Study on the Borehole Stability in Liulin Coal Reservoirs

2014 ◽  
Vol 989-994 ◽  
pp. 903-907
Author(s):  
Li Yang Song ◽  
Li Jia Xiao ◽  
Ji Wei Wang ◽  
Jin Zhang ◽  
Tian Lin Zhuang
Keyword(s):  
Pore Pressure ◽  
Test Method ◽  
Analysis Model ◽  
Borehole Stability ◽  
Core Strength ◽  
The Core ◽  
Equivalent Depth ◽  
Mechanics Analysis ◽  
Ground Stress ◽  
Formation Pore Pressure

This paper studied the borehole stability in Liulin bituminous core reservoirs during under-balanced drilling. The equivalent depth method was applied to study the formation pore pressure. The floor drain test method was applied to study the ground stress. Core strength experiments combined with logging data were used in the establishment of core strength predicting model. Mechanics analysis model was founded to study the borehole stability in the core reservoir. According to the studying and analyzing results, the under-balance drilling in Liulin coal reservoirs enjoys good borehole stability.

Borehole Stability Analysis and its Application in Xujiahe Formation of ZJ Block

2012 ◽  
Vol 524-527 ◽  
pp. 1359-1362
Author(s):  
Kan Hua Su ◽  
Hong Liu ◽  
Jun Wang
Keyword(s):  
Mechanical Test ◽  
Drilling Fluid ◽  
Stress Test ◽  
Field Application ◽  
Wellbore Stability ◽  
Test Method ◽  
Borehole Stability ◽  
Xujiahe Formation ◽  
Ground Stress ◽  
Rock Mechanical Test

The mainly borehole problems are sticking (collapse) and circulation loss in Xujiahe formation of ZJ block, so the drilling rate is very low. In order to improve the penetration of rate of ZJ block, the rock mechanical test method, ground stress test method, well history statistics method, and logging data analysis method were adopted. The borehole stability mechanism of xujiahe formation was analyzed. Combined with the drilling fluid experimental evaluation, the measures of improve wellbore stability of xujiahe formation was Proposed. Field application tests show that, the borehole problems and its processing time are greatly reduced using those proposed measures. The penetration of rate in the Xujiahe formation of test well increased 20-30%, and the application effect is obvious.

Study of the Effect of Borehole Size on Wellbore Stability

2014 ◽  
Vol 574 ◽  
pp. 214-218
Author(s):  
Hao Yong Huang ◽  
Yuan Fang Cheng ◽  
Wei Zhao ◽  
Chong Cheng ◽  
Wen Biao Deng
Keyword(s):  
Drilling Fluid ◽  
Wellbore Stability ◽  
Borehole Diameter ◽  
Analysis Model ◽  
Borehole Stability ◽  
Collapse Pressure ◽  
Drilling Technology ◽  
Ground Stress ◽  
The One ◽  
Borehole Size

Based on the size effect of rock strength, the borehole stability analysis model is established, which the borehole size is taken into consideration. Through this model, the relation between borehole size and collapse pressure under borehole pressure, ground stress and drilling fluid flow function is analyzed. The analysis shows that with the increase of borehole diameter, collapse pressure increases significantly, and borehole stability becomes poor, but the variation of borehole size is not proportional to collapse pressure: the bigger the borehole, the smaller the variation. When borehole diameter increases from 152.4 mm to 444.5 mm, wellbore collapse pressure increases from 1.18g/cm3 to 1.315g/cm3 and the rate of the increase is 11.44%. When slimhole drilling technology is applied, the density of minimum fluid that maintains wellbore stability is lower than the one used in conventional wellbore drilling.

An Input–Process–Output Model of Pilot Core Competencies

2017 ◽  
Vol 7 (2) ◽  
pp. 78-85 ◽  
Author(s):  
Heikki Mansikka ◽  
Don Harris ◽  
Kai Virtanen
Keyword(s):  
Path Analysis ◽  
Team Performance ◽  
Core Competencies ◽  
Core Competency ◽  
Principal Component ◽  
Analysis Model ◽  
Input Process ◽  
The Core ◽  
Performance Framework ◽  
Process Output

Abstract. The aim of this study was to investigate the relationship between the flight-related core competencies for professional airline pilots and to structuralize them as components in a team performance framework. To achieve this, the core competency scores from a total of 2,560 OPC (Operator Proficiency Check) missions were analyzed. A principal component analysis (PCA) of pilots’ performance scores across the different competencies was conducted. Four principal components were extracted and a path analysis model was constructed on the basis of these factors. The path analysis utilizing the core competencies extracted adopted an input–process–output’ (IPO) model of team performance related directly to the activities on the flight deck. The results of the PCA and the path analysis strongly supported the proposed IPO model.

