Steam Stimulation Research Articles

Experimental investigation of EOR mechanisms for cyclic steam injection assisted by flue gas

In Colombia, Cyclic Steam Stimulation (CSS) is deployed as an EOR method to recover heavy oil. However, flue gas from steam generators is a stable long-term CO2 emission source in oil fields. And the adverse effects of this greenhouse gas cannot be ignored, becoming a concern in all countries worldwide. In this study, the cyclic steam-flue gas co-injection process (CSS-FG) is proposed as an alternative to improve the performance of CSS, extend the lifetime of this technology, and collect and use the flue gas from steam generators to reduce greenhouse-gas emissions. In this investigation, CSS and CSS-FG were experimentally represented and compared to understand the effect of flue gas addition on the recovery mechanisms at the different stages of CSS, using a one-dimensional core physical simulation. For CSS representation, five steam injection cycles were carried out, and flue gas was added in a sixth cycle to analyze the effect of flue gas on the recovery factor after several stages. Likewise, in the CSS-FG displacement, five cycles were developed, where flue gas-steam was injected since the second to the fifth cycle. The results show that the final oil recovery factors of CSS-FG using 15% of flue gas molar ratio was 41.1%, compared to 15.2% of CSS. In addition, after five-cycle steam stimulation, the recovery factor increased up to 9.2% by adding flue gas in the sixth cycle. The differences in the recovery factors confirmed the synergy between the flue gas and steam even in mature stages of steam stimulation, which facilitated the identification of the recovery mechanisms associated with adding this gas. Phase interaction between the flue gas and heavy oil is promoted during the injection stages. Thereafter, flue gas expands rapidly in the production period, offering a push mechanism that accelerates the fluids production rate. Additionally, the porous medium pressure increases, and the fast depletion rate near the production port when adding flue gas cause foamy oil formation, improving the mobility of heavy oil since the dissolved gas cannot release from the oil because of its high viscosity. These experimental results provide theoretical guidance for improving the effectiveness of the CSS and demonstrate that CSS-FG is an essential method for reducing greenhouse-gas emissions in oil fields.

The Effects of Combination of Steam Flooding, CO2 and Cyclic Steam Stimulation Injection Pilot Test in Heavy Oilfield in Sudan

Applications of Enhanced Oil Recovery (EOR) are highly required and needed in Sudan to keep oil supply at stable levels. ”FUL” Oilfield in Sudan has shallow reservoir affected by big boundary and bottom water drive with high crude oil viscosity. This research, through a comprehensive analysis of the current producing wells, perforation intervals, CO2 temperature analysis, steam parameters optimization which using two approaches (deterministic and stochastic) were analyzed, using a combination of continues steam flooding, CO2 assisted steam flooding, and cyclic steam stimulation in the pilot test sector. CMG-STARS and CMOST AI simulators software was used in this study. By determining recovery factor (RF) as objective function. It could conclude that: CO2 assisted steam flooding even it could decrease the water cut, but its effect to increase the oil recovery factor is not considerable. Continuous steam flooding has the best oil recovery from these three methods.

Experimental Study on Improvement Mechanism of Electric Heating-Assisted Cyclic Steam Stimulation of Horizontal Well

To resolve the issues of the high porous medium flow resistance, low oil production rate, high oil decline rate, and low oil recovery factor for the cyclic steam stimulation (CSS) of horizontal wells in heavy oil reservoirs, the CSS method assisted by the electric heating (E-CSS) of horizontal wells was proposed in this study. Combining the heat from electric heating and steam during E-CSS, the analytical model of formation temperature rise was established for the three phases of electric-assisted CSS (i.e., injection, soaking, production), and physical experiments were carried out to compare the performance of conventional CSS and E-CSS. The experimental results were used to validate the analytical model and reveal the impact of the key electric heating mechanism on the horizontal CSS performance. Meanwhile, the typical well model was used to forecast the E-CSS potential. The results indicate that electric heating can achieve uniform heating in the steam injection phase, maintain heating around the wellbore in the soak phase, and reduce flow resistance and enhance oil output in the production phase. Forecasts of the typical well model indicate that electric heating can enhance the oil recovery factor by 9.4% and the oil-steam ratio from 0.14 to 0.23, implying a significant application potential in heavy oil reservoirs developed by horizontal CSS.

