В работе осуществлено физическое моделирование вытеснения сверхвязкой нефти из пористой среды. Исследован вариант циклических закачек композиционного растворителя. В качестве базового растворителя использован побочный продукт процесса каталитического риформинга, состав которого представлен в основном легкими насыщенными углеводородами. Осуществлен подбор ингибитора выпадения асфальтенов и минимальной доли в составе вытесняющего растворителя. Оценено влияние нефтенасыщенности, водонасыщенности и времени выдерживания растворителя в модели пласта на скорость вытеснения нефти и величину конечного нефтеизвлечения In this paper, a physical simulation of the displacement of extra-viscous oil from a porous medium was carried out. The variant of cyclic injection of composite solvent was investigated. As a base solvent, a byproduct of a catalytic reforming process was used, the composition of which is represented mainly by light saturated hydrocarbons. An inhibitor of asphaltene precipitation and a minimum fraction in the composition of the displacing solvent was selected. The effect of oil saturation, water saturation, and solvent holding time in the reservoir model on the oil displacement rate and the final oil recovery value is estimated

В настоящее время в Канаде в двух пилотных проектах N-Solv и CSP (Cyclic Solvent Process) осуществляется оценка возможности использования чистого углеводородного растворителя для добычи СВН. По мнению зарубежных специалистов, несомненную важность приобретают вопросы создания адекватных моделей процессов нефтевытеснения при использовании растворителя. В случае использования в качестве растворителей легких алкановых углеводородов необходимы данные об объемах осаждающихся асфальтенов в нефтенасыщенном пласте. С целью выявления особенностей дестабилизирующего влияния легких алканов нефтяных дисперсных систем использованы образцы двух тяжелых нефтей Ашальчинского и Мордово-Кармальского месторождений. В зоне первичного контакта тяжелой нефти (ТН) с растворителем возможны локально высокие соотношения алкан/нефть, что вызовет нежелательные процессы коллоидной дестабилизации с образованием асфальтеновых отложений в пласте. В результате проведенных исследований выявлено, что при соотношении н -пентан/ТН 6:1, 5:1, 4:1 и 3:1 происходит разделение ТН с образованием жидких фаз - легкой фазы в виде раствора и тяжелой малоподвижной фазы в количестве 70-80 % и 20-30 %, соответственно. Показано влияние основных дестабилизирующих факторов для коллоидной устойчивости ТН при контакте с алканами - в тяжелой фазе отмечается пониженное содержание ароматических углеводородов и смол относительно асфальтенов, а для самих асфальтенов тяжелой фазы характерны повышенная ароматичность и пониженная алифатичность. Поэтому для снижения негативных последствий коллоидной дестабилизации в процессах ТН с использованием легкокипящих алканов необходимо введение в состав растворителя специальных добавок-стабилизаторов, которые по отношению к асфальтенам проявляют свойства растворителя или пептизирующего агента. Currently in Canada are underway two pilot projects, N-Solv and CSP (Cyclic Solvent Process), aiming to assess practicability of hydrocarbon solvent for heavy oil production. In this connection, realistic models of heavy oil displacement using hydrocarbon solvents are in demand. In case light alkane hydrocarbons are used as solvents, data about how much asphaltenes bridge across the face of formation are needed. To determine destabilizing effect of light alkanes, two heavy oil samples from the Ashalchinskoye and Mordovo-Karmalskoye fields were used. In the zone of initial interaction between heavy oil and solvent are likely high local alkane/oil ratios resulting in undesirable colloidal destabilization leading to asphaltenes deposition on the formation face. It was found that at n -pentane/heavy oil ratios of 6:1, 5:1, 4:1, and 3:1, heavy oil is segregated into a mobile light phase (70-80 %) and a heavy low-mobile phase (20-30 %). Effect of basic factors affecting colloidal stability of heavy oil upon interaction with alkanes was shown: the heavy phase is characterized by decreased content of aromatics and resins relative to the asphaltenes, while the heavy phase’s asphaltenes are characterized by increased content of aromatic and decreased content of unsaturated hydrocarbons. To control colloidal destabilization in heavy oil displacement processes using low-boiling alkanes, the solvent system must include stabilizing agents, which show dissolving or peptizating properties relative to the asphaltenes.

This paper addresses the problem of asphaltene deposition during oil displacement by n-alkanes. To solve this problem, an experimental modeling of physical and chemical effects of hydrocarbon solvents in oil-saturated reservoir model using a laboratory setting. The purpose was to create a model of oil displacement in the laboratory to determine the optimal number of different inhibitors of asphaltene precipitation. As a result, it was determined that for heavy oil of Tatarstan benzene resins as inhibitors of the effectiveness is not much different from the expensive synthetic products.

This paper addresses the problem of asphaltene deposition during oil displacement by n-alkanes. To solve this problem, an experimental modeling of physical and chemical effects of hydrocarbon solvents in oil-saturated reservoir model using a laboratory setting. The purpose was to create a model of oil displacement in the laboratory to determine the optimal number of different inhibitors of asphaltene precipitation. As a result, it was determined that for heavy oil of Tatarstan de-asphalted oil is effective enough stabilizer of asphaltene precipitation is not conceding ecologically dangerous aromatic hydrocarbons and petroleum resins as inhibitors of the effectiveness is not much different from the expensive synthetic products.

The study is aimed to investigate stability of heavy oil from Ashalchinskoye and Mordovo-Karmalskoye fields in regards to asphaltene precipitation. Microscopic observations intensity asphaltene precipitation by adding n-heptane to the oils were used. The asphaltene stability was investigated based on the optical density versus time of asphaltene toluene/n-heptane solutions by spectrophotometry SARA analysis, gas-liquid chromatography and FTIR spectroscopy were used to characterize the heavy oils components.

The comparative analysis of structure and properties of petroleum asphalte-nes and products of their interaction with sulfuric acid is carried out. Paramagnetic characteristics, structurally-group and element composition of heavy oil asphaltenes Zjuzeevsky, Mordovo-Karmalsky and Ashalchinsky oilfield are investigated. It is es-tablished that in products of interaction oil asphaltenes with sulfuric acid the mainte-nance of free stable radicals increases and the share aliphatic structures concerning aromatic decreases that testifies to their consolidation.

The acid extraction of porphyrins from resins and asphaltenes of heavy crude with high vanadium concentration was conducted. The contrastive analysis of porphyrin fractions received after separation of resins and asphaltenes extracts detected the presence of DFEP, rodo, ethioand phyllo porphyrins in asphaltenes, but resins has only ethioand phyllotypes. No more than 60% of porphyrins from potential content were extracted from asphaltenes, while resins give practically 100% porphyrins extraction ratio.

The major factors, controlling primary preparation of heavy and high emulsified crude oil, are given. At analysis of the gathering system and optimization of the presenting demulsifier in the first place necessary to reveal the bore holes, gaining high stable crude oil and water emulsion, which does not decay in process steady-state sediment by itself.