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Objective. The Monte Carlo simulation software is a valuable tool in radiation therapy, in particular to achieve the needed accuracy in the dose evaluation for the treatment plans optimisation. The current challenge in this field is the time reduction to open the way to many clinical applications for which the computational time is an issue. In this manuscript we present an innovative GPU-accelerated Monte Carlo software for dose valuation in electron and photon based radiotherapy, developed as an update of the FRED (Fast paRticle thErapy Dose evaluator) software. Approach. The code transports particles through a 3D voxel grid, while scoring their energy deposition along their trajectory. The models of electromagnetic interactions in the energy region between 1 MeV—1 GeV available in literature have been implemented to efficiently run on GPUs, allowing to combine a fast tracking while keeping high accuracy in dose assessment. The FRED software has been bench-marked against state-of-art full MC (FLUKA, GEANT4) in the realm of two different radiotherapy applications: Intra-Operative Radio Therapy and Very High Electron Energy radiotherapy applications. Results. The single pencil beam dose-depth profiles in water as well as the dose map computed on non-homogeneous phantom agree with full-MCs at 2% level, observing a gain in processing time from 200 to 5000. Significance. Such performance allows for computing a plan with electron beams in few minutes with an accuracy of ∼%, demonstrating the FRED potential to be adopted for fast plan re-calculation in photon or electron radiotherapy applications.

The high dose conformity and healthy tissue sparing achievable in Particle Therapy when using C ions calls for safety factors in treatment planning, to prevent the tumor under-dosage related to the possible occurrence of inter-fractional morphological changes during a treatment. This limitation could be overcome by a range monitor, still missing in clinical routine, capable of providing on-line feedback. The Dose Profiler (DP) is a detector developed within the INnovative Solution for In-beam Dosimetry in hadronthErapy (INSIDE) collaboration for the monitoring of carbon ion treatments at the CNAO facility (Centro Nazionale di Adroterapia Oncologica) exploiting the detection of charged secondary fragments that escape from the patient. The DP capability to detect inter-fractional changes is demonstrated by comparing the obtained fragment emission maps in different fractions of the treatments enrolled in the first ever clinical trial of such a monitoring system, performed at CNAO. The case of a CNAO patient that underwent a significant morphological change is presented in detail, focusing on the implications that can be drawn for the achievable inter-fractional monitoring DP sensitivity in real clinical conditions. The results have been cross-checked against a simulation study.

This paper provides a first insight of the potential of the β - Radio Guided Surgery ( β - -RGS) in a complex surgical environment like the abdomen, where multiple sources of background concur to the signal at the tumor site. This case is well reproduced by ex-vivo samples of 90 Y -marked Gastro-Entero-Pancreatic Neuroendocrine Tumors (GEP NET) in the bowel. These specimens indeed include at least three wide independent sources of background associated to three anatomical districts (mesentery, intestine, mucose). The study is based on the analysis of 37 lesions found on 5 samples belonging to 5 different patients. We show that the use of electrons, a short range particle, instead of γ particles, allows to limit counts read on a lesion to the sum of the tumor signal plus the background generated by the sole hosting district. The background on adjacent districts in the same specimen/patient is found to differ up to a factor 4, showing how the specificity and sensitivity of the β - -RGS technique can be fully exploited only upon a correct measurement of the contributing background. This locality has been used to set a site-specific cut-off algorithm to discriminate tumor and healthy tissue with a specificity of 100% and a sensitivity, on this test data sample, close to 100%. Factors influencing the sensitivity are also discussed. One of the specimens set allowed us evaluate the volume of the lesions, thus concluding that the probe was able to detect lesions as small as 0.04 mL in that particular case.

