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In terms of the collaborative optimization of CO2 flooding for Enhanced Oil Recovery (EOR) and CO2 sequestration, previous studies have co-optimized both cumulative oil production and CO2 sequestration by various algorithms. However, these solutions fail to optimize the CO2 injection schemes for high-water cut oil reservoirs. This paper presents an optimization methodology for CO2 flooding and sequestration in high-water cut oil reservoirs. The production optimization was carried out by adjusting the injection and production rate. To solve the proposed objective functions, the simultaneous perturbation stochastic approximation (SPSA) algorithm is applied in this paper, and the CMG-GEM module is utilized to simulate the reservoir production performance. A typical high-water cut reservoir in the Shengli oilfield was used to verify the feasibility of the presented methodology. In this paper, the production performance and net present value (NPV) for continuous gas injection under different water cuts were analyzed. The optimal timing of transforming from water flooding to gas displacement for the high-water cut reservoir was optimized. In addition, the optimal water–gas ratios for Water-Alternating-Gas (WAG) flooding were determined. The sensitivity of NPV to gas injection price and carbon subsidy was analyzed. The results show that when the gas price is 0.178 $/m3 and the carbon subsidy is 0.0169 $/m3, the optimal timing of transforming from water flooding to gas injection should be earlier than the time when the water cut is 0.82. Through the combination of NPV, cumulative oil production rate, and CO2 sequestration volume for WAG flooding, the optimal WAG ratio should be 1:2. The presented method in this paper considers various economic indicators and can optimize CO2 flooding and sequestration in high-water cut oil reservoirs efficiently, which can provide some guidance for the design of CO2 flooding schemes in high-water cut oil reservoirs. [ABSTRACT FROM AUTHOR]

Objective: To analyze the diagnostic efficacy of the periportal hypoechoic band (PHB) in the histological stage of patients with primary biliary cholangitis (PBC). Methods: We prospectively included 77 cases of PBC pathologically or clinically confirmed, and high-frequency ultrasound (HFUS) measurements of the PHB were performed in all included patients. Ludwig staging system of histopathology was used as the gold standard. Results: The width of the PHB was positively correlated with histological staging (r = 0.844, p < 0.001). By area under the receiving operating characteristic curve (AUROC), the best cutoff value for PHB for advanced stage (≥ stage 3) was 2.4 mm (AUROC: 0.934; 95%CI: 0.841–0.981) and 0.93 for sensitivity, and 0.91 for specificity, the concordance rates of PHB vs. liver biopsy was 90.3%. The correct rate for early-stage PBC was 87.9% and for the progressive stage was 93.1%. After multi-factor regression analysis, the PHB (OR = 1.331, CI = 1.105–1.603, p = 0.003) and total bilirubin (OR = 1.156, CI = 1.041–1.285, p = 0.007) were independent influencing factors for progressive PBC. Conclusions: Measurement of the PHB to assess advanced PBC is a simple and effective method. This method may complement current methods for the histological staging assessment of patients with PBC. Registration: Clinical trial registration: ChiCTR 2000032053, 2020/04/19. Clinical relevance statement: The measurement of periportal hypoechoic band (PHB) provides a simple and easy assessment of the degree of disease progression in patients with PBC and provides an important clinical reference in predicting the histological staging of PBC from an ultrasound perspective. Key Points: • The PHB is correlated with histological staging in the patient with PBC. • The area under the ROC curves of PHB for detecting advanced stage (≥ stage 3) were 0.934 and 0.93 for sensitivity, and 0.91 for specificity, the concordance rates of PHB vs. liver biopsy was 90.3%. The application of PHB can better assess the advanced PBC. • Measurement of the PHB to assess advanced PBC is a simple and effective method that can significantly reduce the need for liver biopsy. [ABSTRACT FROM AUTHOR]

In this study, the effects of different treatments (annealing, solid solution and Solution + aging) on the bending and thermal conductivity of SiCp/Al composites fabricated by the pressure infiltration method were investigated. The fracture form of the composites was indicated to be characteristic brittle fracture with local ductile fracture. The bending strength of the composites was 674 MPa with Solution + aging, which is 57% higher than that in the as-cast condition. The microhardnesses of the composites increased after heat treatment, resulting in the maximum microhardness 276 HV with Solution + aging. By calculating the thermal conductivity of the composites, the order was determined to be cast < annealed < solid solution < solution + aging, and the thermal conductivity with solution + aging treatment reached 182 m–1 K–1, which is higher than 153 m–1 K–1 in the as-cast condition. [ABSTRACT FROM AUTHOR]

