Soultz-sous-Forêts Geothermal Reservoir: Structural Model Update and Thermo-Hydraulic Numerical Simulations Based on Three Years of Operation Data

The geothermal powerplant of Soultz-sous-Forêts (France) is investigating the possibility of producing more energy with the same infrastructure by reinjecting the geothermal fluid at lower temperatures. Indeed, during the operation of the powerplant, the geothermal fluid is currently reinjected at 60–70 °C in a deep fractured granite reservoir, and the MEET project aims to test its reinjection at 40 °C. A 3D hydrothermal study was performed in order to evaluate the spreading of the thermal front during colder reinjection and its impact on the production temperature. In the first step, a 3D structural model at fault scale was created, integrating pre-existing models from 2D vintage seismic profiles, vertical seismic profiles, seismic cloud structure and borehole image logs calibrated with well data. This geometrical model was then adapted to be able to run hydrothermal simulation. In the third step, a 3D hydrothermal model was built based on the structural model. After calibration, the effect of colder reinjection on the production temperature was calculated. The results show that a decrease of 10 °C in the injection temperature leads to a drop in the production temperature of 2 °C after 2 years, reaching 3 °C after 25 years of operation. Lastly, the accuracy of the structural model on which the simulations are based is discussed and an update of the structural model is proposed in order to better reproduce the observations.

Fishing Ground Mapping Model in The Semi-Enclosed Saleh Bay, West Nusa Tenggara

Saleh Bay is a semi-enclosed area of water in Nusa Tenggara Barat Province that is enriched by fisheries resources. The bay’s strategic position, surrounded by several small islands, makes it an area of fertile water. An area of water is considered a potentially ideal fishing ground if it contains several oceanographic phenomena, including thermal fronts and upwelling. Fishing activities in Saleh Bay have been found to be ineffective and inefficient due to local people’s continued use of traditional methods such as fishing by signs of nature (instincts), wind direction, astrological signs and previous experience. This study aimed to create a mapping model of the fishing grounds in Saleh Bay based on remote sensing satellite data. Spatial analysis of daily level 3 images from the Suomi-National Polar-Orbiting Partnership (SNPP) was conducted throughout January and August 2019. The image acquisition period was adapted based on the seasonal system of Indonesia. The study area was determined based on thermal front events as identified by sea surface temperature (SST) data analysed using statistical regression with a Non-Linear Multi-Channel SST (NLSST) approach. An ideal fishing ground is characterised by several oceanographic settings such as upwelling and thermal front occurrence. The average SST distribution in January 2019 was relatively high, ranging from 30.39 to 33.70 oC, while in August 2019, the temperature declined significantly, ranging from 25.09 to 29.30 oC. Concerning the fishing ground model, a plethora of potential fishing ground areas were identified in August compared to January 2019, at 144 and 42 points respectively. This reflected the density of the fishing grounds observed. The fishing grounds were most likely to be concentrated in the bay mouth during the southwest monsoon and within the bay near the plateau during the northeast monsoon. The seasonal variability of Saleh Bay played a significant role in the spatial extraction of the fishing ground data.

Thermal Front Variability during The El Nino Southern Oscillation (ENSO) in The Banda Sea Using Remotely Sensed Data

The Banda Sea is one of the routes of global ocean currents that move from the Pacific Ocean to the Indian Ocean. This flow is known as Indonesian Through Flow (ITF). The Banda Sea is an area where warm and cold water masses meet, so it has the potential for a thermal front. This study aims to understand the variability of thermal front in the Banda Sea during the El Nino Southern Oscillation period. Southern Oscillation Index (SOI) and sea surface temperature (SST) data in 2010, 2012 and 2015 were used in this study. SOI data was obtained from http://www.bom.gov.au and SST data was obtained from http://oceancolor.gsfc.nasa.gov. The data were processed using ArcGIS 10.4 software and Ms. Office 2013. The results showed the La Nina period occurs in July - December 2010, the Normal period occurs in July - December 2012, and the El Nino period occurs in May - October 2015. In general, during La Nina, the mean SST has higher values than the other periods. On the other hand, the highest thermal front occurs during the El Niño period (10584), followed by the Normal period (7544) and the lowest during the La Niña period (5961), respectively.

Strong long-lived anticyclonic mesoscale eddies in the Balearic Sea: formation and intensification mechanisms

<p><span>Anticyclonic mesoscale eddies are often formed in the Balearic Sea towards the end of summer and autumn. In some years, these eddies become strong and persistent, modifying the ocean currents and water mass properties in the area. The generation and intensification mechanisms of two long-lived events observed in 2010 and 2017 were studied by means of the energy conversion terms associated with eddy-mean flow interactions and through complementary model sensitivity tests.</span></p><p><span>Results show that these eddies were formed through mixed barotropic and baroclinic instabilities. The former was associated with weak meandering of the shelf current near the coast produced by northwesterly wind events, and the latter with the existence of the northward intrusions of relatively warm waters through the intense Pyrenees thermal front. </span><span>The intensification mechanism varied between the two</span> <span>events. While in 2010 it was driven by intense salinity gradients in the Balearic Sea, in 2017 it resulted from an extra barotropic energy term fed by northwesterly winds.</span></p><p><span>These eddies lasted more than two months with a radius varying between 30km and 90km and a vertical structure that reached 1500 m depth. Their presence resulted in a 3ºC anomaly between the warm core waters and the outer parts of the eddies. </span></p>

MODELING OF HEATING AND MELTING PROCESSES OF HYDROCARBON MIXTURES WITH FORCED REMOVAL OF THE MELT

Analysis of the work, which considered the mathematical modeling of the melting process in various industries, currently does not pay attention to modeling the processes of heating and melting of hydrocarbon mixtures, such as vaseline, paraffin, fats, lanolin and others. The issue of optimization of heating and melting processes, calculations of necessary process parameters (speed and depth of thermal front penetration, etc.) and equipment, avoidance of repetition for each hydrocarbon mixture of experimental studies shows the need to develop a mathematical model of these processes. For the method of melting a substance placed in a cylindrical tank, based on the movement of a disc heating element under the action of gravity during melting and overflow of molten substance through the gaps between the disc and the walls of the tank, simulation has been carried out. Simulation of the melt flow in the annular gap is presented, which describes the laminar flow under the influence of the pressure drop and the velocity of the vessel wall relative to the heater, and the melt flow under the heater.

Effective thermal conductivity in granular media with devolatilization: the Lattice Boltzmann modelling

Flow thermomechanics in reactive porous media is of importance in industry including the thermal processing of fossil fuel (coking understood as a slow pyrolysis) involving devolatilisation. On the way to provide a detailed description of the process, a multi-scale approach was chosen to estimate effective transport coefficients. For this case the Lattice Boltzmann method (LBM) was used due to its advantages to accurately model multi-physics and chemistry in a random geometry of granular media. After account for earlier studies, the paper presents description of the model with improved boundary conditions and a benchmark case. Results from meso-scale LBM calculations are presented and discussed regarding the spatial resolution and the choice of relaxation parameter along its influence on the accuracy compared with empirical formulae. Regarding the estimation of effective thermal conductivity coefficient it is shown that occurrence of devolatilization has a crucial effect by reducing heat transfer. Some quantitative results characterise the propagation of thermal front; also presented is the evolution of effective thermal conductivity. The work is a step forward towards a physically sound simulation of thermal processing of fossil fuel.