Steam Injection Research Articles

Effect of dipotassium phosphate and heat on milk protein beverage viscosity and color

Our objective was to determine the effect of addition of dipotassium phosphate (DKP) at 3 different thermal treatments on color, viscosity, and sensory properties of 7.5% milk protein-based beverages during 15 d of storage at 4°C. Micellar casein concentrate (MCC) and milk protein concentrate (MPC) containing about 7.5% protein were produced from pasteurized skim milk using a 3×, 3-stage ceramic microfiltration process and a 3×, 3-stage polymeric ultrafiltration membrane process, respectively. The MCC and MPC were each split into 6 batches, based on thermal process and addition of DKP. The 6 batches were no postfiltration heat treatment with added DKP (0.15%), no postfiltration heat without added DKP (0%), postfiltration high-temperature, short time (HTST) with DKP, postfiltration HTST without DKP, postfiltration direct steam injection with DKP, and postfiltration direct steam injection without DKP. The 6 MCC milk-based beverages and the 6 MPC milk-based beverages were stored at 4°C. Viscosity, color, and sensory properties were determined over 15 d of refrigerated storage. MCC- and MPC-based beverages at 7.5% protein with and without 0.15% added dipotassium phosphate were successfully run through an HTST and direct steam injection thermal process. The 7.5% protein MCC-based beverage contained a higher calcium and phosphorus content (2,425 and 1,583 mg/L, respectively) than the 7.5% protein MPC-based beverages (2,141 and 1,338 mg/L, respectively). Pasteurization (HTST) had very little effect on beverage particle size distribution, whereas direct steam injection thermal processing produced protein aggregates with medians in the range of 10 and 175 μm for MPC beverages. A population of casein micelles at about 0.15 μm was found in both MCC- and MPC-based beverages. Larger particles in the 175-μm range were not detected in the MCC beverages. In general, the apparent viscosity (AV) of MCC beverages was higher than MPC beverages. Added DKP increased the AV of both MCC- and MPC-based beverages, while increasing heat treatment decreased AV. The AV of beverages with DKP increased during 15 d of 4°C of storage for both MCC and MPC, whereas there was very little change in AV during storage without DKP and a similar effect was observed for sensory viscosity scores. The L value of beverages was higher with higher heat treatment, but DKP addition decreased L value and sensory opacity greatly. Sulfur-eggy flavors were detected in MPC beverages, but not MCC-based beverages.

Improving Ecological Efficiency of Gas Turbine Power System by Combusting Hydrogen and Hydrogen-Natural Gas Mixtures

Currently, the issue of creating decarbonized energy systems in various spheres of life is acute. Therefore, for gas turbine power systems including hybrid power plants with fuel cells, it is relevant to transfer the existing engines to pure hydrogen or mixtures of hydrogen with natural gas. However, significant problems arise associated with the possibility of the appearance of flashback zones and acoustic instability of combustion, an increase in the temperature of the walls of the flame tubes, and an increase in the emission of nitrogen oxides, in some cases. This work is devoted to improving the efficiency of gas turbine power systems by combusting pure hydrogen and mixtures of natural gas with hydrogen. The organization of working processes in the premixed combustion chamber and the combustion chamber with a sequential injection of ecological and energy steam for the “Aquarius” type power plant is considered. The conducted studies of the basic aerodynamic and energy parameters of a gas turbine combustor working on hydrogen-containing gases are based on solving the equations of conservation and transfer in a multicomponent reacting system. A four-stage chemical scheme for the burning of a mixture of natural gas and hydrogen was used, which allows for the rational parameters of environmentally friendly fuel burning devices to be calculated. The premixed combustion chamber can only be recommended for operations on mixtures of natural gas with hydrogen, with a hydrogen content not exceeding 20% (by volume). An increase in the content of hydrogen leads to the appearance of flashback zones and fuel combustion inside the channels of the swirlers. For the combustion chamber of the combined-cycle power plant “Vodoley”, when operating on pure hydrogen, the formation of flame flashback zones does not occur.

