bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real-Time Inference and Uncertainty Quantification of Friction for Coiled Tubing Operations
Authors: Su Tianxiang 
Published: March 2022

Abstract
For many years, tubing force models (TFMs) have been used to predict coiled tubing (CT) reach in the wellbore, de-risk interventions, and track CT pipe life. Several input parameters, for example, the friction coefficient, the stripper friction, and the fluid viscosity, are difficult to obtain before an operation. They are typically fitted later during the operation or once the operation is completed. A method is presented here to infer those parameters iteratively in real time during the job. The method is based on the unscented Kalman filter (UKF). A TFM predicts the surface weight from input parameters. The UKF solves the "inverse problem" by observing the noisy surface weight measurement and infers the unknown parameters in a probabilistic way. Unlike the fitting-based optimization methods, UKF is an iterative method and makes an incremental update to the parameters from each measurement. Moreover, based on probabilistic theories, the UKF computes rigorously the uncertainty bounds of the inferred parameters. We implemented a UKF framework in Simulink. To test the model, a synthetic dataset with well-defined ground truth friction and well trajectory was first created. This synthetic well had a vertical section of 2 km (6,562 ft) below the surface, followed by a 2-km deviated section of constant dogleg severity where the well changes from vertical to horizontal, followed by a last horizontal section of 2 km. An analytic solution for the surface weight was derived for this specific well, and Gaussian noise was added to the solution to mimic the measurement noise. The noisy synthetic data were fed into the customized UKF framework with a wrong initial guess of the friction. The UKF framework incrementally and correctly adjusted the friction to the ground truth friction value in a few hundred iterations at 0.1 Hz. In real operations, if there is a sudden condition change, one expects the UKF to take similar steps to adapt to the change. Next, actual data from a previous job were replayed iteratively into the UKF framework. No ground-truth friction value existed for that dataset. But with the real-time inferred friction, the model was observed to provide a much better surface weight prediction compared to a legacy model without parameter inference. To the knowledge of the author, this is the first time UKF is reported to perform parameter inference for CT operations. It provides clear advantages compared to the legacy fitting-based method because (1) it can easily handle multiparameter inference; (2) it is straightforward to quantify the uncertainty of the inference; (3) the filter can incorporate any prior knowledge about the parameters; and (4) the method can be applied iteratively, continuously, and automatically.
Thru-Tubing Cleanouts and Acidization in Unconventional Wells
Authors: Burke Jason , Harrison Cayla , Gamarra Francisco , Turner Matt , Ruby Jim , Nono Brandon 
Published: March 2022

Abstract
Over the last 12 years, technology in the drilling and completions space has reduced cycle time and dramatically lowered costs for operators. With the adoption of re-stimulations, additional production is being gained from existing wells at a cost that is less than the cost of drilling new wells. However, there has been limited development of low-cost intervention techniques to restore lost production or to extend the life of existing wells.
To address this relatively untapped area of intervention, new tools and techniques are needed to revitalize older wells in unconventional reservoirs that are more cost effective than traditional intervention techniques.
The economics of a workover are challenged by the uncertainties of successfully removing the existing production tubing and replacing it with a newly designed completion. In response a tool and cleanout technique has been developed that improves the ability of 1.25 in. coiled tubing to clean out the 5.5 in. casing through the 2.375 in. tubing string, thereby eliminating the need to pull and replace the upper completion.
A recent application of this new technique in an unconventional well demonstrated that a modified jetting tool (Reverse Nozzle Bit Sub or RNBS), along with a regimented cleanout schedule, can clean out most of the lateral length and restore lost production at a greatly reduced time and cost compared to jointed pipe workovers. Additionally, using coiled tubing to spot acid along the length of the lateral in a uniform matter can remove scale buildup and clean up perforations for improved performance.
This paper will review the design, testing and field application of the new tool and technique as well as show early results.
Integrated Approach Yields Improved Efficiency and Lower Risk in High-Pressure Live-Well Perforation Intervention With Expected WHP of 10,500 Psi Gas
Authors: Taghiyev Alizamin , Piven Alexander , Correa Pedro Daniel , McClean Charlie , Mammadov Rufat , Pashayev Nariman , Allahverdiyev Maarif , Akbarov Akbar 
Published: March 2022