Objective: The non-invasive discrimination of significant fibrosis (≥ F2) in patients with chronic liver disease (CLD) is clinically critical but technically challenging. We aimed to develop an updated deep learning radiomics model of elastography (DLRE2.0) based on our previous DLRE model to achieve significantly improved performance in ≥ F2 evaluation. Methods: This was a retrospective multicenter study with 807 CLD patients and 4842 images from three hospitals. All of these patients have liver biopsy results as referenced standard. Multichannel deep learning radiomics models were developed. Elastography images, gray-scale images of the liver capsule, gray-scale images of the liver parenchyma, and serological results were gradually integrated to establish different diagnosis models, and the optimal model was selected for assessing ≥ F2. Its accuracy was thoroughly investigated by applying different F0–1 prevalence cohorts and independent external test cohorts. Analysis of receiver operating characteristic (ROC) curves was performed to calculate the area under the ROC curve (AUC) for significance of fibrosis (≥ F2) and cirrhosis (F4). Results: The AUC of the DLRE2.0 model significantly increased to 0.91 compared with the DLRE model (AUC 0.83) when evaluating ≥ F2 (p = 0.0167). However, it did not show statistically significant differences as integrating gray-scale images and serological data into the DLRE2.0 model. AUCs of DLRE and DLRE2.0 increased, when there was higher F0–1 prevalence. All radiomics models had good robustness in the independent external test cohort. Conclusions: DLRE2.0 was the most suitable model for staging significant fibrosis while considering the balance of diagnostic accuracy and clinical practicability. Key Points: • The non-invasive discrimination of significant fibrosis (≥ F2) in patients with chronic liver disease (CLD) is clinically critical but technically challenging. • We aimed to develop an updated deep learning radiomics model of elastography (DLRE2.0) based on our previous DLRE model to achieve significantly improved performance in ≥ F2 evaluation. • Our study based on 807 CLD patients and 4842 images with liver biopsy found that DLRE2.0 was the most suitable model for staging significant fibrosis while considering the balance of diagnostic accuracy and clinical practicability. [ABSTRACT FROM AUTHOR]

The original version of this article, published on 24 September 2020, unfortunately contained a mistake. [ABSTRACT FROM AUTHOR]

Objectives: To systematically review studies on the diagnostic accuracy of spleen stiffness measurement (SSM) for the detection of clinical significant portal hypertension (CSPH), severe portal hypertension (SPH), esophageal varices (EV), and high-risk esophageal varices (HREV) in patients with chronic liver diseases (CLD). Methods: Through a systematic search, we identified 32 studies reporting the accuracy of SSM for the diagnosis of portal hypertension (PH) and/or EV in adults with CLD. A bivariate random-effects model was performed to estimate pooled sensitivity, specificity, likelihood ratio, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratios (DOR). The clinical utility of SSM was evaluated by Fagan plot. Results: A total of 32 studies assessing 3952 patients were included in this meta-analysis. The pooled sensitivities of SSM were 0.85 (95% confidence interval (CI), 0.69–0.93) for CSPH; 0.84 (95% CI, 0.75–0.90) for SPH; 0.90 (95% CI, 0.83–0.94) for any EV; and 0.87 (95% CI, 0.77–0.93) for HREV. The pooled specificities of SSM were 0.86 (95% CI, 0.74–0.93) for CSPH; 0.84 (95% CI, 0.72–0.91) for SPH; 0.73 (95% CI, 0.66–0.79) for EV; and 0.66 (95% CI, 0.53–0.77) for HREV. Summary PPV and NPV of SSM for detecting HREV were 0.54 (95% CI, 0.47–0.62) and 0.88 (95% CI, 0.81–0.95), respectively. Conclusions: Our meta-analysis suggests that SSM could be used as a helpful surveillance tool in management of CLD patients and was quite useful for ruling out the presence of HREV thereby avoiding unnecessary endoscopy. Key Points: • SSM could be used to rule out the presence of HREV in patients with CLD thereby avoiding unnecessary endoscopy. • SSM has significant diagnostic value for CSPH and SPH with high sensitivity and specificity in patients with CLD. • SSM could be used as a helpful surveillance tool for clinicians managing CLD patients. [ABSTRACT FROM AUTHOR]

