scholarly journals New information about the mechanism of oil displacement from productive reservoirs using flow control technologies

2020 ◽  
Vol 177 ◽  
pp. 01012
Author(s):  
Rustam Mukhametshin ◽  
Gulnara Kvon

The article is devoted to improving the efficiency of methods application to increase oil recovery of deposits that are at the final stage of development. This stage is characterized by a high degree of waterlogging of reservoirs and extracted products. From a wide range of chemical methods for increasing oil recovery in Russian oil deposits, flow-regulating (flow-deflecting) technologies have become widespread. The article analyzes the results of purposeful use of thickened water for the completion of reserves of already flooded sandstone layers. Experimental studies were performed on two specially created five-point elements in the experimental sections of the Romashkinskoye deposit. To monitor the process of low-viscosity and high-viscosity oil displacement the following methods were used: a) intake, monitoring and production wells, in which the interval of productive horizons are lined with fiberglass pipes; b) method of high-frequency resistivity (technology of "VNIIneftepromgeophysics" Institute). The studies performed in the monitoring mode showed that, along with the increase in reservoir coverage by flooding at the macro level, there is also a displacement of part of the capillary-trapped oil in the already flooded layers’ intervals, that is, at the level of micro-uniformity of the porous medium. The paper concludes on the effectiveness of using flow-regulating technologies in conditions of high water availability of development objects.

Author(s):  
B. A. Suleimanov ◽  
S. J. Rzayeva ◽  
U. T. Akhmedova

Microbial enhanced oil recovery is considered to be one of the most promising methods of stimulating formation, contributing to a higher level of oil production from long-term fields. The injection of bioreagents into a reservoir results in the creation of oil-displacing agents along with a significant amount of gases, mainly carbon dioxide. Earlier, the authors failed to study the preparation of self-gasified biosystems and the implementation of the subcritical region (SR) under reservoir conditions. Gasified systems in the subcritical phase have better oil-displacing properties than nongasified systems. In a heterogeneous porous medium, the filtration profile of gasified liquids in the SR should be more uniform than for a degassed liquid. Based on experimental studies, the superior efficiency of oil displacement by gasified biosystems compared with degassed ones has been demonstrated. The possibility of efficient use of gasified hybrid biopolymer systems has been shown.


2012 ◽  
Vol 268-270 ◽  
pp. 547-550
Author(s):  
Qing Wang Liu ◽  
Xin Wang ◽  
Zhen Zhong Fan ◽  
Jiao Wang ◽  
Rui Gao ◽  
...  

Liaohe oil field block 58 for Huancai, the efficiency of production of thickened oil is low, and the efficiency of displacement is worse, likely to cause other issues. Researching and developing an type of Heavy Oil Viscosity Reducer for exploiting. The high viscosity of W/O emulsion changed into low viscosity O/W emulsion to facilitate recovery, enhanced oil recovery. Through the experiment determine the viscosity properties of Heavy Oil Viscosity Reducer. The oil/water interfacial tension is lower than 0.0031mN•m-1, salt-resisting is good. The efficiency of viscosity reduction is higher than 90%, and also good at 180°C.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Du ◽  
Guicai Zhang ◽  
Jijiang Ge ◽  
Guanghui Li ◽  
Anzhou Feng

Oil viscosity was studied as an important factor for alkaline flooding based on the mechanism of “water drops” flow. Alkaline flooding for two oil samples with different viscosities but similar acid numbers was compared. Besides, series flooding tests for the same oil sample were conducted at different temperatures and permeabilities. The results of flooding tests indicated that a high tertiary oil recovery could be achieved only in the low-permeability (approximately 500 mD) sandpacks for the low-viscosity heavy oil (Zhuangxi, 390 mPa·s); however, the high-viscosity heavy oil (Chenzhuang, 3450 mPa·s) performed well in both the low- and medium-permeability (approximately 1000 mD) sandpacks. In addition, the results of flooding tests for the same oil at different temperatures also indicated that the oil viscosity put a similar effect on alkaline flooding. Therefore, oil with a high-viscosity is favorable for alkaline flooding. The microscopic flooding test indicated that the water drops produced during alkaline flooding for oils with different viscosities differed significantly in their sizes, which might influence the flow behaviors and therefore the sweep efficiencies of alkaline fluids. This study provides an evidence for the feasibility of the development of high-viscosity heavy oil using alkaline flooding.


2020 ◽  
Vol 12 (1) ◽  
pp. 1736-1749
Author(s):  
Jincai Wang ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Li Chen ◽  
Jun Ni ◽  
...  

