bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface-Controlled Subsurface Safety Valve Remediation and Lockout with Universal Exercising and Dimpling Solution
Authors: Foucher Pierre , Dyer Clevar , Ramnath Jonathan , Surajbally Rodney , Gunness Craig 
Published: March 2023

Abstract
This case study explains an innovative technique used to mechanically exercise and to lock open the surface controlled subsurface safety valve (SCSSV) in a well. The repair consisted of locking open the valve prior to installing a wireline insert in order to return the well to production. The conventional slickline method of locking open the SCSSV was not possible due to the position of the stuck flow tube.
As an alternate to a costly workover of retrieving the tubing and the SCSSV, a novel wireline technique was deployed providing a solution to exercise the flow tube and then lock open the valve.
This technique helped diagnose the cause of the failure, mechanically shift the stuck flow tube, and then lock out the flow tube in a single run. It can be used subsequently on any safety valve without mobilizing a custom mechanical lockout tool. The instrumentation provided real-time quality control of the process, reducing the risk for subsequent runs through the valve.
The solution consists of a wireline tool composed of two anchors with a linear actuator in between. The top anchor provides a fixed point in the tubing and the linear actuator extends and retracts to exercise the flow tube and measure the displacement and applied forces. At the bottom, a second anchor grips the flow tube and transmits the axial force of the linear actuator. The second anchor can also be used as a dimpling tool to deform the flow tube and lock it out by increasing the force of the lower anchors.
By measuring the amount of force and the opening diameter of the second anchor, the operator can choose either to exercise or to deform the flow tube at a suitable location without pulling out of hole. The final opened diameter of the lower anchor the tool can further confirm if the deformation range has been reached for locking open, providing additional quality control capabilities.
Moreover, the instrumentation generates a signature for each exercising stroke, highlighting the impact of this process. Eventually, the tool can confirm the final flow tube position showing if full movement is possible prior to dimpling.
The tool was deployed in a gas well to first exercise the flow tube, stroking up and down five times and recovering its functionality. This step was followed by leaving the flow tube in the closed position and performing a successful inflow test of the flapper. However, recovering hydraulic functionality of opening and closing via surface control line pressure cycles was not successful.
Eventually, the tool was run to mechanically shift the flow tube in the required position for dimpling in the open position. A subsequent drift run through the valve proved the effectiveness of the lockout.
The successful intervention proved that this advanced solution can exercise and dimple a SCSSV. Additionally, it can also be used on other flow control equipment, such as ball valves and sliding side doors.
Coiled Tubing Utilized to Aid Complex Well Recompletion
Authors: Rahimov Khalid , Soodsakorn Patcharapun , Duguid Gary , Thom Douglas 
Published: March 2023

Abstract
Coiled Tubing (CT) has been proven as a robust and reliable technology most used in the energy industry to address complex well intervention activities. CT intervention was selected as primary solution when an operators gas producing well in the North Sea had developed a leak in the A-Annulus. After careful assessment an operator had decided to de-complete the well and run new economical completion. The identified scope of work presented several major challenges. Scale built up at different wellbore sections necessitating hydraulically activated BHA for mechanical cleanout, pumping salt washer treatment below the collapsed completion section, and setting the plug to isolate the well for next stage were main objectives to achieve as to enable retrieval of an old completion. This paper describes the use of an integrated well remediation methods to aid in de-completing the faulty production tubular. Discussions taken place around accuracy of advanced cleanout software by comparing the predicted value over the actual data captured during the operation. The paper also gives the overview to BHA selection and justification for the different stage of the operation. It also highlights several contingencies that were developed to address the challenges that were not projected earlier.
Improving Milling Efficiency in HP/HT Unconventional Field by Comprehensive Engineering Design and Strategic Planning of Fracturing Plugs
Authors: Alshammari Hamoud , Baki Sohrat , Hamidon Zahaezuani Rafiq , Kurniadi Stevanus , Alzamil Abdullah , Habiballah Zeyad 
Published: March 2023

