利用核磁共振资料定量评价页岩孔隙结构
Quantitative Evaluation of Shale Pore Structure Using Nuclear Magnetic Resonance Data
通讯作者: 王胜建, Tel: 010-64998687, E-mail:wshj0908@163.com
收稿日期: 2020-09-21
基金资助: |
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Received: 2020-09-21
页岩气储层的孔隙结构复杂且非均质性较强,导致储层表征及有效性评价面临极大挑战.为了建立页岩气储层孔隙结构的定量评价方法,本文选取了鄂西宜昌地区陡山沱组二段20块岩心,采用0.069 ms的回波间隔开展饱含盐水状态下的核磁共振(NMR)实验.在此基础上,对T2谱进行了多重分形特征分析,提取了对页岩气储层孔隙结构较敏感的参数,并建立了基于最小与最大广义分维数差值(Dmin-Dmax)和谱宽(Δα)划分页岩气储层类型的方法及标准.该方法对于有效提高页岩气储层的预测精度、指导开发选层等具有重要意义.
关键词:
The pore structure of shale gas reservoir is complex and heterogeneous, leading to great challenges in reservoir characterization and effectiveness evaluation. In order to establish a quantitative evaluation method for pore structure of the shale gas reservoir, 20 cores of the second member of Doushantuo Formation in Yichang area, western Hubei were selected as the experimental sample. An echo interval of 0.069 ms was used to carry out nuclear magnetic resonance (NMR) experiments under 100% salt water saturation. The obtained T2 spectra were analyzed with the multifractal characteristics method, and the parameters sensitive to the pore structure of the shale reservoirs were extracted. A method and a standard to classify shale reservoir types were developed, based on the minimum and maximum generalized fractal dimension difference (Dmin-Dmax) and spectral width (Δα). This method is of great significance for improving the prediction accuracy of shale gas reservoirs and guiding development and selection.
Keywords:
本文引用格式
孟昆, 王胜建, 薛宗安, 侯瑞卿, 肖亮.
MENG Kun.
引言
核磁共振(NMR)测井资料是研究岩石孔隙结构的重要资料,在表征孔隙体积、孔径分布和比表面积等方面具有其它资料所不可比拟的优势[8-12].目前,NMR测井资料广泛用于表征岩石的孔隙结构和划分储层类型,在常规-致密储层中取得了很好的应用效果[13-16].然而,由于页岩气储层孔隙尺寸较小,且相应的岩石物理配套实验资料较少,因此常规的利用NMR测井表征岩石孔隙结构的方法失去了作用.分形理论由Mandelbrot[17]在1975年首次提出,是用来描述不规则几何图形自相似特性的一种常用方法[18, 19].1988年,Krohn[20]用扫描电镜观察岩石断面,发现各种砂岩、页岩及碳酸盐岩在一定尺度内具有良好的分形性质.贾芬淑等[21]利用分维数来定量评价砂岩的孔隙结构,取得了一定的应用效果.然而,大多数自然物体的形状呈现出非均质性和多重分形特征,一个恒定的分形维数不能准确地描述其特征.因此,在分形的基础上,有研究者提出了一种能提供更多孔隙特性信息的多重分形理论,将自相似性度量转化为多重分形函数集[22, 23].目前,国内外学者针对岩心孔径分布开展了大量的分形和多重分形性特征研究.胡琳等[24]基于压汞数据,根据页岩孔隙分形曲线的特征,将孔隙结构划分为渗透孔隙、凝聚-吸附孔隙和吸附孔隙三类.Jiang等[25]基于压汞数据,建立了分形参数与孔隙度和渗透率之间的相关关系.Zhao等[26]基于低温氮气吸附和NMR实验,发现中巴肯地层微孔隙体积和平均孔隙大小与多重分形参数谱宽(Δα)有较好的相关性.王民等[27]发现页岩孔径分布存在明显的多重分形特征,孔径分布的非均质性主要与孔隙比表面积有关.Liu等[28]基于低温二氧化碳和氮气实验,发现了巴肯页岩具有多重分形现象,广义维数随着阶矩的增加而减小,多重分形谱呈现强的不对称性.
