FEATURES FORMATION ZONE OF WAVES AND BURSTS ON THE SURFACE LADLE BATH

The results studies influence physicochemical properties and thickness cover slag, formed during ladle desulfurization pig iron by blowing a mixture of lime and magnesium, features formation a breaker on the surface bath and the level of metal losses with emissions outside ladle from this zone are presented. The necessity creating conditions for ensuring height breaker, which would not exceed thickness slag layer on the surface bath, has been substantiated. Using results of the high-temperature simulation blowing the cast iron melt with a neutral gas supplied through the nozzles tips stationary and rotating submersible lances, features development of counter waves and metal splashes in the absence and during formation slag cover with thickness of 30—80 mm on the surface bath are determined. The features change in the height and area breakers are determined depending on the gas flow rate for blowing bath and thickness slag. Based on the analysis results low-temperature modeling bath blowing, scientific ideas about the combined effect of the bath blowing intensity, speed of rotation submerged lance and thickness slag layer on the diameter bubbling zone, gas saturation of the bath and features wave formation on its surface in the slag-free zone were further developed (so-called «eye»). The nature relationship between length of the gas jet from lance nozzle, diameter «eye», and geometric parameters breaker has been established. It is shown that dependence profile breaker on speed of rotation lance and thickness slag layer is nonlinear. So, blowing bath through tip of a rotating lance with one nozzle at 240 rpm. with a gas flow rate of 2.2 l/min. creates conditions for raising top breaker to a height that is 33 % higher than the current thickness slag layer and contributes to the intensification formation of waves and bursts on the surface bath. With a decrease in the gas flow rate to 1.0 l/min., Under other unchanged conditions, height breaker is already 2/3 of the height slag layer, and as thickness slag decreases proportionally decreases. The smallest, recorded in the experiments, relative height breaker was 33.3% of the slag thickness at a lance rotation speed in the range of 90—120 rpm. Mathematical models are proposed that are suitable for calculating height breakers depending on the thickness slag layer, speed of rotation lance and intensity of gas injection into the bath. Taking into account established mutually opposite effect thickness of the cover slag layer and speed of rotation submerged lance on the «eye» area and height of the breaker, it is advisable to continue search for ways to improve design tip submerged lance and slag mode of ladle desulfurization.

Integration of Post-Fracturing Spectral Noise Log, Temperature Modeling, and Production Log Diagnoses Water Production and Resolves Uncertainties in Openhole Multistage Fracturing

Hydrocarbon development from tight gas sandstone reservoirs is revolutionizing the current oil and gas market. The most effective development strategy for ultralow- to low-permeability reservoirs involves multistage fracturing. A cemented casing or liner completed with the plug-and-perf method allows nearly full control of fracture initiation depth. In uncemented completions equipped with fracturing sleeves and packers, clearly identifying the fracture initiation points is difficult due to lack of visibility behind the completion and long openhole intervals between packers. Also, the number of fractures initiated in each treatment is uncertain. A lateral was completed with access to 3,190 ft of openhole section across five fracturing stages in a high-temperature and high-pressure tight-gas interval. All stages were successfully stimulated, fracture cleanup flowback was conducted, and entry ports were milled out. A high-definition spectral noise log (SNL) was then conducted along with numerical temperature modeling. Additional logging was done with a set of conventional multiphase sensors. A multi-array production log suite was also performed. Finally, the bottom four stages were isolated with a high-temperature isolation plug based on the integrated diagnosis. The SNL helped to analyze the isolation packer integrity behind the liner. The initiation of multiple fractures was observed, with as many as nine fractures seen in a single-stage interval. A correlation was found between the openhole interval length and the number of fractures. A correlation of fracture gradient (FG) and initiation depths was made for the lateral in a strike-slip fault regime. The fractures were initiated at depths with low calculated FG, confirming the conventional understanding and increasing confidence in rock property calculations from openhole log data. SNL and temperature modeling aided quantitative assessment of flowing fractures and stagewise production behind the liner. Multi-array production logging results quantified the flow and flow profile inside the horizontal liner. The production flow assessments from both techniques were in good agreement. The integration of several datasets was conducted in a single run, which provided a comprehensive understanding of well completion and production. High water producing intervals were isolated. Downstream separator setup after the isolation showed a water cut reduction by 95%. The integration of the post-fracturing logs with the openhole logs and fracturing data is unique. The high-resolution SNL provided valuable insight on fracture initiation points and the integrity of completion packers. Fracturing efficiency, compared to the proppant placed, provides treatment optimization for similar completions in the future.

