bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid Bit Technology Deployment Yields Breakthrough Drilling Performance & Cost Savings for Operator
Authors: Al-Salah Fawaz , Al-Mejmed Saad , Abdelhamid Atef , Alnemer Ali , Gada Tahir , Pandya Mehul 
Published: June 2021

Abstract
Optimized drilling performance and minimized cost per well are key objectives for operators in the current challenging oil and gas industry. The process of collecting lessons learned and designing new drill bit technologies based on these learnings is critical for optimizing drilling performance and reducing non-productive time (NPT). Southeast Kuwait onshore wells are drilled with conventional drill bit technology such as tungsten carbide insert (TCI) and polycrystalline diamond compact (PDC) bits on rotary or directional-motor bottom hole assemblies (BHA). This paper discusses the analysis that enabled breakthrough-drilling performance of 16-in. hybrid drill bit technology, delivering outstanding results and cost savings for an operator.
The non-homogeneous carbonate formation in these onshore wells cause impact damage, limit the drilling efficiency of PDC and TCI bits, and result in a low rate of penetration (ROP) and poor dull conditions. A collaborative technical analysis identified key performance objectives to ensure a step change in section drilling performance.
The analysis involved reviewing:
Post-run dull conditions Operating parameters Formation compressive strengths Bit design Previous deployments results
On Multiple wells, advanced hybrid bit technology and optimized drilling methods achieved outstanding 73-percent improvement in ROP over conventional technologies, saving operator's 3.8 drilling days and more than 27% of drilling costs. The hybrid design completed two consecutive best in class (BIC) wells in southeast Kuwait compared with the typical TCI performance of a single well per bit.
The Modified Configuration of Wet Wash System in the Gulf of Thailand
Authors: Sumitra Khemchad , Fernau Marty , Thanomkiat Karn , Ritcey Joseph , Tumtong Chadchai 
Published: June 2021

Abstract
"Wet Wash" is a concept whereby cuttings are fluidized then sent to centrifuges to seperate the fluids from the cuttings. A modified configuration of this Wet Wash system improves fluids performance while minimizing environmental impact and optimizing operating costs.
The original Wet Wash system, introduced in 2006, started at the shale shakers where big cuttings were removed by the scalping deck and diverted overboard. Only the small cuttings from the primary deck were fluidized and transported to a big bowl centrifuge. For the original system, the % Synthetic on Cuttings (SOC) for this process was always over 8.0%. The system was unable to lower the SOC due to concerns for the capability of the big bowl centrifuge to handle big cuttings. With a modified centrifuge unit, a more robust unit with a design change in feed nozzles being able to handle more torque, all cuttings from both scalping deck and primary deck are fluidized and transported to a big bowl centrifuge with no big cuttings diverted overboard.
Utilizing the previous configuration of Wet Wash whereby cuttings from the scalper deck were diverted overboard, the % SOC was always over 8.0%. It was efficient in the removal of solids, but it was still yielding high SOC. In 2012 the use of Cuttings Dryers was introduced to further reduce % SOC. On Jack-up rigs, the Cuttings Dryer can operate in a normal manner, but on Tender Assisted rigs, where the cuttings are fluidized and pumped to the Dryer, there is a trade-off. High content of Low Gravity Solids (LGS) from the continual grinding of the solids to ultrafine particles that could not be removed by centrifuges had become an issue. High dilution rates were required to keep mud system under control due to excessive ultrafine solids.
The Wet Wash system was re-visited for Tender Assisted rigs. With the modified configuration of Wet Wash system where no cuttings were diverted overboard, fluids performance was improved from reduction of ultrafine solids contamination in the mud system, resulting in less dilution rate and mud chemicals treatment. The % SOC was also lower than 8.0%. With proper Preventative Maintenance (PM) program in place, there was neither down time of the centrifuge nor report of excessive wear of equipment from handling big cuttings.
The novelty of the modified Wet Wash configuration is in the ability to improve fluids performance and reduce environmental impact with the optimum operating cost.
Unlock Mono-Trip Gas Lift Completions Limits by using a New Cement-Through Packer and a Sliding Sleeve with Radio Frequency Identification Capability
Authors: Hanjawanich Siriwat , Shelby Taylor , Laonakornthum Kanin , Murdoch Euan , Piemchaw Kanokkorn , Tawatchai Duangkaewwutthikrai Tawatchai , Teerasukakul Wantanee 
Published: June 2021