Particle therapy is increasingly used for the treatment of solid tumours, especially when the tolerance of organs at risk for conventional radiotherapy becomes dose limiting. To take full advantage of the particle therapy potential, the beam range in tissues has to be precisely known and the secondary particles production during the treatment has to be accurately characterised, as it can lead to unwanted dose deposition far from the target volume. Secondary neutrons can release a remarkable dose, also far from the tumour, increasing the probability of secondary cancer late insurgence in the patient. Currently, the treatment planning system software used in clinical routine suffer from the lack of high precision data related to the secondary neutron production in particle therapy treatments. The aim of the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project is to develop a tracking detector for secondary neutrons in the energy range of 20 − 400 MeV. Neutrons flux, energy spectra and angular distribution will become experimentally available by tracking the recoil protons produced after two consecutive neutron elastic scattering interactions in a 10 × 10 × 20 cm 3 matrix of scintillating fibres. A Monte Carlo simulation based on the FLUKA code was developed to optimise the MONDO detector layout, define the tracker trigger logic, evaluate the background contamination and possible strategies for its reduction: preliminary results are reported in this manuscript. A 4 × 4 × 4.8 cm 3 detector prototype was tested with protons at the APSS Proton Therapy Centre in Trento (Italy), where calibration and efficiency measurements were performed. Experimental and simulated results were compared.

This work presents the interpretation of a polymer injectivity test performed in a heavy-oil field (50-200 cP), located in a challenging arctic environment, during the first half of 2019 to assess the feasibility of the polymer injection process. Following the positive results achieved with the injectivity test, a polymer interwell pilot test started in the last months of 2019, but it was suspended in April 2020 due to Covid restrictions. Thanks to the acquired data during the pilot test, polymer model was tuned into a dedicated sector of the reservoir model, including one injector and two producers. Using internal company EOR-screening tools, polymer flooding was identified as the most suitable technology for the asset. An integrated study of 3D-modeling and in-house laboratory activities was performed to assess polymer injection potentialities and select the best chemical product for the asset. 3D dynamic analyses confirm the benefits of polymer injection with a significant oil production gain. Four representative horizontal wells were selected for the injectivity test in order to confirm the injection effectiveness. The selection of injectors was based on an extensive analyses of wells status and performance. The test strategy consisted of 2-weeks polymer injection per well, at constant injection rate and increasing polymer concentration steps. A detailed real-Time surveillance plan was realized to monitor injector pressures and polymer solution properties. The injectivity test was concluded successfully: Target viscosity, defined during the laboratory and modeling analyses, was achieved with a limited impact on injectivity. Pressure increase and stabilization during polymer injection confirmed the feasibility of the technique for the reservoir. Well test and temperature profile acquired before and after polymer injection were interpreted. Once assessed the feasibility of polymer injectivity, a 1-year inter-well pilot started in November 2019. Injection took place up to March 2020 and was suspended due to Covid restrictions. The re-start is planned for mid-2021. During the test several injection and production data were gathered, analyzed and interpreted. In addition to that, starting from the full reservoir model, a detailed sector model was set up in order to match pressures and water cut and forecast the performances of polymer injection. © IOR 2021 - 21st European Symposium on Improved Oil Recovery.

Charged Particle Therapy (CPT) is a powerful radiotherapy technique for the treatment of deep-seated tumours characterized by a large dose released in the Bragg peak area (corresponding to the tumour region) and a small dose delivered to the surrounding healthy tissues. The precise measurement of the fragments produced in the nuclear interactions of charged particle beams with patient tissues is a crucial task to improve the clinical treatment plans. The FOOT (FragmentatiOn Of Target) experiment is an international project, funded by the Istituto Nazionale di Fisica Nucleare (INFN), aimed to study the dose released by the tissues and particle beams fragmentation. The target (16O, 12C) fragmentation induced by 150-400 MeV/n proton beams will be studied via the inverse kinematic approach, where 16O and 12C therapeutic beams collide on graphite and hydrocarbon target to provide the cross section on Hydrogen. A table-top detector is being developed and it includes a drift chamber as a beam monitor upstream of the target to measure the beam direction, a magnetic spectrometer based on silicon pixel and strip detectors, a scintillating crystal calorimeter able to stop the heavier produced fragments, and a ΔE detector, with TOF capability, for the particle identification. A setup based on the concept of the “Emulsion Cloud Chamber”, coupled with the interaction region of the electronic FOOT setup, will complement the physics program by measuring lighter charged fragments to extend the angular acceptance up to about 70 degrees. In this work, the experimental design and the requirements of the FOOT experiment will be discussed and preliminary results on the emulsion spectrometer tests will be presented.

