Investigation of Tool Joint Effect on Equivalent Circulating Density in Deep Offshore Wells

2013 ◽  
Author(s):  
Fardis Najafi Fard ◽  
Ali Karimi Vajargah ◽  
Reza Majidi
Keyword(s):  
Joint Effect ◽  
Tool Joint

Investigation of Tool-Joint Effect on Non-Newtonian Drilling Fluids Following the Herschel–Bulkley Model Flow Behavior in Oil Well Drilling

2021 ◽  
Author(s):  
Ardeshir Gholami ◽  
Zohreh Mansoori ◽  
Majid Saffar Aval ◽  
Goodarz Ahmadi
Keyword(s):  
Pressure Loss ◽  
Drilling Fluid ◽  
Flow Behavior ◽  
Drill Pipe ◽  
Fluid Flows ◽  
Joint Effect ◽  
Drilling Mud ◽  
Pressure Losses ◽  
Drilling Muds ◽  
Tool Joint

Abstract The prediction of frictional pressure loss in many oil wells drillings is of the utmost importance. Most studies in this area concerned fluid flow in pipes and annulus in order to predict friction losses. However, studies on the tool-joint effect in frictional pressure estimations were limited to only a few experimental and theoretical studies on water-based power-law drilling muds. (Tool-joint is the part in which two drill strings connect where the annulus has a gradual decrease and increase, respectively). The tool-joint plays an important role in extending the drill pipe, and its effect on pressure losses cannot be ignored. As of today, drilling muds must have certain qualities such as providing formation integrity, transporting the cuttings from bit to surface, drill pipe lubrication and heat transfer, and low-pressure loss to perform as a qualified and effective drilling fluid. Therefore, drilling muds have become more complex and expensive, and the process of choosing appropriate drilling muds is of great importance. For this reason, oil-based viscoplastic drilling muds are being used in more drilling operations, but for these drilling muds, almost no studies were conducted to predict the effect of the tool-joints on flow behavior and pressure loss. In this paper, the behavior of fluid flows and frictional pressure losses in weld-on tool-joints of different grades according to the IADC standard manual was studied using CFD simulations. The simulations were conducted using a drilling fluid with viscoplastic properties, following the Herschel–Bulkley model of Non-Newtonian fluids. And the characteristics of fluid flows in these tool-joints under different thermal boundary conditions were studied. The results show that tool-joints significantly affect the frictional pressure loss in the annulus. We also provided an accurate pressure loss prediction for the flow of oil-based viscoplastic muds passing through the tool-joint geometry. Furthermore, assuming the thixotropic behavior using the Moore-Cheng model for the drilling mud, the results showed that the flow behavior does not differ significantly from the Herschel-Bulkley drilling fluid in the range of study.

Investigating the Impact of the "Tool Joint Effect" on Equivalent Circulating Density in Deep-Water Wells

2014 ◽  
Author(s):  
Ali Karimi Vajargah ◽  
Fardis Najafi Fard ◽  
Mazdak Parsi ◽  
Besmir Buranaj Hoxha
Keyword(s):  
Deep Water ◽  
Joint Effect ◽  
Water Wells ◽  
The Impact ◽  
Tool Joint

Does It Matter How I Say It?

2015 ◽  
Vol 14 (2) ◽  
pp. 104-108 ◽  
Author(s):  
Dan S. Chiaburu ◽  
Ann Chunyan Peng ◽  
Linn Van Dyne
Keyword(s):  
Perspective Taking ◽  
Joint Effect ◽  
Overall Performance ◽  
Low Levels

We conducted an experiment to examine the effect of how subordinates present ideas (constructive vs. complaining form) on supervisor (receiver) responses (perceptions of subordinate intrusiveness and of overall performance). We demonstrated a joint effect of subordinate idea presentation (manipulated) and supervisor dogmatism (measured) such that supervisors with high levels of dogmatism rated subordinates who presented voice constructively as more intrusive and lower in performance than those with low dogmatism. Supervisor perspective taking mediated these relationships. Our findings highlight the importance of presenting ideas in a constructive form to receivers with low levels of dogmatism.

Access to and Use of Information and Communication Technology and Task Performance

Mousaion ◽  
2018 ◽  
Vol 35 (4) ◽  
Author(s):  
Wuraola J. Oyedipe ◽  
Sunday O. Popoola
Keyword(s):  
Information And Communication Technology ◽  
Communication Technology ◽  
Joint Effect ◽  
Public University ◽  
Relative Effect ◽  
University Libraries ◽  
Job Knowledge ◽  
Ict Use ◽  
Information And Communication ◽  
And Task

The study investigated the relationship between access to and use of information and communication technology and task performances of library personnel in public university libraries in South West Nigeria. The total enumeration technique was used to cover 330 library professionals working in public university libraries in the zone. A self-developed questionnaire was used to obtain data. Out of the 330 copies of questionnaire administered 248 (76.6%) copies were found useable. The findings revealed that the level of task performances of the respondents was high, and the level of access to ICT was high, while the frequency of ICT use was moderate. The results indicated that there was a positive relative effect of ICT access and use on task performances. The study also found a significant relationship between the access to ICT, ICT use and task performances of respondents, while there was a significant joint effect of access to ICT and ICT use on the task performances of library personnel. The study recommended the constant development of personnel regarding job knowledge and skills, the promotion of creativity and adaptability skills to enhance personnel task performances, while library managers should continue to make ICT tools accessible for library personnel to allow their use in improving the workflow in the library.

Morphometric variability in round goby Neogobius melanostomus (Perciformes: Gobiidae) from the Sea of Azov

2017 ◽  
Vol 26 (2) ◽  
pp. 392-405 ◽  
Author(s):  
O.A. Diripasko ◽  
T.A. Zabroda
Keyword(s):  
Round Goby ◽  
Joint Effect ◽  
Neogobius Melanostomus ◽  
Sea Of Azov ◽  
Morphometric Characters ◽  
One Dimensional ◽  
The Sea Of Azov ◽  
Size Dependent ◽  
Size Variability ◽  
Males And Females

A total of 38 morphometric characters of the round goby Neogobius melanostomus melanostomus (Pallas, 1814) were studied in its native range in the Sea of Azov. The aim was to assess joint effect of sexual dimorphism and size variability on overall variability within groups of samples (populations) using appropriate methods of traditional statistical analysis (one-dimensional and multivariate statistics). Sex and size-dependent variability was studied based on model samples of males and females of different size. Most of the studied morphometric characters of round goby from the Sea of Azov demonstrated statistically significant sex- and size-dependent in-group variability. The pattern of the variability suggests that, for a comparison of round goby from different sea regions and between populations, separate samples of males and females within the range 9–13 cm SL should be examined in order to minimise the effect of the size and sex factors. The approach of searching for the most informative size range could be useful not only for further studies of infraspecific variation but for comparisons between morphologically close gobiin species.

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