Investigation of Horizontal Well for Cyclic Steam-Solvent Stimulation to Escalate Heavy Oil Production

Indonesia's oil reserves that have been exploited on a large scale are light oil because the recovery technique is much easier than the heavy oil. Generally, heavy oil has a high viscosity compared to light oil. In most cases, to reduce high oil viscosity (greater than 50 cp) using steam injection. Cyclic steam stimulation (CSS) is one of processes that commercially developed by numerous oil company to producing of heavy oil reservoir. The CSS can apply in vertical well or horizontal well. The research of CSS in horizontal well is still limited reported in the literature. On the other hand, the horizontal well has drainage area more wide compared with vertical well. In this study, solvent addition in cyclic steam stimulation will be tested with reservoir simulation. The steam was injected on the well, after that soaking time and the last was producing of liquid fluid reservoir. As the result, the oil production increases 3 times higher compared to without solvent. Furthermore, cumulative steam oil ratio (CSOR) and cumulative energy oil ratio (CEOS) decrease about 50% and 16%, respectively. In here, effect of solvent added in the steam, the steam distribution and drainage area wider.

Numerical Simulation Study on the Development Effect of Gravity Fire Flooding by Vertical Well Sidetracking

As a development method to replace steam stimulation of heavy oil, in situ combustion often faces many problems in thick reservoir, such as low vertical sweep efficiency and channeling combustion. According to the characteristics and development history of this kind of reservoir, a method of changing plane fire flooding to gravity fire flooding is proposed by using the existing steam stimulation development well pattern and sidetracking horizontal section of vertical production wells. The influence of different factors on sidetracking gravity fire flooding production effect is analyzed from the aspects of reservoir geology and development engineering. The internal stimulation mechanism of this method is further studied, and the evaluation model between recovery factor and main control factor is established by using multiple linear regression equation. The results show that vertical sidetracking gravity fire flooding can improve the recovery of thick heavy oil reservoir by 42%; the better recovery effect can be obtained when the sidetracking length is about 1/2 of the well spacing; the coincidence degree between the established recovery evaluation model and the results of numerical simulation is more than 85%. The research results of this paper can help the mine fire flooding development to change the mining mode and provide some guidance for the medium- and long-term planning.

Influence of Convective Processes on Technological Parameters of Cyclic Steam Stimulation of Oil Reservoirs

Influence of Convective Processes on Technological Parameters of Cyclic Steam Stimulation of Oil Reservoirs

Experimental and Numerical Investigation on Infilled Vertical Well LASER-Assisted SAGD

In the SAGD process with dual horizontal wells in heterogeneous reservoirs, the injection pressure of steam huff-n-puff by infilled interwell vertical wells is too high, and the heat communication between SAGD wellpairs and infilled wells is too long, which leads to a series of problems. The solvent-assisted vertical well stimulation (LASER) technology is proposed to solve the problems above. The solvent formula was optimized, and its key mechanism was studied by viscosity reduction experiments, multicomponent phase behavior experiments at high temperature and high pressure, and scaled two-dimensional physical experiments. The experimental results show that when adding 10% 2# or 3# solvent oil, the viscosity reduction of crude oil can reach 96.65% and 96.73%, respectively. The HTHP visualized phase behavior experiment results show that the mixture of low flash point solvent oil 2# with high flash point solvent oil 3# (volumetric ratio 3 : 2) has excellent high temperature oil solubility stability and is similar to water vapor phase behavior, so it is determined as the ideal formula. The scaled two-dimensional physical experiment results show that the solvent-assisted vertical well huff-n-puff has the key mechanism of reducing injection pressure and porous flow resistance, expanding the sweep region of injected fluid and accelerating thermal communication. The cycle of huff-n-puff was reduced from 6 to 3, which greatly shortened the thermal communication time. From the scaled physical experiments, the oil rate and the oil recovery of SAGD were improved by 19.86% and 6.3%, respectively. Field-scale numerical simulation was performed, and the production performance compared with SAGD and conventional infilled CSS-SAGD was investigated, which shows that by adding solvent into steam stimulation, 6 cycles were reduced, and the incremental oil recovery factor was 27.3% and 13.2%, respectively. The performance of accelerating thermal communication and production improvement by LASER has been validated by 4 SAGD wellpairs in field practice, and its long-term prediction result shows significant potential in similar heterogeneous SAGD reservoirs.

