Forward stratigraphic modelling aims at representing the spatial distribution of lithology as a function of physical processes and environmental conditions at the time of deposition so as to ...integrate geological knowledge into the reservoir modelling workflow, thus increasing predictive capabilities of reservoir models and efficient exploitation of hydrocarbons. Application of process-based models in inverse mode is not yet well-established due to our limited insight into the information content of common subsurface data and the computational overhead involved.
In this paper we examine inverse modelling of stratigraphy by using a typical dataset acquired in the hydrocarbon industry, which consists of seismic data and standard logs from a limited number of wells. The approach is based on the use of a forward model called SimClast, developed at Delft University of Technology, to generate facies distribution and architecture at the regional scale. Three different goodness of fit functions were proposed for model inversion, following an inference approach. A synthetic reservoir unit was used to investigate the impact of the uncertainty affecting the input parameters and the information content of seismic and well data.
The case study showed that the model was more sensitive to the initial topography and to the location of the sediment entry point than to sea level. The depth of the seismic reflector corresponding to the top-reservoir surface was the most informative data source; the initial and boundary conditions of the simulation were constrained by evaluating the depth of this reflector across the whole basin area. In the reservoir area, where the seismic-to-well tie was established, the depth of the reservoir top does not give enough information for constraining the model parameters. Our results thus indicate that evaluation of basin-scale data permits reduction of uncertainty in (geostatistical) reservoir models relative to the current workflow, in which only local data are used. Effective use of well data to generate reservoir models conditioned to basin-scale scenarios requires post-processing methods to downscale the output of the forward model used in the experiments.
•Fluvio-deltaic stratigraphy was simulated with a 2DH process-based model.•Goodness of fit functions were used to infer boundary conditions from subsurface data.•Information content of seismic and well data was evaluated.•Depth of reservoir top across basin is best predictor of reservoir lithology.
•Advanced methodology for thermal front monitoring in ATES•Interpreting harmonic pulse testing in frequency domain in radial composite scenario•Diagnostic loglog plot analogous to conventional ...Pressure Transient Analysis•Methodology does not require production/injection interruption
Seasonal storage of heat in shallow aquifers for increasing the efficiency of geothermal energy systems requires a proper monitoring strategy. We expanded our earlier work on harmonic pulse testing (HPT) to incorporate the effect of a temperature front moving into the reservoir due to injection of hot (or cold) water. Our analytical solutions were applied to monitor the thermal front evolution in a doublet system. Thermal front position and average temperature around the injector could indeed be characterized through the application of the proposed HPT interpretation. Additional analyses were carried out adding noise to evaluate the robustness of the interpretation methodology.
The Po Plain (Italy) is one of the most densely populated and productive regions of Europe, characterized by a flourishing economy (also linked to strategic subsurface resources) and several world ...cultural and natural heritage sites. The coupling of socio-economic interests with geological hazards (i.e. seismic, subsidence, and flooding hazards) in this area requires accurate knowledge of the subsurface geology, the active geological processes, and the impact of human activities on natural environments to mitigate the potential natural and anthropic risks.
Consensus exits about the clinical benefits of an early referral to multidisciplinary Heart Failure Unit-HFU for old frail patients with HF. Nevertheless, few data are present regarding the prognosis ...and the predictors of outcome in oldest-old patients managed in this clinical setting. The aim of present study is to identify predictors of 1-year all-cause mortality in very old patients enrolled in our multidisciplinary HFU after an episode of acute decompensated HF.
This study is a retro-prospective, single-center cohort analysis of patients managed in our multidisciplinary HFU. Inclusion criterion was diagnosis of HF according to ESC guidelines and age ≥ 85 years, while no exclusion criteria were pre-defined. Baseline clinical and comprehensive geriatric evaluations were recorded during the first visit and follow-up visits were repeated according to our standardized timetable protocol. Primary end-point was 1-year all-cause mortality.
We enrolled 75 patients aged 89.2 ± 2.8 years; 39 (52.0%) were females. During 1-year follow-up, seventeen patients (22.7%) died. Residual congestion with higher level (> 4) of EVEREST score (HR 1.24: 95% CI 1.04-1.47) and living alone (HR 3.34: 95% CI 1.16-9.64) resulted the two independent predictors of 1-year all-cause mortality at the multivariate Cox regression model. Finally, patients living alone and with an EVEREST score > 4 experienced a worse prognosis as clearly described by a steeper descendent Kaplan-Meier curve.
In a very old population of patients after an acute decompensated HF, residual congestion and social isolation as living alone identify those with high risk of 1-year death.