低温氮气吸附、低温二氧化碳吸附、压汞和NMR是常用的研究岩心孔径分布的实验方法,岩心孔径分布的多重分形特征分析被用来进一步刻画岩心孔隙结构的复杂性和非均质性.鄂西地区震旦系陡山沱组是中国页岩气勘查的新层系,陡山沱组直井分段压裂的日产气量最高达5 460 m3/d、水平井压裂获得5.53万m3/d稳定页岩气流[29, 30].目前,针对该层系的页岩微观孔隙结构的研究尚不充分.为提高对该层系储层的孔隙结构的有效评价精度,本文基于多重分形理论对饱含盐水状态的岩心T2谱进行多重分形特征分析及敏感参数提取,研究多重分形参数与岩石孔隙结构之间的关系,并通过敏感的多重分形参数建立页岩气储层孔隙结构的定量表征和分类的方法.
1 地质背景
鄂阳页1井位于鄂西地区黄陵背斜的西南部,其震旦系陡山沱组可划分为四段.陡一段为灰色泥质白云岩,厚度11.46 m;陡二段以黑色碳质页岩和灰黑色白云质页岩为主,厚度127.69 m;陡三段以灰色灰质白云岩、浅灰色白云岩为主,厚度57.72 m;陡四段发育一套深灰色泥岩,厚度0.65 m(图 1).本次研究选取鄂阳页1井震旦系陡山沱组陡二段岩心20块,其中黑色碳质页岩9块、灰黑色白云质页岩11块,开展了饱含盐水状态的NMR研究,通过对T2谱的多重分形特征分析,研究页岩气储层的微观孔隙结构.
图1
图1
鄂阳页1井震旦系陡山沱组地层柱状图
Fig.1
Stratigraphic column of the Sinian Doushantuo formation, eyangye 1 well
2 NMR实验和数据分析
2.1 NMR实验
实验基本步骤如下:(1)将岩心切割成直径为2.50 cm、长度在0.50 cm以上的柱塞样品,并将端面磨平、抛光,制备标准柱塞样;(2)对岩心样品进行洗油、洗盐处理;(3)配置浓度为5.0 mg/L的KCl溶液浸泡样品,将真空室内抽真空、加压饱和8 h,饱和压力为0.3 MPa,直到岩心达到完全饱含盐水状态;(4)对饱含盐水状态的岩心进行NMR实验,得到完全饱含盐水状态的T2谱. 实验过程中,考虑到所选取的页岩岩心在长时间浸泡后容易散开,故未做离心处理.
