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Abstract Background Bronchopleural fistula (BPF) is a rare but fatal complication after pneumonectomy. When a BPF occurs late (weeks to years postoperatively), direct resealing of the bronchial stump through the primary thoracic approach is challenging due to the risks of fibrothorax and injury to the pulmonary artery stump, and the surgical outcome is generally poor. Here, we report a case of late left BPF following left pneumonectomy successfully treated using a right thoracic approach assisted by extracorporeal membrane oxygenation (ECMO). Case presentation We report the case of a 57-year-old male patient who underwent left lower and left upper lobectomy, respectively, for heterochronic double primary lung cancer. A left BPF was diagnosed at the 22nd month postoperatively, and conservative treatment was ineffective. Finally, the left BPF was cured by minimally invasive BPF closure surgery via the right thoracic approach with the support of veno-venous extracorporeal membrane oxygenation (VV-ECMO). Conclusions Advanced BPF following left pneumonectomy can be achieved with an individualized treatment plan, and the right thoracic approach assisted by ECMO is a relatively simple and effective method, which could be considered as an additional treatment option for similar patients.

Background and aimsAge-related cognitive impairment impacts a significant portion of the elderly population. Remnant cholesterol (RC) has attracted increased attention in relation to cardiovascular disease, diabetes, hypertension, and fatty liver disease. Nevertheless, its role in cognitive function is still enigmatic, prompting our exploration into the potential associations between them.MethodsA total of 1,331 participants from the NHANES (2011–2014) database, all aged over 60, were included in this investigation. Cognitive function was assessed using four widely applied tests, including the Consortium to Establish a Registry for Alzheimer’s Disease Word Learning (CERAD-WL), CERAD Delayed Recall (CERAD-DR), Animal Fluency Test (AFT), as well as Digit Symbol Substitution test (DSST). Z-score is calculated by scores from the above four tests. The association between RC, total cholesterol (TC) to RC and cognitive performance was assessed by logistic regression analyses. In addition, restricted cubic spline (RCS) regression was performed to assess non-linearity between RC and cognitive function. Subgroup analysis was performed to evaluate the robustness of the results in populations with relevant covariate variables.ResultsThose with Z-scores below the 25% quartile are defined as having cognitive impairment, totaling 498 individuals. Observationally, higher RC levels and a lower TC/RC were associated with an increased risk of cognitive impairment. After adjusting for confounding factors, the impact of RC levels on cognitive performance quartiles was consistent across various subgroups, except in individuals with trouble sleeping, no/unknown alcohol use, and no hypertension. Americans with high RC levels and trouble sleeping are more likely to develop cognitive impairment, with an odds ratio of 2.33 (95% CI: 1.18–4.59).ConclusionThis study suggests that higher RC levels and lower levels of TC/RC are associated with an increased likelihood of cognitive impairment, suggesting that RC can serve as a novel and convenient indicator for predicting the risk of cognitive impairment in the US population.

Abstract Background Emergent airway occurrences pose a significant threat to patient life. Extracorporeal membrane oxygenation (ECMO) has been proven to be an effective method for managing emergent airways. Methods A retrospective analysis was conducted on all patients receiving ECMO as an adjunct for emergent airway management from January 2018 to December 2022 at the People’s Hospital of Zhongshan City. We collected the basic information of the patients, their blood gas data before and after ECMO, the related parameters of ECMO, and the outcome and then analyzed and summarized these data. Results Six patients, with an average age of 51.0(28–66) years, received veno-venous (VV)- ECMO as an adjunct due to emergent airway issues. The average ECMO support duration was 30.5(11–48) hours. All six patients were successfully weaned off ECMO support, with five (83.3%) being successfully discharged after a hospital stay of 15.5(7–55) days. All six patients underwent VV-ECMO through femoral-internal jugular vein cannulation. Among these, five patients, whose airway obstruction was due to hemorrhage, underwent a non-anticoagulant ECMO strategy with no recorded thrombotic events. Conclusions The rapid establishment of ECMO support is aided by the establishment of a standardized ECMO initiation protocol and the formation of a multidisciplinary rapid-response ECMO team, which is particularly crucial for emergent airway management. When airway obstruction results from hemorrhagic factors, the early adoption of a non-anticoagulant ECMO strategy can be considered when implementing VV-ECMO.