This paper discusses the geopolitical and socioeconomic implications the development of shale gas (& oil) has had in the US. The approach has been that of placing shale gas under erasure (or
sous ...rature
). In other words, the assumption that shale is currently both present/absent was made to answer the question of whether it can actually be considered as a resource. Moreover, the success of the “shale revolution” in the US has not only had an impact on the International Oil & Gas, Petrochemical, natural resource and renewable markets, but it has also triggered certain geopolitical events which are modifying the role played by nations globally. Finally, it is suggested that under the prevailing circumstances these unconventional resources appear to still be more of a challenge than part of the solution to the ever growing energy demand, and production of goods associated with societal needs/aspirations worldwide.
Broadband data from the Příbram seismological network was used to investigate the source of two earthquakes, with magnitudes
M
w
= 0.2 and 0.4 respectively, occurring in the period of ...October–November 2009 in the Háje natural gas storage area (Czech Republic). Both events were located inside the limits of the storage area and at depths similar to those of the underground caverns where the gas is stored. We applied an inversion technique using the software ISOLA for moment tensor retrieval in order to assess the source process of both events and recognize whether a significant isotropic component existed that could be interpreted as a possible cavern collapse. We also performed an uncertainty analysis so as to confirm the reliability of the focal mechanism solutions and we controlled the consistency between the inverted focal mechanisms and those calculated using the P-waves first motions. Our results showed that the nodal plane orientation, the centroid depth, and the magnitude remained stable. Furthermore, we calculated synthetic waveforms for collapse-type ruptures and compared them with the original records. The match between the synthetic and the original data was very poor supporting the interpretation of the shear character of the events. The combination of the inversion results, which indicated significant double-couple components and of the synthetic tests, which supported the inexistence of an isotropic component at the source, led to the conclusion that the possibility of rocks falling from the ceiling of the caverns or a cavern collapse is highly unlikely.
The exploitation strategy of hydrocarbon reservoirs can be technically and economically optimized only if a reliable numerical model of the reservoir under investigation is available to predict the ...system response for different production scenarios. A numerical model can be reasonably trustworthy after calibration only, which means the model has at least proved its ability to reproduce the historical behavior of the reservoir it represents. The calibration procedure, also known as history matching, is the most time consuming phase in a reservoir study workflow. On the other hand, a new trend on collective computing offers a solution to CPU intensive tasks by distributing the work among several computers located in different places but globally connected through the World Wide Web. In this study, a novel workflow for assisted history matching is proposed. The results proved that this workflow provides better and more representative solutions in a fraction of the time needed by traditional approaches.
It is not the first time in human history, nor will it be the last for that matter, that a collective problem calls for a collective response. Climate change fueled by greenhouse emissions affects ...humankind alike. Despite the disagreement among policymakers and scientists on the severity of the issue, the truth is that the problem remains. A broad look at different technologies being used today in different fields has led to the idea of bringing them together in an attempt to offer a viable solution to reducing anthropogenic CO2. The following paper describes how the nanotechnologies, available or soon to be available, would make CO2 capture, cache, and conversion (coined the three Cs) a valid way for achieving a more sustainable energy society. Authors also set out to highlight with this work how knowledge transfer is instrumental in the development of technology and how methodical assessment of crossovers can expedite research when time plays against us.
Purpose
At the United Nations Earth Summit, in Rio de Janeiro in 1992, participating nations agreed to work together to achieve the goal of sustainable development. Twenty years on great progress has ...been made, but many challenges remain and overcoming them and ensuring a sustainable future will require the knowledge, skills and input of engineering professionals. Ethics and costs have long been part of engineering, but broader understanding is now needed because the skill set those engineers will need has grown dramatically.
Design/methodology/approach
In this paper the authors describe the ongoing shift to sustainable engineering and discuss a variety of approaches that universities are currently using to introduce engineering students and practitioners to sustainability principles and practice and how those can be utilized in mining and petroleum high education institutions.
Findings
We first place sustainability in an engineering context and vice versa, and then review alternative approaches to incorporating sustainability in engineering curricula, briefly highlighting a few key concepts and documenting an example.
Research limitations/implications
The authors first place sustainability in an engineering context and then review alternative approaches to incorporating sustainability in engineering curricula, briefly highlighting a few key concepts and documenting an example.
Originality/value
The challenge to educators is to ensure that new concepts addressing sustainability are instilled in the next generation of engineers, but also being communicated to practicing engineers. Incorporating sustainability into mining and petroleum engineering education is identified as a way to engage students, encourage their enthusiasm, and interest them in pursuing engineering as a career that is not only interesting, but also contributes to society. Distance education is identified as a way to education practicing engineers about sustainability concepts.
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