Oil Recovery System Research Articles

UNINTERRUPTED DELIVERY PARAMETERS BY OIL-FIELD PIPELINES IN WESTERN-SIBERIAN REGION

Background Up to 70 thousand pipeline accidents occur in the fields annually in Russia, 90 % of which are the result of corrosion damage. Of the total number of accidents, 50-55 % are oil recovery systems. 42 % of pipes do not withstand five years of operation, and 17 % - even 2 years. Pipelines of the same grade and diameter with identical microstructure and chemical composition under similar operating conditions differ significantly in terms of trouble-free operation: some work without damage the entire design period, others are destroyed as a result of through corrosion damage much earlier. Field pipelines are quite metal-intensive and technically complex structures, so their corrosion protection is a very urgent problem. Aims and Objectives Let’s consider the problem of pumping oil at a low speed, which results in the release of a corrosive aqueous phase. Results Based on the calculations, it can be concluded that due to an unreasonable speed limit when calculating the hydraulics of oil pipelines, the operating organization mistakenly chooses a larger pipe diameter for capital construction or repair of pipeline sections. This leads to an increase in metal consumption, as a result there is an increase in the cost of the object and construction and installation works. It is recommended to carry out a hydraulic calculation to determine the diameters of pipelines during the overhaul, not in a single variation in existing parameters, but with a statistical analysis of the experience of pipeline failure-free operation under similar characteristics and transportation conditions in this region.

Application of Oil and Gas Recovery, Storage and Condensation System

Gas station; Oil and gas recovery; Storage and condensation; System application

Estimation of a Mechanical Recovery System’s Oil Recovery Capacity by Considering Boom Loss

Ability to estimate the recovery potential of countermeasures is vital in establishing a rational response solution for oil spills at sea. This requires estimation of how much oil can be recovered and the determination of the rational quantities and operating conditions of the response equipment. In this study, a constant loss rate model and a variable loss rate model were developed to estimate the recovery potential of a mechanical oil recovery system, while considering the escape of oil containment booms. The latter model could calculate the speed at which oil loss began to occur and the volume of oil lost. A case study was performed to analyze the significance of oil loss and to calculate changes in recovery potential with respect to adjustable vital variables. The developed model was able to estimate the best operating situation, which optimizes the recovery potential for different response times and environmental conditions.

Assessment of Arundo donax Fibers for Oil Spill Recovery Applications

In the last years, natural fibers are increasingly investigated as an oil recovery system in order to overcome the oil spillage phenomena, thus preserving environment and aquatic life. In particular, lignocellulose-based fibers have recently been employed with promising results. In such a context, the aim of this paper is to assess the oil sorption capability of natural fibers extracted from the stem of the giant reed Arundo donax L., a perennial rhizomatous grass belonging to the Poaceae family that grows naturally all around the world thanks to its ability to tolerate different climatic conditions. Sorption tests in several pollutants and water as a reference were carried out. The fibers have absorption capacities that are about five to six times their weight. Depending on the high absorption kinetics, possible applicative interests can be identified. Eventually, depending on the fiber size, adsorption properties were related to the microstructure and morphology of Arundo donax fibers.

Superhydrophilic, Underwater Directional Oil-Transport Fabrics with a Novel Oil Trapping Function.

In this study, we have prepared a novel superhydrophilic fabric that has underwater directional oil-transport capability. The fabric was prepared using a two-step process consisting of dip-coating of a cross-linkable polymer, which comprises both oleophilic and hydrophilic groups, onto the fabric substrate and single-side UV irradiation of the coated fabric. The fabric had in-air superhydrophilicity on both sides, and it can be wetted easily once immersed in water. The treated fabric showed underwater oleophobicity on the UV-exposed surface, whereas the unexposed back side still maintained underwater oleophilicity. At the optimized condition, the fabric in water transports oil automatically from the UV-exposed to the unexposed back side but stops oil transport in the opposite direction. Such a directional oil transport takes place without the need for oil prewetting or formation of a plastron layer on fabric. The UV irradiation time showed an effect on oil-transport ability. We further showed that the underwater directional oil-transport fabric had a novel "oil trapping" ability. When used to seal a container, the fabric can trap oil into the container, and once trapped, the oil was kept without releasing. This underwater directional oil-transport fabric may be useful for the development of high-efficiency oil recovery systems.