Effect of calcination temperature on the attrition and activity of CuO/NiO/olivine for producing syngas in biomass chemical looping gasification

An oxygen carrier (OC), with a long lifetime and better reactivity, has become the key to the biomass chemical looping gasification (BCLG) process. In this study, CuO and NiO supported on olivine (Cu/Ni/O) was prepared at different temperatures (900–1300 °C). Various characterizations including XRD, SEM, BET, H2-TPR, TG and TG-FTIR were used to investigate the effect of calcination temperature on the composition, morphology, multiple redox, oxygen carrying capacity and activity of the resultant OCs. And the BCLG experiments were conducted in a micro fluidized bed reactor (MFBR) to examine the performance of OCs. The results showed that CuFe2O4 and NiFe2O4 phases were observed after CuO and NiO were loaded onto peridot. The increase of calcination temperature results in the decrease of surface area and oxygen-carrying capacity of the OC to 1.305 m2/g and 1.93 wt% at 1300 °C from 4.760 m2/g and 3.60 wt% at 900 °C. The final weight loss of OCs with cotton stalk (CS) showed the same variation trend as that of redox process of OCs. However, the anti-resistance of the OC was greatly improved, especially the 1100-Cu/Ni/O calcinated at 1100 °C showed better anti-resistance with the attrition rate of 0.09 wt% and pulverization rate of 0.41 wt%. Under the optimal operating conditions (mass ratio of OC to biomass = 30:1, steam injection rate = 0.05 g/min and temperature = 800 °C), the highest gasification efficiency of 59.2 % and syngas yield of 0.71 Nm3/kg were obtained over 1100-Cu/Ni/O. The cyclic experiments demonstrated better anti-sintering and cyclic performances of 1100-Cu/Ni/O, which made it very attractive for the BCLG.

Effect of Direct Steam Injection and Instantaneous Ultra-High-Temperature (DSI-IUHT) Sterilization on the Physicochemical Quality and Volatile Flavor Components of Milk.

The effects of variations in the heat treatment process of milk on its quality and flavor are inevitable. This study investigated the effect of direct steam injection and instantaneous ultra-high-temperature (DSI-IUHT, 143 °C, 1-2 s) sterilization on the physicochemical properties, whey protein denaturation (WPD) rate, and volatile compounds (VCs) of milk. The experiment compared raw milk as a control with high-temperature short-time (HTST, 75 °C 15 s and 85 °C 15 s) pasteurization and indirect ultra-high-temperature (IND-UHT, 143 °C, 3-4 s) sterilization. The results showed no significant differences (p > 0.05) in physical stability between milk samples with different heat treatments. The DSI-IUHT and IND-UHT milks presented smaller particle sizes (p < 0.05) and more concentrated distributions than the HTST milk. The apparent viscosity of the DSI-IUHT milk was significantly higher than the other samples (p < 0.05) and is consistent with the microrheological results. The WPD of DSI-IUHT milk was 27.52% lower than that of IND-UHT milk. Solid-phase microextraction (SPME) and solvent-assisted flavor evaporation (SAFE) were combined with the WPD rates to analyze the VCs, which were positively correlated with ketones, acids, and esters and negatively associated with alcohols, heterocycles, sulfur, and aldehydes. The DSI-IUHT samples exhibited a higher similarity to raw and HTST milk than the IND-UHT samples. In summary, DSI-IUHT was more successful in preserving the milk's quality due to its milder sterilization conditions compared to IND-UHT. This study provides excellent reference data for the application of DSI-IUHT treatment in milk processing.

Parallel particle swarm optimization for optimal SAGD operating scenario and well placement in a high dimensional search space

Steam-assisted gravity drainage (SAGD) has been commercially tested successfully in many oilfields with different characteristics. The operational parameters and wells’ location substantially affect the performance of SAGD, and designing a scenario optimization to find the optimum values of these parameters would enhance the efficiency of the process. Although most previous studies worked on optimizing some of the mentioned parameters separately, barely any optimized them simultaneously using a full 3D model since optimizing such a high-dimensional problem is time-consuming. In this study, whole-time scenario optimization is designed to simultaneously optimize the operational (steam injection rate, temperature, and production bottom hole pressure of all intervals) and well placement parameters of an 8-year SAGD. Parallel particle swarm optimization (PSO) is developed to determine the desired number of simulations concurrently to reduce computational costs. Also, the SAGD time is divided into four time intervals, and the effect of uniform and non-uniform time intervals on the net present value (NPV) and oil production is investigated. The outcomes showed that conducting parallel PSO would reduce the optimization time by 79.8%. Also, by applying the non-uniform intervals, the highest NPV is achieved, and the SAGD time declines to 6 years.