Abstract
Gas lift is one of the most appropriate artificial lift methods for Gulf of Thailand (GOT) oil operations. As first described in Chapman, W. R. (2005), Mono-trip gas lift (MTGL) completions have continuously improved since their implementation in the early 2000s, increasing recovery by over 15%. MTGL completions enable marginal or sub-economic new wellhead platforms (WHPs) or infill projects to become economical. To overcome the more challenging wellbore environment in which the current technology is unable to be utilized, alternative technology was trialed in 2019 to enhance the MTGL completion without sacrificing the wellbore designs or reserves.
Lessons Learned from the First Chemical Sand Consolidation in Zawtika Field
Authors: Wiwatanapataphee Wiwat , Kiatrabile Thanita , Lilaprathuang Pipat , Nopsiri Noppanan , Kritsanamontri Panyawadee 
Published: June 2021

Abstract
The conventional gravel pack sand control completion (High Rate Water Pack / Extension Pack) was the primary sand control method for PTTEPI, Myanmar Zawtika field since 2014 for more than 80 wells. Although the completion cost of gravel pack sand control was dramatically reduced around 75 percent due to the operation performance improvement along 5 years, the further cost reduction still mandatory to make the future development phase feasible.
In order to tackle the well economy challenge, several alternative sand control completion designs were reviewed with the existing Zawtika subsurface information. The Chemical Sand Consolidation (CSC) or resin which is cost-effective method to control the sand production with injected chemicals is selected to be tested in 3 candidate wells. Therefore, the first trial campaign of CSC was performed with the Coiled Tubing Unit (CTU) in March to May 2019 with positive campaign results. The operation program and lesson learned were captured in this paper for future improvement in term of well candidate selection, operation planning and execution.
The three monobore completion wells were treated with the CSC. The results positively showed that the higher sand-free rates can be achieved. The operation steps consist of 1) Perform sand cleanout to existing perforation interval or perforate the new formation interval. 2) Pumping pre-flush chemical to conditioning the formation to accept the resin 3) Pumping resin to coating on formation grain sand 4) Pumping the post-flush chemical to remove an excess resin from sand 5) Shut in the well to wait for resin curing before open back to production. However, throughout the campaign, there were several lessons learned, which will be required for future cost and time optimization. In operational view, the proper candidate selection shall avoid operational difficulties e.g. available rathole. As well, detailed operation plan and job design will result in effective CSC jobs. For instance, the coil tubing packer is suggested for better resin placement in the formation. Moreover, accommodation arrangement (either barge or additional vessel) and logistics management still have room for improvement.
These 3 wells are the evidences of the successful applications in Zawtika field. With good planning, lesson learned and further optimization, this CSC method can be beneficial for existing monobore wells, which required sand control and also will be the alternative sand control method for upcoming development phases. This CSC will be able to increase project economic and also unlock the marginal reservoirs those will not justify the higher cost of conventional gravel pack.
Bridging Agents Optimization Based on Predicting Induced Fracture Model for Deviated Wells – A Case Study
Authors: Karimi Rad Mohammad Saeed , Kalhor Mohammadi Mojtaba , Tahmasbi Nowtarki Kourosh 
Published: June 2021