2.2 数据分析
表1 20块页岩岩心样品的NMR孔隙度、T50、孔隙比例和T2谱的多重分形参数
Table 1
编号 | 岩性 | Φ-nmr/% | T50/ms | 微孔/% | 中孔/% | 宏孔/% | Dmin* | Dmax* | D-1* | D1* | Δα* | Dmin-Dmax* | ||
1# | 黑色碳质页岩 | 2.02 | 0.598 | 0.376 | 48.681 | 50.942 | 1.236 | 0.293 | 1.097 | 0.762 | 1.026 | 0.943 | ||
2# | 黑色碳质页岩 | 1.19 | 0.604 | 0.638 | 48.506 | 50.856 | 1.167 | 0.378 | 1.072 | 0.838 | 0.854 | 0.789 | ||
3# | 黑色碳质页岩 | 0.86 | 0.257 | 1.026 | 65.735 | 33.239 | 1.231 | 0.227 | 1.111 | 0.669 | 1.071 | 1.004 | ||
4# | 黑色碳质页岩 | 2.19 | 0.542 | 0.338 | 51.067 | 48.595 | 1.235 | 0.313 | 1.100 | 0.765 | 1.006 | 0.923 | ||
5# | 黑色碳质页岩 | 2.08 | 0.769 | 0.367 | 44.567 | 55.065 | 1.199 | 0.457 | 1.066 | 0.873 | 0.854 | 0.742 | ||
6# | 黑色碳质页岩 | 1.11 | 0.327 | 0.585 | 61.891 | 37.524 | 1.238 | 0.229 | 1.115 | 0.679 | 1.076 | 1.009 | ||
7# | 黑色碳质页岩 | 1.07 | 0.378 | 0.636 | 58.550 | 40.814 | 1.231 | 0.312 | 1.095 | 0.777 | 0.999 | 0.919 | ||
8# | 黑色碳质页岩 | 1.99 | 0.307 | 0.723 | 62.884 | 36.393 | 1.232 | 0.266 | 1.106 | 0.724 | 1.036 | 0.965 | ||
9# | 黑色碳质页岩 | 1.69 | 0.421 | 0.252 | 57.065 | 42.684 | 1.246 | 0.262 | 1.112 | 0.709 | 1.053 | 0.984 | ||
10# | 灰黑色白云质页岩 | 1.87 | 0.115 | 2.348 | 70.629 | 27.023 | 1.320 | 0.275 | 1.126 | 0.719 | 1.136 | 1.046 | ||
11# | 灰黑色白云质页岩 | 2.56 | 0.360 | 1.105 | 57.662 | 41.233 | 1.220 | 0.288 | 1.090 | 0.757 | 1.024 | 0.931 | ||
12# | 灰黑色白云质页岩 | 2.15 | 0.344 | 0.713 | 59.893 | 39.394 | 1.226 | 0.308 | 1.101 | 0.759 | 0.998 | 0.919 | ||
13# | 灰黑色白云质页岩 | 1.69 | 0.151 | 0.884 | 85.168 | 13.948 | 1.370 | 0.224 | 1.168 | 0.603 | 1.235 | 1.146 | ||
14# | 灰黑色白云质页岩 | 1.28 | 0.141 | 1.658 | 80.521 | 17.820 | 1.328 | 0.238 | 1.140 | 0.662 | 1.177 | 1.090 | ||
15# | 灰黑色白云质页岩 | 2.10 | 0.253 | 0.835 | 66.570 | 32.595 | 1.236 | 0.270 | 1.109 | 0.721 | 1.031 | 0.966 | ||
16# | 灰黑色白云质页岩 | 1.10 | 0.167 | 1.436 | 69.717 | 28.846 | 1.310 | 0.232 | 1.118 | 0.675 | 1.188 | 1.078 | ||
17# | 灰黑色白云质页岩 | 0.89 | 0.183 | 1.333 | 59.503 | 39.165 | 1.324 | 0.253 | 1.122 | 0.703 | 1.180 | 1.071 | ||
18# | 灰黑色白云质页岩 | 3.17 | 0.102 | 1.960 | 87.002 | 11.037 | 1.364 | 0.217 | 1.171 | 0.607 | 1.228 | 1.147 | ||
19# | 灰黑色白云质页岩 | 1.75 | 0.210 | 0.589 | 74.234 | 25.177 | 1.337 | 0.264 | 1.136 | 0.695 | 1.169 | 1.073 | ||
20# | 灰黑色白云质页岩 | 2.55 | 0.149 | 0.945 | 79.074 | 19.981 | 1.359 | 0.260 | 1.148 | 0.682 | 1.200 | 1.100 |
* T2谱的多重分形参数定义见后文第3节.