Carbon Dioxide Huff and Puff as Environmentally Friendly Method for Enhanced Heavy Oil Recovery

Heavy oil and bitumen are making up approximately 70 percent of the remaining estimated hydrocarbon reserves. Many Enhanced Oil Recovery (EOR) methods such as chemical flooding, thermal recovery, gas injection, etc., were developed to make advances in the production of unconventional oil. Among all the variety of EOR methods, thermal recovery produces practically all of the heavy oil and bitumen among the various EOR methods. But at the same time, throughout its application, there are several disadvantages were revealed such as it is an expensive and not environmentally friendly process, heat loss in surface facilities and distribution lines, the efficiency is low after injection, increases in the extracted oil’s surface viscosity have caused polymerization reactions of free radicals created during the steam injection process, and the requirement for continuous steam injection is attempting to keep a hot oil-water interface at the front of the flow. For these reasons, the solvent-based non-thermal recovery method can be used to enhance heavy oil and bitumen recovery in unconventional reservoirs (thin or deep reservoirs) to prevent or reduce unwanted effects as described above. Toluene, carbon dioxide (CO2), ethane, propane, normal butane, and mixture solvents, among others, can be used as the injection solvent for the solvent-based non-thermal recovery method. That is why the researchers have concentrated on carbon dioxide as a solvent with Huff & Puff method to develop the production of heavy oil and bitumen to overcome all these negative issues because CO2 has several characteristics that make it an excellent option for this application. In this paper, the CO2 Huff and Puff method is reviewed. The CO2 Huff and Puff method’s viscosity reduction and oil swelling procedures have been the most significant factors in increasing heavy oil production. As a results, impacts of oil swelling at various temperatures and pressures as well as the viscosity reduction ratio with CO2 injection have been studied.

Environmentally Friendly Method for Enhanced Heavy Oil Recovery by In-Situ Upgrading Process Based on Catalytic Steam Injection

Any crude oil with an API gravity below 20 is considered heavy crude, and crude oil with an API gravity below 10 is considered extremely heavy. Conventional oil is lighter and less dense than unconventional oil resources such as heavy oil, extra-heavy oil, and bitumen. When the world’s conventional crude oil stocks are depleted, heavy oil resources will be well-positioned to continue satisfying demand for petroleum products. The economic viability of heavy oil depends on its quality being increased. The use of a catalytic steam injection in-situ upgrading technique to improve heavy oil recovery is discussed here. Previous research has shown that in-situ upgrading has a high catalytic ability to upgrade heavy crude oil by decreasing viscosity, increasing the amount of saturates (obviously low carbon number alkanes), and causing the thermal decomposition of high molecular weight substances such as asphaltenes and resin. There may be advantages to in-situ upgrading over more traditional methods of surface upgrading.

Reactivity and performance of steam gasification during biomass batch feeding

The steam gasification characteristics of poplar sawdust were investigated in a piston fed fixed-bed gasifier, reflecting the batch feeding process of fixed-bed gasifiers in industrial applications. The effects of operating conditions, including steam supply, the flow rate of inert gas, gasification temperature, and feeding rate, on gasification reactivity and performance were investigated online. The major gas product during pyrolysis was CO, followed by H2, CH4, and CO2, and the gasification was greatly facilitated by the injection of steam to generate H2. The gasification reactivity and performance were improved with increased steam supply and temperature. The maximum production rate of H2 by char gasification was tripled and doubled, respectively, with an increase in steam supply from 50 to 400 mL/min and a temperature rise from 800 to 900 °C, and the time required for complete gasification was also halved. Compared to pyrolysis, the volume fraction of H2 increased from 23% to 37%, and correspondingly, the H2/CO ratio increased from 0.42 to 0.95.

