11 research outputs found
Production enhancement of Tight Gas Reservoirs
La valorisation des rĂ©servoirs gaziers compacts, dits Tight Gas Reservoirs (TGR), dont les dĂ©couvertes sont importantes, permettrait dâaugmenter significativement les ressources mondiales dâhydrocarbures. Dans lâobjectif dâamĂ©liorer la production de ces types de rĂ©servoirs, nous avons menĂ© une Ă©tude ayant pour but de parvenir Ă une meilleure comprĂ©hension de la relation entre lâendommagement et les propriĂ©tĂ©s de transport des gĂ©omatĂ©riaux. LâĂ©volution de la microstructure dâĂ©prouvettes qui ont Ă©tĂ© soumises prĂ©alablement Ă des chargements dynamiques est Ă©tudiĂ©e. Une estimation de leurs permĂ©abilitĂ©s avec lâendommagement est tout dâabord prĂ©sentĂ©e Ă lâaide dâun modĂšle de pores parallĂšles couplant un Ă©coulement de Poiseuille avec la diffusion de Knudsen. Nous avons ensuite menĂ© des travaux expĂ©rimentaux afin dâestimer lâĂ©volution de la permĂ©abilitĂ© avec lâendommagement en relation avec lâĂ©volution de la distribution de tailles de pores. Les mesures de permĂ©abilitĂ© sont effectuĂ©es sur des cylindres en mortier similaire aux roches tight gas, soumis Ă une compression uniaxiale. La caractĂ©risation des microstructures des mortiers endommagĂ©s est rĂ©alisĂ©e par porosimĂ©trie par intrusion de mercure. Afin dâestimer lâĂ©volution de la permĂ©abilitĂ©, un nouveau modĂšle hiĂ©rarchique alĂ©atoire est prĂ©sentĂ©. Les comparaisons avec les donnĂ©es expĂ©rimentales montrent la capacitĂ© de ce modĂšle Ă estimer non seulement les permĂ©abilitĂ©s apparentes et intrinsĂšques mais aussi leurs Ă©volutions sous lâeffet dâun chargement introduisant une Ă©volution de la distribution de taille de pores. Ce modĂšle, ainsi que le dispositif expĂ©rimental employĂ©, ont Ă©tĂ© Ă©tendus afin dâestimer Ă lâavenir les permĂ©abilitĂ©s relatives de mĂ©langes gazeux. Le dernier chapitre prĂ©sente une Ă©tude de lâadsorption de mĂ©thane dans diffĂ©rents milieux fracturĂ©s par chocs Ă©lectriques. Les rĂ©sultats, utiles pour lâestimation des ressources en place, ont montrĂ© que la fracturation permet de favoriser lâextraction du gaz initialement adsorbĂ©.The valorization of compact gas reservoirs, called tight gas reservoirs (TGR), whose discoveries are important, would significantly increase the global hydrocarbon resources. With the aim of improving the production of these types of gas, we have conducted a study to achieve a better understanding of the relationship between damage and the transport properties of geomaterials. The microstructure evolution of specimens, which were submitted beforehand to dynamic loading, has been investigated. An estimation of their permeability upon damage is first presented with the help of a bundle model of parallel capillaries coupling Poiseuille flow with Knudsen diffusion. Then, we have carried out an experimental work to estimate the permeability evolution upon damage in relation to the evolution of the pore size distribution in uniaxial compression. The measurements of permeability have been performed on mortar cylinders, designed to mimic typical tight rocks that can be found in tight gas reservoirs. Microstructural characterization of damaged mortars has been performed with the help of mercury intrusion porosimetry (MIP). To estimate the permeability evolution, a new random hierarchical model has been devised. The comparisons with the experimental data show the ability of this model to estimate not only the apparent and intrinsic permeabilities but also their evolutions under loading due to a change in the pore size distribution. This model and the experimental set up have been extended to estimate the relative permeabilities of gas mixtures in the future. The final chapter presents a study of the adsorption of methane on different porous media fractured by electrical shocks. The results, concerning the estimation of the in-place resources, have shown that fracturing can enhance the extraction of the initial amount of adsorbed gas
Production enhancement of Tight Gas Reservoirs
La valorisation des rĂ©servoirs gaziers compacts, dits Tight Gas Reservoirs (TGR), dont les dĂ©couvertes sont importantes, permettrait dâaugmenter significativement les ressources mondiales dâhydrocarbures. Dans lâobjectif dâamĂ©liorer la production de ces types de rĂ©servoirs, nous avons menĂ© une Ă©tude ayant pour but de parvenir Ă une meilleure comprĂ©hension de la relation entre lâendommagement et les propriĂ©tĂ©s de transport des gĂ©omatĂ©riaux. LâĂ©volution de la microstructure dâĂ©prouvettes qui ont Ă©tĂ© soumises prĂ©alablement Ă des chargements dynamiques est Ă©tudiĂ©e. Une estimation de leurs permĂ©abilitĂ©s avec lâendommagement est tout dâabord prĂ©sentĂ©e Ă lâaide dâun modĂšle de pores parallĂšles couplant un Ă©coulement de Poiseuille avec la diffusion de Knudsen. Nous avons ensuite menĂ© des travaux expĂ©rimentaux afin dâestimer lâĂ©volution de la permĂ©abilitĂ© avec lâendommagement en relation avec lâĂ©volution de la distribution de tailles de pores. Les mesures de permĂ©abilitĂ© sont effectuĂ©es sur des cylindres en mortier similaire aux roches tight gas, soumis Ă une compression uniaxiale. La caractĂ©risation des microstructures des mortiers endommagĂ©s est rĂ©alisĂ©e par porosimĂ©trie par intrusion de mercure. Afin dâestimer lâĂ©volution de la permĂ©abilitĂ©, un nouveau modĂšle hiĂ©rarchique alĂ©atoire est prĂ©sentĂ©. Les comparaisons avec les donnĂ©es expĂ©rimentales montrent la capacitĂ© de ce modĂšle Ă estimer non seulement les permĂ©abilitĂ©s apparentes et intrinsĂšques mais aussi leurs Ă©volutions sous lâeffet dâun chargement introduisant une Ă©volution de la distribution de taille de pores. Ce modĂšle, ainsi que le dispositif expĂ©rimental employĂ©, ont Ă©tĂ© Ă©tendus afin dâestimer Ă lâavenir les permĂ©abilitĂ©s relatives de mĂ©langes gazeux. Le dernier chapitre prĂ©sente une Ă©tude de lâadsorption de mĂ©thane dans diffĂ©rents milieux fracturĂ©s par chocs