Title: Detection of solid asphaltene phase separation via viscosity monitoring at high pressure high temperature conditions

Authors: Mahdi Zeinali Hasanvand; Farzaneh Feyzi; Reza Mosayebi Behbahani; Seyed Ali Mousavi Dehghani

Addresses: Thermodynamics Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology, Tehran 16846-13114, Iran; Chemical Engineering Department, Ahwaz Petroleum Engineering Faculty, Petroleum University of Technology, Ahwaz, 61118-63146, Iran ' Thermodynamics Research Laboratory, School of Chemical Engineering, Iran University of Science and Technology, Tehran 16846-13114, Iran ' Chemical Engineering Department, Ahwaz Petroleum Engineering Faculty, Petroleum University of Technology, Ahwaz, 61118-63146, Iran ' Petroleum Exploration and Production Section, Research Institute of Petroleum Industry, Tehran, 14857-33111, Iran

Abstract: 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]

Keywords: asphaltene precipitation; viscosimetry; high pressure high temperature filtration; high pressure microscopy; HPM; light refraction.

DOI: 10.1504/IJOGCT.2018.095986

International Journal of Oil, Gas and Coal Technology, 2018 Vol.19 No.4, pp.458 - 476

Received: 08 Feb 2016
Accepted: 05 Oct 2016
Published online: 06 Nov 2018 *

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