ObjectiveSleep disorders is a worldwide public health problem. We sought to examine the association between sarcopenia, a decline in skeletal muscle mass and function, and sleep disorders within the adult demographic of the United States during the period spanning 2011 to 2018.MethodsDiagnosis of sarcopenia and sleep disorders was ascertained through appropriate calculations and a structured questionnaire. The primary correlation analysis was conducted using a weighted multivariate logistic regression model. Furthermore, to confirm the presence of a potential non-linear association between sarcopenia and sleep disorders, additional analyses were performed using multivariate logistic regression and restricted cubic spline (RCS) regression with dose-response curve analysis. Subgroup analyses were also conducted to explore the influence of relevant socio-demographic factors and other covariates.ResultsThe final analysis encompassed 5,616 participants. Model 4, inclusive of all pertinent covariates, revealed a positive correlation between sarcopenia and sleep disorders, yielding an odds ratio (OR) of 1.732 (95% CI: 1.182–2.547; P = 0.002). Further analysis, utilizing the restricted cubic spline model, indicated a decreasing trend in sleep disorders as sarcopenia indices rose. Stratified analyses across diverse variables underscored the significant impact of sarcopenia on sleep disorders prevalence in several subgroups. Specifically, males, individuals aged 40 and above, non-Hispanic whites, those with high school education or equivalent, unmarried individuals, obese individuals (BMI ≥ 30), alcohol drinkers, former smokers, diabetics, and those engaging in less rigorous recreational activities exhibited a more pronounced association between sarcopenia and sleep disorders. The incidence of sleep disorders exhibited an upward trend as the incidence of sarcopenia declined among study participants.ConclusionsIn summary, our study provides evidence of an association between sarcopenia and the prevalence of sleep disorders, with a negative correlation observed between the sarcopenia index and the odds ratio of sleep disorders. These findings suggest that maintaining optimal muscle mass may have a beneficial impact on sleep-related issues. In terms of exploring the mechanisms underlying the relationship between sarcopenia and sleep disorders, more in-depth research is warranted to ascertain the definitive causal relationship.

BackgroundA ruptured sinus of Valsalva aneurysm can lead to rapid heart failure and sudden cardiac death. Management of patients who develop severe heart failure and need to be transferred to a specialized hospital for surgical treatment can be challenging. In patients with severe shock due to a ruptured sinus of Valsalva aneurysm into the right atrium, extracorporeal membrane oxygenation (ECMO) transport is an effective means to ensure patient safety, but increases the right cardiac load. We report the experience of veno-arterial (VA) ECMO transport in the treatment of acute cardiogenic shock caused by rupture of a congenital sinus of Valsalva aneurysm.Case presentationWe describe the case of an 18-year-old male who began having acute episodes of chest pain, shortness of breath, palpitations, and dizziness 18 h before presenting to the emergency department. An echocardiogram revealed an acute ruptured sinus of Valsalva aneurysm and a shunt to the right atrium. The patient presented with severe shock. VA-ECMO was administered to ensure safe transport to the cardiac center. The outcome of emergency surgical repair was good. The patient was on ECMO for 8 h. He returned to the general ward after 7 days and was successfully discharged after 40 days. He had good exercise tolerance 2 years after surgery and no evidence of heart failure.ConclusionAlthough ECMO transport can increase right cardiac load, it is an effective and safe method to move patients with severe shock caused by a ruptured sinus of Valsalva aneurysm into the right atrium. Methods to decrease right cardiac load, such as decreasing ECMO flow combined with cardiotonic drugs, should be adopted. Successful treatment involves rapid establishment of cardiopulmonary bypass and urgent repair of the ruptured sinus of Valsalva aneurysm.