Based on the theory of unsteady elliptical flow in porous media, coupling elliptic flow in a reservoir matrix with high-velocity non-Darcy flow in hydraulic fractures, a new productivity prediction model is presented for multi-fractured horizontal wells (MFHWs) considering multi-fracture drainage response, which includes stress interferences between multi-fracture in a tight sandstone oil reservoir. A reasonable solution of the theoretical model is obtained and verified by the case of a real tight sandstone oil reservoir. Through theoretical calculation, the response law of multi-fracture elliptical drainage is revealed, and the factors influencing productivity are analyzed. The results show that the response areas which are the affected areas of multi-fracture stress interferences influenced by multi-fracture elliptical drainage extend with the production time gradually, and the propagation speed of the minor axis is larger than the major axis, which leads to the flow pattern changing from elliptical flow to pseudo-radial flow. The neighboring drainage areas controlled by fractures will intersect, and mutual interference will occur. The effective drainage area decreases gradually, which causes the production rate to decline quickly. When the threshold pressure gradient is considered, the MFHW production rate decreases obviously. The fracture length has a greater impact on the production rate than flow conductivity. The researched results have practical significance to some extent on improving the flow theory of MFHW in tight sandstone oil reservoirs. [ABSTRACT FROM AUTHOR]

Objectives: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Methods: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Results: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Conclusion: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Clinical relevance statement: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Key Points: The Baveno VII consensus recommends endoscopic screening for varicose veins in cases of liver stiffness measurement (LSM) ≥ 20 kPa or platelet count ≤ 150 × 109/L. Whether this approach was appropriate for patients with primary biliary cholangitis (PBC) remains uncertain. This study expanded the observed risk factors by adding analysis of ultrasound images as a non-invasive tool to predict the risk of esophageal or fundic varices.We enrolled 111 patients with PBC whose complete ultrasound images, measurement data, and LSM data were available. The value of the periportal hypoechoic band (PHB), splenic area, and LSM in determining the risk of varicose veins and variceal rupture was analyzed. A prospective cohort of 67 patients provided external validation.The area under the receiver operating characteristic curve (AUC) for predicting varicose veins using LSM > 12.1 kPa or splenic areas > 41.2 cm2 was 0.806 (95% confidence interval (CI): 0.720–0.875) and 0.852 (95% CI: 0.772–0.912), respectively. This finding could assist in avoiding endoscopic screening by 76.6% and 83.8%, respectively, with diagnostic accuracy surpassing that suggested by Baveno VII guidelines. The AUCs for predicting variceal rupture using splenic areas > 56.8 cm2 was 0.717 (95% CI: 0.623–0.798). The diagnostic accuracy of PHB for variceal rupture was higher than LSM and splenic areas (75.7% vs. 50.5% vs. 68.5%).We recommend LSM > 12.1 kPa as a cutoff value to predict the risk of varicosity presence in patients with PBC. Additionally, the splenic area demonstrated high accuracy and relevance for predicting varicose veins and variceal rupture, respectively. The method is simple and reproducible, allowing endoscopy to be safely avoided.The measurement of the splenic area and identification of the periportal hypoechoic band (PHB) on ultrasound demonstrated high accuracy and relevance for predicting the risk of esophageal or fundic varices presence and variceal rupture, respectively.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided.Predicting varices in patients with primary biliary cholangitis (PBC) can reduce the morbidity and mortality of gastrointestinal hemorrhage.Transient elastography (TE) and ultrasound play an important role in predicting patients with PBC with varices.TE and ultrasound can predict varicose veins and variceal rupture. Liver stiffness measurement and splenic area measurements can allow endoscopy to be safely avoided. [ABSTRACT FROM AUTHOR]

Further development of stimulated reservoir volume (SRV)-fracturing technologies for horizontal wells is necessary to address the current situation of decreasing energy production from conventional sources and continuous increases in the proportion of alternative energy sources (unconventional hydrocarbons). To this end, the theoretical productivity prediction methods used for SRV-fractured horizontal wells must be studied. In this article, based on a structural description of hydraulic fracture networks around horizontal wells, we summarize and evaluate various types of productivity prediction models built by researchers using analytical, semi-analytical, and numerical methods. We find that while these models are convenient and efficient, analytical models are overly ideal and differ considerably from actual fracture network patterns. We also find that semi-analytical models offer high computational accuracy but are applicable only to the prediction of single-well single-phase productivity. Furthermore, numerical models can address more complex fracture network patterns and can be used to calculate the multi-phase productivity of well patterns but involve a complex initial input process. On this basis, we summarize the problems and challenges associated with the existing productivity prediction models and specify five pertinent key techniques involved in building more accurate productivity prediction models: the techniques for describing complex fracture network structures; the technique for simulating multi-phase flows in reservoirs; the multi-scale multi-field flow coupling theory; the technique for calculating numerical solutions for complex models; and the technique for matching well type, well pattern, and fracture network systems. [ABSTRACT FROM AUTHOR]