Abstract After a sandstone oilfield enters the high water-cut period, the viscosity of crude oil has an important influence on remaining oil distribution and waterflooding characteristics under the same factors of, e.g., reservoir quality and development methods. Based on a comprehensive interpretation of the waterflooded layers in new oil wells, physical simulation experiments, and reservoir numerical simulations, we analyzed the waterflooding laws of a high water-cut sandstone reservoir with different oil viscosities in Kazakhstan under the same oil production speed, and we clarified the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The results show that low-viscosity oil reservoirs (1 mPa s) have uniform waterflooding, thick streamlines, small waterflooding areas, and low overall waterflooding degrees because of their homogeneous oil–water viscosities. However, within waterflooded areas, the reservoirs have high oil displacement efficiencies and high waterflooding degrees, and the remaining oil is mainly concentrated in the unwaterflooded areas; therefore, the initial production and water cut in new oil wells vary significantly. High-viscosity oil reservoirs (200 mPa s) have severe waterflooding fingering, large waterflooding areas, and high overall waterflooded degrees because of their high oil–water mobility ratios. However, within waterflooded areas, the reservoirs have low oil displacement efficiencies and low waterflooding degrees, and the remaining oil is mainly concentrated in both the waterflooded areas and the unwaterflooded areas; therefore, the differences in the initial production and water cut of new oil wells are small. Moderate-viscosity oil reservoirs (20 mPa s) are characterized by remaining oil distributions that are somewhere in between those of the former two reservoirs. Therefore, in the high water-cut period, as the viscosity of crude oil increases, the efficiency of waterflooding gradually deteriorates and the remaining oil potential increases. In the later development, it is suggested to implement the local well pattern thickening in the remaining oil enrichment area for reservoirs with low viscosity, whereas a gradual overall well pattern thickening strategy is recommended for whole reservoirs with moderate and high viscosity. The findings of this study can aid better understanding of waterflooding law and the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The research results have important guidance and reference significance for the secondary development of high water-cut sandstone oilfields.


2021 ◽  
Vol 21 (1) ◽  
pp. 28-35
Author(s):  
Stanislav A. Stanislav A. ◽  
◽  
Oleg A. Morozyuk ◽  
Konstantin S. Kosterin ◽  
Semyon P. Podoinitsyn ◽  
...  

As an option for enhancing oil recovery of a high-viscosity Permo-Carboniferous reservoir associated with the Usinskoye field, the use of technology based on technogenic carbon dioxide as an injection agent is considered. In the world practice, several fields are known as close in their parameters to the parameters of the Permo-Carboniferous reservoir, and in which CO2 injection was accepted as successful. Based on this, CO2 injection can potentially be applicable in the conditions of a Permo-Carboniferous reservoir. At present, as a result of the various development technologies implementation, reservoir zones are distinguished, characterized by different thermobaric properties. Depending on reservoir conditions, when displacing oil with gases, various modes of oil displacement can be realized. This article describes the results of studies carried out to study the effect of the concentration of carbon dioxide on the properties of high-viscosity oil in the Permo-Carboniferous Reservoir of the Usinskoye field, as well as the results of filtration experiments on slim models performed to assess the oil displacement regime under various temperature and pressure conditions of the Permo-Carboniferous Reservoir. The study of the influence of CO2 concentration on oil properties was carried out using the standard PVT research technique. The displacement mode was assessed using the slim-tube technique. Based on the performed experiments, it was established that an increase in the concentration of CO2 in high-viscosity oil led to a noticeable change in its properties; for the conditions of a Permo-Carboniferous Reservoir, the most probable mode of oil displacement by carbon dioxide was established. Difficulties associated with the preparation of the CO2-heavy oil system were described separately. Based on a literature review, it was shown that the rate of mixing of oil with carbon dioxide depended on certain conditions.


Georesursy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 103-113 ◽  
Author(s):  
Lyubov K. Altunina ◽  
Vladimir A. Kuvshinov ◽  
Lyubov A. Stasyeva ◽  
Ivan V. Kuvshinov

Physicochemical aspects of enhanced oil recovery (EOR) from heavy high-viscosity deposits, developed in natural mode and combined with thermal methods, using systems based on surface-active substances (surfactants), coordinating solvents and complex compounds are considered, which chemically evolve in situ to acquire colloidal-chemical properties that are optimal for oil displacement. Thermobaric reservoir conditions, interactions with reservoir rock and fluids are the factors causing the chemical evolution of the systems. To enhance oil recovery and intensify the development of high-viscosity deposits, acid oil-displacing systems of prolonged action based on surfactants, inorganic acid adduct and polyatomic alcohol have been created. As a result of experimental studies of acid-base equilibrium in the systems with donor-acceptor interactions – polybasic inorganic acid and polyol, the influence of electrolytes, non-electrolytes and surfactants, the optimal compositions of the systems were selected, as well as concentration ranges of the components in the acid systems. When the initially acid system interacts with the carbonate reservoir to release CO2, the oil viscosity decreases 1.2-2.7 times, the pH of the system rises and this system evolves chemically turning into an alkaline oil-displacing system. As a result it provides effective oil displacement and prolonged reservoir stimulation. The system is compatible with saline reservoir waters, has a low freezing point (minus 20 ÷ minus 60 oC), low interfacial tension at the oil boundary and is applicable in a wide temperature range, from 10 to 200 oC. In 2014-2018 field tests of EOR technologies were successfully carried out to intensify oil production in the test areas of the Permian-Carboniferous deposit of high-viscosity oil in the Usinsk oil field, developed in natural mode and combined with thermal-steam stimulation, using the acid oil-displacing system based on surfactants, coordinating solvents and complex compounds. The pilot tests proved high efficiency of EOR technologies, as far as the oil production rate significantly increased, water cut decreased to intensify the development. The EOR technologies are environmentally safe and technologically effective. Commercial use of the EOR is promising for high-viscosity oil deposits.


