کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8128728 | 1523007 | 2016 | 18 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Quantitative microporosity evaluation using mercury injection and digital image analysis in tight carbonate rocks: A case study from the Ordovician in the Tazhong Palaeouplift, Tarim Basin, NW China
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Quantitative microporosity evaluation using mercury injection and digital image analysis in tight carbonate rocks: A case study from the Ordovician in the Tazhong Palaeouplift, Tarim Basin, NW China Quantitative microporosity evaluation using mercury injection and digital image analysis in tight carbonate rocks: A case study from the Ordovician in the Tazhong Palaeouplift, Tarim Basin, NW China](/preview/png/8128728.png)
چکیده انگلیسی
The heterogeneity of tight carbonate rocks is directly related to the morphology of micropores and the connectivity of the pore network, which have a great influence on the intrinsic microporosity and fluid flow properties of porous media. However, neither can be quantitatively evaluated by conventional techniques. Based on core observation and thin section analysis, combined with high-resolution field emission-scanning electron microscopy (FE-SEM) and mercury injection capillary pressure (MICP) measurements, we can identify carbonate rock types, determine the microporosity and microstructure and calculate the pore structure parameters. Digital image analysis (DIA) and the fractal dimension (FD) method are used to study the relationship between the quantified pore structure parameters, heterogeneity and fluid flow properties. The results indicate that rock types in 12 carbonate samples are dominated by grainstone and packstone, followed by wackestone and dolomitic packstone. The microporosity of rock types has various microstructure characteristics. Crystalline types of microporosity (the small and large intercrystalline pores) increase pore network connectivity whereas micromoldic pores show variations in connectivity of different lithofacies. However, the small intercrystalline pores contribute little to the permeability because of narrow and complex pore networks for fluid flow. MICP data of samples reveal that these samples are relatively tight with low porosity (avg. 3.7%) and permeability (avg. 0.452mD). The pore-throat radius mainly ranges from 0.1 μm to 1.0 μm, which contributes the highest proportion of permeability to the samples. Fractal dimensions calculated from the “J-curve” models vary between 2.0746 and 2.8551 (avg. 2.331), indicating high heterogeneity. Moreover, the fractal dimension is strongly negatively related to the permeability, average pore throat radius and separation coefficient. Additionally, quantified pore geometric parameters from DIA, including dominant pore size (DOMsize), perimeter over area (PoA), pore body-to-throat ratio (BTR) and average roundness (γa), greatly influence the pore structure and fluid flow behavior. The samples with large DOMsize, high γa, low PoA and low BTR show a low fractal dimension and simple pore network but high permeability. Diagenesis can also affect the fractal pore space and self-similarity pore geometries of carbonates across all length scales. This information about the micropore geometry and microstructure of the carbonate rock will further improve the assessment of its reservoir properties.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Natural Gas Science and Engineering - Volume 34, August 2016, Pages 627-644
Journal: Journal of Natural Gas Science and Engineering - Volume 34, August 2016, Pages 627-644
نویسندگان
Jianhua He, Wenlong Ding, Ang Li, Yaxiong Sun, Peng Dai, Shuai Yin, En Chen, Yang Gu,