Series and Parallel Strategies of Combined Heating, Power and Oil Recovery for Oilfields in High Water Cut Period

The combination of geothermal power generation and process flow in high water cut oilfields has complementary advantages, which not only saves the high drilling cost of geo-plants, but also recovers a large amount of oil every year. In addition, petroleum-associated water at temperatures above 85 °C can also replace gathering and transportation of oil-fired boilers. The main purposes of this study are to identify the most suitable working fluid for the organic Rankine cycle subsystem and to find out the application scope of the series and parallel strategies. Therefore, taking exergetic efficiency as the objective function, a case study was conducted based on the series of strategies. Results show that the exergetic efficiency is an effective indicator for the working fluid selection, and R601a shows the highest exergetic efficiency for both strategies. Furthermore, the preheater significantly improves the exergetic efficiency and enlarges the applicable scope of the series strategy. Generally speaking, the combined heating, power generating and oil recovery system has many technical and economic advantages and can be utilized in engineering applications.

Wetting Phase Disintegration and Detachment: Three-Dimensional Confocal Imaging of Two-Phase Distributions

Mobilization of a viscous phase by a less viscous fluid occurs often in nature and engineering. In particular, fluid-fluid-solid interfaces emerge in subsurface flow systems for oil recovery, CO${}_{2}$ sequestration, and soil remediation. Interface evolution is further affected when surface-active materials or suspended particles are present. Here three-dimensional observations of immiscible displacement indicate the differences in the mechanisms underlying viscous oil mobilization by nanofluids and by surfactant solutions. A tuned mixture of nanoparticles and surfactants in the displacing fluid effectively controls the wetting phase distribution.

Role of silica Nano particles in altering rheological properties of drilling fluid in Enhanced Oil Recovery

Abstract Numerous methods have been adopted to alter the interfacial tension during the enhanced oil recovery (EOR) system. Much emphasis was given to the conventional methods of EOR because of its ease in operation and understanding. Efforts were made to use surfactants along with Nano particles as they could modify the rheological properties to a great extent with their complexion in the structure and properties. The combination of a cationic polymer (polyacrylamide) (PAM) in the presence of anionic surfactant (sodium dodecyl sulfate) (SDS) with varied concentrations of anionic Nano particle (silicon dioxide) in their complex aqueous solution form is investigated. At a known concentration of polymer and surfactant, the changes in rheological properties of fluid are studied for varied concentrations of silica Nanoparticles. Hydrated and un-hydrated polyacrylamide solutions were subjected to analysis at the well resembling temperature of 90OC, to know the effect of thermal stability of the polymer. It is observed that the fluid viscosity is reduced by two orders of magnitude with the addition of Nano particles, at low shears. However, the fluid showed shear thickening properties due to the complex structure among the polymer, surfactant and particle. The ionic charges interplay leading to the formation of complex structures at the hydrated state of polymer affects the viscosity of the fluid to a great extent.