Atrial fibrillation (AF) stands as the most prevalent persistent arrhythmia and a common complication after surgical procedures. Although the majority of non-cardiac surgery patients experience postoperative AF (POAF) and the condition is typically self-limited and asymptomatic, its detrimental impact on patient outcomes, prolonged hospitalization, and heightened risk of stroke and overall mortality has become increasingly evident. Of significant concern, POAF emerges as a noteworthy risk factor for stroke, myocardial infarction, and mortality in comparison to patients with non-surgical atrial fibrillation. Multiple studies have corroborated the association between POAF and an elevated risk of stroke and mortality. The development of postoperative atrial fibrillation is multifactorial, with the inflammatory response being a primary contributor; additionally, factors such as hypovolemia, intraoperative hypotension, anemia, trauma, and pain can trigger POAF. Risk factors for POAF in non-cardiac surgery primarily relate to age, hypertension, obesity, prior cardiac disease, obstructive sleep apnea, and male sex. Prophylactic treatment with β-blockers, amiodarone, or magnesium has demonstrated efficacy, but further trials are warranted, especially in high-risk populations. This review provides an account of the incidence rate, pathophysiology, and prognosis of atrial fibrillation after non-cardiac surgery, elucidates the underlying mechanisms of its occurrence, and explores various preventive strategies investigated in this domain.

ABSTRACTThe efficacy of COVID-19 vaccines varies between individuals and populations, and the reasons for this are still not fully understood. Recent clinical studies and animal models have indicated that the gut microbiota may influence the immunogenicity of the vaccine and, thus, its effectiveness. This suggests that there is a bidirectional relationship between the gut microbiota and the COVID-19 vaccine, with the varying components of the microbiota either enhancing or reducing the vaccine’s efficacy. To put an end to the spread of the COVID-19 pandemic, the necessity of vaccines that create powerful and long-term immunity is now more important than ever, and understanding the role of the gut microbiota in this process is essential. Conversely, COVID-19 vaccines also have a significant effect on the gut microbiota, decreasing its total number of organisms and the variety of species present. In this Review, we analyze the evidence that suggesting an interaction between the gut microbiota and COVID-19 vaccine effectiveness, consider the immunological mechanisms that may be responsible for this connection, and explore the possibility of using gut microbiota-focused interventions to improve the efficacy of COVID-19 vaccines.

Fulminant myocarditis (FM) is a rare but serious clinical syndrome which can be characterized by the rapid deterioration of cardiac function, with cardiogenic shock (CS) and arrhythmic electrical storms being common presentations, often requiring adjunctive support with mechanical circulatory devices. With the development of mechanical circulatory support (MCS) devices, there are now more and more studies investigating the application of MCS in FM patients, and the use of extracorporeal membrane oxygenation (ECMO) to treat FM has shown good survival rates. This review elucidates the treatment of FM, and the application and clinical outcomes associated with ECMO intervention.

IntroductionMassive pulmonary embolism (PE) is a life-threatening complication of major surgery with a mortality rate of up to 50%. Extracorporeal membrane oxygenation (ECMO) is primarily used for respiratory and circulatory support. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used to stabilize patients with acute massive PE. Acute brain injury, vascular disease, and immunosuppression are contraindications to ECMO, as stated in the 2021 Extracorporeal Life Support Organization guidelines.Case summaryWe report a case of a patient with craniocerebral trauma whose postoperative course was complicated by massive PE and subsequent cardiac arrest that required urgent VA-ECMO, followed by anticoagulation with heparin. The patient showed hemodynamic improvement and was discharged 68 days after hospitalization.DiscussionECMO has gradually been accepted for patients with craniocerebral injuries. The safety and effectiveness of ECMO in patients with craniocerebral injury, along with the optimal duration of ECMO and anticoagulation strategies, require further study.

