scholarly journals Efficient Assimilation of Crosswell Electromagnetic Data Using an Ensemble-Based History-Matching Framework

SPE Journal ◽  
2019 ◽  
Vol 25 (01) ◽  
pp. 119-138 ◽  
Author(s):  
Yanhui Zhang ◽  
Femke C. Vossepoel ◽  
Ibrahim Hoteit
Keyword(s):  
History Matching ◽  
Reservoir Characterization ◽  
Saline Water ◽  
Advanced Technology ◽  
Added Value ◽  
Original Form ◽  
Cross Sectional ◽  
Integration Schemes ◽  
Reservoir State ◽  
Em Tomography

Summary An ensemble-based history-matching framework is proposed to enhance the characterization of petroleum reservoirs through the assimilation of crosswell electromagnetic (EM) data. As an advanced technology in reservoir surveillance, crosswell EM tomography can be used to estimate a cross-sectional conductivity map and associated saturation profile at an interwell scale by exploiting the sharp contrast in conductivity between hydrocarbons and saline water. Incorporating this information into reservoir simulation in combination with other available observations is expected to enhance the forecasting capability of reservoir models and to lead to better quantification of uncertainty. The proposed approach applies ensemble-based data-assimilation methods to build a robust and flexible framework in which various sources of available measurements can be integrated. A comparative study evaluates two different implementations of the assimilation of crosswell EM data. The first approach integrates the crosswell EM field components in their original form, which entails forward simulation of the observed EM responses from the simulated reservoir state. In the second approach, formation conductivity is derived from the EM data through inversion and is subsequently assimilated into the reservoir model. An image-oriented distance parameterization of the fluid front assimilates the conductivity field in an efficient and robust manner and overcomes issues with data size, errors, and their correlation. Numerical experiments for different test cases with increasing complexity provide insight into the performance of the two proposed integration schemes. The results demonstrate the efficiency of the developed history-matching workflow and the added value of crosswell EM data in enhancing the reservoir characterization and reliability of dynamic reservoir forecasts.

History Matching Time-Lapse Surface-Gravity and Well-Pressure Data With Ensemble Smoother for Estimating Gas Field Aquifer Support—A 3D Numerical Study

SPE Journal ◽  
2012 ◽  
Vol 17 (04) ◽  
pp. 966-980 ◽  
Author(s):  
M.. Glegola ◽  
P.. Ditmar ◽  
R.G.. G. Hanea ◽  
O.. Eiken ◽  
F.C.. C. Vossepoel ◽  
...  
Keyword(s):  
History Matching ◽  
Numerical Study ◽  
Gravity Data ◽  
Time Lapse ◽  
Added Value ◽  
Pressure Data ◽  
Production Forecast ◽  
Gas Field ◽  
Ensemble Smoother ◽  
Reservoir State

Summary Water influx is an important factor influencing production of gas reservoirs with an active aquifer. However, aquifer properties such as size, porosity, and permeability are typically uncertain and make predictions of field performance challenging. The observed pressure decline is inherently nonunique with respect to water influx, and large uncertainties in the actual reservoir state are common. Time-lapse (4D) gravimetry, which is a direct measure of a subsurface mass redistribution, has the potential to provide valuable information in this context. Recent improvements in instrumentation and data-acquisition and -processing procedures have made time-lapse gravimetry a mature monitoring technique, both for land and offshore applications. However, despite an increasing number of gas fields in which gravimetric monitoring has been applied, little has been published on the added value of gravity data in a broader context of modern reservoir management on the basis of the closed-loop concept. The way in which gravity data can contribute to improved reservoir characterization, production-forecast accuracy, and hydrocarbon-reserves estimation is still to be addressed in many respects. In this paper, we investigate the added value of gravimetric observations for gas-field-production monitoring and aquifer-support estimation. We perform a numerical study with a realistic 3D gas field model that contains a large and complex aquifer system. The aquifer support and other reservoir parameters (i.e., porosity, permeability, reservoir top and bottom horizons) are estimated simultaneously using the ensemble smoother (ES). We consider three cases in which gravity only is assimilated, pressure only is assimilated, and gravity and pressure data are assimilated jointly. We show that a combined estimation of the aquifer support with the permeability field, porosity field, and reservoir structure is a very challenging and nonunique history-matching problem, in which gravity certainly has an added value. Pressure data alone may not discriminate between different reservoir scenarios. Combining pressure and gravity data may help to reduce the nonuniqueness problem and provide not only an improved gas- and water-production forecast and gas-in-place evaluation, but also a more-accurate reservoir-state description.