图2
图2
(a) 完全饱含盐水状态的20块页岩岩心的T2谱;(b) T2谱归一化累积曲线
Fig.2
(a) T2 spectra of the 20 shale cores with fully saturated salt water; (b) Normalized cumulative curve of T2 spectra
图3
图3
基于NMR获得的黑色碳质页岩(5#)和灰黑色白云质页岩(13#)样品的孔隙比例分布
Fig.3
The pore size distributions of black carbonaceous shale core (5#) and gray-black dolomitic shale core (13#) acquired with NMR
3 基于T2谱的多重分形分析
3.1 NMR响应机理
(1) 式中
由于孔隙的表面积与体积之比与孔隙半径和形状因子有关,对于具有规则形状的孔隙,可根据(2)式推导出横向弛豫时间与岩石孔隙半径的关系[44]:
(3) 式中
由(3)式可知,T2与孔隙半径呈正比关系,利用该式可将T2谱转化成岩石的孔隙半径分布.
3.2 多重分形理论
本文采用计盒法对多重分形理论进行简要介绍.完全饱含水状态的岩心T2谱经过归一化累积处理,将其分布范围视为数据集长度L,以尺度
(4) 式中,
(5) 式中,
因此,不同的分割集可能具有相同的奇异强度,用
(6) 式中,
定义配分函数为:
(7) 式中,q为阶矩或权重因子,取值范围可为
不同的q值具有不同的广义分形维数,
根据勒让得变换可得阶矩q对应的奇异强度
3.3 T2谱的多重分形特征分析
对20块岩心的T2谱归一化累积曲线进行多重分形分析,选取q的范围为
图4
图4
5#页岩T2谱的多重分形分析. (a)配分函数与不同盒子尺度的双对数图;(b)质量函数谱q~τ(q);(c)广义分维谱q~D(q);(d)多重分形谱α~f(α)
Fig.4
Multifractal analysis of the T2 spectra of the 5# shale core. (a) Log-log plots of the partition function versus different box scales; (b) The mass functional spectrum q~τ(q); (c) The generalized dimension spectrum q~D(q); (d) The multifractal spectrum α~f(α)
20块页岩样品典型的多重分形特征参数如表 1所示,包括最小广义分维数Dmin、最大广义分维数Dmax、阶矩为-1的广义分维数D-1、阶矩为1的广义分维数D1、谱宽
4 结果与讨论
4.1 基于T2谱的多重分形参数的孔隙结构分类
结合T2谱形态和表 1所示各岩心的孔隙比例,依次选取3块不同孔隙结构类型的代表性岩心,开展多重分形分析. 图 5(a)是三块岩心样品在完全饱含盐水状态下的T2谱归一化累积曲线,5#样品的归一化曲线位于图中最右侧,表 1中的孔隙比例指出其微孔和中孔比例最低,宏孔比例最高,指示出具有较好的连通性和储集空间,代表孔隙结构最好的岩心;18#样品的归一化曲线位于图中最左侧,微孔和中孔比例最高,宏孔比例最低,指示出具有较差的连通性和储集空间,代表孔隙结构最差的岩心;8#样品的归一化曲线介于5#和18#之间,孔隙结构中等.图 5(b)是三块样品的广义分维谱.由图可知:阶矩q小于0时,广义分维数与孔隙结构质量呈反比,孔隙结构越好,广义分维数越低;当阶矩q大于0时,广义分维数与孔隙结构质量呈正比,孔隙结构越好,广义分维数越高.广义分维数差值
图5
图5
三类页岩样品的孔隙结构分析. (a) T2谱归一化累积曲线;(b)广义分维谱q~D(q);(c)多重分形谱α~f(α)
Fig.5
Pore structure analysis for three types of shale cores. (a) Normalized cumulative curves of T2 spectra; (b) The generalized dimension spectra q~D(q); (c) The multifractal spectra α~f(α)
根据对广义分维谱和多重分形谱的分析,选择(Dmin-Dmax)和Δα作为孔隙结构分类的敏感参数. 由20块样品(Dmin-Dmax)和Δα的交会图(图 6)可知:随着孔隙质量变差,(Dmin-Dmax)和Δα均变大,且二者之间具有较好的相关性. 根据(Dmin-Dmax)和Δα的值,将孔隙结构质量由高到低分为三类:Ⅰ类孔隙结构,0.74 < (Dmin-Dmax) < 0.95,0.85 < Δα < 1.03;Ⅱ类孔隙结构,0.95≤(Dmin-Dmax) < 1.01,1.03≤Δα < 1.10;Ⅲ类孔隙结构,1.01≤(Dmin-Dmax) < 1.15,1.10≤Δα < 1.25.
