Abstract Shell and PetroChina are partnering in a pioneering Joint Cooperation Project in the Sichuan Basin targeting the Lower Silurian Longmaxi shale gas play. Since 2010, over 20 wells, including both verticals and horizontals, have been drilled and completed with various hydraulic fracturing technologies. Unlike most of the North American shale plays, the Sichuan Longmaxi shale play is characterized by abnormal formation pressure, closure pressure close to overburden, low stress anisotropy, and regionally active tectonics, all of which contribute unique challenges to hydraulic fracturing stimulation. The combination of these geological challenges results in high treating pressures, difficulty in proppant placement, constrained fracture height growth and complex fracture geometry. Under such subsurface complexity, an optimal completion design requires insightful understanding of the geological settings and reservoir characteristics, as well as a large number of wells for technology trials in a "trial and error" approach, which often results in a large capital investment and a long value realization cycle time. To meet these challenges, an advanced workflow that integrates geomechanics modelling for hydraulic fracture simulation and 3D reservoir modelling for well performance using reservoir simulator is developed in collaboration with Shell global experts in unconventional resources. This workflow provided a much more economical and efficient solution in understanding the reservoir responses to hydraulic fracturing, quantification of estimated ultimate recovery (EUR) ranges, and potential maximum EUR uplift by increasing completion intensity or technical limit EUR. The geomechanics modeling workflow (Bai et al. 2016) is a truly 3-D hydraulic fracture simulation platform that integrates structural framework, stress setting, formation characterization, flow dynamics, hydraulic fracturing monitoring, and well completion parameters into a finite-element based modeling environment. Key capabilities that distinguish this platform from conventional hydraulic fracture simulators are the ability to model complex fracture initiation and propagation as a consequence of natural fracture systems, hybrid stress regimes, and formation heterogeneity. Once calibrated with hydraulic fracturing field diagnostics, the model performs hundreds of numerical runs accounting for multiple subsurface realizations and well completion design scenarios. The optimized well completion design is selected based on the modelled Stimulated Rock Volume (SRV) that corresponds to increased EUR at optimized costs. Two suites of models were built for this study, each of which represents key play segment in the concession block in terms of profitability and materiality. EUR uplift potential is identified through optimizing well placement and completion design, such as well orientation, landing interval, pump rate and job volume, perforation spacing, and stage spacing. With the hydraulic fracture or SRV geometries derived from the geomechanics modelling, the reservoir simulation workflow was then performed to evaluate EUR uncertainty and estimate the EUR uplift based on geomechanics modeling results hydraulic fracture or SRV geometries from both the reference and optimized cases. These derived hydraulic fracture geometries and their corresponding SRVs were built in the reservoir simulation model and history matched to generate EUR ranges through multiple-realizations.
Objectives: this study aimed to evaluate the relationship of Nutritional Risk Screening 2002 (NRS2002) and in-hospital major adverse cardiac events (MACE) in patients with severe heart failure. Methods: an observational study was conducted at the emergency intensive care units (EICU) of Shandong University Qilu Hospital from January 2017 to December 2019. Nutritional screening and assessment were performed at the time of admission to hospital with the NRS2002. Results: of the 209 patients included, 16 cases (7.66 %) were not at nutritional risk, and 193 cases (92.34 %) were at risk. Among them, 12 cases (5.74 %) were malnourished, 38 cases (18.18 %) were at high nutritional risk, and 115 cases (55.02 %) were overweight and obese. The differences in prealbumin (PA) and N-terminal B-type natriuretic peptide precursor (NT-proBNP) between the 2 groups were statistically significant (p < 0.05). A total of 134 cases (64.12 %) received nutrition treatment support, of which 39 cases (29.10 %) received enteral nutrition (EN), 77 cases (57.46 %) parenteral nutrition, and 18 cases (13.43 %) enteral nutrition combined with parenteral nutrition (EN + SPN) support treatment. In all, 31 cases (54.39 %) reached 100 % of the target dose. Patients in the EN and EN + SPN groups had 37 MACE (64.91 %) and 31 enteral nutrition complications (54.39 %), with differences between the 3 groups being statistically significant (p < 0.05). Conclusion: the nutritional risk of patients with severe heart failure is high, and age and heart function are positively correlated with nutritional risk. The complications rate