scholarly journals Synergizing Crosswell Seismic and Electromagnetic Techniques for Enhancing Reservoir Characterization

SPE Journal ◽  
2016 ◽  
Vol 21 (03) ◽  
pp. 909-927 ◽  
Author(s):  
Klemens Katterbauer ◽  
Ibrahim Hoteit ◽  
Shuyu Sun
Keyword(s):  
History Matching ◽  
Oil And Gas ◽  
Reservoir Characterization ◽  
Saline Water ◽  
Oil And Gas Industry ◽  
Time Lapse ◽  
Gas Industry ◽  
Matching Process ◽  
Weak Density ◽  
Reservoir History Matching

Summary Increasing complexity of hydrocarbon projects and the request for higher recovery rates have driven the oil-and-gas industry to look for a more-detailed understanding of the subsurface formation to optimize recovery of oil and profitability. Despite the significant successes of geophysical techniques in determining changes within the reservoir, the benefits from individually mapping the information are limited. Although seismic techniques have been the main approach for imaging the subsurface, the weak density contrast between water and oil has made electromagnetic (EM) technology an attractive complement to improve fluid distinction, especially for high-saline water. This crosswell technology assumes greater importance for obtaining higher-resolution images of the interwell regions to more accurately characterize the reservoir and track fluid-front developments. In this study, an ensemble-Kalman-based history-matching framework is proposed for directly incorporating crosswell time-lapse seismic and EM data into the history-matching process. The direct incorporation of the time-lapse seismic and EM data into the history-matching process exploits the complementarity of these data to enhance subsurface characterization, to incorporate interwell information, and to avoid biases that may be incurred from separate inversions of the geophysical data for attributes. An extensive analysis with 2D and realistic 3D reservoirs illustrates the robustness and enhanced forecastability of critical reservoir variables. The 2D reservoir provides a better understanding of the connection between fluid discrimination and enhanced history matches, and the 3D reservoir demonstrates its applicability to a realistic reservoir. History-matching enhancements (in terms of reduction in the history-matching error) when incorporating both seismic and EM data averaged approximately 50% for the 2D case, and approximately 30% for the 3D case, and permeability estimates were approximately 25% better compared with a standard history matching with only production data.

Air Bridge Technology: A Comparison of Novel Interconnect Materials and Integration Schemes for Beyond 45 nm

2003 ◽  
Vol 766 ◽  
Author(s):  
Kenneth Foster ◽  
Joost Waeterloos ◽  
Don Frye ◽  
Steve Froelicher ◽  
Mike Mills
Keyword(s):  
Dielectric Constants ◽  
Advanced Technology ◽  
Effective Dielectric Constant ◽  
Device Performance ◽  
Interlayer Dielectric ◽  
Integration Schemes ◽  
Stepwise Reduction ◽  
Bridge Technology ◽  
Integrated Device ◽  
Compare And Contrast

AbstractThe electronics industry, in a continual drive for improved integrated device performance, is seeking increasingly lower dielectric constants (k) of the insulators that are used as interlayer dielectric (ILD) for advanced logic interconnects. As the industry continually seeks a stepwise reduction of the “effective” dielectric constant (keff), simple extendibility, leads to the consideration of the highest performance possible, namely air bridge technology. In this paper we will discuss requirements, integration schemes and properties for a novel class of materials that has been developed as part of an advanced technology probe into air bridge architecture. We will compare and contrast these potential technology offerings with other existing dense and porous ILD integration options, and show that the choice is neither trivial nor obvious.

scholarly journals Evaluation of e-health (Seha) application: a cross-sectional study in Saudi Arabia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Abeer Alharbi ◽  
Joharah Alzuwaed ◽  
Hind Qasem
Keyword(s):  
Saudi Arabia ◽  
Health Services ◽  
Healthcare Services ◽  
Cross Sectional Study ◽  
Advanced Technology ◽  
Sectional Study ◽  
Cross Sectional ◽  
Technical Problems ◽  
Significant Difference ◽  
Ease Of Access