The high dose conformity and healthy tissue sparing achievable in Particle Therapy when using C ions calls for safety factors in treatment planning, to prevent the tumor under-dosage related to the possible occurrence of inter-fractional morphological changes during a treatment. This limitation could be overcome by a range monitor, still missing in clinical routine, capable of providing on-line feedback. The Dose Profiler (DP) is a detector developed within the INnovative Solution for In-beam Dosimetry in hadronthErapy (INSIDE) collaboration for the monitoring of carbon ion treatments at the CNAO facility (Centro Nazionale di Adroterapia Oncologica) exploiting the detection of charged secondary fragments that escape from the patient. The DP capability to detect inter-fractional changes is demonstrated by comparing the obtained fragment emission maps in different fractions of the treatments enrolled in the first ever clinical trial of such a monitoring system, performed at CNAO. The case of a CNAO patient that underwent a significant morphological change is presented in detail, focusing on the implications that can be drawn for the achievable inter-fractional monitoring DP sensitivity in real clinical conditions. The results have been cross-checked against a simulation study.

We addressadvective transportof a solute traveling toward a single pumping well in a two-dimensional randomly heterogeneousaquifer. The two random variables of interest are the trajectory followed by an individual particle from the injection point to the well location and the particle travel time under steady-state conditions. Our main objective is to derive the predictors of trajectory and travel time and the associated uncertainty, in terms of their first two statistical moments (mean and variance). We consider a solute that undergoes mass transfer between a mobile and an immobile zone. Based on Lawrence et al. [Lawrence, A.E., Sánchez-Vila, X., Rubin, Y., 2002. Conditional moments of thebreakthrough curvesof kinetically sorbing solute in heterogeneousporous mediausing multirate mass transfer models forsorptionand desorption. Water Resour. Res. 38 (11), 1248, doi:10.1029/2001WR001006.], travel time moments can be written in terms of those of a conservative solute times a deterministic quantity. Moreover, the moments of soluteparticles trajectorydo not depend on mass transfer processes. The resulting mean and variance of travel time and trajectory for a conservative species can be written as functions of the first, second moments and cross-moments of trajectory and velocity components. The equations are developed from a consistent second order expansion inσY(standard deviation of the natural logarithm of hydraulic conductivity). Our solution can be completely integrated with the moment equations of groundwater flow of Guadagnini and Neuman [Guadagnini, A., Neuman, S.P., 1999a. Nonlocal and localized analyses of conditional mean steady state flow in bounded, randomly non uniform domains 1. Theory and computational approach. Water Resour. Res. 35(10), 2999–3018.,Guadagnini, A., Neuman, S.P., 1999b. Nonlocal and localized analyses of conditional mean steady state flow in bounded, randomly non uniform domains 2. Computational examples. Water Resour. Res. 35(10), 3019–3039.], it is free of distributional assumptions regarding the log conductivity field, and formally includes conditioning. We present analytical expressions for the unconditional case by making use of the results of Riva et al. [Riva, M., Guadagnini, A., Neuman, S.P., Franzetti, S., 2001.Radial flowin a bounded randomly heterogeneous aquifer. Transport in Porous Media 45, 139–193.]. The quality of the solution is supported by numerical Monte Carlo simulations. Potential uses of this work include the determination of aquifer reclamation time by means of a single pumping well, and the demarcation of the region potentially affected by the presence of a contaminant in the proximity of a well, whenever the aquifer is very thin and Dupuit–Forchheimer assumption holds.