Analysis and Preliminary Design of Primary Heat Exchanger Failure Testing Facility for Lead-Cooled Fast Reactors

This paper presents an assessment aimed at evaluating primary heat exchanger (PHE) failure of the Westinghouse Electric Company Lead-cooled Fast Reactor (LFR) and at designing a facility for testing phenomena involved in such failure. The system thermal-hydraulic code RELAP5/MOD3.3 was used to develop a transient analysis simulation at reactor scale. Because of RELAP5/MOD3.3’s inability to mix working fluids, the steam injection effect was evaluated using the SIMMER-III code. The limits and strengths of both codes are highlighted throughout the paper. The reactor-scale steady-state results are in good agreement with the nominal operating condition. The transient results show that lead pool surface level variation and primary system pressurization during the PHE failure event are limited. The PHE failure testing facility was characterized, and a preliminary layout was developed. A separate-effects transient inside the vessel was analyzed with SIMMER-III and RELAP5/MOD3.3 runs. The simulation outcomes have provided useful data to inform subsequent design stages for the test facility. Different configurations of the facility have been assessed, highlighting the strengths and weaknesses of each design. The most important issue was identified to be lead pool swelling, reaching the vessel’s lid and blocking the pressure relief vent. This poses a safety hazard that must be addressed and has been raised for resolution in subsequent design stages. The so-called V4 configuration is suggested as a starting point for further improvement of the facility. Furthermore, a smaller failure opening and lower lead level in the vessel are suggested.

Numerical simulation of steam flooding in offshore heavy oil reservoir after water flooding

Steam flooding is an effective method to enhance oil recovery in heavy oil reservoirs. However, the influence factors of steam flooding will affect the development of heavy oil reservoir after the traditional water flooding. So the dynamic prediction of steam flooding needs to be performed before the development scheme is implemented. In this study, the 3D reservoir model was established by the reservoir numerical simulation software CMG; Combined with operating parameters of oilfield, the influence of steam temperature, steam injection timing and steam quality on the development effect of L7 block in offshore heavy oil reservoir was studied by using 3D reservoir model. The results show that compared with traditional water flooding, steam flooding has better development effect, and the cumulative oil production can reach 100.673 × 104m3; With the increase of steam temperature and steam quality, the cumulative oil production, incremental oil production and heat efficiency have an increasing trend; This result also suggests that the development method of higher steam temperature and steam quality conforms to the principle of economic development; For steam injection timing, the earlier the steam injection is more conducive to better development results.

TECHNOLOGY EFFICIENCY IN-SITU COMBUSTION AT THE KARAZHANBAS DEPOSIT

The evaluation of the effectiveness of the development of the Northern section of the I object of the Karazhanbas field by injecting a coolant into the reservoir is considered. To intensify oil production in hard-to-recover reserves of the field, thermal methods are considered, such as the use of hot water and steam as an injection agent into the productive reservoir, the creation of a combustion front or a high-temperature zone in the reservoir. Considering the development trend of the northern territory of the Karazhanbas field, it was found that reservoir energy is depleted, reservoir oil properties change, becoming more viscous, resulting in a rapid decrease in production rate and pressure drop, with an increase in water cut. Modeling the application of in situ combustion technology (ICG) is of practical importance in the conditions of the Karazhanbas field and will improve the efficiency of using technically possible heat carriers. An analysis of the development of the Karazhanbas field is presented, as well as the dynamics of the current and accumulated compensation for withdrawals by injection in the Northern area in recent years of development. The analysis of the presented indicators made it possible to conclude that with a decrease in the volume of steam injection into the reservoir, for the uniformity of oil production, it is necessary to consider the technology of using in-situ combustion in this area. The substantiation of the numerical method is given, which makes it possible to represent the formation of fields of pressure, temperature, saturation (oil, water and gas), concentrations of components (oxygen, water vapor and inert gas) when using in-situ combustion. Based on the qualitative behavior of the constructed dependences, one can trace the dynamics of the formation and evolution of zones characteristic of the process of in-situ combustion and draw a conclusion about the implementation of in-situ combustion in the Karazhanbas field.