Blocking Behavior of Organic Solid Phase in the Carbon Dioxide Multiphase and Multicomponent Displacement Process

Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most acknowledged and practical method in enhanced oil recovery system. This is because of its oil sweep efficiency and ability to reduce the level of greenhouse gas emission. Nevertheless, it would lead to the organic solid phase deposition, which causes the changes of the wettability and the damages of wellbores and reservoirs. In this study, we used slim tube test and component test to research the dynamic characteristics of displacement process. In addition, the mechanism of porous media blockage was also investigated. Results show that when the displacement pressure closed to the minimum miscibility pressure, reservoir blockage in pore throat could happen. Component test characterizes that during near miscible displacement process, the components of oil sample varied obviously, the variation range of peak component carbon marks fluctuated strongly. Crude oil component differentiation could happen after carbon dioxide fully contacted with oil. Besides, the rapid extraction mechanism of aromatic hydrocarbons played a significant role in this process under such condition. The reason is that the solubility of saturated hydrocarbons to asphaltene and non-hydrocarbons is obviously weaker than aromatic hydrocarbons. Controlling the pressure is considered as an important link to prevent the occurrence of blocking in the carbon dioxide multiphase and multicomponent displacement process.

Techno-economic analysis of solar-assisted post-combustion carbon capture to a pilot cogeneration system in Mexico

This research evaluates the integration of solar-assisted post-combustion carbon capture into an experimental cogeneration system. A cogeneration system modelled in Thermoflex 25® that includes a 200 kW Capstone microturbine coupled with a thermal oil recovery system was installed at the National Institute of Electricity and Clean Energies (INEEL). Three optimized systems were considered for the economic analysis, namely: a microturbine cogeneration system (COGEN), a microturbine cogeneration system with post-combustion carbon capture plant (COGEN-CCS) and a microturbine cogeneration system with solar-assisted post-combustion carbon capture (COGEN-CCS + SOLAR). The cogeneration system was modelled using Natural Gas (NG) as fuel, applying characteristics typical of Mexico, to obtain the composition of exhaust gas (EG), and thus simulate the CO2 capture system in Aspen Hysys V8.6® using monoethanolamine (MEA) as solvent. Results show that the implementation of CCS results in a sizeable increase in the Levelized Cost Of Electricity (LCOE) (approximately 86%) with near-zero emissions and without the possibility of supplying energy to the process. In addition COGEN-CCS + SOLAR improves overall system performance. CO2 emissions per kilowatt increased by 0.2% with regard to COGEN-CCS, while the LCOE increased by 230% compared to the COGEN case, with near-zero emissions. The use of solar energy would help increase the cogeneration efficiency when coupled with CO2 capture.

Research on the Hydrodynamics of the Mechanism of Viscous-Elastic Fluids Displacing Residual Oil Droplets in Micro Pores

In order to analyze the microscopic stress field acting on residual oil droplets in micro pores, calculate its deformation, and explore the hydrodynamic mechanism of viscous-elastic fluids displacing oil droplets, the viscous-elastic fluid flow equations in micro pores are established by choosing the Upper Convected Maxwell constitutive equation; the numerical solutions of the flow field are obtained by volume control and Alternate Direction Implicit methods. From the above, the velocity field and microscopic stress field; the forces acting on residual oil droplets; the deformations of residual oil droplets by various viscous-elastic displacing fluids and at various Wiesenberg numbers are calculated and analyzed. The result demonstrated that both the normal stress and horizontal force acting on the residual oil droplets by viscous-elastic fluids are much larger compared to that of inelastic fluid; the distribution of normal stress changes abruptly; under the condition of the same pressure gradient in the system under investigation, the ratio of the horizontal forces acting on the residual oil droplets by different displacing fluids (which are water, a power-law fluid with a power law index of 0.6 and a viscous-elastic fluid with a Wiesenberger Number of 0.3 respectively) is about 1:8:20, which means that under the above conditions, the driving force on a oil droplet is 20 times higher for a viscous-elastic fluid compared to that of a Newtonian Fluid. This force must be considered when studying the mechanism of isolated oil droplets mobilization. Furthermore, the viscous-elastic fluids will cause the residual oil droplet to deform much more significantly, beneficial to the mobilization of residual oil droplets. The above results are very beneficial to understanding the mechanism of the mobilization of residual oil droplets by viscous-elastic fluids; the conclusions are supportive of the mechanism that viscous-elastic driving fluids can increase the Displacement Efficiency. This should be of help in designing new chemicals and selecting Enhanced Oil Recovery systems.