The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project addresses the technical challenges posed by a neutron tracker detector: high detection efficiency and good backtracking precision. The project main goal is to develop a tracking device capable of fully reconstructing the four-momentum of the ultra-fast secondary neutrons produced in Particle Therapy treatments via double elastic scattering interactions. The tracker – a 16 × 16 × 20 cm 3 matrix – is made by a matrix of thin squared scintillating fibres (250 μ m ) arranged in layers orthogonally oriented. A custom readout system called SBAM (SPAD-Based Acquisition readout for MONDO experiment), matched to the MONDO needs of single photon detection capability, high spatial resolution and compactness, has been developed in collaboration with Fondazione Bruno Kessler (FBK). A small detector prototype ( 4 × 4 × 4 . 8 cm 3 ) has been built and tested with a sensor prototype, SPADnet-I, in order to experimentally evaluate the light output expected and consequently optimise the final readout. The simulation characterisation of the detector response with monochromatic neutrons in the [20-300] MeV will be presented together with the expected performances of MONDO as neutron beam monitor. The preliminary measurements at electron and proton beams of the prototype with the SPAD array readout will be reported.

In a carbon ion treatment the nuclear fragmentationof both target and beam projectiles impacts on the dose releasedon the tumor and on the surrounding healthy tissues. Carbon ionfragmentation occurring inside the patient body has to be stud-ied in order to take into account this contribution. These dataare also important for the development of the range monitoringtechniques with charged particles. The production of chargedfragments generated by carbon ion beams of 115-353 MeV/ukinetic energy impinging on carbon, oxygen, and hydrogen tar-gets has been measured at the CNAO particle therapy center(Pavia, Italy). The use of thin targets of graphite (C), PMMA(C2O5H8) and polyvinyl-toluene [plastic scintillator (PS), CbHa]allowed to measure fragments production cross sections, exploit-ing a time-of-flight (ToF) technique. PS detectors have been usedto perform the ToF measurements, while LYSO crystals havebeen used for the deposited energy measurement and to performparticle identification. Cross sections have been measured at 90◦and 60◦with respect to the beam direction. The measured pro-ton, deuteron, and triton differential production cross sectionson C, O, and H, obtained exploiting the target subtraction strat-egy, are presented here as a function of the fragment kineticenergy.

Radio Guided Surgery (RGS) is a nuclear medicine technique allowing the surgeon to identify tumor residuals in real time with a millimetric resolution, thanks to a radiopharmaceutical as tracer and a probe as detector. The use of beta(-) emitters, instead of gamma or beta(+), has been recently proposed with the aim to increase the technique sensitivity and reducing both the administered activity to the patient and the medical exposure. In this paper, the possibility to use the commercial CMOS Image Sensor MT9V115, originally designed for visible light imaging, as beta(-) radiation detector RGS is discussed. Being crucial characteristics in a surgical environment, in particular its stability against time, operating temperature, integration time and gain has been studied on laboratory measurements. Moreover, a full Monte Carlo simulation of the detector has been developed. Its validation against experimental data allowed us to obtain efficiency curves for both beta and gamma particles, and also to evaluate the effect of the covering heavy resin protective layer that is present in the "off the shelf" detector. This study suggests that a dedicated CMOS Image Sensor (i.e. one produced without the covering protective layer) represents the ideal candidate detector for RGS, able to massively increase the amount of application cases and the efficacy of this technique.