Abstract
Applying bridging agents to prevent seepage losses is a common practice during drilling reservoir sections which limits the invaded zone and reduces stuck pipe possibility. Unfortunately, the initial particle size distribution (PSD) design of bridging agents based on static models does not prevent actual seepage losses due to the induced fractures which have different sizes comparing to the initial reservoir pore sizes.
This paper reviews an actual case study with provided solutions in an offshore field located in the Middle East which had a seepage loss circulation problem through induced fractures. It also presents analyzing natural and induced fractures size of the reservoir layer to choose optimized possible bridging agents’ PSD to cure/prevent loss circulation problems. The maximum/average pore size of formation can be measured from routine core analyses. A geological method to estimate the induced fracture widths with geo-mechanical data were used. Finally, optimum blends of bridging agents for loss circulation pills or background treatment to prevent mentioned problems were designed.
Based on the laboratory testing on cores taken from previously-drilled wells in the mentioned field, the maximum size of pore throats was measured as 20 microns. Therefore, using the Ideal Packing Theory (IPT) method, the result for selecting bridging agents through pore throats (for seepage loss) indicates that optimum treatment is using of bridging agents with D50 and D90 6.5 and 16 microns, respectively.
Also, for improving the treatment selection through parameters such as PSD of bridging agents, investigation on behavior of fracture growth were done. As a result, induced fracture width in studied well, with provided geo-mechanical (such as Poisson's Ratio & Young Modulus) and drilling fluid data was calculated approximately to be 230 microns through the porous medium in the near-wellbore region. Therefore, optimization for bridging these new fractures while drilling was performed again and it was concluded that optimum bridging agent size distribution at the tip of these newly-created induced fractures is applying bridging agents with D50 and D90 of 64 and 170 microns respectively, which are approximately 10 times higher than normal treatment in size.
This paper describes the historical seepage circulation and related problems in the mentioned field and presents a methodology to prevent these issues by predicting induced fractures and optimizing bridging agent PSD to block them. Considering this methodology, the gap between the design and actual drilling is reduced and both rig downtime and related drilling and drilling fluids costs can be saved.
Improving Accuracy of Checkshot Time-Depth by Applying Advanced Model-Based Correction for Rig-Source Survey on a Highly Inclined Well
Authors: Nguyen The , Iamboon Jakkarin , Nampratchayakul Piyanuch , Tongpan Nirut , Yint Htun Ye , Tran Dong 
Published: June 2021

Abstract
In seismic exploration, checkshot survey is an important method to obtain accurate time-depth profile for depth-to-time or time-to-depth conversion. However, the standard geometry correction for a rig-source survey in a high-inclination well will not provide a reliable time-depth result due to ray-bending effect. The objective of this study was to enhance the accuracy of the time-depth velocity by utilizing an advanced technique called model-based correction or pseudo walk-above simulation.
To obtain model-based vertical times, a flat-layered velocity model was built by using the checkshot velocities as initial guess. The model was then inverted to match the observed checkshot travel times, which were the actual measurement of travel path from source to receivers. The model was iterated to minimize the residual between the observed and modeled travel times in a least-square sense. A pseudo walk-above checkshot simulation was run on the inverted model by positioning the sources exactly on top of the receivers to get the vertical times, which were used for the final time-depth relationship and further image processing.
The residual times of less than 1 millisecond (ms) were observed between the actual measured transit times and modeled travel times from a fixed source to the receivers in the inverted model. This demonstrated the inverted model was realiable to use for obtaining more accurate vertical time-depth through pseudo walk-above checkshot simulation. This optimal inverted model was considered as the best estimation of the true earth model in this case. A comparison of modeled vertical times estimated through the pseudo walk-above simulation and calculated vertical times using standard geometry correction were done. The difference between the two scenarios was 6 ms one-way time (OWT) demonstrated the reduction of 6 ms uncertainty of using the advanced model-based correction versus the standard geometry correction. In short, the advanced technique delivered more reliable time-depth velocity information to reduce depth uncertainties for drilling operation.
The walk-above or vertical incidence checkshot survey, which required boat and navigation system, was unable to acquire in a highly deviated well due to very bad weather conditions. The rig-source survey was carried out instead of employing the walk-above survey in this project. The standard geometry correction using simple trigonometry was not able to provide the correct vertical times. The advanced model-based correction was the optimal solution to improve the accuracy of checkshot time-depth velocity data.
Drilling Performance Improvement Through use of Artificial Intelligence in Bit and Bottom Hole Assembly Selection in Gulf of Thailand
Authors: Tortrakul Nichnita , Pochan Chatwit , Southland Steve , Mala Pimjai , Pichaichanlert Tawpath , Tangsawanich Yuranan 
Published: June 2021

