Modeling of Production Decline Caused by Fines Migration in Deepwater Reservoirs

SPE Journal ◽  
2019 ◽  
Vol 25 (01) ◽  
pp. 391-405
Author(s):  
Yunhui Tan ◽  
Yan Li ◽  
Margaretha C. M. Rijken ◽  
Karim Zaki ◽  
Bin Wang ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Critical Velocity ◽  
Laboratory Data ◽  
Permeability Reduction ◽  
Fines Migration ◽  
The Core ◽  
Decline Rate ◽  
Reduction Function ◽  
Reservoir Simulator

Summary Many deepwater wells experience steep productivity declines. Some field observations indicate that this decline is partly attributable to fines-migration effects. In this paper, we present a numerical workflow to simulate the effect (over time) of flow-induced fines migration on production decline in deepwater reservoirs. A permeability-reduction function was extracted from long-term coreflood tests and implemented into a reservoir simulator. Using the permeability-reduction function, production degradation caused by fines migration was simulated in a detailed single-well model. From previous research, it was understood that fines migration does not start until the flow velocity is greater than the critical velocity. After many long-term coreflood tests, or extended fines-migration (EFM) tests, we concluded that the permeability damage induced by fines migration is a function of the pore-volume (PV) throughput (fluid volume flowing through the core divided by the PV of the core). To address these observations, the numerical model was updated such that the interstitial flow velocity was tracked in each individual cell. When the interstitial velocity is greater than the critical velocity, the cell's permeability follows the permeability-reduction trend obtained from laboratory data. Validation of the workflow is performed using a cylinder model to match the laboratory test core-plug data. A detailed 3D model was constructed to study the fines-migration effect in each part of the near-wellbore (e.g., perforation, fracture) region and the reservoir. As expected, fines migration started near the perforation where the flow velocity was the highest. Depending on the permeability-decline rate, the production asymptotes eventually reached a constant value after a certain period. Both the decline rate and the ultimate residual permeability had a strong effect on the final production. Sensitivities were run to study the effect of fines migration in different completions. To the authors’ understanding, this is the first time that laboratory-based fines-migration data were incorporated into a reservoir simulator to predict the production decline using experiment-based fines-migration functions. This workflow will help reservoir engineers predict the damage caused by fines migration, predict production decline, and plan for remediation.

Russia’s Development Strategy: Guidelines and Restrictions

2008 ◽  
pp. 119-130 ◽  
Author(s):  
V. Senchagov
Keyword(s):  
Economic Development ◽  
Development Strategy ◽  
Conceptual Basis ◽  
The Core ◽  
Economic Development Strategy ◽  
Socio Economic Development ◽  
Rates Of Growth

The core of Russia’s long-term socio-economic development strategy is represented by its conceptual basis. Having considered debating points about the essence and priority of the strategy, the author analyzes the logic and stages of its development as well as possibilities, restrictions and risks of high GDP rates of growth.

scholarly journals Alpha-Fetoprotein-Producing Lung Hepatoid Adenocarcinoma with Brain Metastasis Treated with S-1

2020 ◽  
Vol 13 (3) ◽  
pp. 1552-1559
Author(s):  
Yuki Muroyama ◽  
Hiroyuki Tamiya ◽  
Goh Tanaka ◽  
Wakae Tanaka ◽  
Alexander C. Huang ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Disease Control ◽  
Parietal Lobe ◽  
Laboratory Data ◽  
Stage Iv ◽  
Final Diagnosis ◽  
Alpha Fetoprotein ◽  
Hepatoid Adenocarcinoma ◽  
Clinical Prognosis

Lung hepatoid adenocarcinoma (HAC) is a rare primary lung carcinoma pathologically characterized by hepatocellular carcinoma-like tumor cells, the majority of which produce alpha-fetoprotein (AFP). The clinical prognosis of lung HAC is generally poor, and effective therapeutic regimens for inoperable or recurrent cases have not been established. Here, we report a case of AFP-producing lung HAC with brain metastasis with long-term disease control, treated with the 5-fluorouracil-derived regimen S-1. The patient was a 66-year-old male admitted to the hospital with alexia. Chest X-ray revealed a massive tumor in the left upper lobe, and a head CT scan revealed a metastasis in the left parietal lobe. The laboratory data showed a remarkably elevated AFP level (97,561 ng/mL). Pathological assessment of the resected brain tumor revealed HAC, which was compatible with the lung biopsies. Together with the absence of other metastatic lesions, a final diagnosis of primary lung HAC, stage IV T4N3M1b, was given. The patient first underwent non-small cell lung cancer chemotherapy regimens (carboplatin and paclitaxel as the first line, and pemetrexed as the second line), but had clinical progression. After third-line oral S-1 (tegafur/gimeracil/oteracil) administration, the serum AFP level significantly dropped and the patient achieved long-term disease control without relapse, surviving more than 19 months after disease presentation. The autopsy result was consistent with the diagnosis of primary lung HAC, and immunohistochemical staining was AFP+, glypican 3+, and spalt-like transcription factor 4+. Here, we report the case of a rare primary lung HAC with apparent disease control on S-1 therapy, together with a literature review.