of patients with high nutritional risk is significantly higher than in those with low risk; the higher the nutritional risk, the higher the hospital mortality rate - that is, nutritional risk affects disease outcome.Objetivos: este estudio tuvo como objetivo evaluar la relación del Nutritional Risk Screening 2002 (NRS2002) con los eventos cardiacos adversos mayores intrahospitalarios (MACE) en pacientes con insuficiencia cardiaca grave. Métodos: se realizó un estudio observacional en las unidades de cuidados intensivos de emergencia (UCIE) del Hospital Qilu de la Universidad de Shandong desde enero de 2017 a diciembre de 2019. Se realizaron un cribado y una evaluación nutricional en el momento del ingreso hospitalario con el NRS2002. Resultados: de los 209 pacientes incluidos, 16 casos (7,66 %) no tenían riesgo nutricional y 193 casos (92,34 %) sí lo tenían. Entre ellos, 12 casos (5,74 %) estaban desnutridos, 38 casos (18,18 %) tenían un alto riesgo nutricional y 115 casos (55,02 %) tenían sobrepeso u obesidad. Las diferencias de prealbúmina (PA) y precursor del péptido natriurético de tipo B N-terminal (NT-proBNP) entre los 2 grupos fueron estadísticamente significativas (p < 0,05). En total, 134 casos (64,12 %) recibieron soporte de tratamiento nutricional, de los que 39 casos (29,10 %) recibieron nutrición enteral (NE), 77 casos (57,46 %) nutrición parenteral y 18 casos (13,43 %) nutrición enteral combinada con nutrición parenteral (NE + SPN) como tratamiento de apoyo. Treinta y un casos (54,39 %) alcanzaron la dosis objetivo al 100 %. Los pacientes de los grupos EN y EN + SPN tuvieron 37 MACE (64,91 %) y 31 complicaciones de la nutrición enteral (54,39 %), siendo la diferencia entre los 3 grupos estadísticamente significativa (p < 0,05). Conclusiones: el riesgo nutricional de los pacientes con insuficiencia cardíaca grave es alto; la edad y la función cardiaca se correlacionan positivamente con el riesgo nutricional. La complicación de los pacientes con alto riesgo nutricional es significativamente mayor que la de los de bajo riesgo; cuanto mayor es el riesgo nutricional, mayor es la tasa de mortalidad hospitalaria, es decir, el riesgo nutricional afecta el resultado de la enfermedad.
Intracoronary (IC) glycoprotein IIb/IIIa inhibitors (GPIs) after thrombus aspiration (TA) for patients with ST-segment elevation myocardial infarction (STEMI), as compared with percutaneous coronary interventions (PCI) alone, is still on debate. To address this issue, we performed a meta-analysis of results from prospective or randomized controlled trials on the topic.We searched electronic and printed sources (up to June 20, 2016) according to the selection criteria. Data were abstraction and meta-analysis was performed using RevMan 5.3 software.The cohorts involved 14 articles describing 1,918 participants were included. The incidence of the short-term major adverse cardiac events (MACE) was significantly reduced with intracoronary GPIs after TA (odds ratio [OR]: 0.29; 95% confidence interval [CI]: 0.13 to 0.65, p=0.003). Benefits were noted for short-term mortality (OR: 0.31; 95% CI: 0.17 to 0.57, p=0.0002) and reinfarction (OR: 0.28; 95% CI: 0.10 to 0.78, p=0.01) in subjects who received intracoronary GPIs after TA. Moreover, the Thrombolysis in Myocardial Infarction (TIMI) trial grade 3 postprocedure (OR: 2.29; 95% CI: 1.72 to 3.04, P<0.00001) and complete ST-segment resolution (STR) rate (OR: 2.68; 95% CI: 1.85 to 3.87, P<0.00001) were both improved with intracoronary GPIs after TA. As a result, left ventricular ejection fraction (LVEF) at short-term follow-up showed a significant difference (OR: 7.33; 95% CI: 5.60 to 9.06, p<0.0001) in favor of the TA and intracoronary GPIs administration.Our study demonstrates that intracoronary GPIs may have a synergistic effect with thrombus aspiration on short-term mortality, reinfarction, and cardiac functional recovery.
The use of involved field radiotherapy (IFRT) has generated concern about the increasing incidence of elective nodal failure (ENF) in contrast to elective nodal irradiation (ENI). This meta-analysis aimed to provide more reliable and up-to-date evidence on the incidence of ENF between IFRT and ENI. We searched three databases for eligible studies where locally advanced non-small cell lung cancer (NSCLC) patients received IFRT or ENI. Outcome of interest was the incidence of ENF. The fixed-effects model was used to pool outcomes across the studies. There were 3 RCTs and 3 cohort studies included with low risk of bias. There was no significant difference in incidence of ENF between IFRT and ENI either among RCTs (RR = 1.38, 95 % CI: 0.59–3.25, p = 0.46) or among cohort studies (RR = 0.99, 95 % CI: 0.46–2.10, p = 0.97). There was also no significant difference in incidence of ENF between IFRT and ENI when RCTs and cohort studies were combined (RR = 1.15, 95 % CI: 0.65–2.01, p = 0.64). I 2 of test for heterogeneity was 0 %. This meta-analysis provides more reliable and stable evidence that there is no significant difference in incidence of ENF between IFRT and ENI.
