Impacts of diagenesis of tight sandstone gas reservoir on reservoir physical properties: A case study, Sulige gas field, Ordos Basin, China

Abstract

Diagenesis is one of the most important factors impacting the performance of many reservoirs and is perhaps the most important factor impacting the performance of tight sandstone reservoirs, such as those of the Sulige gas field in the Ordos Basin of China. However, the relationship between diagenesis and related parameters determining reservoir physical properties remains unclear. Therefore, we have analyzed experimental data from high-pressure mercury intrusion porosimetry, scanning electron microscopy, and thin sections in addition to using a porosity recovery calculation model to investigate microscopic characteristics, diagenesis, and pore-evolution processes of the low-permeability tight gas reservoir of the He-8 unit of the Sulige gas field in the Ordos Basin. In addition, we have identified the impacts of diagenesis on reservoir characteristics and established the relationship between diagenesis and reservoir quality evolution. We also used the Beard primary porosity model to recover the primary porosity, and to built the reducing and enhancing calculation models for intergranular pore, dissolution pore, and intercrystalline pore during diagenesis. Based on the quantitative relationship between diagenesis processes and porosity evolution, we found that the results of simulation calculation and experimental works were in close agreement with minimal error.

Characteristics and Controlling Factors of Tight Gas Sandstones from the Upper Shanxi and Lower Shihezi Formations in the Northern Sulige Area, Ordos Basin, China

“…Numerous factors affect the variation in the imbibition slope of reservoir sandstone, and the diagenesis could exert direct impact. , Compaction and cementation reduce the reservoir space, leading to intricate pore structures and enhancing sandstone heterogeneity. Dissolution generates a significant number of micrometer-sized pores within and between mineral particles, thus increasing the seepage capacity of the fluid and facilitating fluid migration and flow-through capillary forces.…”

Review of the Effect of Diagenetic Evolution of Shale Reservoir on the Pore Structure and Adsorption Capacity of Clay Minerals

“…The influence of mechanical and chemical compaction on clay mineral pores is no longer obvious at this stage, and dissolution and metasomatism have an influence on the pores. 196,197 Face porosity of clay minerals is generally lower than 5%. Overall, the face porosity of clay minerals decreases with diagenetic evolution, but the downward trend increasingly slows down in this process (Figure 6).…”

Simulation of Fracturing and Well Pattern Optimization of Fractured Tight Sandstone Reservoirs

“…The continental tight oil reservoirs in the Yanchang Formation in the Ordos Basin are characterized by strong heterogeneity, small single sand body thickness, and low natural productivity (Zou et al, 2013;Yin and Wu, 2020). In recent years, the development of fracturing and well pattern optimization technologies have provided a huge space for the upgrading of reserves production in such oil reservoirs (Salamon, 1984;Ma et al, 2019;Dong et al, 2020;Khan et al, 2020;Xue et al, 2021). However, with different development methods, the complexity of fluid flow between different well patterns in tight oil reservoirs increases.…”

“…For tight oil reservoirs, the injectionproduction well pattern and the natural fracture system must have a reasonable configuration relationship. The previous often adopted the well pattern deployment with parallel fracture main strikes (Ma et al, 2019;Zhao et al, 2020).…”