55 0.402 9 石英砂岩 8.10 7.95 25.54 41.33 58.67 11# 6.50 0.316 1 石英砂岩 6.75 6.54 40.01 38.02 61.98 表 3 砂岩储层样品多重分形参数
Table 3. Multifractal parameters of sandstone reservoir samples
样品号 Dmin D-2 D-1 D0 D1 D2 Dmax Dmin-Dmax Dmin/Dmax Δa 1# 3.02 2.22 1.71 1.00 0.86 0.82 0.75 2.28 4.04 2.61 2# 2.90 2.14 1.65 0.98 0.87 0.85 0.81 2.09 3.57 2.40 3# 3.20 2.21 1.72 0.92 0.73 0.67 0.60 2.6 5.33 2.71 4# 4.48 3.29 2.45 0.93 0.78 0.72 0.65 3.83 6.92 4.33 5# 1.84 1.38 1.14 0.88 0.79 0.75 0.67 1.16 2.73 1.37 6# 3.22 2.35 1.76 0.93 0.71 0.63 0.55 2.68 5.91 3.03 7# 2.60 1.91 1.46 0.92 0.80 0.74 0.65 1.94 3.97 2.23 8# 2.69 1.99 1.54 0.93 0.79 0.72 0.64 2.05 4.22 2.35 9# 2.87 2.14 1.67 1.00 0.84 0.80 0.72 2.16 4.01 2.47 10# 3.23 2.41 1.86 0.87 0.59 0.56 0.52 2.71 6.22 3.05 11# 2.97 2.18 1.65 0.77 0.62 0.58 0.53 2.44 5.63 2.76 -
[1] Wu H, Zhang C, Ji Y, et.al.An improved method of characterizing the pore structure in tight oil reservoirs: Integrated NMR and constant-rate- controlled porosimetry data[J].Journal of Petroleum Science and Engineering, 2018, 166:778-796. http://www.sciencedirect.com/science/article/pii/S0920410518302511 [2] 赵丁丁, 孙卫, 杜堃, 等.特低-超低渗透砂岩储层微观水驱油特征及影响因素:以鄂尔多斯盆地马岭油田长8-1储层为例[J].地质科技情报, 2019, 38(3):157-164. http://www.cnki.com.cn/Article/CJFDTotal-DZKQ201903016.htm [3] 刘晓鹏, 刘燕, 陈娟萍, 等.鄂尔多斯盆地盒8段致密砂岩气藏微观孔隙结构及渗流特征[J].天然气地球科学, 2016, 27(7):1225-1234. http://d.wanfangdata.com.cn/periodical/trqdqkx201607009 [4] 彭军, 韩浩东, 夏青松, 等.深埋藏致密砂岩储层微观孔隙结构的分形表征及成因机理:以塔里木盆地顺托果勒地区柯坪塔格组为例[J].石油学报, 2018, 39(7):775-791. http://www.cnki.com.cn/Article/CJFDTotal-SYXB201807005.htm [5] Liu M, Xie R, Li C, et al.Determining the segmentation point for calculating the fractal dimension from mercury injection capillary pressure curves in tight sandstone[J].Journal of Geophysics and Engineering, 2018, 15(4):1350-1362. http://www.researchgate.net/publication/323374426_Determining_the_segmentation_point_for_calculating_the_fractal_dimension_from_mercury_injection_capillary_pressure_curves_in_tight_sandstone [6] 操应长, 葸克来, 刘可禹, 等.陆相湖盆致密砂岩油气储层储集性能表征与成储机制:以松辽盆地南部下白垩统泉头组四段为例[J].石油学报, 2018, 39(3):247-265. http://www.cnki.com.cn/Article/CJFDTotal-SYXB201803001.htm [7] 宋磊, 宁正福, 孙一丹, 等.联合压汞法表征致密油储层孔隙结构[J].石油实验地质, 2017, 39(5):700-705. http://www.cnki.com.cn/Article/CJFDTOTAL-SYSD201705017.htm [8] 朱如凯, 吴松涛, 崔景伟, 等.油气储层中孔隙尺寸分级评价的讨论[J].地质科技情报, 2016, 35(3):133-144. http://www.cnki.com.cn/Article/CJFDTotal-DZKQ201603017.htm [9] 盛军, 孙卫, 赵婷, 等.致密砂岩气藏微观孔隙结构参数定量评价:以苏里格气田东南区为例[J].西北大学学报:自然科学版, 2015, 45(6):913-924. http://www.cnki.com.cn/Article/CJFDTotal-XBDZ201506010.htm [10] 王玉霞, 周立发, 焦尊生, 等.基于三参数非线性渗流的低渗透砂岩油藏CO2非混相驱相渗计算模型[J].西北大学学报:自然科学版, 2018, 48(1):107-114, 131. http://www.cnki.com.cn/Article/CJFDTotal-XBDZ201801017.htm [11] 陶士振, 高晓辉, 李昌伟, 等.煤系致密砂岩气渗流机理实验模拟研究:以四川盆地上三叠统须家河组煤系致密砂岩气为例[J].天然气地球科学, 2016, 27(7):1143-1152. http://www.cnki.com.cn/Article/CJFDTotal-TDKX201607001.htm [12] 郑江韬.低渗透岩石的应力敏感性与孔隙结构三维重构研究[D].北京: 中国矿业大学(北京), 2016. [13] 聂昕.页岩气储层岩石数字岩心建模及导电性数值模拟研究[D].北京: 中国地质大学(北京), 2014. [14] 苏娜.低渗气藏微观孔隙结构三维重构研究[D].成都: 西南石油大学, 2011. [15] 冯小哲, 祝海华.鄂尔多斯盆地苏里格地区下石盒子组致密砂岩储层微观孔隙结构及分形特征[J].