Abstract:

Carbonate rocks account for ~20% of Phanerozoic sedimentary rocks while carbonate reservoirs hold at least 60% of the world’s proven hydrocarbon reserves. Calcite, as a common carbonate mineral, plays an important role in the formation of secondary pores in the shallow part of the Earth’s crust. This paper summarizes previous studies on the key factors and mechanisms affecting calcite growth and dissolution. For calcite growth, the key influencing factors include temperature, pressure, degree of supersaturation, as well as the types and ionic radius of ions in the surrounding solution, where the decrease of pressure and the increases of ionic strength and calcite surface supersaturation are beneficial for calcite growth. For calcite dissolution, the key influencing factors are temperature, pressure, p(CO₂), ionic strength, pH/chemical composition of the surrounding solution, Zeta potential, and degree of calcite saturation, where Zeta potential of calcite is the main factor determining whether ions in the surrounding solution promote or inhibit dissolution. The surface micromorphology of calcite varies depending on the composition of the surrounding solution during calcite growth/dissolution, which makes it possible to reconstruct the palaeo-fluid by observing the surface morphology of calcite. This paper also analyzes in great detail the inconsistency in previous experimental results and interprets the inconsistency from a novel viewpoint. By focusing on the influencing factors of calcite dissolution, this paper seeks to find the optimal conditions for carbonate dissolution so as to provide a reliable theoretical basis for delineating high-quality carbonate reservoirs. This paper can be helpful for researchers to quickly learn about research hot-spots and latest progresses in this field.

Key words: carbonate rocks, calcite, Zeta potential, growth, dissolution, high-quality reservoirs