Petroleum Engineering
Siavash Ashoori; Ehsan Safavi; Jamshid Moghaddasi; Parvin Kolahkaj
Abstract
Formation damage is reported during the secondary and tertiary stages of reservoir lifespan. One of the unpleasant sequences of formation damage caused by fine particles is permeability reduction due to pore plugging and bridging. The fine particles might exist initially in a porous medium or be introduced ...
Read More
Formation damage is reported during the secondary and tertiary stages of reservoir lifespan. One of the unpleasant sequences of formation damage caused by fine particles is permeability reduction due to pore plugging and bridging. The fine particles might exist initially in a porous medium or be introduced by external sources. In addition, there is a variety of particle types and sizes. The current research focuses on the effects of non-swelling clay minerals motions, such as the laminar ones found in Iranian sandstone reservoirs, on permeability. For this purpose, sand packs in various glass bead sizes and containing aluminum oxide as fine particles were designed to scrutinize the motion of fine particles under various pressure differences, flow rates, and concentrations. It was concluded that for each of the three sand packs regarded as the porous media in this study and composed of fine glass beads with different sizes, there is a critical flow rate as a function of glass bead size. For the flow rates lower than the critical flow rate, bridges form stably and lead to the most severe formation damage. After reaching the critical flow rate, the bridges weaken and break, and relative permeability will be independent of the flow rate. It was deduced that permeability reduction and formation damage are directly proportional to particle concentration and inversely proportional to glass bead size.
Petroleum Engineering – Reservoir
Vahid Karamnia; Siavash Ashoori
Volume 10, Issue 1 , January 2021, , Pages 107-126
Abstract
< p>One of the most important factors through the miscible gas injection process is to determine the Minimum Miscibility Pressure. According to the definition, the minimum miscibility pressure is the minimum pressure at which, at a constant temperature, the oil and gas injected can dissolve together ...
Read More
< p>One of the most important factors through the miscible gas injection process is to determine the Minimum Miscibility Pressure. According to the definition, the minimum miscibility pressure is the minimum pressure at which, at a constant temperature, the oil and gas injected can dissolve together to form a single phase. This pressure is typically abbreviated as MMP. Among the available methods for determining the minimum miscibility pressure, laboratory methods including slim tube test and ascending bubble apparatus test are more widely utilized. Although the mentioned tests have high measurement accuracy, they are very time consuming and expensive. Therefore, the determination of the minimum miscibility pressure is usually done using computational and simulation approaches that also have high accuracy. Conducting PVT tests and determining their MMP using slim tube method was previously performed. In this study, the minimum miscibility pressure of reservoirs was determined by applying three methods of simulation with PVTi software, simulation with Eclipse 300 software and using Empirical Correlations. By comparing the obtained results and the laboratory results, it was revealed that the simulation by Eclipse 300 is regarded as the fastest and most accurate approach.