3D Measurement of ESP Motor Skin Thermal Profile in Horizontal SAGD Well

A high-density 3D Electric Submersible Pump (ESP) motor skin thermal measurement project was carried out in an operating Steam Assisted Gravity Drainage (SAGD) well under varying ESP operating conditions. Utilizing high density Bragg grating fiber and a novel fiber optic interrogator technology a fiber optic measurement string was developed to allow for temperature measurement in 4 cm spacing and on 5 sides of an ESP motor. Utilizing this technology, a special ESP motor housing was developed, and a novel means of fiber optic string deployment engineered which allowed an instrumented ESP motor to be installed in an operating SAGD wellbore and a 3D high density thermal profile to be obtained under operating conditions. The ESP was installed in a SAGD well in a relatively horizontal orientation and utilized a bottom-inflow style pump intake. The ESP was operated in several loading and flow rate scenarios to observe the effects of operating in different conditions. The objective of the testing program was to measure the thermal profile around the circumference and length of the ESP motor both to understand potential temperature differentials across the ESP motor and what thermal transfer may be occurring to the surrounding production fluid passing the ESP motor. The information collected from this testing program is intended to further the understanding of how the thermal profile of the ESP motor correlates with wellbore temperature, ESP motor loading and motor temperature modeling predictions.

Daily soil temperature modeling improved by integrating observed snow cover and estimated soil moisture in the USA Great Plains

Soil temperature (Ts) plays a critical role in land–surface hydrological processes and agricultural ecosystems. However, soil temperature data are limited in both temporal and spatial scales due to the configuration of early weather station networks in the USA Great Plains. Here, we examined an empirical model (EM02) for predicting daily soil temperature (Ts) at the 10 cm depth across Nebraska, Kansas, Oklahoma, and parts of Texas that comprise the USA winter wheat belt. An improved empirical model (iEM02) was developed and calibrated using available historical climate data prior to 2015 from 87 weather stations. The calibrated models were then evaluated independently, using the latest 5-year observations from 2015 to 2019. Our results suggested that the iEM02 had, on average, an improved root mean square error (RMSE) of 0.6 ∘C for 87 stations when compared to the original EM02 model. Specifically, after incorporating the changes in soil moisture and daily snow depth, the improved model was 50 % more accurate, as demonstrated by the decrease in RMSE. We conclude that, in the USA Great Plains, the iEM02 model can better estimate soil temperature at the surface soil layer where most hydrological and biological processes occur. Both seasonal and spatial improvements made in the improved model suggest that it can provide a daily soil temperature modeling tool that overcomes the deficiencies of soil temperature data used in assessments of climatic changes, hydrological modeling, and winter wheat production in the USA Great Plains.

Fe-based superconducting transition temperature modeling by machine learning: A computer science method

Searching for new high temperature superconductors has long been a key research issue. Fe-based superconductors attract researchers’ attention due to their high transition temperature, strong irreversibility field, and excellent crystallographic symmetry. By using doping methods and dopant levels, different types of new Fe-based superconductors are synthesized. The transition temperature is a key indicator to measure whether new superconductors are high temperature superconductors. However, the condition for measuring transition temperature are strict, and the measurement process is dangerous. There is a strong relationship between the lattice parameters and the transition temperature of Fe-based superconductors. To avoid the difficulties in measuring transition temperature, in this paper, we adopt a machine learning method to build a model based on the lattice parameters to predict the transition temperature of Fe-based superconductors. The model results are in accordance with available transition temperatures, showing 91.181% accuracy. Therefore, we can use the proposed model to predict unknown transition temperatures of Fe-based superconductors.