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Using underground space to store natural gas resources is an important means by which to solve emergency peak shaving of natural gas. Rock salt gas storage is widely recognized due to its high-efficiency peak shaving and environmental protection. Damage and stress concentrations inside the cavern injection during withdrawal operations and throughout the storage facility life have always been among the most important safety issues. Therefore, accurate evaluation of the stability of rock salt gas storage during operation is of paramount significance to field management and safety control. In this study, we used the finite element numerical analysis software Flac3D to numerically simulate large displacement deformations of the cavern wall during gas storage—in addition to the distribution of the plastic zone of the rock around the cavern and the surface settlement—under different working conditions. We found that the maximum surface settlement value occurred near the upper part of the cavern. The surface settlement value increased as a function of creep time, but this increase leveled off, that is, a convergence trend was observed. The value was relatively small and, therefore, had little impact on the surface. The application of gas pressure inhibited the growth of the plastic zone, but on the whole, the plastic zone’s range increased proportionally to creep time. For the 20-year creep condition, the deformation value of the cavern’s surrounding rock was large. Combined with the distribution of the plastic zone, we believe that the cavern’s surrounding rock is unstable; thus, corresponding reinforcement measures must be taken.

The detection of casing leakage in oil and gas wells or water injection wells is an important element of wellbore integrity management. Ultrasonic technology is suitable to detect and identify the position of leakage in oil and gas well shafts, providing engineering guidance for subsequent treatment. In this paper, the finite element calculation model of casing leakage in oil and gas wells is established by using the computational fluid dynamics method, and the large eddy simulation model and Ffowcs Williams-Hawkings acoustic model are utilized to simulate the casing leakage condition. The acoustic pressure signals of each monitoring point on the inner axis of the pipeline are obtained, and the influences of the pipeline pressure difference, the leakage hole diameter and the pipeline fluid on the leakage acoustic field are analyzed. The simulation results indicate that the acoustic pressure level measured on the pipeline axis rises with the increase of pipeline pressure difference and leakage hole diameter. The size and variation rule of acoustic pressure level also vary with the type of pipeline fluid. Overall, the results obtained show that ultrasonic logging can accurately locate and detect tubing leakage, and they provide theoretical guidance for practical casing leakage detection, assisting with wellbore integrity management.

With the promotion of China’s carbon peaking and carbon neutrality goals, the energy industry is transforming from traditional fossil energy to renewable energy, which is sustainable, clean and safe. The development of renewable energy is not only an important measure to achieve the above goals but also a significant factor to alleviate the global energy crisis. Salt caverns, with good air tightness, have been considered as the best choice for large-scale underground energy storage. To elaborate on the research and future development of salt cavern compressed air energy storage technology in China, this paper analyzes the mode and characteristics of compressed air energy storage, explores the current development, key technologies and engineering experience of the construction of underground salt caverns for compressed air energy storage at home and abroad. Focusing on salt cavern compressed air energy storage technology, this paper provides a deep analysis of large-diameter drilling and completion, solution mining and morphology control, and evaluates the factors affecting cavern tightness and wellbore integrity. The future development and challenges of underground salt caverns for compressed air energy storage in China are discussed, and the prospects for the three key technologies of large-diameter drilling and completion and wellbore integrity, solution mining morphology control and detection, and tubing corrosion and control are considered. This paper aims to provide a useful reference for the development of underground salt cavern compressed air energy storage technology, the transformation of green and renewable energy, and the realization of carbon neutral vision.