地质科技情报, 2019, 38(3):147-156. http://www.cnki.com.cn/Article/CJFDTotal-DZKQ201903015.htm [16] 邓浩阳, 司马立强, 吴玟, 等.致密砂岩储层孔隙结构分形研究与渗透率计算:以川西坳陷蓬莱镇组、沙溪庙组储层为例[J].岩性油气藏, 2018, 30(6):76-82. http://d.wanfangdata.com.cn/periodical/yxyqc201806009 [17] Gould D J, Vadakkan T J.Multifractal and lacunarity analysis of microvascular morphology and remodeling[J].Microcirculation, 2011, 18(2):136-151. [18] Zhang Z Y, Weller A.Fractal dimension of pore-space geometry of an Eocene sandstone formation[J].Geophysics, 2014, 79(6):377-387. [19] Bu H L, Ju Y W, Tang J Q, et al.Fractal characteristics of pores in non-marine shales from the Huainan Coalfield, eastern China[J].Journal of Natural Gas Science and Engineering, 2015, 24:166-177. http://www.sciencedirect.com/science/article/pii/s1875510015001213 [20] 王民, 焦晨雪, 李传明, 等.东营凹陷沙河街组页岩微观孔隙多重分形特征[J].油气地质与采收率, 2019, 26(1):72-79. http://www.zhangqiaokeyan.com/academic-journal-cn_petroleum-geology-recovery-efficiency_thesis/0201270874162.html [21] 郭明磊, 肖佳, 左胜浩.水泥-石灰石粉胶凝材料孔结构多重分形特征以及与渗透性的关系[J].硅酸盐学报, 2019, 47(5):617-624. http://www.cnki.com.cn/Article/CJFDTotal-GXYB201905006.htm [22] 管孝艳, 杨培岭, 李柳, 等.长期再生水灌溉后土壤孔隙分布的多重分形特征[J].排灌机械工程学报, 2018, 36(11):1163-1167. http://www.cnki.com.cn/Article/CJFDTotal-PGJX201811020.htm [23] 贾承造, 郑民, 张永峰.中国非常规油气资源与勘探开发前景[J].石油勘探与开发, 2012, 39(2):129-136. http://www.cnki.com.cn/Article/CJFDTotal-SKYK201202002.htm [24] 邹才能, 董大忠, 王社教, 等.中国页岩气形成机理、地质特征及资源潜力[J].石油勘探与开发, 2010, 37(6):641-653. [25] 李文厚, 庞军刚, 曹红霞, 等.鄂尔多斯盆地晚三叠世延长期沉积体系及岩相古地理演化[J].西北大学学报:自然科学版, 2009, 39(3):501-506. http://d.wanfangdata.com.cn/periodical/xbdxxb200903020 [26] 杨华, 张文正.论鄂尔多斯盆地长_7段优质油源岩在低渗透油气成藏富集中的主导作用:地质地球化学特征[J].地球化学, 2005, 34(2):147-154. http://www.cnki.com.cn/Article/CJFDTotal-DQHX200502006.htm [27] Ge X, Fan Y, Zhu X, et al.Determination of nuclear magnetic resonance T2 cutoff value based on multifractal theory:An application in sandstone with complex pore structure[J].Geophysics, 2015, 80(1):11-21. [28] Gutierrez C G, Jose F S.Multifractal analysis of soil micro and macro porosity using digital images obtained with fluorescent dye[J].Geophysics Research Abstract, 2006, 8:60. [29] Chhabra A, Jensen R V.Direct determination of the α-f(α) singularity spectrum[J].Physical Review Letters, 1989, 62(11):1327-1330. [30] 王金满, 张萌, 白中科, 等.黄土区露天煤矿排土场重构土壤颗粒组成的多重分形特征[J].农业工程学报, 2014, 30(4):230-238. http://www.cnki.com.cn/Article/CJFDTotal-NYGU201404028.htm [31] Miranda J G V, Montero E, Alves M C, et al.Multifractal characterization of saprolite particle-size distributions after topsoil removal[J].Geoderma., 2006, 134(3/4):373-385. [32] Martín M A, Rey J M, Taguas F J.An entropy-based parametrization of soil texture via fractal modelling of particle-size distribution[J].Proceedings of the Royal Society A-Mathematical Physical and Engineering Sciences, 2001, 457:937-947. doi: 10.1098/rspa.2000.0699 [33] Lee C K.Multifractal characteristics in air pollutant concentration time series[J].Water Air Soil Pollution, 2002, 135(1/4):389-409. doi: 10.1023/A%3A1014768632318 [34] 马超, 秦颦, 周尚文, 等.含气页岩实验评价指标与测试方法综述[J].地质科技情报, 2019, 38(2):161-169. http://www.cnki.com.cn/Article/CJFDTotal-DZKQ201902019.htm