Seyed Ali Mousavi Dehghani

Water injection into porous media serves various purposes such as maintaining reservoir pressure, wastewater removal, and enhancing hydrocarbon production recovery. One significant challenge in the water injection process is the formation of mineral scale due to the incompatibility between the injected water and the formation water. The dispersion coefficient, which characterizes the behavior of different ions in mixed waters, is a critical factor in water flooding studies. It determines the size of the mixing zone during miscible processes. This study calculates the dispersion coefficient using non-interacting and non-precipitating tracers in both homogeneous and heterogeneous cores. Experimental data were mathematically modeled, revealing previously unreported correlations between the dispersion coefficient and injection velocity for both types of rocks.

The purpose of this study is to explore the impact of additives on the displacement of the onset point of asphaltene precipitation in crude oil using the interfacial tension measurement method, based on the examined oil has been taken from Iran reservoirs. The experimental results suggest that the addition of surfactants of dodecyl benzene sulfonic acid (DBSA) and coconut diethanolamide (CDEA) to the oil has triggered the onset of asphaltene precipitation. These findings imply that CDEA has a more effective role in preventing asphaltene precipitation. Also, it was observed that increasing the concentration of the surfactants has led to obtaining greater results. Finally, critical micelle concentration was calculated to be 5000 and 4700 ppm in the cases of CDEA and DBSA, respectively.

In this study, the viscosimetry method is used for detection of onset of asphaltene precipitation at HPHT conditions. The results are compared to other common methods (HPHT filtration, high pressure microscopy and light refraction). Five different live field oil samples are examined over a pressure and temperature range of 34.72 MPa to 65.90 MPa and 368.4 K to 408.4 K, respectively. A modified version of the Krieger (1972) equation is proposed and used for calculating the amount of precipitation based on viscosity measurements. The results show that the viscosimetry method is an accurate method for determining asphaltene content of crude oils with a gravity range of 18 to 40 American Petroleum Institute (API) degrees in a vast pressure and temperature range from reservoir to atmospheric conditions. The measured phase separation pressure at constant reservoir temperature for light to heavy oil samples ranged from 42.74 to 24.13 MPa, respectively. [Received: February 8, 2016; Accepted: October 5, 2016]