Affiliation:
1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploration Chengdu University of Technology Chengdu People's Republic of China
2. PetrolChina Sichuan Chengdu Marketing Company Chengdu People's Republic of China
3. Division of Oil & Gas Development PetroChina Southwest Oil & Gas field Company Chengdu People's Republic of China
4. PetroChina Southwest Oil & Gasfield Company Shunan Gas District Luzhou People's Republic of China
5. College of Petroleum and Natural Gas Engineering Southwest Petroleum University Chengdu People's Republic of China
Abstract
Structural fractures are formed when the underground rock mass deforms and exceeds its own strength limit, so they represent the complex geomechanical properties of rock. Small or core‐scale fractures usually extend less than 10 m in length, which affects the productivity of tight sandstone. Therefore, core‐scale fracture is the core factor for the prediction of reservoir sweet spots. In this paper, the research on the evolution and prediction of natural fractures in tight sandstone is investigated using the core, thin section, logging materials and numerical simulation methods. The results show that a large number of vertical and horizontal sliding fractures with shearing properties are developed in the tight sandstones of the Yanchang Formation. The particle size affects the compactible space inside the reservoir, which then affects the fracture development degree. Since the superimposed thin sand bodies are formed by the frequent lateral migration of the underwater distributary channels in the study area, therefore, the natural fractures in the thin sand bodies at the edge of river channels are relatively developed. According to statistics, the vertical extension distance of fractures is usually less than 2 m. Meanwhile, the fractured zones are mainly located in the cumulative sand body thickness range of 3 ~ 10 m. Moreover, the fractured zones are generally located in the high part of the structure and its wings. Regional structure and thin sand body distribution jointly affect the evolution of fractures in tight sandstones. Through this study, we found that fractures are more developed in thin sand bodies, and the controlling factors include lithology, sedimentary microfacies, sand thickness and local structure. The comprehensive evaluation of fractures in tight sandstones with high accuracy from 1D to 3D was achieved using core observation, logging interpretation, and three‐dimensional (3D) fracture modelling.
Reference67 articles.
1. Frack parameter development characteristics of reservoir in Lutai Oilfield, Songliao Basin;Bai X.;Petroleum Geology and Development of Daqing,1999
2. Stress Mohr's circle and envelope line analysis of high angle normal fault area in the south of Qinshui Basin;Bai Y.;Petroleum Geology and Engineering,2019
3. Barnett Shale gas production, Fort Worth Basin: Issues and discussion
4. Controlling factors of gas accumulation in the Yuxi gas field in western Shanxi fold belt in Ordos Basin;Cao B. D.;Changan University,2012
5. Mechanical properties and failure mechanism of combined bodies with different coal‐rock ratios and combinations;Chen G. B.;Journal of Mining and Strata Control Engineering,2021
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