Automate Short Cyclic Well Job Candidacy Using Artificial Neural Networks–Enabled Lean Six Sigma Approach: A Case Study in Oil and Gas Company

Artificial Neural Networks (ANNs) are a part of Artificial Intelligence (AI) that is commonly used for pattern recognition, regression and classification. This technology allows us to learn historical data and generate patterns from the precedent data. In oil and gas companies, large amounts of data are produced every day. Many accurate decisions in this type of company are made from the data. Cilon Indonesia (CI) Co. Ltd. is one of the oil and gas companies currently operating the largest oil field in Indonesia. This type of company's operation and financial profit depends on oil price, which is affected by global oil supply and demand. If oil prices fall suddenly, all oil and gas companies need to run their businesses more efficiently and effectively. There are many ways to make this kind of company run their business effectively and efficiently by implementing several strategies such as capital cost efficiency, operational cost efficiency and even laying off some employees. One of the major costs in operation in oil and gas companies is the cost for well workover. This well workover does not always produce oil gain. In fact, even it is resulting in oil gain, but not all well workover programs are economical whenever the oil price is low. This condition makes Petroleum Engineer (PE) need to select the best well workover for certain wells. Well candidates for workover are usually selected manually using data from many resources, reports and information. Well candidates are reviewed one by one, and with several criteria, the well is proposed to a certain type of well workover. This research explains how this company improves their selection of well candidates for the most economic workover called Short Cyclic Steam Stimulation (SCSS). The process improvement is done using the hybrid method: lean six sigma method and big data analytics method, which utilize ANNs to predict the oil after workover executed. The result demonstrates how this hybrid method can improve the process with a sustainable solution. Its successful improvement in PE time selects SCSS well candidates from 2 hours to 10 minutes to generate 20 wells per day. Its also improve the success rate of SCSS workover from 61% to 73%.

Experimental Measurements and Numerical Simulation of H2S Generation during Cyclic Steam Stimulation Process of Offshore Heavy Oil from Bohai Bay, China

Cyclic steam stimulation (CSS) is successfully applied to increase heavy oil recovery in heavy oil reservoirs in Bohai Bay, China. However, during the CSS processes, hydrogen sulfide (H2S) was detected in some heavy oil reservoirs. The existing literature mainly focused on the H2S generation of onshore heavy oil. There is no concrete experimental data available, especially about the level of H2S generation during CSS of offshore heavy oil. In addition, there is still a lack of effective reaction kinetic models and numerical simulation methods to simulate H2S generation during the CSS of offshore heavy oil. Therefore, this paper presents a case study from Bohai Bay, China. First, the laboratory aquathermolysis tests were conducted to simulate the gases that are produced during the CSS processes of heavy oil. The effects of the reaction temperature and time on the H2S generation were studied. Then, a one-dimensional CSS experiment was performed to predict H2S generation under reservoir conditions. A kinetic model for the prediction of H2S generation during the CSS of heavy oil was presented. The developed model was calibrated with the experimental data of the one-dimensional CSS experiment at a temperature of 300 °C. Finally, a reservoir model was developed to predict H2S generation and investigate the effects of soaking time, steam quality, and steam injection volume on H2S generation during CSS processes. The results show that the H2S concentration increased from 0.77 ppm in the first cycle to 1.94 ppm in the eighth cycle during the one-dimensional CSS experiment. The average absolute error between the measured and simulated H2S production was 12.46%, indicating that the developed model can accurately predict H2S production. The H2S production increase with soaking time, steam quality, and steam injection volume due to the strengthened aquathermolysis reaction. Based on the reservoir simulation, the H2S production was predicted in the range of 228 m3 to 2895 m3 within the parameters of this study.

Distinct chemical and stable isotope compositions of smectite formed during steaming of Clearwater Formation oil-sands from Cold Lake, Alberta

Chemical reactions between oil-sands and injected steam or steam condensate during cyclic steam stimulation (CSS), commonly used to mobilize heavy oil and bitumen, result in decomposition of pre-existing minerals and formation of new phases including clay minerals. These changes can reduce reservoir permeability and limit hydrocarbon recovery. In this study, the chemical and stable isotope compositions of berthierine and smectitic clay minerals contained in pre- and post-steam Clearwater Formation oil-sands from Cold Lake, Alberta were analyzed to investigate how these phases were affected by CSS. Berthierine abundance in the injection-zone decreased after steaming whereas the abundance of smectitic clay minerals increased. Pre- and post-steam berthierine exhibited the same range of chemical compositions, while those of pre- and post-steam smectitic clay minerals commonly differed. Some post-steam smectitic clay minerals from the steam injection-zone, in particular, contain significantly more Fe and Si but less Al than pre-steam samples. It is proposed that that berthierine contributed to the formation of new smectitic clay minerals during CCS through partial inheritance of the berthierine 1:1 structure. This inheritance model approximates the unique chemical compositions of the post-steam smectitic clay minerals. The model also helps to explain the incomplete oxygen and hydrogen isotope exchange between injection fluids and smectitic clay minerals formed during CSS.