Microfluidic devices containing thin rock sections for oil recovery studies

While there has been a shift towards renewable energy sources, oil remains an important source of not only energy but also raw materials. Oil recovery is currently an inefficient process with as much as 50% of the original oil remaining in a field. Improvement of oil recovery techniques requires a model system that is both chemically and physically representative to achieve accurate results. Current large laboratory scale systems use large cores drilled from target rock and large, high-pressure systems to recreate oil recovery systems. The cores and associated equipment required to accurately model oil recovery are expensive and time consuming to obtain and operate. As a result, there has been a continual quest to develop alternative solutions that are faster, less complicated, and less expensive while still providing accurate representation of reservoirs. An alternative to large-scale models are optically transparent two or three-dimensional microfluidic devices. Several examples of microfluidic devices used to study oil recovery processes have been published. Unfortunately, most microfluidic devices require complicated fabrication techniques, inaccurately replicate the reservoir rock surface chemistry and geometry, and are made from materials not representative of surfaces found in oil reservoirs. Herein, the Flow On Rock Device is described as an easy to fabricate microfluidic device that acts as a bridge between fully synthetic microfluidics and large laboratory models due to incorporation of reservoir rock samples directly into the microfluidic device. Results of flooding studies are presented on shale and sandstone models as an example of the potential for this system in studying oil recovery.

Microbial enhanced oil recovery in Baolige Oilfield using an indigenous facultative anaerobic strain Luteimonas huabeiensis sp. nov

A facultative strain Luteimonas huabeiensis sp. nov. HB-2 isolated from Baolige Oilfield of China was examined for its growth, biosurfactant production, hydrocarbon degradation and the effects on interfacial properties of oil recovery system. Specifically, the effects on reduction of fluid surface tension and oil viscosity, and on increase in emulsification activity for crude oil were evaluated. This was attributed to the combination of the strain's activities including the production of biosurfactants (cyclic lipopeptides) and the degradation of crude oil. The produced biosurfactants can effectively reduce the interfacial tension of oil-water and viscosity of crude oil. Meanwhile, the long-chain hydrocarbons (C20-C35) of crude oil also can be degraded by bacteria resulting in the increase in shorter chain (C10-C19). These activities demonstrated the suitability of strain HB-2 for application in microbial enhanced oil recovery (MEOR). This was confirmed by a laboratory-based core column flooding evaluation, showing an average increase of 11% in oil recovery, which was followed by an oilfield test involving two water injection wells and eight oil production wells over 16 months, resulting in a remarkable increase in the average single well oil production from 0.48 ton/day (without MEOR) to 1.77 ton/day with the highest reaching 9.5 ton/day by MEOR.

Homogenization of nonisothermal immiscible incompressible two-phase flow in porous media

In this paper, we consider nonisothermal two-phase flows through heterogeneous porous media with periodic microstructure. Examples of such models appear in gas migration through engineered and geological barriers for a deep repository for radioactive waste, thermally enhanced oil recovery and geothermal systems. The mathematical model is given by a coupled system of two-phase flow equations, and an energy balance equation. The model consists of the usual equations derived from the mass conservation of both fluids along with the Darcy–Muskat and the capillary pressure laws. The problem is written in terms of the phase formulation, i.e. the saturation of one phase, the pressure of the second phase and the temperature are primary unknowns. The major difficulties related to this model are in the nonlinear degenerate structure of the equations, as well as in the coupling in the system. As fluid properties are defined as a function of temperature and pressure, there is a strong coupling between the mass balance and energy balance equations. Under some realistic assumptions on the data, we obtain a nonlinear homogenized coupled system of three coupled partial differential equations with effective coefficients (porosity, permeability, thermal conductivity, heat capacity) which are computed via solving cell problems. We give a rigorous mathematical derivation of the upscaled model by means of the two-scale convergence.