Objectives/Scope
The goal for the project was to perforate a new high-pressure interval in live well conditions in one single run. Completion fluid was displaced to a lighter fluid, followed by gun deployment of 466 ft. to perforate a high-pressure gas interval.

Methods, Procedures, Process
It is understood that electric wireline, slick line and coiled tubing can be used to lubricate shorter intervals multiple times in and out of a well which is live. However, this can remove the advantages of dynamic underbalance and effective underbalanced perforating clean up. Operation was staged to prepare the wellbore for perforating, displacing the completion fluid from 1.7 SG CaBr2, to seawater, to 1.13 SG KCl brine. With the well ready for perforating, the use of the advanced live-well deployment system and intelligent coiled tubing BHA a 466ft long perforating assembly was conveyed to target depth in one run and successfully perforated the interval of interest in an underbalanced condition.

Results, Observations, Conclusions
The project efficiencies were maximized by taking an integrated approach to the overall project. By utilizing an Advanced Live Well deployment system, virtually any length of assembly can be safely deployed and recovered from a live well. Furthermore, by integrating this system with the Intelligent Coiled Tubing bottom hole assemblies for deployment and detonation, utilizing "rock optimized "perforating guns and Thru-Tubing Intervention systems, a complete solution can be provided for the operator. The application of the systems, resulted in a flawless execution, and a reduction in the operational risks associated with an operation that historically was classed as a high-risk project.
Sand Control Screen Clogging Remediation with Innovative High-Density Slot Machining Solution
Authors: Foucher Pierre , Raghavan Anand , Sheiretov Todor , Engel David , Babin Christopher , Wurtz Josh , Melvin Hayden , Garzon Francisco 
Published: March 2022

Abstract
A gravel pack equipped with sand screen completion is commonly used in deepwater Gulf of Mexico. Over time, fines migration and asphaltenes clog the screens of the completion, which negatively affects the well production. In order to remediate the damage, openings are created in the concentric base pipe inside the screen (Fig. 1). This process creates a flow path that allows for cleaning of debris from the screens through jetting and bull heading of stimulation fluids. The combination of these operations restores the productivity of the well.
In the conventional method, the cuts are machined one at a time with a blade spinning in the horizontal plane. To achieve sufficient flow area, this step is repeated approximately hundred times to distribute the cuts along the target screen interval. Such an operation can require up to 14 days including the downhole cutting time as well as trips in and out of the well to replace the blades.
The blades protrude only slightly from the base pipe to avoid damaging the screen. The screens are separated from the base pipe with standoff to maintain a constant clearance. Thus, the blades cannot damage the screen.
Simulation and Optimization of the Nitrogen Injection-Assisted Flowback with Coiled Tubing
Authors: Zhu Zhiyong , Han Guoqing , Rui Ray , Zhang He , Wu Xiaodong , Xiang Huizhu 
Published: March 2022