Charged Particle Therapy is a non-invasive technique for radio-resistant tumor treatment performed with protons or light ions, aiming to deliver a high precision treatment. Compared to conventional radiotherapy, ions allow for a higher dose deposition in the tumor region while sparing the surrounding healthy tissue. To really exploit the potential benefits of this technique, the highest possible accuracy in the calculation of dose and its spatial distribution is required in treatment planning. Commonly used Treatment Planning Software solutions adopt a simplified beam-body interaction model. An alternative is the use of Monte Carlo simulations which explicitly take into account the interaction of charged particles with actual human tissues hence providing highly accurate results. However, Monte Carlo simulations are used in a restricted number of cases due to substantial computational resources required. The code FRED has been developed to allow a fast optimization of the treatment plans in Charged Particle Therapy while profiting from the dose release accuracy of a Monte Carlo tool. Currently, the most refined module is the transport of proton beams in water. A comparison with measurements shows that the lateral dose tails are reproduced within 2% in the field size factor test up to 20 cm. Models for the interaction of ion with the matter are currently under development in the FRED code. The status of new developments and the performance of FRED will be presented.

Particle therapy (PT) is a radiation therapy technique in which solid tumors are treated with charged ions and exploits the achievable highly localized dose delivery, allowing to spare healthy tissues and organs at risk. The development of a range monitoring technique to be used online, during the treatment, capable to reach millimetric precision is considered one of the important steps toward an optimization of the PT efficacy and of the treatment quality. To this aim, charged secondary particles produced in the nuclear interactions between the beam particles and the patient tissues can be exploited. Besides charged secondaries, neutrons are also produced in nuclear interactions. The secondary neutron component might cause an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignant neoplasms that can develop even years after the treatment. An accurate neutron characterization (flux, energy and emission profile) is, hence, needed for a better evaluation of long-term complications. In this contribution, two tracker detectors, both based on scintillating fibers, are presented. The first one, named dose profiler (DP), is planned to be used as a beam range monitor in PT treatments with heavy ion beams, exploiting the charged secondary fragments production. The DP is currently under development within the Innovative Solutions for In-Beam DosimEtry in Hadrontherapy project. The second one is dedicated to the measurement of the fast and ultrafast neutron component produced in PT treatments, in the framework of the monitor for neutron dose in hadrontherapy project. Results of the first calibration tests performed at the Trento Protontherapy Center and at Centro Nazionale di Adroterapia Oncologica (Italy) are reported, as well as simulation studies.

Purpose Radio Guided Surgery (RGS) is a technique that helps the surgeon to achieve an as complete as possible tumor resection, thanks to the intraoperative detection of particles emitted by a radio tracer that bounds to tumoral cells. In the last years, a novel approach to this technique has been proposed that, exploiting β - emitting radio tracers, overtakes some limitations of established γ -RGS. In this context, a first prototype of an intraoperative β particle detector, based on a high light yield and low density organic scintillator, has been developed and characterised on pure β - emitters, like 90 Y . The demonstrated very high efficiency to β - particles, together with the remarkable transparency to photons, suggested the possibility to use this detector also with β + emitting sources, that have plenty of applications in nuclear medicine. In this paper, we present upgrades and optimisations performed to the detector to reveal such particles. Methods Laboratory measurement have been performed on liquid Ga 68 source, and were used to validate and tune a Monte Carlo simulation. Results The upgraded detector has an ~ 80 % efficiency to electrons above ~ 110 keV , reaching a plateau value of ~ 95 % . At the same time, the probe is substantially transparent to photons below ~ 200 keV , reaching a plateau value of ~ 3 % . Conclusions The new prototype seems to have promising characteristics to perform RGS also with β + emitting isotopes.

