An Open-Source Code For Fluid Flow Simulations In Unconventional Fractured Reservoirs

In this article, an open-source code for the simulation of fluid flow, including adsorption, transport, and indirect hydromechanical coupling in unconventional fractured reservoirs is described. The code leverages cutting-edge numerical modeling capabilities like automatic differentiation, stochastic fracture modeling, multicontinuum modeling, and discrete fracture models. In the fluid mass balance equation, specific physical mechanisms, unique to organic-rich source rocks, are included, like an adsorption isotherm, a dynamic permeability-correction function, and an Embedded Discrete Fracture Model (EDFM) with fracture-to-well connectivity. The code is validated against an industrial simulator and applied for a study of the performance of the Barnett shale reservoir, where adsorption, gas slippage, diffusion, indirect hydromechanical coupling, and propped fractures are considered. It is the first open-source code available to facilitate the modeling and production optimization of fractured shale-gas reservoirs. The modular design also facilitates rapid prototyping and demonstration of new models. This article also contains a quantitative analysis of the accuracy and limitations of EDFM for gas production simulation in unconventional fractured reservoirs

The recent floods in the Asso Torrent basin (Apulia, Italy): An investigation to improve the stormwater management

Stormwater management is of concern to public institutions and academies. In the Asso Torrent endorheic basin (Salento peninsula, Southern Italy), a network of natural and artificial channels crossing urban and rural areas and flowing towards six swallow karst holes, several floods occurred in the last six years, after the end of extensive hydraulic works. In this paper, the results of an observational study on the meteorological and hydrological factors concurring to these floods are reported. It was inferred that soil saturation, cumulative precipitation anticipating the events, and clogging of the swallow holes are of relevance and must be considered in the definition of new criteria in decision-making procedure. The adoption of both innovative modeling techniques and real-time control should be an efficient solution to properly regulate the flow control devices before and during the precipitation events. With a view to providing solutions for a sustainable management of the water resources, easy-to-implement measures are suggested, such as the selection of flood-tolerant crops and construction of harvesting systems for alternative water uses

Application of abscisic acid rapidly upregulated UFGT gene expression and improved color of grape berries

The effect of abscisic acid (ABA) on the color of 'Crimson Seedless' grapes was linked to expression of the key anthocyanin pathway gene UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT). In the skins of ABA treated fruits, the level of mRNA UFGT increased markedly within one week and then returned to levels that were similar to those of non-treated fruits after three weeks. The mRNA UFGT levels from untreated fruits were similar from veraison to nine weeks later. The color of ABA treated fruit also changed quickly. One week after application, the skins of trated fruits had lower lightness (L*) and hue (h°), and they remained darker and more red-colored throughout the experiment.

The experience of southern Apulia (Italy) coastal karst aquifer: Indications for the management

Prediction of the salt water intrusion in coastal karst aquifers is a key issue in several regions of the world. Southern Apulia (Italy) hosts a huge aquifer of karstified lime-stones, that provides 90% of the water demand of this sub-region. The exploitation of the aquifer currently exceeds its natural recharge capacity. The groundwater in wide coastal areas of the sub-region underwent an increase of the salt content. Salinization of the groundwater in such an aquifer cannot be predicted by means of conventional models. An effective model for a quantitative prediction of the fluid flow and transport of solute in the aquifer, aimed at a better understanding of the phenomenon, is therefore needed. This model should account for the discrete nature of the aquifer. In this paper, several situations are reported in order to describe the importance of the inhomogeneities (fracture systems, fault zones, karst conduit, preferential flow levels) in the salinization process of the southern Apulia karst aquifer

Analysis of Interaction of Multiple Cracks Based on Tip Stress Field Using Extended Finite Element Method

This is the final version. Available on open access from Hindawi via the DOI in this recordData Availability: The data supporting this paper are from previously reported studies and datasets, which have been cited. The processed data are available from the corresponding author upon request.A new method is presented to study the interaction of multiple cracks, especially for the areas near crack tips by using the extended finite element method. In order to track the cracks, a new geometric tracking technique is proposed to track enriched elements and nodes along the crack instead of using the narrow band level set method. This allows to accurately determine enriched elements and nodes and calculate enrichment values. A method is proposed for constructing a multicrack matrix, which involves numbering enriched nodes of multiple cracks and solving the global stiffness matrix. In this approach, the stress fields around multiple cracks can be studied. The interaction integral method is employed to study the crack propagation and its direction by calculating the stress intensify factor. The developed model has been coded in MATLAB environment and validated against analytical solutions. The application of the model in the crack interaction study is demonstrated through a number of examples. The results illustrate the influence of the interaction of multiple cracks as they approach each other.Chinese Scholarship CouncilUniversity of Exete

Analysis of Fracture Mechanics Tests on Opalinus Clay

Many studies have recently been conducted to evaluate various mechanical characteristics of the Opalinus Clay (OPA) formation in view of its potential use as the hosting rock for the Swiss nuclear waste repositories. Its sedimentary bedding makes OPA a transversely isotropic rock and its directional mechanical properties need to be measured. This paper reports on an experimental and computational approach that was adopted to define the parallel-to-bedding fracture mechanics (FM) parameters of OPA in Mode-I. OPA cores from Mont Terri Underground Research Laboratory (URL) were submitted to laboratory tests on notched semi-circular specimens under three-point bending (SCB). In these tests, crack propagation is forced along the notch direction. However, the 45° bedding inclination of the specimen axis frequently deviated the crack from the expected direction. An analysis of the SCB tests was performed by means of non-linear FM techniques and the pertinent Mode-I parameters along the bedding were estimate

Comportamento vegetativo e produtivo da videira e composição da uva em São Joaquim, Santa Catarina

O objetivo deste trabalho foi avaliar o comportamento vegetativo e produtivo das variedades de videira Cabernet Sauvignon, Merlot e Sauvignon Blanc, e a composição da uva em São Joaquim, Santa Catarina. Foram avaliadas plantas de um vinhedo comercial, cultivado em espaldeira, a 1.293 m de altitude, durante os ciclos fenológicos 2005/2006 e 2006/2007. As variáveis meteorológicas, a fenologia, o desenvolvimento do dossel e a composição da uva na colheita foram comparados entre os ciclos. As temperaturas mais amenas influenciaram o ciclo fenológico das variedades Cabernet Sauvignon, Merlot e Sauvignon Blanc, que é mais longo e tardio que nas outras regiões vitícolas do Brasil. Houve influência significativa da precipitação pluvial sobre a maturação da uva, no ciclo 2006/2007. Os índices de desenvolvimento indicam a necessidade de ajuste no manejo do dossel para um maior equilíbrio entre o crescimento vegetativo e a produção. As variedades Cabernet Sauvignon, Merlot e Sauvignon Blanc apresentam elevada qualidade da uva no momento da colheita, sendo adequadas ao cultivo em São Joaquim, SC