Abstract
This paper describes a method of transforming legacy manual bit/BHA planning process into a digital solution to enhance drilling assembly selection efficiency and consistency. The solution presented improves overall capital stewardship thru an effective and semi-automated use of data to deliver high quality decisions and improve decision consistency across drilling applications and drive drilling performance.
Data science and machine learning is applied to streamline the data preparation process and present to the user a statistically sound drilling assembly solution for the drilling environment input. A large +6000 well database is used to explore alternatives and rank potential solutions using performance and directional compatibility characteristics unique to the Gulf of Thailand.
The digital project goal presented is two-fold. The first is to streamline all related data and decision processes in the office to improve work efficiency and information accessibility. The second goal is to improve field drilling performance by installation of a self-learning advisory tool.
There is a requirement for multiple sub-processes to work in parallel. The population of data in the database and quality checks must be automated to handle hourly/daily data updates. A system for auto-loading drilling data from rigsite was created. A second system containing data science and machine learning was created to identify similar wells, rank their respective performance and directional compatibility to a future well of interest, and offer a statistically relevant solution recommendation.
A benefit of such a system is a more efficient workflow with improved field drilling results while effectively capturing Chevron Thailand methods for many drilling engineers to use in the future.
Adopting agile concept during development phase is one of the keys to success for this project. Additionally, utilization of digital transformation technology is a key enabler to handle big data, data science and data foundation.
Comparison of International Federation of cervical pathology and colposcopy nomenclature (2011) and Swede score for assessment of cervical lesions
Authors: Gupta Bindiya , Shreya Rashmi , Rajaram Shalini , Singla Anshuja , Jain Sandhya , Prasad Bhavya 
Published: June 2021

Abstract
Purpose: Standardization of colposcopic evaluation is important as it is observer dependent.The aim of the study was to compare the strength of association of colposcopic findings by International Federation of Colposcopy and Cervical Pathology (IFCPC) nomenclature and Swede score. Methods: In the prospective study, 150 women aged 30 to 60 years with abnormal screening results underwent colposcopy, the findings were evaluated using both IFCPC and Swede score and biopsy was taken from abnormal areas. Performances by both the methods were calculated taking biopsy as gold standard. Results: Nineteen ≥ CIN2 lesions were detected. The sensitivity, specificity, positive predictive value and negative predictive value for detecting ≥ CIN2 lesion by IFCPC scoring was 63.6%, 96.0%, 78.7%, 91.9%. Using Swede score, sensitivity, specificity, positive predictive value and negative predictive value at cut off of 8 were 42.4, 95%, 96.6% and 81.8% while at cut-off of 5, these were 96%, 88.3%,76.7% and 93.6%. The agreement between IFCPC major lesion and Swede score ≥ 8 for ≥ CIN2 was 0.626 (p<0.01). Conclusion: Swede score is an easier and more objective method for colposcopic evaluation and a score >8 can be applied to the screen and treat programme.
A morphological and molecular survey of Neoconidiobolus reveals a new species and two new combinations
Authors: Nie Yong , Wang Zi-Min , Liu Xiao-Yong , Huang Bo 
Published: June 2021

Abstract
The genus Neoconidiobolus was recently established to accommodate all members of the Conidiobolus subgenus Conidiobolus. Based on mitochondrial small subunit (mtSSU), nuclear large subunit (nucLSU) of rDNA and translation elongation factor 1-alpha (TEF1), this study further resolved the genus Neoconidiobolus into three clades, with three new taxa being added. They are N. kunyushanensis B. Huang & Y. Nie, sp. nov., N. lamprauges (Drechsler) B. Huang & Y. Nie, comb. nov., and N. nanodes (Drechsler) B. Huang & Y. Nie, comb. nov. Meanwhile, a morphologial comparison among species in the three clades and a key to the species of the genus Neoconidiobolus are provided herein.
Distribution of butyltin compounds in the coastal environment of the Bahía Blanca estuary, Argentina
Authors: Quintas Pamela Yanina , Arias Andrés , Álvarez Mónica , Domini Claudia , Garrido Mariano , Marcovecchio Jorge 
Published: June 2021