Abstract
The requirement of tapping new hydrocarbon reserves has pushed the Middle East region to develop its unconventional resources. During the development, longer laterals are drilled to achieve more stages and increase well productivity. This generates more complex intervention activities, including the post-fracturing plug millout with coiled tubing (CT). This study outlines comprehensive evaluation of frac plug milling practices integrated with designing and execution of CT operations to improve overall milling efficiency for these unconventional horizontal wells.
Milling optimization was obtained by tackling key enablers of higher efficiency. First, the CT string was precisely engineered to serve the well trajectory and completion size. The tapered wall thickness configuration was strategically planned to maximize stiffness at the highly deviated section while reducing weight on the long horizontal lateral. Plug selection and placement strategy were also meticulously planned to configure the best combination of composite and dissolvable plugs. Since different plug types behave differently during milling, the millout strategy was tailored specifically for each type and their actual downhole environment.
The new engineered CT design, coupled with an extended reach tool (ERT), was proven effective in overcoming reach challenges across the long lateral while maintaining sufficient weight-on-bit (WOB) to mill the plugs. The ERT was also observed to enhance milling action due to the vibrations it generated. Those improvements led to faster and smoother operations, resulting in 70% reduction of operating time compared to the baseline established prior to the start of the project. The comprehensive plug placement strategy and better understanding of different plugs behavior in different environments further improved the milling efficiency, as the average milling time per plug was reduced by 80%. Additionally, the reduction in operating time improved the environmental sustainability of the project, as carbon emissions from the CT unit were reduced.
The comprehensive engineering design and plug selection strategy delivers significant improvements in millout efficiency. Implementation of key enablers led to performance increase, better resource utilization, and further cost optimization. This achievement also aligns with initiatives to reduce the impact of oil and gas operations on the environment, thus contributing to the goal of achieving net-zero in carbon emission.
Precise and Efficient Multi Ball Seat Milling Operation Executed in a Single Run Utilizing an Electric Line Deployed Milling String and Bespoke Multi-Step Mill
Authors: Murchie Stuart William , Iman Md Yousuf , Riise Knut Eirik , Storhaug Jens 
Published: March 2023

Abstract
An operator had a critical offshore water injection well which was not performing as expected, having an injection rate well below target. The well had a lower completion comprised of four frac sleeves in the horizontal section. A light well intervention (LWI) operation was carried out to evaluate the ball seats and valve status, any blockage that might be present, and to determine the required intervention scope going forward. A camera diagnostic run indicated the presence of debris.
A subsequent LWI operation was planned, to deploy an electric line powered mechanical toolstring to mill out all four ball seats and perform a perforation operation across all zones to generate the desired injectivity rate. Ball seats of reducing sizes had been deployed in the lower completion ranging from 3.403 in. ID for the uppermost to 2.697 in. ID for the lowermost. The operator wanted the efficiency of a single run solution to execute the entire milling operation. This required a multistep mill of appropriate sizing to be designed, one that would mill all four ball seat sizes in the completion to a common maximum ID. This would then enable passage for subsequent deep penetrating or big hole perforation charges to be run.
The electric line string incorporated a high level of instrumentation to provide real-time measurement and control of the critical parameters for milling optimization. A Tractor would provide toolstring conveyance, rotational anchoring, and weight-on-bit (WOB). Tension/compression subs would provide in-situ measurements of the WOB. A rotational sub would provide the torque. Monitoring and adjusting the torque, WOB, and rotational speed in real-time would enable an optimized rate of penetration throughout all steps across all ball seats confronted.
Thorough pre-job tests were carried out on identical ball seats placed in a test-jig set up. Key toolstring parameters were monitored and the time required to mill through each ball seat was captured, this to determine the optimal tool parameters to use throughout the operation.
All four ball seats were milled out successfully in a single run operation, with the toolstring providing both milling and back reaming, this ensuring no sharp edges remained as a result of the milling. The full milling operation was completed in a matter of hours, far below those experienced by the operator on previous operations. Upon return to surface little to no wear was found on the step mill and all mill sections were found to still be well in gauge. In effect, the step mill was used as a drift run, post milling operation, allowing the perforation runs to immediately follow. Following the subsequent perforation operation the transient injection rate increased considerably. Longer term injection and production data will determine pressure support and sweep efficiency.
Reducing Emissions for Extended-Reach Well Stimulation Without the Need of Intervention
Authors: Watkins Tom , Najafov Jeyhun , Watson Edward , Livescu Silviu K. 
Published: March 2023