Abstract Background The Ministry of Health in Saudi Arabia is expanding the country’s telemedicine services by using advanced technology in health services. In doing so, an e-health application (app), Seha, was introduced in 2018 that allows individuals to have face-to-face visual medical consultations with their doctors on their smartphones. Objective This study evaluated the effectiveness of the app in improving healthcare delivery by ensuring patient satisfaction with the care given, increasing access to care, and improving efficiency in the healthcare system. Methods A cross-sectional study design was used to assess the perceptions of users of the Seha app and non-users who continued with traditional health services. The data were collected using an online survey via Google Forms between June 2020 and September 2020. Independent t tests and chi-square (χ2) tests were conducted to answer the research questions. Results There was a significant difference between users and non-users in terms of ease of access to health services (t =  − 9.38, p < 0.05), with app users having a higher mean score (4.19 ± 0.91) than non-users (3.41 ± 1.00); satisfaction with health services (t =  − 6.33, p < 0.05), with users having a higher mean score (3.96 ± 0.91) than non-users (3.45 ± 0.94); and efficiency (only one visit needed for treatment) (t =  − 3.20, p < 0.05), with users having a higher mean score (3.71 ± 0.93) than non-users (3.45 ± 0.93). There were significant associations between the use of the Seha app and age (χ2 = 8.79, p < 0.05), gender (χ2 = 22.19, p < 0.05), region (χ2 = 19.74, p < 0.05), and occupation (χ2 = 22.05, p < 0.05). There were significant relationships between the three items (on access, satisfaction, and efficiency) and experiencing technical issues (t = 4.47, t = 8.11, and t = 3.24, respectively, p < 0.05), with users who faced technical problems having significantly lower mean scores for all three items. Conclusion This study provided evidence that the Seha app improved the delivery of healthcare in Saudi Arabia. Users of the app had a better health experience in terms of their perceived ease of access to healthcare services; their satisfaction with healthcare services; and the efficiency of the system, measured by the number of required doctor visits. Other factors that appeared to influence the use of the app included age, gender, usual source of care, and technical difficulties.

scholarly journals Radiomics and Magnetic Resonance Imaging of Rectal Cancer: From Engineering to Clinical Practice

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 756
Author(s):  
Francesca Coppola ◽  
Valentina Giannini ◽  
Michela Gabelloni ◽  
Jovana Panic ◽  
Arianna Defeudis ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Rectal Cancer ◽  
Magnetic Resonance ◽  
Accuracy Assessment ◽  
Unmet Need ◽  
Quantitative Information ◽  
Added Value ◽  
Diagnostic Tools ◽  
Resonance Imaging ◽  
Cross Sectional

While cross-sectional imaging has seen continuous progress and plays an undiscussed pivotal role in the diagnostic management and treatment planning of patients with rectal cancer, a largely unmet need remains for improved staging accuracy, assessment of treatment response and prediction of individual patient outcome. Moreover, the increasing availability of target therapies has called for developing reliable diagnostic tools for identifying potential responders and optimizing overall treatment strategy on a personalized basis. Radiomics has emerged as a promising, still fully evolving research topic, which could harness the power of modern computer technology to generate quantitative information from imaging datasets based on advanced data-driven biomathematical models, potentially providing an added value to conventional imaging for improved patient management. The present study aimed to illustrate the contribution that current radiomics methods applied to magnetic resonance imaging can offer to managing patients with rectal cancer.

Experience sampling research in psychopathology: opening the black box of daily life

2009 ◽  
Vol 39 (9) ◽  
pp. 1533-1547 ◽  
Author(s):  
I. Myin-Germeys ◽  
M. Oorschot ◽  
D. Collip ◽  
J. Lataster ◽  
P. Delespaul ◽  
...  
Keyword(s):  
Daily Life ◽  
Experience Sampling ◽  
Added Value ◽  
Cross Sectional ◽  
Gene Environment ◽  
Psychological Models ◽  
Research Findings ◽  
Underlying Mechanisms ◽  
New Research ◽  
Momentary Assessment

A growing body of research suggests that momentary assessment technologies that sample experiences in the context of daily life constitute a useful and productive approach in the study of behavioural phenotypes and a powerful addition to mainstream cross-sectional research paradigms. Momentary assessment strategies for psychopathology are described, together with a comprehensive review of research findings illustrating the added value of daily life research for the study of (1) phenomenology, (2) aetiology, (3) psychological models, (4) biological mechanisms, (5) treatment and (6) gene–environment interactions in psychopathology. Overall, this review shows that variability over time and dynamic patterns of reactivity to the environment are essential features of psychopathological experiences that need to be captured for a better understanding of their phenomenology and underlying mechanisms. The Experience Sampling Method (ESM) allows us to capture the film rather than a snapshot of daily life reality of patients, fuelling new research into the gene–environment–experience interplay underlying psychopathology and its treatment.