To achieve China's goal of carbon neutrality by 2030 and achieving a true carbon balance by 2060, it is imperative to implement large-scale energy storage (carbon sequestration) projects. In underground salt formations, the salt cavern constructed by the leaching method is large, stable, and airtight, an ideal space for large-scale energy storage. Currently, salt caverns have been widely used for natural gas, crude oil, hydrogen, compressed air, and other energy storages. With the demand for peak-shaving of renewable energy and the approach of carbon peaking and carbon neutrality goals, salt caverns are expected to play a more effective role in compressed air energy storage (CAES), large-scale hydrogen storage, and temporary carbon dioxide storage. Herein the innovation of this paper lies in conducting a comprehensive review of the history, current status, and future development trends of salt cavern energy storage (SCES) technology. Firstly, we provide an overview of natural gas and oil storage in various types of salt caverns worldwide and assess the future prospects for CAES and hydrogen storage. Secondly, we propose a novel model for carbon dioxide storage in salt caverns based on the carbon cycle to effectively address the spatiotemporal disparity between carbon capture and utilization. In the future plans, salt caverns will play a crucial role throughout the entire carbon cycle by facilitating carbon storage, compressed air storage, and hydrogen storage. Additionally, we introduce the concept of utilizing sediment space for large-scale energy storage purposes. Finally, we anticipate the future development of salt caverns for energy storage in China to focus on large-scale, integrated, and intelligent projects, emphasizing their significance in achieving enhanced efficiency and sustainability. Accordingly, this review promotes thorough knowledge of SCES, provides guidance on operating large-scale SCES projects, encourages energy engineers to focus more on SCES

This study investigated the large-scale hydrogen storage in several forms of underground space (depleted gas reservoirs, aquifers, hard rock caverns, and salt caverns,). according to relevant geological, technical, environmental, health and financial factors, different alternatives of underground hydrogen storage were evaluated. It is pointed out that salt caverns are the most favorable underground space for large-scale hydrogen storage, so at least at present, we should pay more attentions to the scientific research and engineering practice of underground hydrogen storage in salt caverns. China is rich in salt resources, but most of these resources have the characteristics of bedded structures, thin salt layers, and complicated geological conditions, which make it very difficult to construct energy storage caverns in the these strata. Moreover, salt mining and gas storage have occupied a large part of salt resources with large thickness and high ore grade. Three methods of salt cavern construction were detailed described and compared, which consists of Single-well-vertical, Two-well-vertical (TWV), and Two-well-horizontal. Therefore, for the construction of hydrogen storage caverns in China, we suggest to adopt the technology of Two-well-horizontal cavern, which is more suitable for the construction of caverns in the remaining thinly bedded salt rocks. The highlights of Two-well-horizontal caverns method were presented and it has better construction efficiency and larger cavern volume. Influencing factors of construction technology were summarized: water injection direction, tubing/oil-blanket lifting, water injecting rate and inter-well distance. Based on “TWHSMC V2.0”, a series of tests were carried out, and multi-factor influences analysis were also carried out. The recommended process parameters in the process of Two-well-horizontal cavern construction are: repeatedly alternating “Injection” and “Withdrawal” operation every 30 days; lifting tubings/oil-blanket

Los equipos de investigación de los centros de la Delegación del CSIC en Canarias (IPNA, IEO e IGME) desempeñaron un papel crucial en la erupción de La Palma abordándola desde diferentes perspectivas: tierra, mar y aire. Su misión: entender el comportamiento del volcán y proporcionar información valiosa a las autoridades locales y equipos de emergencias para la toma de decisiones en gestión de desastres y protección de la población. Con idea de visibilizar este trabajo, esta labor se plasmó en una exposición 360° que es un testimonio poderoso de cómo la colaboración científica puede iluminar fenómenos naturales y su impacto en nuestra comunidad.

Unconventional geothermal resource development can contribute to increase power generation from renewable energy sources in countries without conventional hydrothermal reservoirs, which are usually associated with magmatic activity and extensional faulting, as well as to expand the generation in those regions where conventional resources are already used. Three recent drilling experiences focused on the characterization of unconventional resources are described and compared: the Campi Flegrei Deep Drilling Project (CFDDP) in Italy, the United Downs Deep Geothermal Power (UDDGP) project in the United Kingdom, and the DEEP Earth Energy Production in Canada. The main aspects of each project are described (geology, drilling, data collection, communication strategies) and compared to discuss challenges encountered at the tree sites considered, including a scientific drilling project (CFDDP) and two industrial ones (UDDGP and DEEP). The first project, at the first stage of pilot hole, although not reaching deep supercritical targets, showed extremely high, very rare thermal gradients even at shallow depths. Although each project has its own history, as well as social and economic context, the lessons learned at each drilling site can be used to further facilitate geothermal energy development.