Experimental Investigation of Steam Conformance Evolution in Vertical-CSS and Optimization of Profile Improvement Agents

Production performance of heavy oil deposits in Xinjiang oilfield developed by vertical-well cyclic steam stimulation (CSS) is increasingly challenged by reservoir heterogeneity, which is comprised of original sedimental heterogeneity and steam-induced heterogeneity. In order to understand the impacts of sedimental heterogeneity and high-speed steam injection to steam conformance, and strategies to maximize steam swept volume, a series of experiments were designed and implemented. Three-tube coreflooding experiments were performed to study the steam displacement dynamics under heterogeneous conditions, and a high-temperature plugging agent was developed. The coreflooding experiments indicate that the injection conformance deteriorates once the steam breakthrough occurs in a high-permeability tube, leaving the oil in the medium and low permeability tubes being surpassed. The optimized plugging agent could resist high temperatures over 260 °C and its compressive strength was 13.14 MPa, which is higher than maximal steam injection pressure. The plugging rate of high permeability core was greater than 99.5% at 220–280 °C with a breakthrough pressure gradient over 25 MPa/m. The field test validated its profile improvement feasibility with cyclic oil, 217.6% of the previous cycle. The plugging agent optimized in this study has significant potential for similar heterogeneous reservoirs.

Analysis of the numerical solution of the three-phase nonisothermal fluid flow problem

This paper is devoted to the construction and study of the stability and convergence of a numerical method for solving the problem of three-phase non-isothermal fluid flow in porous media, taking into account capillary forces, which was carried out within the framework of the grant project No. AP08053189 provided by the Ministry of Education and Science of the Republic of Kazakhstan. The model under consideration describes the processes occurring in oil reservoirs during the production of heavy oil by the method of thermal steam stimulation of the reservoir. The formulation of the differential problem is based on the introduction of a change of variables called global pressure, which makes it possible to exclude the capillary pressure gradient from the pressure equation. For the numerical solution, a numerical scheme was constructed. An a priori estimate in the energy norm is obtained, which expresses the stability of the constructed scheme with respect to the initial data and the right-hand sides of the equations. The theorem on the convergence of the solution of a numerical scheme to the solution of a differential problem is presented.

An integrated framework based on deep learning algorithm for optimizing thermochemical production in heavy oil reservoirs

The development of heavy oil reservoirs with active edge and bottom water is one of the most challenging problems in petroleum engineering. In response to the limited thermal recovery of these reservoirs, a multi-phase and multi-component numerical simulation model for thermal and chemical recovery is proposed. An edge-water assisted chemical flooding (EAC flooding) is proposed, which can improve oil displacement efficiency and sweep efficiency by rational utilization of edge-water energy when compounding multi-component chemical system. Then, a deep reinforcement learning algorithm is proposed to predict dynamic production parameters and determine the optimal working system to maximize the oil recovery according to the above mathematical model. The deep reinforcement learning (DRL) model can predict the dynamic production curves according to given states with optimal strategy. At the same time, the proposed model can determine the best conversion timing from cyclic steam stimulation to EAC flooding. Finally, the DRL model can automatically obtain the optimal working system, effectively improving the oil recovery while considering the economic benefits. Thus, the DRL model can solve traditional numerical simulation's time-consuming and labor-intensive challenges and accurately give the optimal working system for developing heavy oil reservoirs with edge water in the field.

Experimental Study and Thoughts on Safety and Environmental Protection of Steam Flooding of Horizontal Wells in a Heavy Oil Reservoir.

Based on similarity criteria, a scaled physical model was fabricated, containing four horizontal wells and representing one-fourth of an inverted nine-spot steam-flooding pattern. A series of steam-flooding physical simulation experiments were carried out after different types of integral cyclic steam stimulations. Temperature distributions in the model reservoir, overburden, and substratum were measured at intervals. Production performance could be exactly recorded. The spatial temperature distribution of the whole model could be obtained. The phenomena of steam channeling, steam override, and secondary heterogeneity were observed obviously. The results that show steam flooding would cause steam overlap and characteristics of steam channeling during steam flooding after different types of integral cyclic steam stimulation were very distinct. The reservoir would have different temperature fields and different flow resistance because of different integral cyclic steam stimulations. The formation fluid would bypass the place with large flow resistance (low-temperature zone), forming secondary heterogeneity and affecting the displacement effect and thus the development effect. The recovery percent of a heavy oil reservoir developed by steam flooding was low, and it would bring some potential safety risks and problems with environmental protection. The experimental results provide theoretical support for further study of the mechanism of steam flooding.