Abstract
For most wells in North America, hydraulic fracturing is usually performed by plug-and-perf. It requires perforating guns, plugs and milling bottom hole assemblies (BHAs), large water volumes, as well as coiled tubing and friction reduction technologies such as vibratory tools or tractors, in the case of extended-reach wells. To reduce operational complexity, time, and cost time and meet Environmental, Social, and Governance (ESG) goals, operating companies are in a continuous search for alternative innovative fracturing systems. A new approach to traditional hydraulic fracturing is presented in this paper showing significantly improved project economics and lower environmental impact.
A contactless sleeve recognition technology, consisting of any number of compact programmable dissolvable darts, is used to open and close sliding sleeves without the need of well intervention technologies. The new fracturing system was used in a horizontal well with a 16,568-ft long lateral. In this well, darts enabled the opening of 133 sleeves. The darts have miniature electronic sensors allowing real-time monitoring of their exact location as they move through the well and real-time dart control to activate them before landing on their target sleeves. The details presented show the acoustic monitoring confirmation of stages being successfully treated, the high-definition ultrasonic confirmation of no erosion or casing deformation, and the darts dissolution after the treatment.
The significant advancement of this hydraulic fracturing technique made it possible to completely eliminate the need for coiled tubing in an extended-reach well, gain confidence in casing deformation risked areas, maintain maximum wellbore inner diameter (ID) before and after completion, eliminate issues of mechanical indexing, ensure continuous pumping without rate limitations, exclude milling operations and avoid casing erosion. The field data demonstrates the efficiency of the new fracturing technology that allows stimulation of horizontal wells without the need for well intervention. The article summarizes the field results of the hydraulic fracturing operation and quantifies its outcomes for sustainable resource development and strong financial results.
The industry is under increasing pressure to reduce project costs and environmental impact. The new fracturing system described in this paper becomes a more efficient alternative to traditional plug-and-perf technology. It allows for reduced risks and costs, enabling operators to successfully complete extended-reach wells without need of intervention, overcome issues of casing deformation, improve operational efficiency, enhance energy production and reduce environmental impact.
Novel Coiled Tubing Post-Fracturing Cleanout of Unconventional Wells Without Downhole Motor: A Case Study from Argentina
Authors: Mirande Juan Martin , Palombizio Giovanni , Arevalo Lucas , Marro Alejandro , Rodriguez Marcelo , Krasuk Raul , Vecchietti Matias 
Published: March 2023

Abstract
Unconventional wells that are completed with plug-and-perf fracturing techniques require coiled tubing (CT) to mill the plugs. In Argentina, CT must mill upwards of 60 plugs to bring the well into production. The CT downhole motors are leading contributors to service quality incidents because: 1) they mill challenging materials over extended periods of time, and 2) they limit the pump rate, which reduces cleanout effectiveness and increases the risk of stuck pipe.
A completion campaign selected soluble plugs instead of composite ones to improve efficiency. Initial CT runs were still completed with a milling bottomhole assembly (BHA) to address the risk of low plug solubility. However, as evidenced during the initial campaign runs, the plugs dissolved nearly completely, leaving only the steel buttons inside the well. Those buttons required a high pump rate to carry them to surface. Given the excellent plug dissolution and the fluid velocity requirement to clean out buttons, the BHA was simplified to an extended reach tool (ERT) and a customized, high-rate jetting nozzle, thus eliminating the downhole motor.
The new and simplified BHA extended the pump rate limit from an average of 3.8 to 4.5 bbl/min with no adverse effect on circulating pressure. The operator observed a tenfold increase in the number of plug buttons recovered at surface, which reduced the risk of stuck CT pipe during interventions in those wells. The cleanout speed was also increased, reducing total operating time by 25%, costs, and diesel consumption.
A special procedure was developed for the cases when the BHA encountered consolidated sand and plug debris during the operations, a situation that occurred an average of three times per well. To clean those accumulations, the pump rate was increased to generate high jetting energy and stronger ERT agitation, and the CT was run in hole at slow speed until tagging the solids. This procedure allowed passing all the restrictions found during the execution of the CT cleanout jobs. This approach also made it possible to clean wells with known casing deformations, a common situation in Argentina unconventional wells.
Over the course of 44 wells, 13 were cleaned with the simplified BHA. This new approach addressed the two main sources of nonproductive time before initiation of the project: BHA failures decreased from 16% to 8% and no CT stuck pipe event occurred.
This is the first published case study of a post-fracturing cleanout in an unconventional well without the use of a downhole motor and which, instead, combined soluble plugs and a tailored BHA. Eliminating the downhole motor in this application significantly improved operational reliability and efficiency. The use of this simplified BHA to clean the well down to total depth is only possible with a good dissolution performance of the plugs present in the well.
Hydrate Reservoir Stimulation and Sand Control by Liquid-Solid Phase Change Proppant Filled in Radial Well
Authors: Liu Xiaoqiang , Han Zhongxi , Yu Lu , Wei Wei , Lu Hailong , Sun Ying 
Published: March 2023