Enhanced Oil Recovery

Abstract: Enhanced oil recovery procedures, which are part of improved oil recovery, are used to recover the leftover oil include Steam injection, Polymer flooding, Gas injection and Water injection. Only a small percentage of the total hydrocarbons in the reservoir can be recovered using standard oil recovery technologies. Even if normal recovery procedures are implemented, almost 2 trillion barrels of conventional oil and 5 trillion barrels of heavy oil will remain in reservoirs around the world. Many factors, both economic and technological, influence the strategy chosen and the projected recovery. The study evaluates the EOR approaches that are currently in use in the field. The current EOR technologies are put into context, with the technical reasons for their failure highlighted. Recovering additional oil is difficult and expensive, and it has only been done successfully in a few cases under strict conditions. Despite this, EOR will continue to play a significant role in oil production due to rising energy demand and constrained supply. It is estimated that a significant amount of research is required to develop new technologies for recovering almost two-thirds of the oil that remains unrecoverable in the reservoir. New methods of enhanced oil recovery improves the efficiency of existing processes and reduce demand for new reserves in the longer term. This paper represents the new technologies evolved in the petroleum industry for Enhanced oil recovery.

Current Status and Development Direction of Low-Carbon Exploitation Technology for Heavy Oil

With the strategic goal of “carbon peaking and carbon neutral” in China, new requirements are also put forward for the thermal recovery of heavy oil. In view of the problems of excessive greenhouse gas emission, low steam utilization rate, poor economic efficiency, and limited reservoir application of steam stimulation replacement technology in China, the emerging technologies of medium- and low-temperature thermal fluid, solvent-assisted high-temperature steam injection, solvent-based medium- and low-temperature waterless recovery and in situ electric heating-assisted recovery are discussed in terms of technical principles, technical parameters, experimental/field effects, and technical and economic potential. The technical principles, technical parameters, experimental/field results, and techno-economic potential of low-carbon heavy oil recovery technologies are summarized and future development directions and trends are anticipated. The study’s findings indicate that some of the technologies that have been tested in the field, such as HWVP, EMVAPEX, AH-VAPEX, LASER, and ESEIEH, can be developed by relying on the original well groups for production and can reduce greenhouse gas emissions, such as CO2, by about 80% and improve crude oil recovery by 5% to 10%, while the technologies concerned have outstanding effects on increasing oil production rate and lowering upfront capital investment. Some of the technologies that have been tested significantly increase oil production rate, lower initial capital expenditure, and enable solvent recycling, among other things. Among them, COBEEOR and N-SOLV technologies can also lower the amount of asphaltene in the output crude oil, enhance the API of the recovered crude oil, and provide strong economic advantages. CSP, CHSI, and hot water solvent injection were tested in indoor two-dimensional and three-dimensional experiments to validate their feasibility, while CO2, propane, and butane solvents were initially screened and some of the technologies’ mechanisms were revealed to lay the groundwork for pilot projects. The executive summary of the research findings will serve as a guide for future low-carbon extraction technology research and development in China.

Mechanism study of nano-laponite modified by low molecular alkylamine to reinforce the stability of high-temperature foam

The stability of high-temperature foam is crucial to mobility control in steam injection for enhanced heavy oil recovery. In this study, nano-laponite was modified by low molecular alkylamine with different chain lengths to reinforce the stability of high-temperature foam. It is found that the addition of nano-laponite modified by n-hexylamine can greatly improve the foam stability under high temperature conditions. There is an optimal concentration of n-hexylamine for the modification of nano-laponite to ensure the foam stability reaches the highest. The zeta potential and contact angle measurements indicate that hydrophilic nano-laponite can be changed to intermediate hydrophobic and causing slightly aggregation of the modified nano-laponite, which results in significant increase of bulk viscosity and interfacial dilational modulus. The laser-induced confocal microscopy observations confirm that the modified nano-laponite with optimal hydrophobicity adsorbed at the gas-liquid interface can greatly increase the mechanical rigidity of the liquid film to inhibit the bubbles coalescence and disproportionation. Moreover, the modified nano-laponite formed a three-dimensional network structure between the bubbles can increase the viscosity and structural strength of liquid film to slow down the liquid drainage and bubbles coalescence, and thus significantly improving the foam stability under high temperature conditions.