Electrical Heating Can Optimize Production in Heavy-Oil Fields With Intelligent Multilaterals

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 20134, “Production Optimization Through Intelligent Multilateral Wells in Heavy-Oil Fields by Electrical Heating,” by Cenk Temizel, SPE, Saudi Aramco; Celal Hakan Canbaz, Ege University; and Fatma Bahar Hosgor, Petroleum Software, et al. The paper has not been peer reviewed. Copyright 2020 International Petroleum Technology Conference. Reproduced by permission. Electrical resistive heating provides key advantages over other thermal methods in the recovery of heavy-oil resources. However, the recovery efficiency with electrical heating is relatively lower compared with more-conventional methods such as cyclic steam stimulation, steamflooding, and steam-assisted gravity drainage (SAGD) because it does not introduce a (pressure) drive mechanism and the radius of effect is relatively small, which may result in marginal economics. In this study, the application of electrical resistance heating on multilateral wells is studied in order to illustrate the enhanced physical and economic benefits of the method in such a setting. Smart Tools in Multilateral Wells Placement of a multilateral well is a decision that must be considered carefully. The easiest method of determining whether the approach is the right one for a field is to analogize multilateral wells with the traditional single-bore wells that penetrate to the same formation area. The multilayered well has less drilling depth and reduced rig time compared with the conventional wells. Thus, multilaterals are an advantageous completion design in locations such as offshore platforms or harsh-weather areas. However, multilateral well-completion design is challenging because of its increased complexity. Most smart wells include hydraulic-control systems to satisfy a simpler, more-reliable operation. Current wellhead-control systems allow a limited number of penetrations. The indications are that smart tools controlled with electrical systems will be an emerging focal point of the industry. The cost of a multilateral well is higher because of the equipment used and operational complexity. It also includes a higher risk compared with the risk of a conventional well. Any problem that results in abandoning the well will bring a major economic loss equal to the cost of several conventional wells.

Enhancing temperature resistance of polymer gels by hybrid with silica nanoparticles

The steam channeling channel formed during steam huff and puff can be blocked by temperature-resistant gel to improve the steam stimulation effect. In this study, a terpolymer prepared by the polymerization of acrylamide, N-Vinyl-pyrrolidone, and 2-acrylamide-2-methypropanesulfonic acid was selected as gelatinizer, hydroquinone, and hexamethylene tetramine were used as cross-linking agents to prepare gel. The stabilization time of the gel at 175 °C was dramatically extended from 3 days to more than 50 days by adding nanoparticles. The gel prepared with 0.6 wt% polymer, 0.1 wt% hydroquinone, 0.1 wt% hexamethylene tetramine, and 0.9 wt% silica nanoparticles can exist stably for 70 days at 175 °C, which provided a potential choice for plugging the steam channeling channel. The rheological experiments showed that the addition of nanoparticles increased the elastic tendency of the polymer solution to improve the structural strength of the heterogeneous network chain. Dynamic light scattering experiments showed that nanoparticles contribute to the dispersion of polymers in water. The micrographs of the gel were observed by scanning electron microscope, verified that the addition of silica nanoparticles strengthened the gel grid structure and increased the gel grid density, which might be one of the main factors to improve the thermal stability of gels.

A Production Performance Model of the Cyclic Steam Stimulation Process in Multilayer Heavy Oil Reservoirs

Cyclic steam stimulation (CSS) is a typical enhanced oil recovery method for heavy oil reservoirs. In this paper, a new model for the productivity of a CSS well in multilayer heavy oil reservoirs is proposed. First, for the steam volume of each formation layer, it is proposed that the total steam injection volume will be split by the formation factor (Kh) for the commingled steam injection mode. Then, based on the equivalent flow resistance principle, the productivity model can be derived. In this model, the heavy oil reservoir is composed of a cold zone, a hot water zone, and a steam zone. Next, using the energy conservation law, the equivalent heating radius can be calculated with the consideration of the steam overlay. Simultaneously, a correlation between the threshold pressure gradient (TPG) and oil mobility is also applied for the productivity formula in the cold zone and the hot water zone. Afterward, this model is validated by comparing the simulation results with the results of an actual CNOOC CSS well. A good agreement is observed, and the relative error of the cumulative oil production is about 2.20%. The sensitivity analysis results indicate that the effect of the bottom hole pressure is the most significant, followed by the TPG, and the effect of the steam overlay is relatively slight. The formation factor can affect the splitting of the steam volume in each layer; thus, the oil production rate will be impacted. The proposed mathematical model in this paper provides an effective method for the prediction of preliminary productivity of a CSS well in a multilayer heavy oil reservoir.

