Multi-scaling Properties of 2D Reservoir Micro-pore Heterogeneity Based on Digital Casting Thin-Section Images

An Experiment-Based Study of Formation Damage Using a Microetching Model Displacement Method

“…Therefore, with the gradual advancement of exploration and the development of low-porosity and low-permeability sandstone reservoirs, the study of the microscopic mechanism of formation damage by drilling fluid has received increasing attention in recent years. At present, the experimental methods for studying the damage to rocks caused by drilling fluid at the microscopic scale include thin-section observations [13,14], scanning electron microscope (SEM) observations [15,16], X-ray diffraction (XRD) [17], nuclear magnetic resonance (NMR) imaging [18], CT scanning [19], etc. The main idea of these methods is similar: first, obtaining rock samples (from drilling) before drilling fluid damage and rock samples (from core flooding experiments) after drilling fluid damage and then scanning or observing the rock samples before and after drilling fluid damage at the microscopic scale, and comparing the differences between them to determine the characteristics of formation damage.…”

“…The main idea of these methods is similar: first, obtaining rock samples (from drilling) before drilling fluid damage and rock samples (from core flooding experiments) after drilling fluid damage and then scanning or observing the rock samples before and after drilling fluid damage at the microscopic scale, and comparing the differences between them to determine the characteristics of formation damage. Among these methods, the advantage of both the thin-section and SEM observation methods is that high-resolution microscopic images can be obtained, which can characterize the formation damage caused by the solid particles from drilling fluid blocking the pores [13][14][15][16]. The advantage of the XRD method is that the influence of the composition and content of the solid particles in drilling fluid on the formation damage can be quantitatively analyzed [17].…”

“…The advantage of the NMR imaging and CT scanning methods is that the damage of core samples by drilling fluid can be observed from a three-dimensional scale, but the resolution of the images is relatively low, such that the characterization of the microscopic details is insufficient [18][19][20]. In addition, some studies have shown that drilling fluids with different liquid components (oil and water) undergo changes in viscosity, dynamic shearing force, static shearing force, wettability, and other properties under formation temperature and pressure conditions, which At present, the experimental methods for studying the damage to rocks caused by drilling fluid at the microscopic scale include thin-section observations [13,14], scanning electron microscope (SEM) observations [15,16], X-ray diffraction (XRD) [17], nuclear magnetic resonance (NMR) imaging [18], CT scanning [19], etc. The main idea of these methods is similar: first, obtaining rock samples (from drilling) before drilling fluid damage and rock samples (from core flooding experiments) after drilling fluid damage and then scanning or observing the rock samples before and after drilling fluid damage at the microscopic scale, and comparing the differences between them to determine the characteristics of formation damage.…”