In recent decades, creep in salt cavern Underground Gas Storage (UGS) has caused accidents at different locations around the world. Most of them were caused by volume shrinkage of salt caverns. In order to analyze the stability condition of the two-well-horizontal (TWH) salt cavern more realistically, we apply the TWHSMC V2.0 code that was calculated using the cavern geometry, and we used FLAC3D to study the stability of the cavern. Our results show that for a TWH salt cavern: 1) the optimal maximum and minimum operating pressures are 23 MPa and 16 MPa, 2) that the UGS remains stable under static pressure and for a long period of time, and 3) that the horizontal displacement of the cavern is relatively small compared to the vertical displacement. More cycles per unit time and a shorter continuous operation of low-pressure time, result in a smaller volume shrinkage rate and thus less cavern deformation. The recommended casing shoe height should be at least 12 m from the top of the cavern.

Underground TWH (Two-well-horizontal) salt caverns are an ideal storage medium for large-scale energy storage, having large usable volumes and high construction efficiency. Different tubing/oil-blanket lifting techniques relate to different solution mining rates and help define cavern geometries based on the previous experience of SWV (Single-well-vertical)-cavern construction. In this study, we present a complete and comprehensive evaluation of the influence of a particular tubing/oil-blanket lifting method on TWH-cavern leaching and geometric shapes. Based on the solution mining numerical simulation original program TWHSMC V2.0 (Two-well-horizontal solution mining cavern V2.0), we carried out a set of numerical simulations, such that the cavern construction process is real-time display and easily recorded. The results demonstrate that with a matching water injection rate, the outlet brine concentration is not sensitive to tubing/oil-blanket lifting. During construction of a horizontal cavern with a volume of 300,000 m3, lifting tubing on both sides simultaneously yields the shortest leaching time (near 307 days). Only lift the tubing on one side will form an asymmetrical cavern, with the height of the cavity near the side being higher than on the opposite side. The lower the frequency of tubing and oil blanket lifting, the smaller the height/length ratio coefficient is, meaning the cavern is closer to the horizontal. Therefore, when constructing TWH-caverns in thinly-bedded rocksalt formations, simultaneously lifting the both sides of tubing and oil-blanket, in addition to a lower lifting rate, are required. This research provides theoretical basis and engineering guidance for TWH-cavern constructing in thinly bedded rocksalt formations.

Monitoring submarine volcanic eruptions is quite an ambitious task, and it is difficult to accomplish. We present the monitoring of a submarine volcanic eruption that took place near the southernmost emerged land of El Hierro Island (Canary Islands, Spain), from October 2011 to February 2012. Right after the beginning of the eruption, in mid-October 2011, a geophone array was deployed offshore for the purpose of monitoring the submarine eruptive activity signals. It acquired continuous data from October 2011 to May 2012, sometime after the end of the eruption. The array consisted of 8 high frequency, 3-component geophones assembled into a cable string, with 6 m of separation. The geophone string was installed in La Restinga Harbor at a distance of less than 2 km away from the volcanic edifice. The dataset acquired with the array is a unique continuous acoustic record of the activity associated with the eruption. We analyzed the continuous signal of the eruptive activity, with special interest in high frequency events. Our results show that the geophone array was recording acoustic waves from a back-azimuth source compatible with the position of the submarine vent, travelling at a speed of 1510 m/s, compatible with the speed of sound in the water. Acoustic data shows a good correlation with the seismic data recorded on land and with the observed sea surface activity (ash, lava emission and degassing) indicating that this methodology can be successfully used in cases of remote submarine eruptions.

With high construction efficiency and large usable volumes, underground TWH caverns in rock salt formations provide optimal storage for large-scale compressed natural gas. Previous studies of SWV cavern construction indicate that different water injection methods will result in different leaching rates and will therefore form different cavern geometries. Therefore the influence of the water injection method on the TWH cavern construction process and geometries were thoroughly evaluated in this study. Based on the leaching numerical simulation code TWHSMC V2.0, we conducted a series of simulation experiments. The results illustrate that under the same water injection rate, the cavern construction speed of the alternate injection method is faster than the unidirectional injection method. Using the unidirectional method will form asymmetrical triangular pyramidal caverns. In contrast, using the alternate method will form symmetrical elliptical cone caverns. Under repeated alternating “Injection” and “Withdrawal” operations, the larger the flow rate, the shorter the cavern construction time, and the smaller the H/L ratio coefficient, as well as the closer the cavern geometry is to the horizontal cavern. Thus, during construction of a TWH-cavern in thinly-bedded rock salt (halite) deposits, repeated and alternating injections and withdrawals with high flow rates are necessary.