In hadron therapy, the accelerated ions, interacting with the body of the patient, cause the fragmentation of both projectile and target nuclei. The fragments interact with the human tissues depositing energy both in the entrance channel and in the volume surrounding the tumor. The knowledge of the fragments features is crucial to determine the energy amount deposited in the human body, and - hence - the damage to the organs and to the tissues around the tumor target. The FOOT (FragmentatiOn Of Target) experiment aims at studying the fragmentation induced by the interaction of a proton beam (150-250 MeV/n) inside the human body. The FOOT detector includes an electronic setup for the identification of Z ≥ 3 fragments integrated with an emulsion spectrometer to measure Z ≤ 3 fragments. Charge identification by nuclear emulsions is based on the development of techniques of controlled fading of the particle tracks inside the nuclear emulsion, that extend the dynamical range of the films developed for the tracking of minimum ionising particles. The controlled fading strongly depends on temperature, relative humidity and treatment duration. In this study the performances in terms of charge separation of proton, helium and carbon particles, obtained on a batch of new emulsion films produced in Japan are reported.

Particle therapy is a therapy technique that exploits protons or light ions to irradiate tumor targets with high accuracy. Protons and 12C ions are already used for irradiation in clinical routine, while new ions like 4He and 16O are currently being considered. Despite the indisputable physical and biological advantages of such ion beams, the planning of charged particle therapy treatments is challenged by range uncertainties, i.e. the uncertainty on the position of the maximal dose release (Bragg Peak - BP), during the treatment. To ensure correct 'in-treatment' dose deposition, range monitoring techniques, currently missing in light ion treatment techniques, are eagerly needed. The results presented in this manuscript indicate that charged secondary particles, mainly protons, produced by an 16O beam during target irradiation can be considered as candidates for 16O beam range monitoring. Hereafter, we report on the first yield measurements of protons, deuterons and tritons produced in the interaction of an 16O beam impinging on a PMMA target, as a function of detected energy and particle production position. Charged particles were detected at 90° and 60° with respect to incoming beam direction, and homogeneous and heterogeneous PMMA targets were used to probe the sensitivity of the technique to target inhomogeneities. The reported secondary particle yields provide essential information needed to assess the accuracy and resolution achievable in clinical conditions by range monitoring techniques based on secondary charged radiation.

Summary The present work aims to assess the potentialities of foam in mitigating the gas injection issues foreseen during water alternating gas injection (WAG) scheme, such as premature gas breakthrough at producers and gas cycling. Main objective is to demonstrate foam efficiency for an offshore oil field by integrating extensive dedicated laboratory testing, accurate reservoir modeling and preliminary facilities feasibility, key steps for field EOR application. The adopted workflow focused on the close integration of different analyses allowing the characterization of the different phenomena and criticalities that may arise during foam injection application. Lab tests started with an accurate in bulk surfactants screening to identify the best performer for the candidate reservoir. Eleven foamers were tested and the best one was selected for the following core flood tests. Core flood tests were performed at reservoir pressure and temperature conditions. Berea cores were first flooded under WAG scheme and then adding also a buffer of the optimized foamer solution (FAWAG scheme). Core flood results showed that injection of foam decreases gas and fluid mobility. The reduction of foamer performance in presence of oil was also evaluated. Core floods results were matched and main foam parameters were obtained to perform field scale foam injection simulations. Two sets of parameters matching the available lab data were defined. Both of them were applied providing an optimistic and a pessimistic scenario. Field scale simulations highlighted that foam injection provided a positive effect on field oil production and GOR reduction; the best scenario highlights additional reserves of about 3% after 15 years of production associated with a 30% GOR reduction. The pre-feasibility study identified the most suitable injection scheme and it assessed no major show stoppers from flow assurance. The preliminary cost estimate per incremental barrel associated to the implementation of the technology was also done. Main conclusion of the study was that laboratory tests, numerical simulations and preliminary facilities assessment confirm the potentialities of foam injection for the candidate reservoir. An integrated and comprehensive workflow was set-up to estimate the efficiency and benefits of foam injection. The presented workflow is currently being applied to assess foam injection potentiality for other fields within the company's portfolio.