图6
图6
谱宽Δα与最小最大广义分维数差值(Dmin-Dmax)的交会图
Fig.6
Intersection graph between spectral width Δα and the difference of minimum and maximum generalized fractal dimension (Dmin-Dmax)
表 2是20块页岩样品三类孔隙结构的多重分形特征参数的分布范围和平均值,Dmin和D-1能较好的区分Ⅲ类孔隙结构和其他两类孔隙结构.Dmax和D1能较好的区分Ⅰ类孔隙结构和其他两类孔隙结构.Dmin-Dmax、Δα和D-1对三类孔隙结构分布范围均有明确的界限,可用作孔隙结构定量划分的敏感参数.
表2 20块页岩样品三类孔隙结构的多重分形特征参数的分布范围和平均值
Table 2
类型 | Dmin | Dmax | D-1 | D1 | Δα | Dmin-Dmax |
Ⅰ | 1.167~1.236 | 0.288~0.456 | 1.066~1.101 | 0.757~0.873 | 0.854~1.026 | 0.742~0.943 |
1.216 | 0.336 | 1.089 | 0.790 | 0.966 | 0.881 | |
Ⅱ | 1.231~1.245 | 0.227~0.270 | 1.106~1.115 | 0.669~0.724 | 1.031~1.075 | 0.965~1.009 |
1.237 | 0.251 | 1.111 | 0.700 | 1.053 | 0.986 | |
Ⅲ | 1.310~1.370 | 0.217~0.275 | 1.118~1.171 | 0.603~0.719 | 1.136~1.235 | 1.046~1.147 |
1.339 | 0.245 | 1.141 | 0.668 | 1.189 | 1.093 |
4.2 可靠性验证
图 7(a)~(c)是基于图 6所示的分类标准将20块样品分为三类,并得到的从第Ⅰ类至第Ⅲ类岩心的饱含盐水状态的T2谱,而图 7(d)则为三类样品的平均T2谱. 从图中可以看到,Ⅰ类和Ⅰ类岩心的T2谱主要呈现为双峰分布,且以小孔隙分布为主,T2谱上波谷的位置在10 ms左右.但大孔隙所占的比例完全不同,Ⅰ类储层大孔隙所占的比重大于Ⅱ类储层.而Ⅲ类岩心则主要以多峰分布为主,主峰的T2介于0.01~1.0 ms,大孔隙所占的比例进一步降低.
图7
图7
基于多重分形参数分类的三类T2谱和平均T2谱. (a) Ⅰ类;(b) Ⅱ类;(c) Ⅲ类;(d)平均T2谱
Fig.7
Three types of T2 spectra based on multifractal parameter classification. (a) type Ⅰ; (b) type Ⅱ; (c) type Ⅲ; (d) Average T2 spectra
表3 20块页岩样品三类孔隙结构的NMR孔隙度、T50,以及孔隙比例的分布范围和平均值
Table 3
类型 | Φ-nmr/% | T50/ms | 微孔/% | 中孔% | 宏孔/% |
Ⅰ | 1.07~2.56 | 0.344~0.769 | 0.338~1.105 | 44.567~59.893 | 39.394~55.065 |
1.89 | 0.514 | 0.596 | 52.704 | 46.700 | |
Ⅱ | 0.86~2.10 | 0.253~0.421 | 0.252~1.026 | 57.065~66.570 | 32.595~42.684 |
1.55 | 0.313 | 0.684 | 62.829 | 36.487 | |
Ⅲ | 0.89~3.17 | 0.102~0.210 | 0.589~2.348 | 59.503~87.002 | 11.037~39.165 |
1.79 | 0.152 | 1.394 | 75.731 | 22.875 |
5 结论
(1)基于多重分形特征参数的孔隙结构定量表征和分类,为鄂西宜昌地区陡山沱组二段的页岩气储层的孔隙结构评价提供了新思路.