scholarly journals Hybrid Scour Depth Prediction Equations for Reliable Design of Bridge Piers

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2019
Author(s):  
Hossein Hamidifar ◽  
Faezeh Zanganeh-Inaloo ◽  
Iacopo Carnacina
Keyword(s):  
Flow Velocity ◽  
Critical Velocity ◽  
Depth Estimation ◽  
Hybrid Models ◽  
Velocity Estimation ◽  
Bridge Piers ◽  
Critical Flow ◽  
Scour Depth ◽  
Critical Flow Velocity ◽  
Estimation Equations

Numerous models have been proposed in the past to predict the maximum scour depth around bridge piers. These studies have all focused on the different parameters that could affect the maximum scour depth and the model accuracy. One of the main parameters individuated is the critical velocity of the approaching flow. The present study aimed at investigating the effect of different equations to determine the critical flow velocity on the accuracy of models for estimating the maximum scour depth around bridge piers. Here, 10 scour depth estimation equations, which include the critical flow velocity as one of the influencing parameters, and 8 critical velocity estimation equations were examined, for a total combination of 80 hybrid models. In addition, a sensitivity analysis of the selected scour depth equations to the critical velocity was investigated. The results of the selected models were compared with experimental data, and the best hybrid models were identified using statistical indicators. The accuracy of the best models, including YJAF-VRAD, YJAF-VARN, and YJAI-VRAD models, was also evaluated using field data available in the literature. Finally, correction factors were implied to the selected models to increase their accuracy in predicting the maximum scour depth.

Semantic Desktop for the End-UserSemantic Desktop für Anwender

i-com ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 25-32 ◽  
Author(s):  
Gunnar Aastrand Grimnes ◽  
Benjamin Adrian ◽  
Sven Schwarz ◽  
Heiko Maus ◽  
Kinga Schumacher ◽  
...  
Keyword(s):  
Knowledge Management ◽  
Knowledge Work ◽  
Personal Knowledge ◽  
Term Study ◽  
The Core ◽  
Personal Knowledge Management ◽  
Long Term Study ◽  
Core Components

AbstractThis article describes the Semantic Desktop. We give insights into the core services that aim to improve personal knowledge management on the desktop. We describe these core components of our Semantic Desktop system and give evaluation results. Results of a long-term study reveal effects of using the Semantic Desktop on personal knowledge work.

Fines Migration in Fractured Wells: Integrating Modeling With Field and Laboratory Data

2014 ◽  
Vol 29 (04) ◽  
pp. 309-322 ◽  
Author(s):  
Maricel Marquez ◽  
Wade Williams ◽  
Mark M Knobles ◽  
Pavel Bedrikovetsky ◽  
Zhenjiang You
Keyword(s):  
Laboratory Data ◽  
Fines Migration

Contrasting effects of fire on populations of two small rodent species in fragments of Atlantic Forest in Brazil

2004 ◽  
Vol 20 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Marcos de Souza Lima Figueiredo ◽  
Fernando Antonio dos Santos Fernandez
Keyword(s):  
Atlantic Forest ◽  
Feedback System ◽  
Rodent Species ◽  
Primary Forest ◽  
Small Rodent ◽  
Forest Species ◽  
The Core ◽  
Higher Temperature ◽  
Disturbed Habitats