Particle therapy (PT) can exploit heavy ions (such as He, C or O) to enhance the treatment efficacy, profiting from the increased Relative Biological Effectiveness and Oxygen Enhancement Ratio of these projectiles with respect to proton beams. To maximise the gain in tumor control probability a precise online monitoring of the dose release is needed, avoiding unnecessary large safety margins surroundings the tumor volume accounting for possible patient mispositioning or morphological changes with respect to the initial CT scan. The Dose Profiler (DP) detector, presented in this manuscript, is a scintillating fibres tracker of charged secondary particles (mainly protons) that will be operating during the treatment, allowing for an online range monitoring. Such monitoring technique is particularly promising in the context of heavy ions PT, in which the precision achievable by other techniques based on secondary photons detection is limited by the environmental background during the beam delivery. Developed and built at the SBAI department of "La Sapienza", within the INSIDE collaboration and as part of a Centro Fermi flagship project, the DP is a tracker detector specifically designed and planned for clinical applications inside a PT treatment room. The DP operation in clinical like conditions has been tested with the proton and carbon ions beams of Trento proton-therapy center and of the CNAO facility. In this contribution the detector performances are presented, in the context of the carbon ions monitoring clinical trial that is about to start at the CNAO centre.

Particle therapy is a therapy technique that exploits protons or light ions to irradiate tumor targets with high accuracy. Protons and

The use of C, He and O as beam particles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of the enhanced relative biological effectiveness and oxygen enhancement ratio of such projectiles with respect to protons. The advantages in the tumor control probability, related to the improved efficacy of ions, are calling for an online monitor of the dose release spatial distribution. Such technology is currently missing in PT treatments clinical routine. In this contribution the status of Z > 1 ions PT treatments monitoring, exploiting the detection of either charged secondary particles or neutrons, is reviewed. While charged fragments can be used to provide an online feedback to the beam control system, by correlating their emission profile with the position of the Bragg peak, neutrons have to be monitored to improve the experimental description of the secondary radiation component that significantly contributes to an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignancies development after the treatment. Two tracker detectors, employing scintillating fibers , are presented: the Dose Profiler designed for charged secondary fragments measurements and the MONDO tracker dedicated to the characterisation of the secondary fast and ultrafast neutron component, within the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project.

A robust analysis of a polymer flooding inter-well pilot has been performed. The main objective was to analyze the polymer injection performance and to confirm the in-situ designed viscosity of the polymer injected, necessary to estimate the expected EOR effect. The adopted workflow focused on the integration of different sources of data and analyses. Indeed, several phenomena may occur during polymer injection, such as complex injectivity behavior due to polymer non-Newtonian rheological nature, formation damage caused by particles adsorption, fractures opening, and mechanical degradation of polymer. The injection performance analysis focused the following aspects: previous case history, polymer laboratory tests, shear stress through perforation evaluation, diagnostic plots, injectivity test interpretation, well test analysis, and fracturing investigation. Lastly, numerical simulation allowed us to integrate the different analysis, thoroughly capturing the subsurface polymer behavior. Main result is that injection under fracturing conditions occurred during pilot start-up. These small-scale fractures, localized in the near-wellbore zone, are not detrimental to polymer flooding and rather increase the well injectivity. Furthermore, no evidence of mechanical polymer degradation was detected. The evaluation of the subsurface polymer behavior during an inter-well pilot is crucial to verify the correct polymer injection process. In this work different source of data and analysis have been integrated to understand the injectivity behavior. Robust reservoir monitoring is ongoing and preliminary promising effects are now being shown.