Acord transformatiu CRUE-CSIC, UDHEBRON, Background: The value of serum triglycerides (TGs) related to complications and the severity of acute pancreatitis (AP) has not been clearly defined. Our study aimed to analyze the association of elevated levels of TG with complications and the severity of AP. Methods: The demographic and clinical data of patients with AP were prospectively analyzed. TG levels were measured in the first 24 h of admission. Patients were divided into two groups: one with TG values of<200 mg/dL and another with TG≥200 mg/dL. Data on the outcomes of AP were collected. Results: From January 2016 to December 2019, 247 cases were included: 200 with TG<200 mg/dL and 47 with TG≥200 mg/dL. Triglyceride levels≥200 mg/dL were associated with respiratory failure (21.3 vs. 10%, p=0.033), renal failure (23.4 vs. 12%, p=0.044), cardiovascular failure (19.1 vs. 7.5%, p=0.025), organ failure (34 vs. 18.5%, p=0.02), persistent organ failure (27.7 vs. 9.5%, p=0.001), multiple organ failure (19.1 vs. 8%, p=0.031), moderately severe and severe AP (68.1 vs. 40.5%, p=0.001), pancreatic necrosis (63.8 vs. 34%, p<0.001), and admission to the intensive care unit (27.7 vs. 9.5%, p=0.003). In the multivariable analysis, a TG level of≥200 mg/dL was independently associated with respiratory, renal, and cardiovascular failure, organ failure, persistent organ failure, multiple organ failure, pancreatic necrosis, severe pancreatitis, and admission to the intensive care unit (p<0.05). Conclusions: In our cohort, TG≥200 mg/dL was related to local and systemic complications. Early determinations of TG levels in AP could help identify patients at risk of complications.

[ES] La presente invención se refiere a un método y un sistema para reconocimiento automático de minerales, integrable por ejemplo en una sonda de adquisición, que analiza en tiempo real las imágenes hiperespectrales capturadas por la misma usando un procedimiento basado en redes neuronales adaptadas a imágenes hiperespectrales. El entrenamiento de dichas redes neuronales se realiza usando una base de datos de imágenes hiperespectrales de minerales creada mediante la transformación de muestras de datos de imágenes hiperespectrales de cajas de núcleos perforados de minerales, adquiridas por sensores hiperespectrales heterogéneos., [EN] The present invention relates to a method and a system for automatic recognition of minerals, that can be integrated for example in an acquisition probe, which analyses in real time the hyperspectral images captured by the probe using a method based on neural networks adapted to hyperspectral images. Said neural networks are trained using a database of hyperspectral images of minerals created by transforming samples of hyperspectral image data from mineral drill core boxes, acquired by heterogeneous hyperspectral sensors., [FR] La présente invention se rapporte à une méthode et un système pour la reconnaissance automatique de minéraux pouvant être intégré par exemple dans une sonde d'acquisition, qui analyse en temps réel, les images hyperspectrales capturées par celle-ci, au moyen d'un procédé basé sur des réseaux neuronaux adaptés à des images hyperspectrales. L'entraînement des réseaux neuronaux est effectué au moyen d'une base de données d'images hyperspectrales de minéraux créée par la transformation d'échantillons de données d'images hyperspectrales de blocs de noyaux sondés de minéraux, acquises par des capteurs hyperspectraux hétérogènes.

Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100–200 km3 Campanian Ignimbrite (CI) eruption at ∼39 ka and the 40 km3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore–offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sedim

The interpretation of logging while drilling (LWD) resistivity oriented images and geophysical logs from Hole C0002 drilled during the International Ocean Discovery Program (IODP) Expeditions 338 and 348 of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) project revealed a complex structure of the accretionary prism characterized by steep bedding and abundant folds and fault zones, indicative of specific areas of deformation within the clay‐dominated prism sediments. Local faults were undoubtedly interpreted on images from Hole C0002P (2162.5‐3058.4 mbsf), whereas folds were identified in both Holes C0002P and C0002F (860‐2005.5 mbsf). The clay mineral analysis of rock samples (cuttings) shows that clay mineralization occurs within the range of the faulted and fractured zones. This linkage between local deformation and clay mineralization can have implications for enhanced fluid flow and localized fluid‐rock interaction within the highly fractured areas of the accretionary prism. We conclude that dissolution and neomineralization of illitic and smectitic phases within fractures and faults is a process that probably continues during active creep and fault reactivation, and plays a key role in influencing weak fault and creep behavior within the Nankai Trough, and likely in shallow fault systems elsewhere.

