Rapid Determination of Complete Distribution of Pore and Throat in Tight Oil Sandstone of Triassic Yanchang Formation in Ordos Basin, China

作     者：DU Shuheng SHI Yongmin DU Shuheng;SHI Yongmin

作者机构：State Key Laboratory of Nonlinear MechanicsInstitute of MechanicsChinese Academy of SciencesBeijing 100190China Oil and Gas InstitutePeking UniversityBeijing 100871China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2020年第94卷第3期

页      面：822-830页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：This work was jointly supported by National Natural Science Foundation of China(Grant No.41902132,11872363,51861145314) PetroChina Innovation Foundation(Grant No.2019D-5007-0214) Chinese Academy of Sciences(CAS)through the CAS Key Research Program of Frontier Sciences(Grant No.QYZDJ-SSW-JSC019) the CAS Strategic Priority Research Program(Grant No.XDB22040401) National Science and Technology Mega Project of China(Grant No.2017ZX05013005-009) 

主　　题：complete distribution tight oil reservoir multi-precision imaging mathematical statistics 

摘      要：This study aimed to investigate the complete distribution of reservoir space in tight oil sandstone combining casting slices, field emission scanning electron microscopy(FE-SEM), the pore-throat theory model, high-resolution image processing, mathematical statistics, and other technical means. Results of reservoir samples from the Xin’anbian area of Ordos Basin showed that the total pore radius curve of the tight oil sandstone reservoir exhibited a multi-peak distribution, and the peaks appeared to be more focused on the ends of the range. This proved that pores with a radius of 1–50,000 nm provided the most significant storage space for tight oil, indicating that special attention should be paid to this range of the pore size distribution. Meanwhile, the complete throat radius curve of the tight oil sandstone reservoir exhibited a multipeak distribution. However, the peak values were distributed throughout the scales. This confirmed that the throat radius in the tight oil sandstone reservoir was not only in the range of hundreds of nanometers but was also widely distributed in the scale approximately equal to the pore size. The new rapid determination method could provide a precise theoretical basis for the comprehensive evaluation, exploration, and development of a tight oil sandstone reservoir.