Sharif Digital Repository

Formation damage in petroleum engineering is an important and fundamental phenomenon. During drilling operation, penetration of either the solid phase of drilling fluid or the base-fluid into the porous medium, reduces the permeability of the formation. While most experiments in the literature have focused on core-scale and beyond, there is lack of pore-scale studies. Moreover, presence of fractures has an undeniable effect on the extent of formation damage. Thus, the main objective of this dissertation is to investigate the effects of fractures on the severity of formation damage caused by the water-based drilling fluid and the mechanisms of formation damage at the pore scale, using glass... 

Various methods have been developed to improve the production capacity of hydrocarbon wells, one of the most successful method is hydraulic fracture. This method, despite improving well production and increasing production levels in a reservoir, causes secondary damages such as water blockage, which is a result of the leakage of fracturing fluid into the fracture matrix and the deformation of the reservoir. This damage can reduce the production rate of a well. Studies prior to this study have mainly examined the damages caused by the leakage of fracturing fluids on a core scale. In most of these studies, damages has been studied only by measuring the pressure and changes in the permeability... 

During all operations in oil and gas reservoirs, it is possible to cause formation damage. These damages can greatly reduce the rate of production. One of the major damages that can seriously affect the performance of a reservoir is the damage caused by drilling fluid. The main purpose of this thesis is to study the main mechanisms of formation damage caused by water-based drilling fluid using a glass micromodel for the first time. An accurate understanding of the mechanisms of formation damage can provide a good understanding of the selection of the type and concentration of materials used, as well as appropriate methods to control and eliminate damages. for controlling the drilling fluid... 

Acidizing as the most frequent stimulation technique in the field, has been extensively used to increase the production rate. Even though acidizing treatments is well established, there is still an inherent risk for self-induced formation damage through incompatibilities of the fluids involved in this process.
A main potential problem during acidizing is the incompatibility of the acid and the reservoir’s crude oil. Acid interaction with crude oil can produce two major damage mechanisms that could offset partially, if not totally the benefit of the acid stimulation. These mechanisms are the rigid film emulsion formation and the acid-sludge precipitation, result in well productivity... 

Oil composition plays an undeniable role on the low salinity water flooding (LSWF) efficiency. This property directly affects the kinetics of wettability alteration through electrostatic interactions and interfacial tension (IFT). For instance, mixing in stagnant zones through a thin water film is considered as one of the most important diffusion controlled phenomenon which is goverened by Non-Fickian solute transport model. The major two potentials controlling the solute transport in thin film are salinity gradient and electrostatic potentials, which can be affected by oil composition and surface charges. This study aims to investigate the effect of oil composition on low salinity...