Streamline Tracing and Sensitivity Calculation in Fractured Reservoir with Complex Geometry: Field Application to History Matching and Flood Optimization

The popularity of streamline application mainly depends on two aspects: efficient tracing algorithm to generate streamline, and effective flow and transport analysis along streamline. Previous studies proved its applicability for conventional resources such as waterflood in single and dual porosity models. Streamline technology has limited success in extension to fractured reservoir with discrete fracture networks due to lack of efficient tracing method in the complex porous media geometry. Streamline based application such as history matching and rate optimization also has limitation to gas reservoir depletion or fractured reservoir waterflood due to lack of effective streamline-based flow and transport analysis for highly compressible fluid and highly contrasted porous media. In this study, we first develop streamline tracing method in complex geometry such as faults and discrete fractures. The discrete fractures here are depicted by embedded discrete fracture model (EDFM). We are going to propose novel methods to construct boundary layers for fault non-neighbor connections and EDFM non-neighbor connections. The novel methods reduce the treatment of complex grid geometry to a minimum level and honor the flux of each connection. The utility and validity of this proposed approach is demonstrated using both 2D and 3D examples. Second, we propose an amended streamline-based travel time sensitivity formulation. This novel sensitivity formulation has improved accuracy than the legacy one when compared to numerical perturbed sensitivity, thus results in faster data misfit reduction. We also develop general streamline-based bottom hole pressure sensitivity calculation method suitable for highly compressible fluids or complex geometry caused by non-neighbor connections. The bottom hole pressure sensitivity calculation is validated by a successful history matching application to a high pressure high temperature gas reservoir. Finally, we develop a rate allocation optimization method based on fast estimation of oil recovery, which also applies to fractured reservoirs. The oil recovery is estimated along streamline within the drainage volume by the end of optimization period. The injection/production rates are updated to maximize the field oil recovery. The novel optimization method results in better performance than equalizing well pair injection efficiency or equalizing well pair time of flight when applying to a waterflood case in fractured reservoir. Its validation is further established by the waterflood optimization application to a field scale EDFM reservoir. We concluded that our proposed approach of streamline tracing, inversion and optimization algorithm extends streamline technology application to fractured media represented by discrete fracture networks and highly compressible fluid, leading to a highly effective reservoir management tool

Streamline Tracing and Sensitivity Calculation in Fractured Reservoir with Complex Geometry: Field Application to History Matching and Flood Optimization

The popularity of streamline application mainly depends on two aspects: efficient tracing algorithm to generate streamline, and effective flow and transport analysis along streamline. Previous studies proved its applicability for conventional resources such as waterflood in single and dual porosity models. Streamline technology has limited success in extension to fractured reservoir with discrete fracture networks due to lack of efficient tracing method in the complex porous media geometry. Streamline based application such as history matching and rate optimization also has limitation to gas reservoir depletion or fractured reservoir waterflood due to lack of effective streamline-based flow and transport analysis for highly compressible fluid and highly contrasted porous media. In this study, we first develop streamline tracing method in complex geometry such as faults and discrete fractures. The discrete fractures here are depicted by embedded discrete fracture model (EDFM). We are going to propose novel methods to construct boundary layers for fault non-neighbor connections and EDFM non-neighbor connections. The novel methods reduce the treatment of complex grid geometry to a minimum level and honor the flux of each connection. The utility and validity of this proposed approach is demonstrated using both 2D and 3D examples. Second, we propose an amended streamline-based travel time sensitivity formulation. This novel sensitivity formulation has improved accuracy than the legacy one when compared to numerical perturbed sensitivity, thus results in faster data misfit reduction. We also develop general streamline-based bottom hole pressure sensitivity calculation method suitable for highly compressible fluids or complex geometry caused by non-neighbor connections. The bottom hole pressure sensitivity calculation is validated by a successful history matching application to a high pressure high temperature gas reservoir. Finally, we develop a rate allocation optimization method based on fast estimation of oil recovery, which also applies to fractured reservoirs. The oil recovery is estimated along streamline within the drainage volume by the end of optimization period. The injection/production rates are updated to maximize the field oil recovery. The novel optimization method results in better performance than equalizing well pair injection efficiency or equalizing well pair time of flight when applying to a waterflood case in fractured reservoir. Its validation is further established by the waterflood optimization application to a field scale EDFM reservoir. We concluded that our proposed approach of streamline tracing, inversion and optimization algorithm extends streamline technology application to fractured media represented by discrete fracture networks and highly compressible fluid, leading to a highly effective reservoir management tool

Transcoding of MPEG-4 compressed video

MPEG-4 is an ISO/IEC standard, developed by the MPEG (Moving Picture Experts Group). The transmission of MPEG-4 compressed video over channels with different capacities may require a reduction in bit rate if the transmission media has a lower capacity than the capacity required by the bitstream. There are many different approaches to this problem of bit rate conversion. A feasible and effective method is transcoding. The emphasis in this thesis is on transcoding of MPEG-4 compressed video both in the pixel domain and in the DCT domain. In the pixel domain, (joint) transcoding of MPEG-4 compressed video with drift error correction is discussed in this thesis. In the DCT domain, a new DCT Coefficient Translation and Truncation Transformation Matrix (DCTTTM) based motion composition scheme is proposed, and several suboptimal approaches to reducing the computational complexity are discussed. In addition, frame-skipping transcoding of MPEG-4 compressed bitstreams in the DCT domain is addressed as well