Simulation of jets induced by steam injection through multi-hole sparger using effective heat and momentum models

Direct contact condensation (DCC) of steam in the pressure suppression pool (PSP) is used to control containment pressure in Boiling Water Reactors (BWRs) and Advanced Pressurized Water Reactors (APWRs). The competition between momentum and heat sources induced by steam injection through multi-hole spargers and blowdown pipes determines whether the pool is thermally stratified or mixed. Development of thermal stratification affects capacity of the PSP to condense steam. To enable computationally efficient modeling of the PSP transients, the Effective Heat Source (EHS) and Effective Momentum Source (EMS) models have been proposed previously. The EHS/EMS models enable simulation of the large scale pool behavior without explicit modeling of the steam water interface and DCC phenomena. One of the problems for an optimal implementation of the EHS/EMS models is the definition of the boundary conditions that impose distribution of the momentum and heat sources. In this work, EHS/EMS models are implemented using “Unit Cell” approach in ANSYS Fluent to provide detailed numerical analysis of the individual turbulent jets induced by steam injection through the sparger holes. The model is validated against data from Particle Image Velocimetry (PIV) and temperature measurements for a range of steam injection conditions in the PANDA HP5 tests. Good agreement between the test data and simulations suggests that the proposed model can provide sufficiently accurate prediction of both local and large scale phenomena induced by steam injection into the pool.

Numerical analysis of hot steam injection through an embedded channel inside a 3D steam turbine blade

The steam expands rapidly and releases its latent heat at the last stages of steam turbines, forming a large number of tiny liquid droplets. This non-adiabatic process results in a sudden phenomenon known as condensation shock, leading to significant thermodynamic losses. Given that the condensation phenomenon can reduce the performance of steam turbines and shorten their lifespan, several studies in recent years have been proposed to eliminate liquid droplets, some focusing on surface heating, others on hot steam injection. However, providing a practical platform design for hot steam injection remains to be studied, which defines the primary goal of this investigation. In this research, a channel is installed inside the 3D turbine blade, allowing hot steam to enter and be stored there. Then, the stored hot steam enters the mainstream flow through eight injection holes with unequal mass flow rates from each hole. Six criteria are defined to see how hot steam injection contributes to decreasing wet steam losses and affects other key parameters. The results of CFD simulations indicate that hot steam injection reduces the rate of erosion, condensation losses, and wetness, respectively, by 58%, 28.5%, and 31.5%. Notwithstanding the advantages of this method, kinetic energy decreases by about 0.5%. This, however, seems to be acceptable due to the remarkable reduction of erosion and condensation losses. Finally, the obtained results indicated the fact that injecting hot steam through the designed channel costs roughly 0.45 ($/hour).

Experimental investigation on condensation regimes and transition boundary during bubble condensation in narrow rectangular channel

Direct steam contact condensation in subcooled water is widely used in various industries because of high efficiency in heat and mass transfer. A visual experiment is carried out to investigate the condensation process of vapor bubble in narrow rectangular channel. The steam injection mass flux, subcooled water temperature and water mass flow are 0.43–40 kg/m2·s, 50–93 °C, and 0–200 kg/m2·s, respectively. In order to obtain more accurate parameters of vapor bubble in narrow rectangular channel, a new bubble volume model was developed and compared with existed models. A three-dimensional condensation regime map is developed with the coordinates of steam injection flux, water mass flow, and water temperature. Five condensation patterns such as chug, oscillatory bubble, growth bubble, transition region and oscillatory jet are determined based on the dynamic behavior of steam-water interface. The bubble equivalent diameter and aspect ratio during evolution process are calculated, and these two parameters in each pattern exhibit a significant periodicity, except for the oscillatory Jet. The true area of heat transfer interface between bubble and subcooled water is much larger than the actual measured value under high steam injection mass flux. A transition criterion from oscillatory bubble regime to oscillatory jet regime is proposed by the analysis of the bubble critical diameter and the condensation heat transfer of steam-water interface.