Ischemic manifestations of atherosclerosis are mainly due to thrombus formation upon superficially eroded (denudation of luminal endothelium) plaques or deeply ruptured (fibrous cap rupture) plaques. Eroded plaques, atherosclerotic plaques without rupture, are found common in young patients of sudden death with coronary thrombosis. Our study aimed to investigate the role of endothelial cell (EC) apoptosis in eroded plaque with thrombosis using an atherosclerotic rabbit model. Atherosclerotic plaques were established by post-balloon-injury high-cholesterol feeding in 33 rabbits. After three-month feeding, a 2-cm segment of plaque-rich abdominal aorta for each animal was clamped in vivo and filled with staurosporine, which induces endothelial apoptosis, or saline for 20 minutes. Three days later, serum lipids and high sensitive C-reactive protein (hs-CRP), a valuable inflammatory parameter, were quantified, and abdominal aorta angiography was conducted. In addition, immunohistochemistry staining was performed for all processed aortae. In the staurosporine-treated aorta, endothelium integrity of plaques was disrupted partially or in large areas, but fibrous cap rupture was not observed, the findings of which were similar to eroded plaques detected in human subjects. As compared to saline controls, staurosporine-treated rabbits showed higher apoptosis scores and thrombotic scores, and more angiographic overt thrombosis and histological thrombosis (P < 0.01, respectively), despite the similar serum levels of lipids and hs-CRP. We further confirmed that apoptosis score was linearly associated with thrombotic score. These results suggest that endothelial apoptosis may be an independent risk factor for thrombosis. In conclusion, the increase in endothelial apoptosis is involved in the formation of thrombotic eroded plaques.
Background: Double blood supply to the anterior descending artery is a rare finding of coronary angiography. However, infective endocarditis (IE) combined with anomalous double blood supply to the anterior descending artery has not been reported. Case presentation: A 58-year-old male previously diagnosed with IE came to the emergency department with complaints of chest tightness and dyspnea. Further examination confirmed severe aortic valve regurgitation combined with IE and anomalous double blood supply to the anterior descending artery. The cardiopulmonary bypass surgery was performed by direct perfusion through the normal left and right coronary openings. After surgery, the heart started beating again normally without any cardiogenic ischemic events. Conclusion: Cardiopulmonary bypass by direct perfusion was safe in the patient with anomalous double blood supply to the anterior descending artery.
Abstract Does the sub-surface drive completion design or is the rock less of a concern with industry trends to higher proppant-, fluid- and stage-intensities? To address this challenge it was first necessary to understand; 1) how the sub-surface could potentially influence completion and stimulation design, 2) what are the available engineering levers and moreover, 3) whether well performance has actually been impacted by tailoring completions in different plays from specific case-studies. Although there is a multitude of published field examples of how completion design changes have driven value, clarity around the inter-connectedness with sub-surface variability, either between plays or within a play, is commonly missing. New templates have been developed that describe the conceptual links between the nine key 'Sub-surface Drivers' for hydraulic fracturing and their associated engineering Levers categorized by well-, fluid-, proppant- and stage-design. These templates are a compilation of extensive empirical observations from both operations and field performance reviews incorporating thousands of wells across North America, supported with learnings from geomechanical theory and modeling. The nine Sub-surface Drivers that influence completion design and control the access to hydrocarbons are, 1) mobility, 2) reservoir pressure, 3) gross thickness, 4) layering heterogeneity, 5) rock stiffness, 6) natural fractures, 7) stress anisotropy, 8) risk of fraccing faults and, 9) risk of fraccing out of zone. Drivers 1-7 govern the connectivity, whereas 8 and 9 influence stimulation ineffectiveness. It is proposed that there are approximately fifteen primary engineering Levers related to these nine Drivers, which have been shown to have a measurable impact on completion effectiveness and/or production. Case studies illustrate that the Sub-surface Drivers play a significant role in most plays, but they are not all relevant in every play. The challenge is to acknowledge the variability, or lack of, and pursue completion design optimization goals, while managing the variance in the well performance range. Whereas industry trends of increasing completions intensity have delivered more value in many plays, the Sub-surface Drivers concept have primarily proven useful to mitigate against poor wells in development and explain exploration failures. By developing a systematic set of templates for Drivers and their respective levers, learnings from other operators can be high-graded through the formulation of connectivity analogues with the goal of showing where changes in completion design may be more, or less applicable.
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