Role of crystal-field-splitting and longe-range-hoppings on superconducting pairing symmetry of La3_3Ni2_2O7_7

We study the bilayer two-orbital model for superconducting pairing symmetry of La$_3$Ni$_2$O$_7$ under pressure. By combining density-functional-theory (DFT), maximally-localized-Wannier-function, and linearized Eliashberg equation with random-phase-approximation, we find that the superconducting pairing symmetry of La$_3$Ni$_2$O$_7$ is robustly $d_{xy}$ if its DFT band structure is accurately reproduced in the downfolded model. We further show that fine-tuning of crystal-field-splitting between two Ni-$e_g$ orbitals qualitatively affects superconducting pairing symmetry of the bilayer two-orbital model, which changes from $d_{xy}$ to $s_{\pm}$ as the crystal-field-splitting exceeds a critical value. When the model only includes nearest-neighbor and second-nearest-neighbor hoppings, the crystal-field-splitting obtained by fitting to the DFT band structure is larger than the critical value and thus leads to $s_{\pm}$ superconducting pairing symmetry. When all nonzero long-range-hoppings are also included in the model, the fitted crystal-field-splitting is reduced and smaller than the critical value, which makes $d_{xy}$ superconducting pairing symmetry more favorable than $s_{\pm}$ symmetry. Our work demonstrates that in downfolded effective models, the details of band structure can play a crucial role in determining pairing symmetry in multi-orbital unconventional superconductors (such as La$_3$Ni$_2$O$_7$).Comment: 11 pages and 4 figure

Reasonable Planning of King County's E-bus Replacement Plan

With the increasingly intensified global warming severe air pollutions, governments all over the world have begun or is right now looking for ways to fix the problem. Among all the solutions, sustainable urban transportation system is what many governments pay attention to because of their apparent contribution to the reduction in greenhouse gases emissions and pollutants. In this passage, we focus on the exact ecology impacts the promotion of e-buses will cause. On the other hand, the potential financial burdens the transitioning processes will bring are perceived by us in order to make a decent plan for the government to implement.For the first part of constructing the model to measure the ecology impact of transition in one area, we start with the identification of King County as a metropolitan area suitable for prediction. Then we collect information and data of its local bus fleet and e-bus transitioning plan, find out the exact number of each type of buses (diesel, hybrid and electric) around these years and the emissions of corresponding buses. We use both ARIMA and Least Squares Regression to predict the number these buses in the future until the year the local government aim to complete the plan but choose the result displayed by the better one. In this case, we obtain the data for emission of carbon dioxide, oxynitride and PM10 in each year and evaluate the ecological impact. At the same time, we predict the data for the emissions later if the bus fleet keep the same and observed over 90% of decline when we compare the value after transition to the control group.Afterwards, to estimate the financial cost, we identify the main parts involved in the processes of transitioning, classify them with one group of cost for long-term and the other for short-term---that is, changed as the plan is gradually implemented. We build models for each factor we identified and use Riemann Sum to unify the long-term and short-term costs. Based on the data we predict in problem one and from the local government’s website, we easily gain the financial implications of for about 50 million dollars in King County. Through the analysis of the government’s grant in other area, we roughly verify that 50 million dollars would be an acceptable cost.Finally, in our 10-year roadmap development, we explored further into the population distribution of King County and the existing traits for public transportation. Our starting point in this article is to classify the urban pattern into four types of bus operation routes, and then define the passenger flow from high to low. At the same time, we define the total number of vehicles that need to be replaced for different types to develop transportation replacement plans. Based on our assumptions, calculate the carrying capacity of each type of bus in line with the passenger flow. Eventually, it can be proven that the total carrying capacity of the bus meets the transportation needs of all King counties. Then apply to other regions

Comparación de las metodologías de clasificación de Marca País.

Una marca-país bien gestionada es un activo intangible muy valioso para cualquier nación del mundo actual. Muchos países han investigado e invertido en su marca nacional, por ejemplo, creando una institución nacional específica y transdepartamental para consolidar la influencia de la nación p.ej. Marca España; para mejorar su reputación e impulsar el turismo p.ej. Uruguay Natural; o para aumentar la exportación y la inversión extranjera p.ej. InvestHK. La marca-país forma parte del valor intangible de un país, es una medida importante para evaluar la imagen y la reputación de un país, es interdisciplinar e incluye el turismo, la economía, la comunicación o la diplomacia, entre otros aspectos. El objetivo de esta investigación es estudiar los trece rankings más conocidos de marcas nacionales existentes en el mercado (The Anholt-GfK Nation Brands Index (NBI), Futurebrand Country Brand Index, The FutureBrand Country Index y Global Soft Power Index) para comparar. Estos rankings se utilizan para evaluar la marca-país de más de 100 países, incluyendo dimensiones como la exportación, la gobernanza, la cultura y el patrimonio, la gente, el turismo, la inversión y la inmigración, etc. Utilizaremos un diseño metodológico que combina un análisis comparativo de los diferentes aspectos que miden cada ranking y entrevistas en profundidad, para conocer las opiniones de expertos sobre su utilidad y conveniencia, contactaremos con jefes de oficinas de turismo, agencias de inversiones, académicos y empresarios del sector, entre otros. Como resultados esperados, identificamos cuáles son las dimensiones esenciales en las mediciones de la marca país, así como los pros y los contras de los diferentes rankings y las futuras líneas a seguir.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effect of a Traditional Chinese Medicine combined therapy on adolescent idiopathic scoliosis: a randomized controlled trial