BackgroundApplying Extracorporeal membrane oxygenation (ECMO) to patients with acute fulminant myocarditis (AFM) reduces their mortality. The survival rate is 55.6-71.9% for adult AFM patients, which is lower than that for paediatric patients (63-81%). In our centre, the survival rate of ECMO for adult patients with AFM was 66.7% from January 2003 to 2012. In January 2013, the therapeutic regimen was optimised, and then the survival rate increased to 89.1% by January 2022. This article analyses the reasons for the improved survival rate following the optimisation of treatment protocols.MethodsThe data for adult patients with AFM who underwent ECMO for a poor response conventional treatment from January 2003 to January 2022 were reviewed. According to different treatment regimens, the AFM patients were divided into an old and a new regimen group. Univariate and multivariate logistic regression analyses were performed on the data before and after ECMO.ResultsFifty-five patients were enrolled in the age (31.2 ± 11.3), including 24 males. Forty-nine patients were weaned successfully from ECMO [duration: (4.1 ± 1.8) d], all of whom were discharged from the hospital, with a survival rate of 89.1%. Compared with the old regimen group, the new regimen group had a shorter duration of shock to ECMO, a lower proportion of patients receiving extracorporeal cardiopulmonary resuscitation (ECPR), a lower Vasoactive Inotropic Score (VIS), and lower levels of lactic acid, and high-sensitivity troponin T before ECMO (p < 0.05). Compared with the old regimen group, after ECMO, the new regimen group had lower ECMO flow, lower proportion of left ventricular dilation and lower limb ischemia injury, the duration of ECMO was shorter, and significantly improved the survival rate, the difference was statistically significant (P < 0.05). The duration of shock to ECMO and VIS before ECMO were independent risk factors for the survival rate (p < 0.05).ConclusionEarly ECMO initiation in adult AFM patients with a poor response to conventional therapy and low-flow ECMO to meet metabolic needs can reduce serious complications affecting the prognosis, may be associated with better outcomes.

PurposeTo investigate the predictive performance of the combined model by integrating clinical variables and radiomic features for the accurate detection of prostate cancer (PCa) in patients with prostate-specific antigen (PSA) serum levels of 4-10 ng/mL.MethodsA retrospective study of 136 males (mean age, 67.3 ± 8.4 years) with Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 category ≤3 lesions and PSA serum levels of 4-10 ng/mL were performed. All patients underwent multiparametric MRI at 3.0T and transrectal ultrasound-guided systematic prostate biopsy in their clinical workup. Radiomic features were extracted from axial T2-weighted images (T2WI) and apparent diffusion coefficient (ADC) maps of each patient using PyRadiomics. Pearson correlation coefficient (PCC) and recursive feature elimination (RFE) were implemented to identify the most significant radiomic features. Independent clinic-radiological factors were identified via univariate and multivariate regression analyses. Seven machine-learning algorithms were compared to construct a single-layered radiomic score (ie, radscore) and multivariate regression analysis was applied to construct the fusion radscore. Finally, the radiomic nomogram was further developed by integrating useful clinic-radiological factors and fusion radscore using multivariate regression analysis. The discriminative power of the nomogram was evaluated by area under the curve (AUC), DeLong test, calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC).ResultsThe transitional zone-specific antigen density was identified as the only independent clinic-radiological factor, which yielded an AUC of 0.592 (95% confidence interval [CI]: 0.527-0.657). The ADC radscore based on six features and Naive Bayes achieved an AUC of 0.779 (95%CI: 0.730-0.828); the T2WI radscore based on 13 features and Support Vector Machine yielded an AUC of 0.808 (95%CI: 0.761-0.855). The fusion radscore obtained an improved AUC of 0.844 (95%CI: 0.801-0.887), which was higher than the single-layered radscores (both P

