Mass and Heat Transfer of Thermochemical Fluids in a Fractured Porous Medium

The desire to improve hydraulic fracture complexity has encouraged the use of thermochemical additives with fracturing fluids. These chemicals generate tremendous heat and pressure pulses upon reaction. This study developed a model of thermochemical fluids’ advection-reactive transport in hydraulic fractures to better understand thermochemical fluids’ penetration length and heat propagation distance along the fracture and into the surrounding porous media. These results will help optimize the design of this type of treatment. The model consists of an integrated wellbore, fracture, and reservoir mass and heat transfer models. The wellbore model estimated the fracture fluid temperature at the subsurface injection interval. The integrated model showed that in most cases the thermochemical fluids were consumed within a short distance from the wellbore. However, the heat of reaction propagated a much deeper distance along the hydraulic fracture. In most scenarios, the thermochemical fluids were consumed within 15 ft from the fracture inlet. Among other design parameters, the thermochemical fluid concentration is the most significant in controlling the penetration length, temperature, and pressure response. The model showed that a temperature increase from 280 to 600 °F is possible by increasing the thermochemical concentration. Additionally, acid can be used to trigger the reaction but results in a shorter penetration length and higher temperature response

Hypertensive disorders in women with peripartum cardiomyopathy: insights from the ESC EORP PPCM Registry

Aims: Hypertensive disorders occur in women with peripartum cardiomyopathy (PPCM). How often hypertensive disorders co-exist, and to what extent they impact outcomes, is less clear. We describe differences in phenotype and outcomes in women with PPCM with and without hypertensive disorders during pregnancy. Methods: The European Society of Cardiology PPCM Registry enrolled women with PPCM from 2012-2018. Three groups were examined: 1) women without hypertension (‘PPCM-noHTN’); 2) women with hypertension but without pre-eclampsia (‘PPCM-HTN’); 3) women with pre-eclampsia (‘PPCM-PE’). Maternal (6-month) and neonatal outcomes were compared. Results: Of 735 women included, 452 (61.5%) had PPCM-noHTN, 99 (13.5%) had PPCM-HTN and 184 (25.0%) had PPCM-PE. Compared to women with PPCM-noHTN, women with PPCM-PE had more severe symptoms (NYHA IV in 44.4% and 29.9%, p<0.001), more frequent signs of heart failure (pulmonary rales in 70.7% and 55.4%, p=0.002), higher baseline LVEF (32.7% and 30.7%, p=0.005) and smaller left ventricular end diastolic diameter (57.4mm [±6.7] and 59.8mm [±8.1], p<0.001). There were no differences in the frequencies of death from any cause, re-hospitalization for any cause, stroke, or thromboembolic events. Compared to women with PPCM-noHTN, women with PPCM-PE had a greater likelihood of left ventricular recovery (LVEF≥50%) (adjusted OR 2.08 95% CI 1.21-3.57) and an adverse neonatal outcome (composite of termination, miscarriage, low birth weight or neonatal death) (adjusted OR 2.84 95% CI 1.66-4.87). Conclusion: Differences exist in phenotype, recovery of cardiac function and neonatal outcomes according to hypertensive status in women with PPCM