Quantifying the Impact of Permeability Heterogeneity on Secondary Recovery Performance

Author(s):  
Bilal Rashid ◽  
Glyn Williams ◽  
Astor-Lonice Bal ◽  
Ann Muggeridge
SPE Journal ◽  
2012 ◽  
Vol 17 (02) ◽  
pp. 455-468 ◽  
Author(s):  
B.. Rashid ◽  
A.H.. H. Muggeridge ◽  
A.. Bal ◽  
G.. Williams

Summary An improved heterogeneity/homogeneity index is introduced that uses the shear-strain rate of the single-phase-velocity field to characterize heterogeneity and rank geological realizations in terms of their impact on secondary-recovery performance. The index is compared with the Dykstra-Parsons coefficient (Dykstra and Parsons 1950) and the dynamic Lorenz coefficient (Shook and Mitchell 2009). The results show that the index's ranking ability is preserved for miscible and immiscible displacements at different viscosity/mobility ratios. Neither the Dykstra-Parsons coefficient (Dykstra and Parsons 1950) nor the dynamic Lorenz coefficient (Shook and Mitchell 2009) can consistently discriminate between different realizations in terms of breakthrough time and oil recovery at 1 pore volume injected (PVI) for tracer flow or adverse-viscosity-ratio miscible and immiscible floods.


2014 ◽  
Vol 17 (03) ◽  
pp. 304-313 ◽  
Author(s):  
A.M.. M. Shehata ◽  
M.B.. B. Alotaibi ◽  
H.A.. A. Nasr-El-Din

Summary Waterflooding has been used for decades as a secondary oil-recovery mode to support oil-reservoir pressure and to drive oil into producing wells. Recently, the tuning of the salinity of the injected water in sandstone reservoirs was used to enhance oil recovery at different injection modes. Several possible low-salinity-waterflooding mechanisms in sandstone formations were studied. Also, modified seawater was tested in chalk reservoirs as a tertiary recovery mode and consequently reduced the residual oil saturation (ROS). In carbonate formations, the effect of the ionic strength of the injected brine on oil recovery has remained questionable. In this paper, coreflood studies were conducted on Indiana limestone rock samples at 195°F. The main objective of this study was to investigate the impact of the salinity of the injected brine on the oil recovery during secondary and tertiary recovery modes. Various brines were tested including deionized water, shallow-aquifer water, seawater, and as diluted seawater. Also, ions (Na+, Ca2+, Mg2+, and SO42−) were particularly excluded from seawater to determine their individual impact on fluid/rock interactions and hence on oil recovery. Oil recovery, pressure drop across the core, and core-effluent samples were analyzed for each coreflood experiment. The oil recovery using seawater, as in the secondary recovery mode, was, on the average, 50% of original oil in place (OOIP). A sudden change in the salinity of the injected brine from seawater in the secondary recovery mode to deionized water in the tertiary mode or vice versa had a significant effect on the oil-production performance. A solution of 20% diluted seawater did not reduce the ROS in the tertiary recovery mode after the injection of seawater as a secondary recovery mode for the Indiana limestone reservoir. On the other hand, 50% diluted seawater showed a slight change in the oil production after the injection of seawater and deionized water slugs. The Ca2+, Mg2+, and SO42− ions play a key role in oil mobilization in limestone rocks. Changing the ion composition of the injected brine between the different slugs of secondary and tertiary recovery modes showed a measurable increase in the oil production.


2019 ◽  
Vol 28 (2) ◽  
pp. 12-14

Purpose The purpose of this study is to examine the impact of JIS on quitting intentions and service recovery performance (SRP) with JE as a mediating factor. Design/methodology/approach Data was gathered from 313 full time FHEs working in four and five star hotels in Iran. Questionnaires on JIS, JE, and quitting intentions were given in three waves to the FHEs over a two-week period and in addition supervisors provided a rating of SRP. Findings The findings support the mediating effect of JE with JIS related to the outcomes indirectly through JE. The greater the level of JIS the lower the JE of FHEs. The greater the level of JE the lower the quitting intentions and the higher the SRP of FHE’s. JE completely mediates the impact of JIS on quitting intentions and SRP. Practical implications Organizations should put steps in to retain key workers through adherence to the psychological contract, reduce the impact of JIS through providing clear information on career opportunities and progression, invest in high quality training to improve SRP and hire a workforce from the local communities to increase off-the job JE Originality/value This paper has contributed to an area where research is scarce with regard to how JIS can be reduced and the structure that links it to employee outcomes.