(2)多重分形参数中,(Dmin-Dmax)和Δα是表征页岩孔隙结构优劣的敏感参数,依据(Dmin-Dmax)和Δα可将目标储层划分为三类,该分类结果可以为页岩气储层勘探有利区域及开发选层提供指导.
(3)T2谱形态特征、T50和孔隙比例与多重分形参数建立的孔隙结构定量划分标准有较好的一致性,验证了(Dmin-Dmax)和Δα定量划分孔隙结构的可靠性.
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参考文献
Reservoiring mechanism of shale gas and its distribution
[J].DOI:10.3321/j.issn:1000-0976.2004.07.005 [本文引用: 1]
页岩气成藏机理和分布
[J]. ,DOI:10.3321/j.issn:1000-0976.2004.07.005 [本文引用: 1]
Fractured shale-gas systems
[J]. ,
Shale gas potential of the lower jurassic uordondale member, northeastern British Columbia, Canada
[J]. ,DOI:10.2113/gscpgbull.55.1.51 [本文引用: 1]
Effect of pore structure on methane sorption capacity of shales
[J].
页岩孔隙结构对甲烷吸附能力的影响
[J]. ,
Microstructural characteristics of the cretaceous Qingshankou formation shale, Songliao basin
[J].
松辽盆地白垩系青山口组泥页岩孔隙结构特征
[J]. ,
Pore structure and fractal characteristics of Longmaxi formation shale in the Changning region of Sichuan basin
[J].
四川盆地长宁构造地区龙马溪组页岩孔隙结构及其分形特征
[J]. ,
Experimental study on the wettability of Longmaxi gas shale from Jiaoshiba gas field, Sichuan Basin, China
[J]. ,DOI:10.1016/j.petrol.2017.01.036 [本文引用: 1]
Fractal analysis on heterogeneity of pore-fractures in middle-high rank coals with NMR
[J]. ,DOI:10.1021/acs.energyfuels.6b00563
Insight into the pore structure of tight sandstones using NMR and HPMI measurements
[J]. ,DOI:10.1021/acs.energyfuels.6b01982
Investigation of organic related pores in unconventional reservoir and its quantitative evaluation
[J]. ,DOI:10.1021/acs.energyfuels.6b00590
NMR technologies for evaluating oil & gas shale: a review
[J].
页岩油气层核磁共振评价技术综述
[J]. ,
Reservoir productivity evaluation based on NMR pore structure
[J].DOI:10.3969/j.issn.1673-064X.2011.03.008 [本文引用: 1]
基于核磁共振孔隙结构的产能评价
[J]. ,DOI:10.3969/j.issn.1673-064X.2011.03.008 [本文引用: 1]
Application of NMR log to reservoir evaluation in Shinan oilfield
[J].
核磁共振测井在石南油田储层分类评价中的应用
[J]. ,
A new methodology of constructing pseudo capillary pressure (Pc) curves from nuclear magnetic resonance (NMR) logs
[J]. ,DOI:10.1016/j.petrol.2016.05.015
Quantitative evaluation of reservoir separation with MR-ML technology
[J].DOI:10.3969/j.issn.1000-4556.2010.02.009 [本文引用: 1]
利用核磁共振录井技术定量评价储层的分选性
[J]. ,DOI:10.3969/j.issn.1000-4556.2010.02.009 [本文引用: 1]
Fractals: Form, chance, and dimension
[J]. ,DOI:10.1063/1.2995555 [本文引用: 1]
A protocol for fractal studies on porosity of porous media: High quality soil porosity images
[J]. ,DOI:10.1007/s12583-017-0777-x [本文引用: 1]
Fractal analysis of rainfall-induced landslide and debris flow spread distribution in the Chenyulan Creek Basin, Taiwan
[J]. ,DOI:10.1007/s12583-016-0633-4 [本文引用: 1]
Fractal measurements of sandstones, shales, and carbonates
[J]. ,DOI:10.1029/JB093iB04p03297 [本文引用: 1]
Fractal features and application research of sandstone pore structure
[J].