Abstract
This study evaluates for the first time the distribution and accumulation of butyltin compounds (BTs) in different compartments as seawater, sediments, suspended particulate matter (SPM) and mussels (Brachidontes rodriguezii) in the Bahía Blanca estuary. The samples were collected from six sampling sites with different anthropogenic impact. A better visualization and interpretation of data were achieved using chemometric tools (Tucker4 model), which made it possible to reveal the main relationships between the variables. This analysis showed the presence of BTs in all environmental compartments along the estuary, even in sites with low human intervention. The relationships found between BTs levels, seasons and environmental matrices show the importance of biological processes such as phytoplankton blooms and remobilization of sediments (by tidal dynamics and/or periodic dredging) in the BTs distribution and degradation. In addition, partition coefficients showed that mussels mainly bioaccumulate tributyltin through sediment, water and, to a lesser extent, from SPM.
Climate Change and Ecological Engineering Jointly Induced Vegetation Greening in Global Karst Regions From 2001 to 2020
Authors: Huang Jing , Ge Zhongxi , Huang Yuqing , Tang Xuguang , Shi Zhan , Lai Peiyu , Song Zengjing , Hao Binfei , Yang Hong , Ma Mingguo 
Published: June 2021

Abstract
Backgrounds

Vegetation dynamic plays a dominant role in the global carbon cycle and climate, especially in vulnerable karst ecosystem. Many studies have examined past several decades changes in vegetation greenness and the associated with climate drivers. Yet, few studies have analyzed the vegetation change in global karst regions particularly in the last decades when climate change and anthropogenic disturbance widely occurred.
Methods

In this study, we investigated the spatio-temporal variations of vegetation dynamic using the Seasonally Integrated Normalized Difference Vegetation Index (SINDVI) and examined their relationship to climate changes by correlation analysis, the ordinary least squares method investigate the variation trends and the Mann-Kendal test to detect the turning point from 2001 to 2020.
Results

As expected, there have greening trend in global karst SINDVI from 2001 to 2020, with significant increasing trend in China (range = 0.836, P < 0.05), Europe (range = 0.456, P < 0.05) and many other regions. According to correlation analyses, SINDVI is water-limited in arid and semi-arid regions, such as Middle East and central Asia, and temperature-limited in northern high-latitude.
Conclusions

consistent with previous studies, our results suggest that anthropogenic activities are mainly responsible for increasing vegetation greenness in tailoring management measures (e.g., Ecological Engineering, the Grain to Green Project) of China and Europe, intensive farmed in Middle East. Coupling warming temperature and increasing precipitation, southeastern Asia and Russia showed an increasing trend in SINDVI. In general, climate factors were the dominant drivers of the variation in vegetation greenness in globally karst regions during research period.
The role of Resveratrol, Sirtuin1 and RXRα as prognostic markers in ovarian cancer
Authors: Chen Fangfang , Kolben Thomas , Meister Sarah , Czogalla Bastian , Kolben Theresa M , Hester Anna , Burges Alexander , Trillsch Fabian , Schmoeckel Eisa , Mayr Doris , Mayerhofer Artur , Mahner Sven , Jeschke Udo , Beyer Susanne 
Published: June 2021

Abstract
Objective: Ovarian cancer is the most lethal gynecologic cancer. Resveratrol (RSV) is known to alter metabolism in cancer. It affects the nuclear retinoid-X-receptor (RXR), which implies a modulating effect of RXR to gynecologic cancers. Furthermore, RSV targets Sirtuin1 (Sirt1), a histone deacetylase. Study design: 123 tissue samples of patients with serous or mucinous ovarian cancer were examined for expression of Sirt1 and RXR. Ovarian cell-lines were treated with RSV and consequences on viability and apoptosis were evaluated. The influence of RSV to Sirt1 and RXR expression was analyzed by western blotting. Results: A correlation of nuclear Sirt1 and RXRα expression could be detected (p=0.006). Co-expression of nuclear RXRα and cytoplasmic (p=0.026) or nuclear (p=0.041) Sirt1 was associated with significantly increased overall survival in advanced tumor stages. Viability was decreased in all cell-lines after stimulation with resveratrol, while cell apoptosis was increased. RSV treatment led to significant lower Sirt1 expression in A2780 cells (p=0.025) and significant increased RXR expression in cisA2780 cells (p=0.012). Conclusion: In order to use RSV as medical target, studies could be developed to improve the understanding of drug resistance mechanisms and consequently improve treatment outcome.