Core analytical data, including petrographic and epoxy-impregnated thin sections and scanning electron microscopy (SEM), were used to investigate in detail the mechanisms of pore development in the Lower Shihezi–Shanxi tight sandstone reservoirs of the Sulige Gas Field. The results show that the reservoir sandstones contain abundant lithic fragments and mineralogically complex framework and interstitial components, resulting in marked differences in diagenesis and pore development among rocks with different mineral assemblages. Depositional environment, rock composition and texture, and diagenesis interact with and constrain one another, jointly controlling the preservation of primary pores and the development of secondary pores. Coarse-grained sandstones deposited under high-energy hydrodynamic conditions and enriched in rigid components (quartz minerals plus quartzite lithic fragments) effectively resist compaction and therefore constitute favorable lithofacies for the preservation of primary pores. Moderate amounts of interstitial materials, such as grain-rimming chlorite coatings or micaceous matrix, can suppress quartz overgrowths and resist compaction, thereby playing an important role in preserving primary pores. Superimposed dissolution and alteration of multiple minerals directly generate secondary pores. Among these processes, extensive dissolution of quartz-rich components (quartz grains and quartzite fragments) makes the largest contribution to reservoir pore space. Feldspar is relatively scarce and is mainly altered to kaolinite, producing intercrystalline micropores and minor intragranular dissolution pores. The reservoirs also contain micaceous matrix derived from tuffaceous alteration and kaolinite as interstitial material; these components include unstable, readily soluble constituents, and their dissolution produces intergranular dissolution pores, while kaolinite contributes intercrystalline pores, substantially improving porosity and permeability. Structural microfractures, diagenetic shrinkage fractures, residual primary pores, and matrix micropores together form flow pathways for mineral-dissolving fluids, thereby facilitating dissolution of the various mineral constituents.
tight sandstone; reservoir pore-development mechanism; multi-mineral composition; primary pores; secondary pores; Sulige Gas Field; Shihezi–Shanxi formations
Tian H. Pore Development Mechanisms and Controlling Factors in Tight Sandstone Reservoirs —A Case Study of the Shihezi–Shanxi Formations in the Sulige Gas Field. Int. J. Eng. Sci. Technol., 2026, 4(3), doi: 10.58531/ijest/4/3/1