砂岩孔隙结构的分形特征及应用研究
[J]. ,
Multifractal measures, especially for the geophysicist
[J]. ,
Characterization of the North Sea chalk by multifractal analysis
[J]. ,DOI:10.1029/94JB00117 [本文引用: 1]
Fractal characteristics of shale pore structure of Longmaxi formation in Shuanghe area in southern Sichuan
[J].
蜀南双河龙马溪组页岩孔隙结构的分形特征
[J]. ,
Multifractal characteristics and classification of tight sandstone reservoirs: a case study from the triassic Yanchang formation, Ordos Basin, China
[J]. ,
Multifractal analysis of pore structure of Middle Bakken formation using low temperature N2 adsorption and NMR measurements
[J]. ,DOI:10.1016/j.petrol.2019.01.040 [本文引用: 1]
Multi-fractal characteristics of micro-pores of Shahejie Formation shale in Dongying Sag
[J].
东营凹陷沙河街组页岩微观孔隙多重分形特征
[J]. ,
Multifractal analysis of gas adsorption isotherms for pore structure characterization of the Bakken Shale
[J]. ,
Discussion on petrophysical evaluation of shale gas reservoir in the second member of Sinian Doushantuo formation in western Hubei province, south China
[J].
鄂西地区震旦系陡山沱组二段页岩气储层测井评价初探
[J]. ,
Reservoir accumulation model at the edge of palaeohigh and significant discovery of shale gas in Yichang area, Hubei province
[J].
古隆起边缘成藏模式与湖北宜昌页岩气重大发现
[J]. ,
Differences about organic matter enrichment in the shale section of Ediacaran Doushantuo Formation in West Hubei of China
[J].
鄂西地区陡山沱组页岩段有机质富集的差异性
[J]. ,
Deposit environment of the ediacaran doushantuo formation in Yichang area, western Hubei province, China and its geological significance for shale gas
[J].
鄂西宜昌地区埃迪卡拉系陡山沱组页岩沉积环境及其页岩气地质意义
[J]. ,
Effects of echo time on NMR apparent porosity and correction methods
[J].
回波间隔对核磁共振表观孔隙度的影响及矫正方法
[J]. ,
Investigation on the pore structure and multifractal characteristics of tight oil reservoirs using NMR measurements: Permian Lucaogou Formation in Jimusaer Sag, Junggar basin
[J]. ,DOI:10.1016/j.marpetgeo.2017.07.011 [本文引用: 1]
Estimation of permeability by integrating nuclear magnetic resonance (NMR) logs with mercury injection capillary pressure (MICP) data in tight gas sands
[J]. ,
Study on the response mechanisms of nuclear magnetic resonance (NMR) log in tight oil reservoirs
[J]. ,
Physical chemistry division commission on colloid and surface chemistry, subcommittee on characterization of porous solids: Recommendations for the characterization of porous solids (Technical Report)
[J]. ,DOI:10.1351/pac199466081739 [本文引用: 1]
Determination of nuclear magnetic resonance T2 cutoff value based on multifractal theory-An application in sandstone with complex pore structure
[J]. ,
A new methodology of constructing pseudo capillary pressure (Pc) curves from nuclear magnetic resonance (NMR) logs
[J]. ,
Fractal measures and their singularities: The characterization of strange sets
[J]. ,
Multifractal analysis of soil micro and macroporosity using digital images obtained with fluorescent dye
[J]. ,
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