Tag Archives: асфальтены
The article presents the results of a study of the composition of petroleum bituminous rocks of the Alimbai field located in the Zhylyoi district of the Atyrau oblast to the north-east of the city of Kulsary (Western Kazakhstan). On the territory of the Republic of Kazakhstan, according to experts, reserves of natural bitumen are 1 billion tons, and petroleum bituminous rocks – over 15-20 billion tons.
The purpose of this work was to study the organic components of petroleum bituminous rocks of this field as an additional source of fuel, energy and chemical resources. Samples of oil bituminous rocks of different depths were taken for the study.
As the results of the analysis showed, the yield of the organic part of the investigated deposit ranges from 3.4 to 13.7% by weight. Natural bitumens of the Alimbai deposit are characterized by a content of oils from 57.8% to 71.3% by weight. In connection with the increase in the depth of occurrence of oil bituminous rocks, a decrease in molecular weight from 587 to 476 amu is observed.
It is shown that the content of paraffin-naphthenic and monocycloaromatic hydrocarbons is much higher than that of bi- and polycycloaromatic hydrocarbons.
The distribution of hydrocarbons by fractions shows the predominant content of paraffin-naphthenic hydrocarbons and alcohol-benzene resins with a low content of asphaltenes and benzene resins.
The obtained results show that even within a small thickness of the rock there are processes of migration of organic matter by analogy with secondary oil migration processes.
STUDY OF ADSORPTION AND DESORPTION OF ASPHALTENE-PARAFFIN-RESIN INHIBITOR DEPOSITS IN THE PORE SPACE OF CARBONATE RESERVOIRS
The research of the formation of asphaltene-paraffin-resin deposition (APRD) in the micro pore volume of the reservoir for the study of oil found in microvolume long oil paraffin saturation temperature at 6-9 °C higher than in the void volume. Early transition paraffins in the solid phase leads to complications associated with the formation of APRD, reduces the effectiveness of the use of physical and chemical methods of preventing the formation of APRD dosing of the inhibitor on the bottom of the well. To prevent the formation of paraffin in the oil reservoir authors proposed the use of bottomhole formation zone as a natural inhibitor of the dispenser APRD in oil. Studies on adsorption of the inhibitor on the walls of the breed in its injection into the formation, and subsequent desorption elution inhibitor of the formation of crude oil. Analysis of experimental results has allowed to establish an effective concentration of the inhibitor in paraffin oil during its injection into the bottomhole formation zone, the adsorption of the inhibitor on the walls of rock, as well as the duration of the desorption of the inhibitor from the formation. It was found that the injection of paraffin inhibitor solution in the bottomhole formation zone will reduce the saturation temperature of the paraffin oil in the pore space of the collector.
RESEARCH OF INFLUENCE OF ASPHALTENE-RESIN SUBSTANCES INTO OIL ON THE FORMATION OF ASPHALTENE-PARAFFIN-RESIN DEPOSITION
The completion phase of an oil field development is characterized by increased water cutting of well production, reservoir and bottom-hole pressures decline, growth of high molecular weight (HMW) components content in crude oil. These aspects make field operations more hazardous as they lead to formation of asphaltene-paraffin-resin deposition (APRD) on borehole walls and equipment. The impact of HMW components in crude oil and water-cut on pressure and temperature conditions of APRD and on its rate needs detailed study.
This paper presents some results of the analysis of oil paraffin saturation point depending on asphaltene-resin substances (ARS) content under reservoir conditions. Dependence of the rate of APRD on a cold well walls and resin substances content in oil is studied. The results of experiments with low-resin and high-paraffin crude oil show that asphaltenes and resins in oil dispersion system can result in depressive effects. According to the results, asphaltene-resin substances are natural depressants, making the temperature of paraffin appearance in oil lower, and their properties depend on the base of oil.
The results of the rate of APRD show that sedimentation stability of dry crude oil with increasing of ARS content remains almost stable and does not have any impact on deposition, whereas in experiments with wet crude oil increased ARS content leads to significantly higher deposition.
AN IMPACT ANALYSIS OF A NON-IONIC SURFACTANT ON THE ORGANICS STATE IN AN OIL SAMPLE WHEN MODELLING DOWNHOLE CONDITIONS
In this study a gelation problem in oil disperse systems under downhole conditions which is a cause of oil viscosity anomalies, formations of organic deposits on oilfields, stabilizing of water-in-oil emulsions during the production of water-cut reservoir fluids is set up. The object of the study compliant with the task in hand for estimation of a non-ionic surfactant operating that is a reaction product of unsaturated fatty acids and complex ethylenamines, hydroxy amines (an active base) in an organic solvent is selected.
On the basis of the performed studies conditions of an asphaltene precipitation onset in a live oil sample (an isothermal pressure depletion under reservoir temperature) are determined. Appearance of peptizating effect of the reagent on gel forming oil components (asphaltenes) is confirmed, and also a foundation of an optimal dosage of the inhibitor for prevention of solid organic deposits formation in the downhole conditions are effected by a complex of methods (“capillary technique”, photocolorimetric analysis).
By two independent methods (a method of light scattering and microscopy under high pressure with particle size distribution analysis) effect of pressure on paraffin saturation point in an original oil sample and oil sample with addition of the reagent is estimated. An assumption that with pressure increasing early crystallisation of high-molecular paraffin hydrocarbons at temperature drop is caused by growth of their packaging density and rise of intermolecular interaction energy is made. A conclusion that drop of paraffin saturation point on addition of the examined inhibitor to the live oil sample results from peptization of the asphaltene particles and redistribution of paraffin between multiple crystallization grains is drawn.
All laboratory research were carried out according to the conventional techniques.
THE MOBILE DEVICE DESIGN FOR OIL OPTICAL PROPERTIES MEASURING IN THE PERFORMANCE OF FIELD-GEOLOGIC TASKS
Theoretical and practical basis of oil optical properties was described in the paper. Results of numerous laboratory experiments of density, viscosity, optical density D and coefficient of light absorption Cla of oil probe were analyzed in various oil and gas provinces in the Russian Federation. The brief description of an oil sample photocolorimetry researches procedure was reported. The statistical data processing was conducted that consist in estimation of a mean-square deviation, variance of the deviation and variation coefficient of oil coefficient of light absorption. It fixed up correlative dependency between density and coefficient of light absorption, also between viscosity and coefficient of light absorption.
It showed up description, international and Russian oil ranging, where oil is permeated with a hyperviscosity and an average density. The oil typification in character of density and mean-square deviation of Cla approximation was conducted, 3oil classes were selected with sufficiently high value approximation validity – light (with density ρ<870kg/m3), middle (with density 870<ρ<920kg/m3) and heavy oil (with density ρ>920kg/m3). In character of viscosity and mean-square deviation of Cla approximation 3oil classes were selected with sufficiently high value approximation validity – low-viscosity (with viscosity 1<μ<5mPa·s), over viscosity (with viscosity 5<μ<30mPa·s) and high-viscosity oil (with viscosity μ>30mPa·s).
Came up with the decision to improve of oil optical researches and optical method control of oil field development. The mobile device hook up of automated optical properties measurement and processing of oil on the well mouth was established by oil density, viscosity and coefficient of light absorption that let enhance precision and reliability of optical method field-geological control of oil field development and get reliable field-geological information in real-time.