Author(s):  
Maksim B. Savchik ◽  
◽  
Daria V. Ganeeva ◽  
Aleksei V. Raspopov ◽  
◽  
...  

Development of the Upper Permian high viscosity oil deposit is expected to involve thermal methods of enhanced oil recovery, in particular, cyclic steam treatment of wells. The simulator used for the deposit modeling is to be capable of computing the change in the rock fluid thermal properties, and of solving the heat and mass transfer equations. The modeling of the cyclic steam treatments used CMG STARS, a numerical simulator with a wide range of applications including modeling of thermal processes. The cyclic steam treatment includes three basic stages, such as the steam injection period, the soak period, and the production period. The number of cycles has been selected by computation on the basis of an optimum well operation. To determine the optimum quantity, computations with 7, 5 and 3 cycles were performed. Another predictive computation was performed for a well operation without cyclic steam treatments. The computations helped to determine the operation scenario with the highest cumulative oil production. During the assessment of the cyclic steam treatment efficiency by using hydrodynamic modeling, we obtained dependencies on a number of geological and physical factors, such as steam dryness fraction, formation thickness, steam injection rate, soaking time. The numerical experiments resulted in conclusions and recommendations concerning the case-by-case approach to selecting optimum parameters of the cyclic steam treatments for each individual well, taking into account the structure and specific features. Factor analysis was used to select the optimum parameters for the cyclic steam treatment of the wells drilled in the Upper Permian deposit of the Usinskoye field. For comparison, three predictive scenarios of the well operation have been computed. Cost-performance indicators of the well operation scenarios in the Upper Permian deposit of the Usinskoye field were evaluated, assuming that the wells will be operated in conditions of the natural recovery drive and multiple cyclic steam treatments, in the baseline and recommended scenarios.


2021 ◽  
pp. 136-146
Author(s):  
V. V. Kozlov ◽  
L. K. Altunina ◽  
L. A. Stasyeva ◽  
U. V. Chernova ◽  
M. R. Sholidodov

The development of deposits of hard-to-recover reserves, including heavy and high-viscosity oil, dictates the need to search for new and improve existing enhanced oil recovery methods. One of the well-known methods of increasing oil recovery is the use of reservoir treatments with chemical compositions containing surfactants. A new multifunctional chemical oil-displacing composition (MFC) capable of operating in a wide temperature range has been created at the Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences. The oil-displacing composition of MFC based on a surfactant, an adduct of inorganic acid, polyol, ammonium and aluminum salts, and urea is designed to increase the oil recovery of fields at both early and late stages of development.The article presents the results of laboratory tests of the developed MFC for enhanced oil recovery. Experiments were carried out on the setup to study the filtration characteristics of models of heterogeneous formation.As a result of experiments, it was found that the use of the MFC composition leads to a significant increase in the oil displacement coefficient at both low and high temperatures. The high oil-displacing capacity of MFC at low temperature is caused by the interaction of inorganic acid and polyol, which are part of the composition, with the formation of a strong acid that reacts with the carbonate rock of the reservoir. At high temperature, due to the processes of hydrolysis of urea and aluminum salt, MFC evolves into an alkaline composition with the formation of an alkaline buffer system (pH = 9), which is optimal for oil displacement purposes.


2020 ◽  
Vol 15 (3-4) ◽  
pp. 208-211
Author(s):  
A.D. Nizamova ◽  
Valiev A.A. Valiev

Unstable displacement of immiscible liquids in a plane channel is a topical research in both theoretical and practical applications. In this paper, we consider a plane channel filled with an incompressible fluid. Over time, another fluid is injected into the channel. The fluids are immiscible. The paper builds a mathematical model of the process of oil displacement by water in a plane channel, which allows further numerical studies and comparison of the results with the obtained experimental data using the example of the Hele-Show cell. The mathematical model for a multiphase, multicomponent flow consists of the Navier-Stokes equations, the equations of conservation of mass, momentum and energy. Modern methods for modeling the dynamics of "viscous fingers“ are based mainly on numerical methods for solving systems of differential equations using the pressure gradient, viscosity and capillary forces as parameters. The influence of these parameters must be determined experimentally. To solve the problem, a quasi-hydrodynamic approach is used, based on the addition of a certain small parameter and allowing one to describe stable schemes with central differences. The complexity of solving such problems lies in the size of the considered models, which in practice have a wide range of applications from micro-scale to orders of one centimeter. A comprehensive study will allow us to evaluate and analyze the entire process as a whole, as well as to establish flow parameters to improve the efficiency of displacement and increase oil recovery, since in the numerical modeling of the process it is easier to create many independent experiments with the same initial data, in contrast to the experimental study.


Sign in / Sign up

Export Citation Format

Share Document