Underground TWH caverns in salt rock have high construction efficiency and large usable volumes and provides an ideal space for large-scale natural gas storage. In this study, the solution mining process of TWH cavern is thoroughly analyzed. Applying basic principles of the Navier-Stokes equation method and reasonable assumptions, we established a new 3D mathematical model which includes flow and mass transfer and boundary movement for TWH salt cavern construction. Then, the velocity field and the concentration field can be solved by the SIMPLE algorithm, while the boundary movement of cavern expansion can be solved by the VOF algorithm. We developed a new VC++ computer code program TWHSMC for solution mining and herein we present the numerical results. Finally, the simulation cavern shapes results by program are compared with the experimental ones. The results indicate that our model successfully and accurately predicts the cavern shape and demonstrates the reliability and applicability of the model. © 2019 Elsevier B.V.

La presente invención se refiere a un método y un sistema para reconocimiento automático de minerales, integrable por ejemplo en una sonda de adquisición, que analiza en tiempo real las imágenes hiperespectrales capturadas por la misma usando un procedimiento basado en redes neuronales adaptadas a imágenes hiperespectrales. El entrenamiento de dichas redes neuronales se realiza usando una base de datos de imágenes hiperespectrales de minerales creada mediante la transformación de muestras de datos de imágenes hiperespectrales de cajas de núcleos perforados de minerales, adquiridas por sensores hiperespectrales heterogéneos.

The extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway involves a three-step cascade of kinases that transduce signals and promote processes such as cell growth, development, and apoptosis. An aberrant response of this pathway is related to the proliferation of cell diseases and tumors. By using simulation modeling, we document that the protein arginine methyltransferase 5 (PRMT5) modulates the MAPK pathway and thus avoids an aberrant behavior. PRMT5 methylates the Raf kinase, reducing its catalytic activity and thereby, reducing the activation of ERK in time and amplitude. Two minimal computational models of the epidermal growth factor (EGF)-Ras-ERK MAPK pathway influenced by PRMT5 were proposed: a first model in which PRMT5 is activated by EGF and a second one in which PRMT5 is stimulated by the cascade response. The reported results show that PRMT5 reduces the time duration and the expression of the activated ERK in both cases, but only in the first model PRMT5 limits the EGF range that generates an ERK activation. Based on our data, we propose the protein PRMT5 as a regulatory factor to develop strategies to fight against an excessive activity of the MAPK pathway, which could be of use in chronic diseases and cancer.

Más de 20 investigadoras procedentes de 11 centros del CSIC en Cataluña participan en los más de 30 actos de divulgación. El 11 de febrero, Día Internacional de la Mujer y la Niña en la Ciencia, es una fecha para reivindicar el papel de la mujer en la ciencia y despertar la vocación científica en las más pequeñas. Visita de las investigadoras Gemma Fabrias y Arantzazu Gonzalez a la Escola Cal Maiol el 11 de febrero de 2019. Visita de las investigadoras Gemma Fabrias y Arantzazu Gonzalez a la Escola Cal Maiol el 11 de febrero de 2019. Científicas de once centros del CSIC en Cataluña se suman a la iniciativa del 11 de Febrero, Día Internacional de la Mujer y la Niña en la Ciencia. Charlas, proyecciones y visitas a escuelas son algunas de las actividades en las que participan más de 20 investigadoras que quieren despertar la curiosidad científica en niñas y niños. El 11 de febrero es una iniciativa internacional que se celebra desde hace 4 años en España. Una fecha declarada por las Naciones Unidas para reivindicar el papel de la mujer en la ciencia y convertir a las científicas de hoy en un referente para las de mañana. La intención de las actividades celebradas en este marco es la de despertar la curiosidad y la vocación científica en las niñas y niños, especialmente en las edades más tempranas. Las estadísticas indican que la representación de hombres y mujeres en las distintas disciplinas científicas no es paritaria, especialmente en ámbitos como la física o las ingenierías. Este año, 11 centros de Cataluña pertenecientes al Consejo Superior de Investigaciones Científicas se han sumado a la iniciativa, con más de 20 investigadoras que llevarán a cabo proyecciones, visitas a institutos, charlas y conferencias en la semana del 11 de febrero. En total, están programados más de 30 actos por Barcelona y zonas próximas.

