Open Access

ARTICLE

Study on the Seepage Characteristics of Deep Tight Reservoirs Considering the Effects of Creep

Yongfu Liu¹, Haitao Zhao¹, Xingliang Deng¹, Baozhu Guan¹, Jing Li^2,*, Chengqiang Yang², Guipeng Huang²

1 R&D Center for Ultra-Deep Complex Reservoir Exploration and Development, China National Petroleum Corporation, Korla, 841000, China
2 National Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, 266580, China

* Corresponding Author: Jing Li. Email:

(This article belongs to the Special Issue: Selected Papers from the SDEWES 2024 Conference on Sustainable Development of Energy, Water and Environment Systems)

Energy Engineering 2025, 122(5), 1735-1754. https://doi.org/10.32604/ee.2025.063706

Received 21 January 2025; Accepted 27 March 2025; Issue published 25 April 2025

Abstract

The seepage characteristics of shale reservoirs are influenced not only by multi-field coupling effects such as stress field, temperature field, and seepage field but also exhibit evident creep characteristics during oil and gas exploitation. The complex fluid flow in such reservoirs is analyzed using a combination of theoretical modeling and numerical simulation. This study develops a comprehensive mathematical model that integrates the impact of creep on the seepage process, with consideration of factors including stress, strain, and time-dependent deformation. The model is validated through a series of numerical experiments, which demonstrate the significant influence of creep on the seepage behavior. The results indicate that the rock mechanical parameters and creep constitutive model were determined through triaxial compression tests and uniaxial creep tests. A creep-seepage coupling control equation for shale was established based on the Burgers creep model. The absolute value of the volumetric strain of shale increases rapidly in the initial creep stage, and the increase in vertical stress accelerates the rock’s creep deformation. During the deceleration creep stage, the volumetric strain of the reservoir increases rapidly, leading to a significant decrease in permeability. In the stable creep stage, the pores and fractures in the rock are further compressed, causing a gradual reduction in permeability, which eventually stabilizes.

---

Keywords

---