To improve the oil recovery of a block in the Wutonggou Formation of the Changji Oilfield, viscosity reducing and foaming agent was optimized to improve the development effect of the water flooding reservoir. The core flooding experiment and microscopic visual experiment were conducted to investigate the production characteristics and EOR mechanism of nitrogen foam flooding. The results show that the 0.5 wt% viscosity reducing and foaming agent DXY-03 was optimized. In the process of microscopic oil displacement by nitrogen foam, nitrogen foam continuously expands and spreads, improves oil displacement efficiency, and greatly improves oil recovery through emulsification and viscosity reduction, squeezing action, dragging action, and Jamin effect. The core flooding experiment shows that on the basis of the water flooding recovery rate of 20.3%, the nitrogen foam huff and puff is increased by 9.2%. The viscosity reducing and foaming agent flooding is increased by 7.8%, and the nitrogen foam flooding is increased by 12.9%. The main EOR mechanism of the viscosity reducing and foaming agent is that it can reduce the interfacial tension between oil and water and can promote heavy oil emulsification and dispersion, thereby forming an oil/water- (O/W-) type emulsion. The reduction in the viscosity of heavy oil makes crude oil easier to extract, realizing the synergistic viscosity reducing and efficiency enhancing effect of nitrogen and viscosity reducing and foaming agents. This study is helpful to provide reference for the development of low-permeability and high-viscosity medium-deep heavy oil reservoirs by chemical agents combined with cold production.

In heavy oil development, flue-gas-assisted steam flooding can not only improve oil recovery but also reduce carbon emissions and realize the resource utilization of flue gas. In this paper, the variation in crude oil components produced by steam flooding and flue-gas-assisted steam flooding was studied by indoor displacement experiments and component determination, and the production properties of different components in flue gas, and the influence of flue gas proportion on residual oil components was explored. The results indicate that flue gas can enhance distillation and the production of light components in the steam flooding process. When the ratio of flue gas to steam ranges from 1 : 1 to 3 : 1, the larger the proportion of flue gas injection is, the larger the scope of steam thermal sweep is, the stronger the steam distillation effect is, and the greater the content of light components in residual oil and the change value of each component at the outlet and inlet are. Due to the difference in the dissolution of N2 and CO2 in heavy oil, at the early stage of displacement, the retention rate of CO2 in the formation in the early stage of displacement was higher, and the proportion of CO2 output was lower than the initial injection proportion. With the progress of displacement, the proportion of CO2 gradually increased, and the proportion of N2 gradually decreased. After gas channeling occurs, the N2 proportion increases and gradually approaches the injection proportion. The dissolution and precipitation of flue gas contribute to the formation of foam oil and improve the flow and production of crude oil. The research results are helpful to further understand the mechanism of flue-gas-assisted steam flooding and provide a theoretical basis for the improvement of this technology.

Abstract The fracture system is a vital component of fractured low‐permeability reservoirs. The presence of fractures can improve reservoir flow capacity and injected carbon dioxide (CO2) utilization, thus leading to higher oil recovery. In this study, the effects of the presence of fracture, fracture morphology, soaking time, and CO2 injection volume on CO2 huff and puff were investigated through 11 low‐permeability cores with different properties. The experimental results indicated that the presence of fractures enhanced cyclic oil recovery and increased the effective cycle numbers during CO2 huff and puff in low‐permeability cores. Moreover, compared with low‐permeability cores without fractures, ultimate oil recovery of CO2 huff and puff was risen up by ~11% in fractured cores. Longer soaking time was conducive to enhancing ultimate oil recovery of CO2 huff and puff in fractured low‐permeability cores, but the excessive soaking time had little effect on ultimate oil recovery. Meanwhile, excessive CO2 injection volume did not significantly improve the performance of CO2 huff and puff, but it did reduce the CO2 utilization. Moreover, gravity caused the produced oil to deposit on the bottom surface of the blowout end of the fracture, which made oil recovery of the core with a horizontal fracture slightly higher (~7%) than that of the core with a vertical fracture. In addition, variation in the intersection angle of fractures had little effect on ultimate oil recovery of CO2 huff and puff in fractured low‐permeability cores. It, however, did change the conductivity of the entire core, thus affecting oil recovery during the first two cycles remarkably.