Computational optimal control of 1D colloid transport by solute gradients in dead-end micro-channels

Diffusiophoresis is a common phenomenon that occurs when colloids are placed in the non-uniform solute concentration. It generates solute gradients which force the colloids to transfer toward or away from the higher solute concentration side. In this paper, we consider the input sequence control of the colloid transport in a dead-end micro-channel with a boundary solute concentration being manipulated, which has a wide range of applications such as drug delivery, biology transport, oil recovery system and so on. We model this process by a coupled system, which involves the solute diffusion equation and the colloid transport model. Then an optimal control problem is formulated, in which the goal is to minimize colloid density distribution deviation between the computational one and the target at a pre-specified terminal time. To solve this partial differential equation (PDE) optimal control problem, we first apply the control parameterization method to discretize the boundary control and transfer it into an optimal parameter selection problem. Then, using the variational method, the gradient of the objective function with respect to the decision parameters can be derived, which depends on the solution of the coupled system and the costate system. Based on this, we propose an effective computational method and a gradient-based optimization algorithm to solve the optimal control problem numerically. Finally, we give the simulation results to demonstrate that the objective function based on the proposed method is less nearly two orders of magnitude than that of a constant value control strategy, which well illustrates the effectiveness of the proposed method.

Spatial Distribution Characteristics of NMHCs in Spring in Cangzhou City

Simultaneous collections of non-methane hydrocarbons (NMHCs) were carried out at 15 sampling sites including urban, suburb and potential pollution areas in Cangzhou City in spring 2015. The results showed that NMHCs were generally higher in urban areas than those in suburb and rural areas; the highest concentration of NMHCs was observed at Cangzhou High-tech zone (urban area); the concentrations of NMHCs were significantly lower at rural sites than in most urban sites except Hejian site; vehicular emissions were the main sources of NMHCs in Cangzhou; Cangzhou chemical fertilizer plant and Cangzhou oil refinery had no significant influence on urban NMHCs during their shutdown period; Dagang Oilfield, with better oil and gas recovery systems, did not have a significant impact on urban NMHCs. In general, alkanes, alkenes and aromatics accounted for 65%, 16% and 19% of NMHCs in Cangzhou City, respectively; xylene (19%), ethylene (14%), toluene(11%), propylene (5%), isopentane (5%) and isopentene (5%) were the most dominant contributors to ozone formation potential; aerosol formation potential was mainly derived from toluene (28%), pinene (28%), xylene(16%), ethylbenzene (9%) and benzene (9%).

CO2-Enhanced Oil Recovery System Optimization for Contract-based versus Integrated Operations

CO2-enhanced oil recovery (CO2-EOR), with its incremental hydrocarbon revenue, is considered a more economical approach among potential carbon capture, utilization, and storage (CCUS) strategies. The economic performance of CO2-EOR, however, is critically affected by factors such as associated energy penalty, time-varying CO2 injection requirement for hydrocarbon production, volatile hydrocarbon prices, and the substitution effect of CO2-EOR for gas-EOR for certain producers. As one of the first steps to understand the economic potential of CO2-EOR, this paper presents two CO2-EOR system optimization models corresponding to two regulatory regimes: (1) a contract operator focusing on minimizing the direct cost including energy penalty, and (2) an integrated operator concerned about maximizing broader payoffs including marginal hydrocarbon revenue. We apply the two models to a set of power plants and oil production reservoirs in California and show that the optimal infrastructure networks can be substantial different under different operation schemes. Market regulation is thus one of the influencing factors that shall be considered in the planning of CO2-EOR.