Predicting Formation Pore-Pressure from Well-Log Data with Hybrid Machine-Learning Optimization Algorithms

2021 ◽  
Author(s):  
Mohammad Farsi ◽  
Nima Mohamadian ◽  
Hamzeh Ghorbani ◽  
David A. Wood ◽  
Shadfar Davoodi ◽  
...  
Keyword(s):  
Machine Learning ◽  
Pore Pressure ◽  
Optimization Algorithms ◽  
Well Log ◽  
Log Data ◽  
Hybrid Machine ◽  
Formation Pore Pressure

scholarly journals The effects of core training given to female soccer players on different vertical jumping methods

2019 ◽  
Vol 16 (3) ◽  
pp. 791-798 ◽  
Author(s):  
Mehmet Göktepe ◽  
Meral Miyaç Göktepe ◽  
Ferhat Güder ◽  
Mehmet Günay
Keyword(s):  
Strength Training ◽  
English Summary ◽  
Soccer Players ◽  
Favorable Effect ◽  
Rank Test ◽  
Average Height ◽  
Core Strength ◽  
The Core ◽  
Vertical Jumping ◽  
Core Training

This study aims to determine the effects of core training given to female soccer players on their methods of different vertical jumping. 16 female certified soccer players playing in the female soccer team of Bartın University with average age of 21.07±3.56 years, average height of 163.00±7.18 cm and with weight of 56.60±7.15 kg were included in the study on the basis of volunteering. Prior to the tests, all the female soccer players completed a survey form used in determining their medical status and filled in a form to confirm that they participated in the study voluntarily. The core training programme was applied for 8 weeks two times a week regularly. The pre-test and post-test measurements were made and then  subjects’ height and weight were measured,   they were asked to run for 10 minutes for warm-up and  the activity was ended by making jumping measurement. The research was performed in the physiology laboratory of Bartın University School of Physical Education and Sport (BESYO). Statistical evaluation was made by using SPSS 22.0 programme. The values obtained were compared after checking normality distribution through Shapiro-Wilk test with the help of Wilcoxon signed rank test.  This study, we aimed to determine the effect of core strength training on different vertical jump methods applied to female soccer players. It has been observed that it has a favorable effect on counter movement jumping (CMJ) and static jumping (SJ) values (p <0.05). It was found that there was no statistically significant effect on drop jumping (DJ) values (p> 0.05). As a result; It can be said that the core strength training practiced in female soccer players developed counter movement jumpingand static jumping characteristic of vertical jumping methods and did not affect the drop jumpingfeature. In line with these results, it is recommended to take into account the core training programs because the strength training that will be applied in female soccer players can improve the counter movement jumping and static jumping feature. Extended English summary is in the end of Full Text PDF (TURKISH) file.   Özet Bu araştırmanın amacı, kadın futbolculara uygulanan kor kuvvet antrenmanlarının farklı dikey sıçrama yöntemlerine etkisinin belirlenmesidir. Çalışmaya Bartın Üniversitesi Kadın Futbol Takımında lisanslı, yaş ortalamaları 21,07±3,56 yıl, boy ortalamaları 163,00±7,18 (cm) ve vücut ağırlıkları 56,60±7,15 (kg) olan gönüllü 16 kadın futbolcu dahil edilmiştir. Testlerden önce araştırmaya katılan kadın futbolcular sağlık durumlarını belirtir sağlık anketini ve gönüllü katılım formunu doldurup imzalamışlardır. Kor antrenman programı 8 hafta boyunca, haftada 2 gün düzenli olarak uygulanmıştır. Çalışmaya katılan kadın futbolculara sırasıyla; boy ve vücut ağırlığı ölçümü yapıldı. 10 dakika ısınma koşusu yaptırıldıktan sonra, sıçrama ölçümleri yapılarak çalışma sonlandırıldı. Bu araştırma Bartın Üniversitesi BESYO Fizyoloji Laboratuvarında yapılmıştır. İstatistiksel değerlendirme SPSS 22.0 programı kullanılarak yapıldı. Ön test ve son testten elde edilen değerler,  Shapiro-Wilk testi ile normallik dağılımına bakıldıktan sonra Wilcoxon İşaretli Sıralar testi yardımı ile istatistiksel olarak karşılaştırılmıştır. Çalışmamızın bulgularına göre; kadın futbolculara uygulanan kor kuvvet antrenmanlarının farklı dikey sıçrama yöntemlerine etkisinin belirlenmesi amacıyla yapmış olduğumuz çalışmamızda uygulanan kor kuvvet antrenmanlarının dikey sıçrama yöntemlerinden; yaylanarak sıçrama (YS) ve statik sıçrama (SS) değerlerine olumlu düzeyde etki ettiği gözlemlenmiştir (p<0.05). Düşerek sıçrama (DS) değerlerine ise istatistiksel olarak etkisinin olmadığı tespit edilmiştir (p>0.05). Sonuç olarak; kadın futbolcularda uygulanan kor kuvvet antrenmanlarının dikey sıçrama yöntemlerinden statik sıçrama ve yaylanarak sıçrama özelliğini geliştirdiği, düşerek sıçrama özelliğine ise etki etmediği söylenebilir. Bu sonuçlar doğrultusunda kadın futbolcularda uygulanacak kor kuvvet antrenmanlarının statik sıçrama ve yaylanarak sıçrama özelliğine olumlu yönde etkisi olabileceğinden antrenman programlarında göz önünde bulundurulması önerilebilir.

scholarly journals Correlation between Core Strength and Stability with Body Mass Index among Postmenopausal Women.