Abstract Many factors will affect the result of nitrogen-assisted gravity drainage (NAGD). In this work, sandpack and 2-dimensional (2D) visual plate model were employed to investigate the influence factors of NAGD, such as gas cap volume, formation dip angle, and back pressure. Nitrogen foam was also studied to improve the gas channeling and breakthrough. The experimental results indicated that the gas cap volume was the most significant influence factor on the oil recovery. With the increase of the gas cap volume, the oil recovery increased first and then decreased, and finally increased. The NAGD had a better performance in big dip angle of formation. There was a critical value of back pressure to obtain the maximum oil recovery. However, the gas channeling was intensely observed by experiments of both sandpack and 2D visual plate model. Fortunately, nitrogen foam could effectively inhibit the gas channeling and improve the result of NAGD.

In view of the serious heat loss in the process of steam injection for heavy oil recovery, nonhydrocarbon gas combined with steam has attracted much attention in recent years to realize the efficient development of heavy oil. Due to the wide variety of nonhydrocarbon gases, their performance in pressurization, dissolution, viscosity reduction, and heat loss decrease is changeable. In this paper, four groups of one-dimensional physical simulation experiments on different nonhydrocarbon gas-assisted steam flooding methods were carried out, and the effect on oil displacement characteristics under high temperature and pressure conditions was studied. Moreover, the differences in N2, CO2, and flue gas in energy supplementation, heat transfer, and oil recovery efficiency were also analyzed. The results showed that the three nonhydrocarbon gas-assisted steam flooding methods could significantly improve the oil displacement efficiency, which was specifically embodied as a faster oil production rate and longer production period. Compared with pure steam flooding, the recovery was increased by 12.13%, 16.71% and 13.01%, respectively. The effects of N2 in energy supplementation and heat transfer reinforcement were the greatest among the three nonhydrocarbon gases, followed by those of flue gas, and the CO2 effects were the worst. The temperature at the end of the sandpack model increased by 14.3 °C, 8.8 °C and 13.1 °C, respectively. In addition, CO2-assisted steam flooding had a prominent oil recovery effect, and the oil content of the sands in the front and middle of the model was significantly lower than that of other displacement methods. Most importantly, combined with the analysis of the remaining oil in the oil sands after displacement, we explained the contrasting contradictions of the three non-hydrocarbon gases in terms of recovery and energy supply/heat transfer, and further confirmed the gas properties and reservoir adaptability of the three non-hydrocarbon gases. The results may provide a theoretical basis for the selection of nonhydrocarbon gases for heavy oil reservoirs with different production requirements.

Steam injection is an important process for the thermal recovery of heavy oil reservoirs. As a non-condensable gas CO2-assisted steam injection can not only improve the development effect but also reduce carbon emissions. In this study, the simulation method was combined with the experimental method. Based on an experiment using steam condensation with or without CO2, the influence of the condensation mode on steam heat transfer was considered. The effect of changes in the steam flow rate on phase transition and steam quality were analyzed. The heat transfer effects of the gas-steam mixture with different contents of CO2 were compared. The results show that the surface condensation mode changes from dropwise condensation to film condensation with the addition of CO2, and the average temperature of the condensation block decreases by 20.05%. With increases in the steam flow rate, the quality of steam increases, and the heat transfer coefficient of steam on the condensation surface increases. With increase in CO2 content, the temperature of the gas-steam mixture decreases, and the inhibition effect on steam heat transfer is more obvious.

Abstract In this work, wall slipping behavior of foam with nanoparticle-armored bubbles was first studied in a capillary tube and the novel multiphase foam was characterized by a slipping law. A crack model with a cuboid geometry was then used to compare with the foam slipping results from the capillary tube and also to evaluate the flow resistance factor of the foam. The results showed that the slipping friction force F FR in the capillary tube significantly increased by addition of modified SiO2 nanoparticles, and an appropriate power law exponents by fitting F FR vs. Capillary number, Ca, was 1/2. The modified nanoparticles at the surface were bridged together and formed a dense particle “armor” surrounding the bubble, and the interconnected structures of the “armor” with strong steric integrity made the surface solid-like, which was in agreement with the slip regime associated with rigid surface. Moreover, as confirmed by 3D microscopy, the roughness of the bubble surface increased with nanoparticle concentration, which in turn increased the slipping friction force. Compared with pure SDBS foam, SDBS/SiO2 foam shows excellent stability and high flow resistance in visual crack. The resistance factor of SiO2/SDBS foam increased as the wall surface roughness increased in core cracks.