Cyclic In-Situ Combustion Process for Improved Heavy Oil Recovery after Cyclic Steam Stimulation

Summary Cyclic in-situ combustion (ISC) is a novel process with great potential for thermal enhanced oil recovery (EOR). In this study, a 3D physical simulation experiment of cyclic ISC after cyclic steam stimulation (CSS) was carried out for the first time. The mass loss during heavy oil oxidation was studied by thermogravimetry (TG) and the preheating temperature of sandpack was determined by differential scanning calorimeter (DSC). The oxidation process of heavy oil in a porous medium was investigated by a heavy oil static oxidation experiment. The development characteristics and EOR mechanism of cyclic ISC after CSS were studied through 3D physical simulation experiments and the characteristics of the coking zone was studied by scanning electron microscope (SEM) and computed tomography (CT). The results of the thermal analysis indicate that three different regions were observed with increasing temperature: low-temperature oxidation zone (LTO), fuel deposition zone (FD), and high-temperature oxidation zone (HTO). When the temperature reaches 480°C, the mixed oil sand has the most exothermic effect and the high-temperature oxidation reaction is the most vigorous. The results of the 3D physical simulation show that steam channeling and steam overlay in CSS reduced the swept volume of steam and heat usage rate. During the cyclic ISC, the oil bank can overcome the heterogeneity of the oil reservoir caused by steam channeling and steam overlay, which makes the combustion front move forward smoothly. Cyclic ISC can greatly increase the temperature of the zone near the well, and upgrade the crude oil through cracking to reduce the viscosity of heavy oil. The foaming oil formed by the dissolution of flue gas improves the fluidity of the crude oil. The oil recovery of CSS is 19.3%, and the oil recovery of cyclic ISC increased by 13.2%. SEM and CT show that flake black solid coke was attached to the surface of the sand at the coking zone. The coking zone is a porous medium structure with a porosity of 35.14%, which has little effect on the oil recovery in the process of cyclic ISC.

The Development of Forecasting Technique for Cyclic Steam Stimulation Technology Effectiveness in Near-Wellbore Area

The analytical review has shown that the scientific inquiry for effective technologies for high-viscosity oil field development is a critical task of the present-day oil industry. The paper presents a technique for determining the expediency and effectiveness of deploying the near-wellbore cyclic steam stimulation technology for oil recovery enhancement. The method involves the calculation of process parameters of the technology cycle and the comparative analysis of cumulative oil production before the treatment (base case) and after its deployment. Separately, the work focuses on studying the impact of dynamic oil viscosity over the entire temperature range on the technology effectiveness and expediency. The laboratory studies showed dynamic viscosity correlation dependencies for six different oils of the Nozhovskaya group of oil fields (Russian Federation) characterized as viscous and highly viscous. As a case study of the proposed method application, a numerical simulation of the technology deployment was carried out for six oil samples. The calculations determined inexpediency of cyclic steam stimulation for one of the samples since oil well downtime for workover operation prevailed over the time of near-wellbore cooling.

A Review of High‐Temperature Foam for Improving Steam Flooding Effect: Mechanism and Application of Foam

With the exploitation of light oil approaching saturation, the exploitation of heavy oil is of particular importance. Thermal recovery technology is typically used in heavy oil recovery, such as steam flooding (SF), steam‐assisted gravity drainage, and cyclic steam stimulation. However, SF technology brings problems such as gravity overlap, viscous fingering, and channeling, reducing the sweep efficiency and oil recovery efficiency. Some studies have proposed that foam and steam should be injected into the reservoir together to plug, turn, and reduce viscosity. Heavy oil production occurs mostly under high‐temperature conditions, which require that the foaming agents have good foaming ability in this environment. The generated foam should have good stability. Meanwhile, the mechanism of steam foam enhancing oil recovery (EOR) also changes. Therefore, the research on the mechanism and application of steam foam technology is discussed. First, the basic theory of foam is introduced, and the research on the mechanism of steam foam EOR is discussed. Second, the application of steam foam in the laboratory and the field is summarized. Finally, the full text is summarized and some prospects are made, to provide some help for future research.