Study on the kinetic analysis and pyrolysis evolution in transition zone of metal salt catalyzed steam injection in-situ maoming oil shale upgrading

In order to study the kinetic characteristics and pyrolysis evolution in the transition zone of oil shale during metal salt catalyzed steam in-situ production, the oil shale and semi-cokes under different heating conditions were studied by using a self-made reactor and various analysis methods. The results show that the pyrolysis temperature of semi-cokes in the transition zone increases gradually from front to back, the mass loss in the front is greater than that in the back, and the activation energy is less than that in the back. Compared with conventional and steam heating, metal salt catalyzed steam heating enlarges the activation energy difference between the front and back of the transition zone. With the increase in pyrolysis temperature, the aliphatic content in the transition zone decreased rapidly. The front of the transition zone is the main oil and gas generation area, and the oil and gas generation potential in the back is significantly reduced. Metal salt catalyzed steam heating accelerates the pyrolysis and release of aliphatic groups and reduces the degree of aliphatic branching in the transition zone. During the initial pyrolysis, the oxygen-containing functional groups and aromatic structures in the transition zone decreased, and then increased with the increase of pyrolysis temperature. The content of oxygen-containing functional groups in the transition zone of metal salt catalyzed steam heating is generally higher than that of conventional and steam heating, while the content of aromatic structures is generally low, indicating that their interaction increases the oxidation effect, promotes the pyrolysis and release of aromatic structures, and inhibits the condensation of aromatic structures. In the presence of potassium feldspar, the high temperature accelerates the illitization of kaolinite in oil shale, and there is basically no potassium feldspar and pyrite in the back of the transition zone. Compared with metal salt catalysts and steam, temperature is the most important factor affecting the pyrolysis of inorganic minerals in oil shale and semi-cokes.

Effect of Rock on Aquathermolysis Reactions at Laboratory Scale (A Review)

Enhanced recovery methods are an important stage in the oilfield development and exploitation program. They allow generating an increase in production related to the decrease of the remaining oil in the reservoir, which was not possible to remove in previous production schemes. Among them, steam injection is one of the methods used, whose main objective is to reduce the viscosity of the crude oil. In the literature there are researches where is evident an interaction between the steam and the crude oil in the reservoir, giving way to the occurrence of chemical reactions called Aquathermolysis. This transformation is a chemical result that occurs at temperatures between 200 to 325°C typical for steam injection. However, the investigations have been focused more on the fluid-fluid interaction than the rock-fluid synergy. The present work aims to better understand the synergy generated in the fluid-rock interaction through a systematic review of the research found in the literature associated with the use of rock fragments, minerals, or porous media in steam injection conditions. For analyzing the data, a descriptive bibliometric study was made with the selected studies where a rock sample was used. As a result, the addition of the mineral and rocks over the reactions generates a catalytic effect observed in the physical and chemical crude oil properties changes. This additional effect is generated for the presence of some minerals in the rock sample and this behavior could change according to its composition. Also, the gas production and its variation under different operational parameters are evidence of rock presence benefits over the process.

Thermomechanical behaviour of well cement in different geological formations under the coupled effects of temperature and pressure

It is crucial to ensure that the cement sheaths remain intact in all types of deep well applications subject to high temperatures and high pressures underground. It should be noted, however, that the behaviour of annulus cement sheath is not self-controlled and is governed by the response of steel casing and the surrounding rock formation in such extreme underground conditions. In this study, we investigate the thermomechanical response of wellbore materials in a typical oil well consisting of steel casing, annulus cement sheaths and surrounding rock formations subjected to continuous steam injection. A section of an oil well was simulated by using the COMSOL Multiphysics, a finite element method, using Class G Portland cement as the annulus cement. In two formation scenarios, stiff (carbonate) and compliant (sandstone), temperature and pressure were coupled to evaluate wellbore material behaviour. It was found that wellbore materials in carbonate were more susceptible to stress than those in sandstone. Despite the fact that all materials reached their highest temperatures in both formations, the retention time of the maximum temperature in the cement sheath in sandstone was shorter than in carbonate. Regardless of the thickness of the cement sheath, the highest strains were located at the casing-cement interface in carbonates. As a result of the temperature and pressure ramp, the cement sheath in sandstone failed by generating tensile radial cracks along the lowest layer thickness of the cement sheath. In compliant formations such as sandstone, the cement sheath would likely fail due to tensile cracking along its lowest thickness.