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
S Bhosale Komal ◽  
V Bhosale Siddhi ◽  
Anandh Dr. S
Keyword(s):  
Body Mass Index ◽  
Postmenopausal Women ◽  
Body Mass ◽  
Pearson Correlation ◽  
The Body ◽  
P Value ◽  
Endurance Test ◽  
Core Strength ◽  
The Core ◽  
Flexion Test

Women in postmenopausal period of their life face various physical and physiological changes causing lack of estrogen and progesterone hormones, changes in the reproductive and genitals organs, vasomotor system in the body along with mood related symptoms such as anxiety, etc. Lifestyle, body fat distribution and anthropometric changes adds on to the bone strength in postmenopausal women. It may be a risk factor for osteoporotic fracture, cardiovascular, metabolic diseases, etc. Core strength and stability is greatly influenced by body composition and adiposity. The aim of the study was to correlate the core strength assessed with the Body Mass Index (BMI) among postmenopausal women. The objective of the study is to find the correlation between the core strength assessed with the Body Mass Index using 60° flexion test, Beiring Sorenson test and Unilateral Hip Bridge Endurance test among postmenopausal women with age ranging from 46-70 years. 96 healthy postmenopausal women in Karad city with a natural history of menopause were selected for the study. Based upon BMI values, the subjects were grouped as Underweight (<18.5 kg/m2), Normal weight (18.5-24.9 kg/m2), Overweight (25-29.9 kg/m2 and more). The outcome values for strength were correlated with the BMI of postmenopausal women. In the study, the Pearson correlation(r) was -0.361 and the P value was 0.0003 showing extremely significant correlation between the BMI and 60° Flexion test. For the Beiring Sorenson Test, the Pearson correlation value was -0.305 and the P value was 0.0025 showing very significant correlation between the BMI and Beiring Sorenson Test. Correlation of BMI and Unilateral Hip Bridge Endurance Test shows a Pearson Correlation value of -0.322 and the P value 0.0013 claiming very significant correlation between the BMI and Unilateral Hip Bridge Endurance Test. The study concludes that there is a significantly negative correlation between the core strength and stability with the Body Mass Index among postmenopausal women.

Face Wrinkling and Core Strength in Sandwich Construction

1960 ◽  
Vol 64 (591) ◽  
pp. 164-167 ◽  
Author(s):  
S. Yusuff
Keyword(s):  
High Stress ◽  
Core Layer ◽  
High Strength ◽  
Bending Rigidity ◽  
Core Strength ◽  
Surface Smoothness ◽  
Lightweight Material ◽  
The Core ◽  
Sandwich Construction ◽  
Strength Material

The effect of initial waviness on the wrinkling of faces in sandwich construction is studied. Formulae are derived to determine the failing stress when the faces wrinkle due to failure of the core in tension, compression or shear. The importance of core strength requirements in maintaining surface smoothness is noted. A comparison of theory with experiments is made, and the agreement between the two is found to be reasonably good.A sandwich construction consists of two thin face layers of high-strength material and a thick core layer of lightweight material. The function of the core is twofold. Firstly, it increases the bending rigidity of the faces and second, it stabilises them so that they will not wrinkle until high stress is reached.

scholarly journals Mounting a Regional Response to the COVID-19 Pandemic: Another Reason to “Keep” Your Lab

2020 ◽  
Vol 144 (11) ◽  
pp. 1321-1324
Author(s):  
Tamera A. Paczos
Keyword(s):  
Health System ◽  
Medical Center ◽  
Academic Medical Center ◽  
Diagnostic Testing ◽  
Turnaround Time ◽  
Test Method ◽  
Regional Health ◽  
The Core ◽  
Local Access ◽  
Average Turnaround Time

Context.— Declining reimbursement shifts hospital laboratories from system assets to cost centers. This has resulted in increased outsourcing of laboratory services, which can jeopardize a hospital systems' ability to respond to a health care crisis. Objectives.— To demonstrate that investment in a core laboratory serving an academic medical center equipped a regional health system to respond to the Coronavirus disease 2019 (COVID-19) pandemic. Design.— COVID-19 diagnostic testing data were analyzed. Volumes were evaluated by result date (March 16, 2020–May 6, 2020), and the average of received-to-verified turnaround time was calculated and compared for in-house and send-out testing, and different in-house testing methodologies. Results.— Daily viral diagnostic testing capacity increased by greater than 3000% (from 21 tests per day to 658 tests per day). Total viral diagnostic testing reported by the core laboratory increased by 128 times during 22 days of test method validation and 826 times during the analysis period, while average turnaround time per day for send-out testing increased from 3.7 days to 21 days. Decreased overall average turnaround time was observed at the core laboratory (0.45 days) versus send-out testing (7.63 days) (P &lt; .001). Conclusions.— Investment in a core laboratory provided the health system with the necessary expertise and resources to mount a robust response to the pandemic. Local access to testing allowed rapid triage of patients and conservation of scarce personal protective equipment (PPE). In addition, the core laboratory was able to support regional health departments and several hospitals outside of the system.

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