Minerals are key resources for several industries, such as the manufacturing of high-performance components and the latest electronic devices. For the purpose of finding new mineral deposits, mineral interpretation is a task of great relevance in mining and metallurgy sectors. However, it is usually a long, costly, laborious, and manual procedure. It involves the characterization of mineral samples in laboratories far from the mineral deposits and it is subject to human interpretation mistakes. To address the previous problems, an automatic mineral recognition system is proposed that analyzes in real-time hyperspectral imagery acquired in different spectral ranges: VN-SWIR (Visible, Near and Short Wave Infrared) and LWIR (Long Wave Infrared). Thus, more efficient, faster, and more economic explorations are performed, by analyzing in-situ mineral deposits in the subsurface, instead of in laboratories. The developed system is based on a deep learning technique that implements a semantic segmentation neural network that considers spatial and spectral correlations. Two different databases composed by scanned drilled mineral cores from different mineral deposits have been used to evaluate the mineral interpretation capability. The first database contains hyperspectral images in the VN-SWIR range and the second one in the LWIR range. The obtained results show that the mineral recognition for the first database (VN-SWIR band) achieves an 86% in accuracy considering the following mineral classes: Actinolite, amphibole, biotite-chlorite, carbonate, epidote, saponite, whitemica and whitemica-chlorite. For the second database (LWIR band), a 90% in accuracy has been obtained with the following mineral classes: Albite, amphibole, apatite, carbonate, clinopyroxene, epidote, microcline, quartz, quartz-clay-feldspar and sulphide-oxide. The mineral recognition capability has been also compared between both spectral bands considering the common minerals in both databases. The results

Multi-fractured horizontal wells (MFHW) is one of the most effective technologies to develop tight gas reservoirs. The gas seepage from tight formations in MFHW can be divided into three stages: early stage with high productivity, transitional stage with declined productivity, and final stage with stable productivity. Considering the characteristics and mechanisms of porous flows in different regions and at different stages, we derive three coupled equations, namely the equations of porous flow from matrix to fracture, from fracture to near wellbore region, and from new wellbore region to wellbore then an unstable productivity prediction model for a MFHW in a tight gas reservoir is well established. Then, the reliability of this new model, which considers the multi-fracture interference, is verified using a commercial simulator (CMG). Finally, using this transient productivity prediction model, the sensitivity of horizontal well’s productivity to several relevant factors is analyzed. The results illustrate that threshold pressure gradient has the most significant influence on well productivity, followed by stress sensitivity, turbulence flow, and slippage flow. To summarize, the proposed model has demonstrated a potential practical usage to predict the productivity of multi-stage fractured horizontal wells and to analyze the effects of certain factors on gas production in tight gas reservoirs.

Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100–200 km3 Campanian Ignimbrite (CI) eruption at ∼39 ka and the 40 km3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore–offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sedim

The Camp dels Ninots is located in the western part of the town of Caldes de Malavella (Girona), at 20 km to the south of the city of Girona, with a 275.000 m2 surface. Its UTM (ETRS89) coordinates are 483202E and 46311454N, and with a height of 93 m according to sea level (Fig. 1). The name Camp dels Ninots (field of puppets) is related to the presence of abundant diagenetic silica nodules with rounded shapes (menilites), which are mostly made of opal (SiO2·nH2O), that have been classically collected by locals. The Camp dels Ninots site is a phreatomagmatic explosion volcano of Pliocene age (3.1 Ma) which subsequently formed a lake. The specific geological conditions, corresponding to lake sedimentation, make it ideal for the preservation of fossils. The appearance of complete skeletons mostly in anatomical connection makes the site to be considered, according to the German term, a Fossil-Lagerstätte. Currently, the lands that make up the Camp dels Ninots are agricultural fields, mostly cereals, although, they are also remarkable for the many wells that, until a few years ago, were employed to extract water for industrial use.