Habitat fragmentation causes a sharp increase in the forested area affected by edge effects (Murcia 1995). Compared with the core of the forest, edges present higher litterfall rates, air and soil humidity reduction, higher temperature and increased wind incidence (Bierregaard et al. 1992, Didham & Lawton 1999, Laurance et al. 1998, Matlack 1993). These features of edges may increase the probability of fire occurrence, especially if the surrounding vegetation is composed of grasses (D'Antonio & Vitousek 1992, Freifelder et al. 1998). After a fire, the damaged edge will grow substantial amounts of herbaceous vegetation, extending the inflammable area into the forest, and thereby creating a positive feedback system of fire susceptibility and intensity (Cochrane & Schulze 1999, Cochrane et al. 1999). Fires may affect the structure and composition of the vegetation (Cochrane & Schulze 1999, Didham & Lawton 1999, Sanaiotti & Magnusson 1995), favouring, in the long-term, the dominance of the community by species characteristic of disturbed habitats and making the habitat unsuitable to primary forest species (Malcolm 1994, Possingham et al. 1994). Unfortunately, there are few studies on the effects of fires on neotropical small-mammal populations (Borchert & Hansen 1983, Ojeda 1989, Vieira & Marinho-Filho 1998). The objective of this study was to analyse the influence of a fire on populations of two rodent species, Akodon cursor (Winge) and Oecomys concolor (Wagner) in two fragments of Atlantic Forest in Brazil.

scholarly journals Intercommunity interactions and killings in central chimpanzees (Pan troglodytes troglodytes) from Loango National Park, Gabon

Primates ◽  
2021 ◽  
Author(s):  
Laura Martínez-Íñigo ◽  
Pauline Baas ◽  
Harmonie Klein ◽  
Simone Pika ◽  
Tobias Deschner
Keyword(s):  
Pan Troglodytes ◽  
National Park ◽  
Camera Traps ◽  
Encounter Rate ◽  
Visual Contact ◽  
Intergroup Interactions ◽  
Killing Rate ◽  
The Core ◽  
Pan Troglodytes Troglodytes

AbstractIntercommunity competition in chimpanzees (Pan troglodytes) has been widely studied in eastern (P. t. schweinfurthii) and western (P. t. verus) communities. Both subspecies show hostility towards neighboring communities but differ in rates of lethal attacks and female involvement. However, relatively little is known about the territorial behavior of the two other subspecies, central (P. t. troglodytes) and Nigeria-Cameroon chimpanzees (P. t. ellioti). Here, we present the first insights into intercommunity interactions of individuals of a community of central chimpanzees living in the Loango National Park in Gabon. The presence of individuals of neighboring communities in the Rekambo home range was assessed using 27 camera traps. Information was compiled on intergroup interactions recorded before (2005–2016) and after (January 2017–June 2019) the habituation of the community. Individuals from neighboring communities entered the core area, where nine out of 16 recorded intercommunity encounters occurred. Males were the main participants in territorial patrols and intercommunity aggressions. Females were part of all six territorial patrols recorded and dependent offspring participated in five patrols. Females were involved in intercommunity aggression in five out of twelve recorded encounters in which there was visual contact between communities. While the intercommunity encounter rate was lower than that reported across most other long-term chimpanzee sites, the annual intercommunity killing rate was among the highest. These results suggest that the frequency of lethal attacks at Loango is comparable to that reported for the eastern subspecies. In contrast, female involvement in intercommunity interactions mirrors that of the western subspecies.

scholarly journals Accountability reporting objectives of Māori organizations

2018 ◽  
Vol 30 (4) ◽  
pp. 433-443 ◽  
Author(s):  
Russell Craig ◽  
Rawiri Taonui ◽  
Susan Wild ◽  
Lũcia Lima Rodrigues
Keyword(s):  
New Zealand ◽  
Design Methodology ◽  
Indigenous Communities ◽  
Core Values ◽  
Annual Reports ◽  
Content Type ◽  
Cultural Activities ◽  
The Core ◽  
Regional Associations

Purpose This paper aims to highlight the accountability reporting objectives of four Māori-controlled organizations. The examples cited reflect the core values of the indigenous Māori people of New Zealand (Aotearoa) and help demonstrate how these values are manifest in the accountability reporting of Māori-controlled organizations. Design/methodology/approach Narrative sections of ten annual reports of two small and two large Maori organizations, drawn variously from their financial years ending in the calendar years 2009 to 2014, are read closely. These organizations represent diverse tribal and regional associations in terms of size, scope and structure; and in terms of the business, social and cultural activities they pursue. Findings Three core Māori values are identified: spirituality (wairuatanga); intergenerationalism and restoration (whakapapa); and governance, leadership and respect (mana and rangatiratanga). The commitment to these values and the way this commitment is reflected in accountability reports of Maori organizations, is presented. Originality/value The examples provided, and the associated discussion, should help inform reporting initiatives of organizations that are seeking better accountability in terms of their long-term engagement with indigenous communities, the environment and broader society.

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