Summary
The depressurization method for natural gas hydrate exploitation encounters the difficulties of low productivity and sand production. Enhancing hydrate production efficiency and reducing massive sand production are the key issues to be solved in hydrate development. This paper proposes a new approach to hydrate reservoir stimulation and sand control by liquid-solid phase change proppant (LSP) filled in radial well (SCRP). A multicomponent flow model of sand-water-gas-hydrate is established and applied to evaluate the effect of SCRP on hydrate development. The results obtained show that the application of SCRP realizes an integrative effect of both reservoir stimulation and sand control. Radial wells increase the sweep area of pressure drop and promote hydrate decomposition. Solid particles, which are formed by LSP, not only fill and support radial wells but also act as sand control medium, preventing sand from flowing into the production well. It is found that reducing the production pressure difference can effectively reduce sand production. To achieve a large-scale stimulated reservoir volume, it is necessary to increase the length of a single radial well, the number of radial wells in the same layer, and the number of radial well layers. The spiral layout of radial wells has a better effect on improving gas production. A single radial well achieves good sand control effect with the application of the LSP system, but an increase in radial well number leads to an increase in sand production, resulting in massive amounts of sand gathered in the production well. As a result, in the case of multiple radial wells, other sand control technologies, such as mechanical sand screening, should be used along with SCRP to further reduce sand production.
WITHDRAWN: Availability, Reliability, Maintainability and Capability based Effectiveness Measure of Power System Radial Networks
Authors: Hazarika Kalpana , Bhadoria Vikas Singh , Khemariya Manish 
Published: March 2023

Abstract
Reliability of the Power System dictates system adequacy and security. Generally, power system networks reliability is estimated based on its service availability from the customer's viewpoint of satisfaction. Parameters in this analysis interpret the service uptime and downtime frequencies, duration and count of affected customers, etc. Corresponding to these indices expected losses in terms of service, load, and revenues are estimated. But to work upon very fundamental issues for overall improvement of power system networks performance, assessment of systems effectiveness remains a rarely studied area. For example, although it is understood that a radial network configuration has low reliability, still major primary distribution structures and rural power distribution networks of (5KV -35KV) are mostly configured in radial structure only. Because it remarkably reduces the cost involved in network duplication especially the cost incurred for vital equipment. For this significant analysis, authors have extended the concept of Barringer for analysis of Dual generator fed radial power system networks Reliability, Availability, Maintainability, and Capability based Effectiveness (RAMCE) measure. This paper demonstrates here the technique for analysis of a Dual Generator set feeding to 5-load bus radial systems is considered here.
Evaluation of Vitamin D binding protein gene polymorphism and serum free and bioavailable levels among tuberculosis patients: A cross sectional study
Authors: Acen Ester Lilian , Joloba Moses L. , Akintola Ashraf , Nabi Rizwana Begum Syed , Biraro Irene Andia , Worodria William , Okeng Alfred , Bbuye Mudarshiru , Hwang Ui Wook , Kateete David Patrick 
Published: March 2023

Abstract
Background
Genetic variants influence the distribution of vitamin D in circulation leading to vitamin D deficiency. The two extensively studied non-synonymous DBP single nucleotide polymorphisms (SNPs) rs7041 and rs4588 are found in different populations. The aim of this study was to determine the frequency distribution of DBPgene polymorphism andcompare the free and bioavailable vitamin D levels among active tuberculosis patients, latent tuberculosis infection individuals,and those without tuberculosis infection. This was across-sectional study with 53 active tuberculosis patients,23 latent tuberculosis individuals, and27 individuals without tuberculosis infection.Free and bioavailable vitamin D levels were measured using ELISA method.DNA extraction and PCR were performed and a product of 498 bp was obtained. We genotyped the DBP gene by Sanger sequencing and the single nucleotide polymorphisms were identified using the BioEdit tool.
Results
The study frequency distributions of the DBP genotypes were reported as97% Gc1F, 2% Gc2 and 1% Gc1S.Significantly low vitamin D levels were found among the TB patients, p=,0.001.The median (IQR) vitamin D levels of the predominant genotype, Gc1F were 3.8(1.1–10.5) ng/ml,Gc1S individuals, 2.2ng/ml, and Gc2 individuals were 1.9 ng/ml. A non significant association was found between the vitamin D binding protein genes and free and bioavailable vitamin D levels, p = > 0.05.
Conclusion
The Gc1F genotype was predominantly found in the study population with the minor alleles associated with active and latent TB states. Significantly low free and bioavailable vitamin D levels were found among TB patients compared to other TB states. However a non- significant association was found between the DBP gene polymorphismsand the free and bioavailable vitamin D levels.