Leukocyte count in 48Â h cohort. (PDF 64Â kb)

Baseline and clinical characteristics between cohorts. Table S2.2. Ficolins and MBL vs confounding factors. (PDF 170Â kb)

Univariate and multivariate predictors of functional outcome assuming the worst scenario for patients lost to follow-up. (PDF 88Â kb)

Comparison of the crude performance of early ficolin-1 and diagnostic markers of functional outcome in patients enrolled within 6Â h. (PDF 12Â kb)

Multivariate analyses for stroke diagnosis. (PDF 77Â kb)

P-terphenyl crystals are high light yield organic scintillators characterised by a relatively short intrinsic light attenuation length. The effective value of this physical quantity depends on the actual design of the detector and can be tuned for a specific application with the appropriate combination of crystal size and shape, its bulk and superficial optical properties and the light sensor choice. In this paper we investigate the feasibility to use this feature to realize a simple, mono crystal, position sensitive, β− particle counter able to identify both the presence and the position of a β− point source located in close proximity of the detector. This simple design allows an integration of this detection technique into specific β−-RGS (Radio Guided Surgery) surgical devices of use in brain tumour-ectomy and in endoscopic applications, giving the surgeon a better guidance to spot the tumour localisation. We present the results obtained with two devices: a single channel particle counter built on a cylindrical crystal (=10 mm, h=10 mm) designed to probe and identify the position of a point β− source located around the surface of the detector, and a four channels particle counter built on a smaller (=7 mm, h=3 mm), ring shaped, crystal designed to identify the position of a point β− source placed just ahead of the detector. In both configurations we were able to clearly identify the presence and the position, relative to the detector, of a radio-active point source set off axis with respect to the crystal. The four channel detector shows an angular resolution of ±8 degree and an effective light absorption length of 4.2±0.1 mm. The single channel cylindrical crystal have a 8.0±0.5 mm effective light absorption length and the same discovery potential.

The main purpose of this work is to get an insight into thermal development strategies to be applied in an extra-heavy oil field. The goals of this study are: to study the feasibility of thermal EOR techniques; to perform a risk analysis highlighting the main uncertainties on reservoir development. Firstly, a general overview of the field is given. Steamflooding has been thoroughly investigated, by optimizing operating parameters and evaluating their effect on oil recovery and steam-oil-ratio (SOR). Similar sensitivity analyses have been performed for the down-hole electrical heating technique, focusing particularly on power input, and evaluating the propagation of heat in the reservoir. Risk analyses have been then performed in order to highlight the main uncertainties affecting the field development, in cold production as well as in steamflooding and electrical heating. Risk analysis was carried out by applying both the classic Monte Carlo workflow and the Experimental Design and Response Surface Modelling. This methodology becomes advisable when simulation runtime is excessive and a classic Monte Carlo workflow is too expensive. The last part of the paper covers basic pseudo-economic analysis to assist in the comparison between cost-benefits of steamflooding and electrical heating. The main outcomes of this work are the following: steamflooding proved to be an effective way to improve oil recovery, although for pessimistic scenarios (i.e. very high viscosity) its convenience should be properly evaluated; electrical heating can cheaply provide additional oil recovery. The performed analysis has highlighted the risk and the opportunities of the two thermal recovery techniques.

[1] Chemical reactions are driven by disequilibrium, which is often caused by mixing. Therefore quantification of the mixing rate is essential for evaluating the fate of solutes in natural systems, such as rivers, lakes, and aquifers. We propose a novel mixing ratios-based formulation to evaluate solute concentrations and reaction rates when equilibrium aqueous reactions and precipitation/dissolution of minerals are driven by mixing of different end-members. Each end-member corresponds to a water from a given source with a specific chemical signature. The approach decouples the solute transport and chemical speciation problems, so that mixing ratios can be first obtained from the solution of conservative transport and then be used in general speciation codes to obtain the concentration of reacting species. One key finding is a general expression for reaction rates which demonstrates that the amount of reactants evolving into products depends on the rate at which solutions mix. Our formulation constitutes a general framework according to which one can design and interpret experimental analyses devoted to study mixing-driven reactive processes and obtain transverse dispersion coefficients. The formulation is also proposed as a useful tool to derive analytical solutions of reactive transport problems and may result computationally advantageous when compared to previous approaches to reactive transport modeling. We apply the developed formulation to provide an analytical solution of the reactive transport process resulting from mixing different CaCO3-saturated waters in a two-dimensional setup.