Ă©lectriques. Les rĂ©sultats, utiles pour lâestimation des ressources en place, ont montrĂ© que la fracturation permet de favoriser lâextraction du gaz initialement adsorbĂ©.The valorization of compact gas reservoirs, called tight gas reservoirs (TGR), whose discoveries are important, would significantly increase the global hydrocarbon resources. With the aim of improving the production of these types of gas, we have conducted a study to achieve a better understanding of the relationship between damage and the transport properties of geomaterials. The microstructure evolution of specimens, which were submitted beforehand to dynamic loading, has been investigated. An estimation of their permeability upon damage is first presented with the help of a bundle model of parallel capillaries coupling Poiseuille flow with Knudsen diffusion. Then, we have carried out an experimental work to estimate the permeability evolution upon damage in relation to the evolution of the pore size distribution in uniaxial compression. The measurements of permeability have been performed on mortar cylinders, designed to mimic typical tight rocks that can be found in tight gas reservoirs. Microstructural characterization of damaged mortars has been performed with the help of mercury intrusion porosimetry (MIP). To estimate the permeability evolution, a new random hierarchical model has been devised. The comparisons with the experimental data show the ability of this model to estimate not only the apparent and intrinsic permeabilities but also their evolutions under loading due to a change in the pore size distribution. This model and the experimental set up have been extended to estimate the relative permeabilities of gas mixtures in the future. The final chapter presents a study of the adsorption of methane on different porous media fractured by electrical shocks. The results, concerning the estimation of the in-place resources, have shown that fracturing can enhance the extraction of the initial amount of adsorbed gas
A Hierarchical Model for the Computation of Permeation Properties of Porous Materials and Their Enhancement due to Microcracks
International audienceThis paper presents a model capable of providing estimates of the apparent permeability directly from the pore-size distribution and from the properties of the fluid to be considered. The model is based on a hierarchical assembly of capillaries with decreasing diameter, generated randomly. The technique yields a porous network, which mimics the pore space measured experimentally by mercury intrusion. The intrinsic permeability and the evolution of the apparent permeability with mean pressure are provided by equating Darcyâs law and a combination of Poiseuilleâs and Knudsenâs laws. Comparisons with experimental data on mortar specimens show that the model provides the intrinsic permeability and its evolution when the material is subjected to mechanical loads. For a given pore-size distribution, the evolution of the apparent permeability is also provided and test data with several types of gases compare quite well with the model
Upscaling Poiseuilleâs and Knudsenâs flows to predict gas permeability in damaged porous media
International audienc
Upscaling Poiseuilleâs and Knudsenâs flows to predict gas permeabilities in tight porous media
International audienc
Intrinsic, apparent and relative permeability estimation of cementitious materials based on pore size distributions
International audienc
A new model for estimating fluid transfer properties of cementitious materials
International audienc
Fracture and fluid-solid coupled effects in porous quasi-brittle materials
International audienc
Novel immunotherapeutic options for BCGâunresponsive highârisk nonâmuscleâinvasive bladder cancer
Abstract Background Highârisk nonâmuscleâinvasive bladder cancer (HRâNMIBC) presents a challenge to many physicians due to its ability to resist Bacillus CalmetteâGuĂ©rin (BCG) intravesical therapy and the substantial rate of progression into muscleâinvasive bladder cancer (MIBC). Patients who are BCGâunresponsive have worse prognosis and thus require further management including radical cystectomy (RC), which significantly impacts quality of life. Moreover, the ongoing worldwide shortage of BCG warrants the need for policies that prioritize drug use and utilize alternative treatment strategies. Hence, there is a significant unmet need for bladder preserving therapy in this subset of patients. Methods To address this issue, we searched the relevant literature in PUBMED for articles published from 2019 through May of 2023 using appropriate keywords. All clinical trials of patients with HRâNMIBC treated with immuneârelated agents were retrieved from clinicaltrials.gov. Findings and Future Perspectives Exploratory treatments for BCGâUnresponsive HRâNMIBC included immune checkpoint inhibitors (ICI), oncolytic viral therapy, cytokine agonists, and other immunomodulators targeting TLR, EpCaM, FGFR, MetAP2, and IDO1. Some combination therapies have been found to work synergistically and are preferred therapeutically over monotherapy. Three drugsâpembrolizumab, valrubicin, and most recently, nadofaragene firadenovecâvncgâhave been FDA approved for the treatment of BCGâunresponsive NMIBC in patients who are ineligible for or decline RC. However, all explored treatment options tend to postpone RC rather than provide longâterm disease control. Additional combination strategies need to be studied to enhance the effects of immunotherapy. Despite the challenges faced in finding effective therapies, many potential treatments are currently under investigation. Addressing the landscape of biomarkers, mechanisms of progression, BCG resistance, and trial design challenges in HRâNMIBC is essential for the discovery of new targets and the development of effective treatments
Fracture, deformation, and fluid-solid coupled effects in porous quasi-brittle materials
International audienc