1968 ◽  
Vol 8 (04) ◽  
pp. 347-350 ◽  
Author(s):  
R.W. Parsons

Abstract When a displacement front encounters an isolated permeability heterogeneity, it will be perturbed permeability heterogeneity, it will be perturbed The details of this perturbation will depend on the heterogeneity size and shape, the permeability contrast, and the mobility ratio. This paper deals with the displacement front behavior for one, simple, mathematically tractable model: a circular permeability discontinuity and unit mobility ratio. The progress of an initially planar front is shown or four permeability planar front is shown or four permeability contrasts: k2/k1 = 0, 1, 2,... The front distortion is more pronounced than streamline and isopotential distortion and it approaches a constant shape downstream from the discontinuity. Introduction The impact of reservoir heterogeneities on oil displacing processes depends upon the variation of the heterogeneous property (frequency distribution), its disposition (spatial distribution), and the inherent stability of the displacement mechanism. The interplay of these factors plus the impracticability, if not impossibility, of describing a natural rock system in any detail makes exact displacement front movements difficult to determine. It is useful, however, to be able to qualitatively visualize what heterogeneities will do to a displacement front. In this respect certain simple models that can be treated analytically are of value. The following analysis will show the displacement front behavior for one such model. MODEL DESCRIPTION The flow field two-dimensional and infinite in extent. The fluid flow is single phase, steady state and unidirectional at x, y - +/- 00, or before insertion of the discontinuity. A circular permeability discontinuity is placed at the origin. permeability discontinuity is placed at the origin. Porosity and thickness are the same within and exterior to the Porosity and thickness are the same within and exterior to the heterogeneity. This is exactly the same model that was used by Greenkorn et al. to check analytically streamlines as determined by Hele-Shaw flow models and finite difference computer techniques. FRONT POSITION CALCULATIONS The results of displacement front calculations are presented in Figs. 1 through 4 for four different permeability contrasts: k2/ki = 0, 1/2, 2. m. The permeability contrasts: k2/ki = 0, 1/2, 2. m. The times corresponding to the front locations are the same for the 0 and oo cases, and for the 1/2 and 2 cases. The determination of front positions at various times is based on known analytical expressions for velocity potentials (phi) and stream functions (psi). SPEJ P. 347


2012 ◽  
Vol 13 (4) ◽  
pp. 614-636 ◽  
Author(s):  
Osman M. Karatepe ◽  
Georgiana Karadas

The purpose of this study is to develop and test a conceptual model that examines job embeddedness as a partial mediator of the impact of management commitment to service quality on service recovery performance and extra-role customer service. Training, empowerment, and rewards are regarded as the three important indicators of management commitment to service quality. Data were obtained from a sample of fulltime frontline hotel employees with a time lag of one week in Romania. The results reveal that training, empowerment, and rewards are positively related to job embeddedness. As hypothesized, empowerment, rewards, and job embeddedness enhance service recovery performance, while training and empowerment increase extra-role customer service. The results further demonstrate that job embeddedness acts as a partial mediator of the effects of empowerment and rewards on service recovery performance. Implications of the results are discussed and future research directions are offered.


2006 ◽  
Author(s):  
David Francis Hadley ◽  
Elias Chukwu Arochukwu ◽  
Kosuke Nishi ◽  
Marcus John Sarginson ◽  
Hadizah Md Salleh ◽  
...  

2018 ◽  
Vol 29 (1) ◽  
pp. 168-197 ◽  
Author(s):  
Maryam Lotfi ◽  
Soroosh Saghiri

Purpose Regarding today’s volatile and turbulent markets accompanied by natural disasters and political upheavals, being resilient has become crucially important for many firms. It is widely accepted that the firm’s operations need to be cost efficient as well as customer responsive. Lean and agile have been proven to be pertinent strategies toward efficiency and responsiveness. But the operations also need to be resilient against disruptions to quickly return to their original state or even a better one. While the question of how leanness and agility impact operational performance outcomes has been researched, the question of how resilience can boost operational performance outcomes is yet to be investigated. The purpose of this paper is to show how resilience is distinguished from leanness and agility. It then examines the impact of resilience, along with leanness and agility, on operational performance outcomes. Design/methodology/approach A structural model is drawn up based on the literature to relate lean, agile and resilient practices to performance outcomes. Leanness, agility and resilience are measured through bundles of practices and operational performance outcomes are measured in terms of cost, quality, delivery, flexibility and time to recovery. The model is tested using SPSS 19 and AMOS 19 based on the data collected via survey from a sample of 151 automotive parts suppliers. Findings The results show that a higher level of resilience will lead to a better performance in terms of delivery, cost and time to recovery, while it does not have a significant impact on flexibility performance. Regarding leanness, the results confirm that lean operations positively affect cost, delivery and flexibility performances. The results also reject the hypothesis stating that higher level of leanness will lead to worse recovery performance, inferring that higher level of leanness leads to better time to recovery performance (i.e. helps time to recovery reduction). Originality/value The present research emphasizes the importance of operations resilience and demonstrates its contribution, alongside leanness and agility, to operational performance. The developed structural model contributes to the nascent theories around resilience, and the use of empirical data makes the results valuable practically. This may inform operations strategy decisions in terms of the results expected from resilience, leanness and agility.


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