Comparison of carbon balance measuring tools in an enhanced oil recovery project based on the carbon dioxide from the ammonia production process streams

A number of studies addressing the environmental impact of deploying carbon capture utilization and storage are focused on sources of CO2 in the power sector. However, there is a lack of environmental studies on the use of CO2 from process stream within the oil and gas industries. The carbon balance of an enhanced oil recovery project for the specific case of using CO2 process stream of ammonia production from emission factors and regional databases in the Mexican oil and gas sector was assessed. Two independent tools to assess life cycle assessment according to guidelines ISO 14040/14044 were utilized: (i) use of Umberto software to quantify the environmental impact with ReCiPe model midpoint; and, (ii) The American Petroleum Institute method through the use of emissions factor for each source and emission gas of the activity/facility in a spread sheet. The results of the tools were compared and the dissimilarities analysed. The emissions profiles from all direct and indirect activities associated with the enhanced oil recovery system were compared with a “cradle-to-grave” model. The functional unit is one barrel of crude oil extracted and consumed. Global warming as the environmental indicator of both tools was used. Additionally, the energy balance of the project was estimated. The global warming impact of the enhanced oil recovery system was 0.51 tCO2e/barrel (bbl) using the American Petroleum Institute tool, whilst the emissions using Umberto software were 0.54 tCO2e/bbl. Also, for each MJ of energy produced a value of 72 tCO2e/MJ oil and of 66 tCO2e/MJ oil, were obtained. This study demonstrates that both tools delivered an accurate estimation of the greenhouse gas emissions in the enhanced oil recovery system for the oil and gas industries. However, American Petroleum Institute has the advantage that the calculations can be performed ´manually' in a spread sheet using emissions factor adjusted to the facilities and Country. Regarding the results of both tools, this work shows that American Petroleum Institute results have proven to be an efficient tool for practitioners and researchers that intend to analyse the greenhouse gas emission of carbon capture utilization and storage systems to estimate, with accuracy, the global warming impact.

Modeling of the Initial Parameters in the Adjustment of an Oil Recovery Process Control System. Part 2. Determination of Limits on the Vectors of the State Variables and Disturbances*

Constraints on the degree of specification and the statement of models of limits on the vectors of state variables of an oil recovery and intrastratal disturbance process control system are given. The structures of the models are found through a solution of the dual problems of the classical theories of filtration and underground hydrodynamics. The limits on the constraints placed on the vectors of the input and output variables of the control systems are the result of an improvement in the dynamic models of the determination of drill hole dip and direction of existing wells.

Life cycle assessment of carbon capture and utilization from ammonia process in Mexico

Post-combustion CO2 capture (PCC) of flue gas from an ammonia plant (AP) and the environmental performance of the carbon capture utilization (CCU) technology for greenhouse gas (GHG) emissions to an enhanced oil recovery (EOR) system in Mexico was performed as case study. The process simulations (PS) and life cycle assessment (LCA) were used as supporting tools to quantify the CO2 capture and their environmental impacts, respectively. Two scenarios were considered: 1) the AP with its shift and CO2 removal unit and 2) Scenario 1 plus PCC of the flue gas from the AP primary reformer (AP-2CO2) and the global warming (GW) impact. Also, the GW of the whole of a CO2-EOR project, from these two streams of captured CO2, was evaluated. Results show that 372,426 tCO2/year can be PCC from the flue gas of the primary reformer and 480,000 tons/y of capacity from the AP. The energy requirement for solvent regeneration is estimated to be 2.8 MJ/kgCO2 or a GW impact of 0.22 kgCO2e/kgCO2 captured. GW performances are 297.6 kgCO2e emitted/barrel (bbl) for scenario one, and 106.5 kgCO2e emitted/bbl for the second. The net emissions, in scenario one, were 0.52 tCO2e/bbl and 0.33 tCO2e/bbl in scenario two. Based on PS, this study could be used to evaluate the potential of CO2 capture of 4080 t/d of 4 ammonia plants. The integration of PS-LCA to a PCC study allows the applicability as methodological framework for the development of a cluster of projects in which of CO2 could be recycled back to fuel, chemical, petrochemical products or for enhanced oil recovery (EOR). With AP-2CO2, “CO2 emission free” ammonia production could be achieved.