Tag Archives: парафины
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.