In order to improve the recovery effect of steam huff and puff in a super-heavy oil reservoir, the displacement efficiency of CO2 and viscosity breaker assisted steam flooding was studied through in-lab displacement experiments. The viscosity reduction mechanism of CO2 and viscosity breaker assisted steam huff and puff for horizontal wells was realized by numerical simulation. The results show that the displacement efficiency of CO2 and viscosity breaker assisted steam flooding (80.8%) is higher than that of steam flooding (65.4%). The CO2 and viscosity breaker assisted steam huff and puff technology for horizontal wells realizes the rolling replacement of viscosity reduction of viscosity breaker, CO2 and steam, thus effectively reducing the steam injection pressure, expanding the steam sweep area, i.e., expanding the viscosity reduction region and improving oil production rate. The viscosity region can be divided into four compound viscosity reduction areas according to temperature distribution and viscosity reduction mechanism. They are steam compound viscosity reduction region, hot water compound viscosity reduction region, low temperature water compound viscosity reduction region, and CO2-viscosity breaker compound viscosity reduction region. Field tests show that the CO2 and viscosity breaker assisted steam huff and puff technology for horizontal wells is effective in reducing viscosity and improving production of super-heavy oil reservoirs with deep and thin layers, deep and heavy layers, shallow and thin layers. Key words: super-heavy oil, steam huff and puff, reservoir simulation, physical simulation, CO2, viscosity breaker

There isn't any mature technique to develop ultra-heavy oil reservoirs in the Shengli Oilfield because of large oil viscosity, deep and thin layer, high rate of resin and asphaltene. The multi-combination exploiting technique is developed which combines the techniques of under-pressure foam flow-back, efficient oil-soluble viscosity reducer, CO2 immiscible and steam huff and puff. The following experiments were conducted about the recovery mechanism of the technique: (1) measuring foam viscosity, sands suspension property and sands washing capacity; (2) comparing the capacities of viscosity breaking and emulsion breaking of oil-soluble viscosity reducer with the conventional viscosity reducer; (3) measuring emulsion breaking of CO2. The experimental results show: Foam has the advantages of greater viscosity, remarkable capacities of suspending and washing sands; the combination viscosity reducer has greater advantage on viscosity breaking over xylene. The emulsion breaking capacity of the combination viscosity reducer and CO2 is excellent, and the higher the W/O emulsion, the greater the capacity of emulsion breaking. Field tests show that the multi-combination exploiting technique is good in improving production of ultra-heavy oil reservoirs. 摘要: ： 胜利油田超稠油埋藏深、储集层薄、原油黏度大、胶质和沥青质含量高，采用目前成熟的稠油开发方式无法有效动用。结合超负压泡沫混排技术、高效油溶性降黏剂降黏技术、CO2非混相驱油技术和蒸汽吞吐技术，提出深薄层超稠油多元复合开采技术。针对多元复合开采技术的开采机理，进行相关实验：①测定泡沫黏度以及泡沫悬砂、冲砂性能；②油溶性复合降黏剂与常规降黏剂降黏效果对比实验和破乳实验；③CO2破乳能力实验。实验表明：泡沫具有良好的悬砂、冲砂性能；复合降黏剂的降黏效果远好于二甲苯，复合降黏剂和CO2均具有很好的破乳效果，原油乳化程度越高，破乳效果越好。现场试验显示多元复合开采技术开发深薄层超稠油具有良好效果。图5表4参14 Key words: ultra-heavy oil, multi-combination exploiting technique, foam, viscosity reducer, CO2