scholarly journals Objective assessment of alcohol consumption in early pregnancy using phosphatidylethanol: a cross‐sectional study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Leonieke J. Breunis ◽  
Sophie Wassenaar ◽  
Barbara J. Sibbles ◽  
Ab A. Aaldriks ◽  
Hilmar H. Bijma ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Early Pregnancy ◽  
Gestational Age ◽  
Care Provider ◽  
Objective Assessment ◽  
Obstetric Care ◽  
Tertiary Hospital ◽  
Maternal Blood ◽  
Added Value ◽  
Cross Sectional

Abstract Background Alcohol consumption during pregnancy is associated with major birth defects and developmental disabilities. Questionnaires concerning alcohol consumption during pregnancy underestimate alcohol use while the use of a reliable and objective biomarker for alcohol consumption enables more accurate screening. Phosphatidylethanol can detect low levels of alcohol consumption in the previous two weeks. In this study we aimed to biochemically assess the prevalence of alcohol consumption during early pregnancy using phosphatidylethanol in blood and compare this with self-reported alcohol consumption. Methods To evaluate biochemically assessed prevalence of alcohol consumption during early pregnancy using phosphatidylethanol levels, we conducted a prospective, cross-sectional, single center study in the largest tertiary hospital of the Netherlands. All adult pregnant women who were under the care of the obstetric department of the Erasmus MC and who underwent routine blood testing at a gestational age of less than 15 weeks were eligible. No specified informed consent was needed. Results The study was conducted between September 2016 and October 2017. In total, we received 1,002 residual samples of 992 women. After applying in- and exclusion criteria we analyzed 684 samples. Mean gestational age of all included women was 10.3 weeks (SD 1.9). Of these women, 36 (5.3 %) tested positive for phosphatidylethanol, indicating alcohol consumption in the previous two weeks. Of women with a positive phosphatidylethanol test, 89 % (n = 32) did not express alcohol consumption to their obstetric care provider. Conclusions One in nineteen women consumed alcohol during early pregnancy with a high percentage not reporting this use to their obstetric care provider. Questioning alcohol consumption by an obstetric care provider did not successfully identify (hazardous) alcohol consumption. Routine screening with phosphatidylethanol in maternal blood can be of added value to identify women who consume alcohol during pregnancy.

The mediating role of autonomy in the effect of pro-innovation climate and supervisor supportiveness on innovative behavior of nurses

2019 ◽  
Vol 22 (1) ◽  
pp. 41-58 ◽  
Author(s):  
Betül Sönmez ◽  
Aytolan Yıldırım
Keyword(s):  
Organizational Climate ◽  
Linear Regression Analysis ◽  
Professional Autonomy ◽  
Added Value ◽  
Innovative Behavior ◽  
Cross Sectional ◽  
Content Type ◽  
Mediating Role ◽  
Innovation Climate

PurposeThe purpose of this paper is to test the mediating role of autonomy in the effect of a pro-innovation organizational climate and supervisor supportiveness (SS) on the innovative behavior (IB) of nurses.Design/methodology/approachThe sample of this cross-sectional, correlational study consisted of 332 nurses, who were selected, on the basis of the convenience sampling method, from among the nurses working at two public university hospitals in Istanbul. The data of the study were collected between February and May of 2015. Descriptive analysis and linear regression analysis were used for data analysis, and the bootstrapping method was applied to test the significance of the mediating role.FindingsThe model used for examining the mediating role of autonomy was found to be statistically significant, as it explained 36 percent of the variance of IB. When the significance of the mediating role was tested, its effect on both innovation climate and SS was observed to be significant.Originality/valueThe obtained results indicated that a pro-innovation organizational climate and SS functioned as premises for autonomy. In turn, the rise in autonomy level that served to innovative climate and SS increased the IB of the nurses through boosting their autonomy level. From these results, it can be argued that nurses with a high level of professional autonomy can create innovative outputs and provide added value through the IB they practice in providing patient care and general health services.

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