ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 4, pp. 424−427. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © I.K. Ivanova, L.P. Kalacheva, E.Yu. Shits, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 4, pp. 429−432.
OF SYSTEMS AND PROCESSES
Choice of Potentially Effective Solvents of Asphalt–Tar–Parafﬁ n
Deposits on the Basis of Kinetic Parameters
of Their Dissolution
I. K. Ivanova
, L. P. Kalacheva
, and E. Yu. Shits
Institute of Oil and Gas Problem, Siberian Branch, Russian Academy of Sciences,
ul. Oktyabr’skaya 1, Yakutsk, Sakha Republic, 677891 Russia
Ammosov North-Eastern Federal University in Yakutsk, ul. Belinskogo 58, Yakutsk, Sakha Republic, 677980 Russia
Received April 2, 2014
Abstract—Kinetic study of the dissolution of asphalt-tar-parafﬁ n deposits in hexane and hexane–benzene, hexane–
cyclohexane, and hexane–cyclohexane–benzene systems in the temperature range 10–60°C demonstrated that
parafﬁ n-naphthenic solvents are the most effective solvents of parafﬁ n deposits in well operation at the Irelyakh
gas-and-oil ﬁ eld.
Asphalt–tar–parafﬁ n deposits were ﬁ rst described by
J.G. Bonet in 1865. The interest of domestic researchers
in the problem of deposits has not been declining since
the beginning of the mass development of oil ﬁ elds.
Despite the considerable number of publications [1–9],
in-depth summarizing empirical-theoretical materials
on this issue are still scarce. The present aggravation of
oil-gas-extraction problems associated with asphalt-tar-
parafﬁ n deposits has initiated a wide-scale application of
various combined-effect chemical substances to remove
deposits. At the same time, the existing solvent-selection
procedures disregard the chemical nature of various inter-
molecular interactions of the solvent and macromolecular
compounds in oil [10–15].
Because of the complex composition of asphalt-tar-
parafﬁ n deposits, it is necessary, when choosing a solvent,
to take into account not only thermodynamic, but also
kinetic characteristics of the dissolution process [7–9].
The goal of the present study was to develop a pro-
cedure for choosing an effective solvent of deposits on
the basis of kinetic characteristics of model processes in
which asphalt-tar-parafﬁ n deposits are dissolved in vari-
ous hydrocarbon systems in a wide temperature range.
Experiments aimed to study kinetic characteristics of
the dissolution of oilﬁ eld asphalt-tar-parafﬁ n deposits
(Irelyakh gas-and-oil ﬁ eld) in various hydrocarbon sol-
vents were performed at 10 and 25°C, which corresponds
to the seasonal working conditions at this ﬁ eld, and at
higher temperatures (40, 60°C) to determine the general
temperature dependence of the deposit dissolution rate.
Because the deposits under study are of the parafﬁ nic
type , hexane was chosen as the base component of
the dissolving hydrocarbon system. The rate-determining
stages n of the dissolution process, dissolution rate con-
stants k, and the time τ
of 50% dissolution of deposits,
effective activation energies E
of deposit disintegration in
the hydrocarbon systems under study were determined by
the method described in . The adequacy of application
of this method was demonstrated in [18–21].
RESULTS AND DISCUSSION
Asphalt-tar-parafﬁ n deposits are a complex dispersed
system mostly composed of paraffins, tars, and