AbstractObjectiveTo evaluate the effectiveness of a combined Traditional Chinese Medicine (TCM) therapy versus conventional treatment on adolescent idiopathic scoliosis.MethodsOne hundred twenty outpatients with mild and moderate adolescent idiopathic scoliosis were randomly divided into a TCM group (TCMG) and a brace group (CG). TCMG patients underwent Daoyin, Tuina, and acupotomology therapies. CG patients were treated with a Milwaukee brace. Each patient's Cobb angle was measured after 12 and 24 months of treatment, and pulmonary function was determined after 12 months of treatment. Average electromyogram (AEMG) ratio of the surface electromyogram was measured after 6 and 12 months of treatment and followed-up after 18 and 24 months.ResultsThe Cobb angle significantly decreased in both groups after 12 months of treatment compared with before treatment (P < 0.05). The percentages of original Cobb angle in TCMG and CG were 51.4% and 47.8% (P > 0.05) after 12 months and 62.5% and 34.7% (P < 0.05) after 24 months, respectively. Pulmonary function significantly improved after 12 months in TCMG (P < 0.05) but significantly decreased in CG (P < 0.05). The AEMG ratio was significantly lower (P < 0.01) and tended to remain at 1 after stopping treatment in TCMG, but increased in CG (P < 0.05).ConclusionTCM combined therapy can prevent the progression of scoliosis. The AEMG ratio is a promising index that could replace radiography in the evaluation of treatment effect and progression in scoliosis

Fabrication of ultrahigh-density nanowires by electrochemical nanolithography

An approach has been developed to produce silver nanoparticles (AgNPs) rapidly on semiconductor wafers using electrochemical deposition. The closely packed AgNPs have a density of up to 1.4 × 1011 cm-2 with good size uniformity. AgNPs retain their shape and position on the substrate when used as nanomasks for producing ultrahigh-density vertical nanowire arrays with controllable size, making it a one-step nanolithography technique. We demonstrate this method on Si/SiGe multilayer superlattices using electrochemical nanopatterning and plasma etching to obtain high-density Si/SiGe multilayer superlattice nanowires

First identification of long non-coding RNAs in fungal parasite Nosema ceranae

International audienceAbstractNosema ceranae is a unicellular fungal parasite of honey bees and causes huge losses for apiculture. Until present, no study on N. ceranae long non-coding RNAs (lncRNAs) was documented. Here, we sequenced purified spores of N. ceranae using strand-specific library construction and high-throughput RNA sequencing technologies. In total, 83 novel lncRNAs were predicted from N. ceranae spore samples, including lncRNAs, long intergenic non-coding RNAs (lincRNAs), and sense lncRNAs. Moreover, these lncRNAs share similar characteristics with those identified in mammals and plants, such as shorter length and fewer exon number and transcript isoforms than protein-coding genes. Finally, the expression of 12 lncRNAs was confirmed with RT-PCR, confirming their true existence. To our knowledge, this is the first evidence of lncRNAs produced by a microsporidia species, offering novel insights into basic biology such as regulation of gene expression of this widespread taxonomic group

Electronic Structure of Superconducting Infinite-Layer Lanthanum Nickelates

Revealing the momentum-resolved electronic structure of infinite-layer nickelates is essential for understanding this new class of unconventional superconductors, but has been hindered by the formidable challenges in improving the sample quality. In this work, we report for the first time the angle-resolved photoemission spectroscopy of superconducting La$_{0.8}$Sr$_{0.2}$NiO$_{2}$ films prepared by molecular beam epitaxy and ${\mathrm{\textit{in situ}}}$ atomic-hydrogen reduction. The measured Fermi topology closely matches theoretical calculations, showing a large Ni-$d_{x^2-y^2}$ derived Fermi sheet that evolves from hole-like to electron-like along $k_{z}$, and a three-dimensional (3D) electron pocket centered at Brillouin zone corner. The Ni-$d_{x^2-y^2}$ derived bands show a mass enhancement ($m^*/m_{\rm{DFT}}$) of 2-3,while the 3D electron band shows negligible band renormalization. Moreover, the Ni-$d_{x^2-y^2}$ derived states also display a band dispersion anomaly at higher binding energy, reminiscent of the waterfall feature and kinks observed in cuprates.Comment: 29 pages,13 figure