Abstract
Nitrogen (N2) injection-assisted flowback with coiled tubing (CT), CT flowback for short, is more and more widely used due to its convenience in implementation and flexibility in control. The unique feature of gas injection with CT is that the injection depth can be changed continuously (Zhou et al., 2011), which makes flowback become a more complex dynamic process. However, scarce research has been done on such a dynamic process, especially in the optimization of operation parameters such as CT running into hole (RIH) speed and N2 injection rate.
In this paper, numerical models are established using the transient multiple flow simulator to reproduce the dynamic process of CT flowback. And based on this, the characteristics of CT gas injection are explored by comparing fixed-point gas injection with variation-depth gas injection. The influence of formation flowback capacity, CT RIH speed and N2 injection rate on CT flowback process is analyzed. And finally the optimization suggestions for CT operating parameters are put forward.
The simulation results show that, compared with fixed-point gas injection, variation-depth gas injection (i.e. CT gas injection) can achieve a more controlled flowback, significantly reduce the gas injection pressure, and realize the gentle unloading of bottom hole pressure. Formation flowback capacity has an important effect on the CT flowback process, different formation flowback capacities result in different gas well unloading degrees. With the increase of formation flowback capacity, the unloading degree of gas well decreases. CT RIH speed can to a large extent control wellbore unloading rate, i.e. the flowback intensity. The increase in RIH speed is at the expense of the increase in gas injection pressure and will lead to a more aggressive bottom hole pressure unloading. So in determining the RIH speed, both surface gas injection facility limitations and downhole pressure control requirements need to be taken into account. For a given CT RIH speed, there is a minimum N2 injection rate, which is required to achieve the continuous drainage, i.e., the lower limit for N2 injection rate. On the basis of this lower limit, further increasing the N2 injection rate will accelerate the wellbore unloading, and reduce the peak of gas injection pressure, but there is also an upper limit for N2 injection rate beyond which the benefits are no longer apparent.
Inhibition Testing with High Strength Quench and Tempered Coiled Tubing
Authors: Elliott Kevin J , Rentas Chris , Fenwick Jamie , Hayworth Jason , Albaugh John D , Ables William Colt , Tyler Woitas , Ben Stang 
Published: March 2022

Abstract
High strength quenched and tempered coiled tubing (CT) has been developed and commercialized as far back as the 1990s, however in recent years it has grown to be a substantial, if not the main, type of CT in many markets. Testing programs for sour environment compatibility using inhibition exist for similar strength levels of conventionally produced coiled tubing and has been used as justification for utilization of Q&T coiled tubing with existing CT equipment and operations in sour environments.
Quenched and tempered coiled tubing is given final heat treatments which yield a more homogeneous microstructure than conventional products. The field performance of this homogenized product has generally shown that the quenched and tempered tubing performs better in sour environments. This paper then explores the existing body of work with respect to accepted operational guidelines and sour gas testing of coiled tubing.
A test program for 140-grade quenched and tempered coiled tubing was developed to explore sour compatibility using an inhibition system. The development and test results of the testing program are described in this paper. The paper concludes with field history of high strength quenched and tempered coiled tubing in Western Canada operations.
World's First Fishing Operation on Wireline, Where 100,000 Lbs of Pull Force Was Applied: A Case Story
Authors: Prabhakaran Sudesh , Khogali Mamoun , Nobile Blanco Juan Jose , Santos Alexander Delos Santos , Rathod Chirag Harish , Sequeira Steven Rajesh 
Published: March 2022

Abstract
A high producing offshore oil well was shut down after an unsuccessful slickline plug-retrieval operation, which led to the slickline toolstring and isolation plug stuck at a shallow depth. Heavy duty fishing was performed using electric wireline self-anchoring hydraulic stroking tool. While pulling, 100Klbs of force was applied to free the slickline toolstring from the plug. This paper is written to share the experience gained while planning, preparing, and executing this high-profile job.
After reviewing all available options, it was decided to use the high-capacity version of the electric wireline hydraulic stroking tool, rated to 100,000 lbs. Approach to the job was to retrieve the slickline toolstring either as one piece or break it into parts by applying maximum force and retrieve in several runs. After fish retrieval, further plan was to retrieve the isolation plug using slickline. Preparation phase included function test at the base with full reconstruction of well situation, to confirm that this approach is correct.
Base function test was performed to determine if the high force from the electric wireline hydraulic stroking tool would break the slickline toolstring or release it from the plug. For the test, the exact fish components, including the plug, were set up in a horizontal tubing. A long overshot was designed to swallow the jars in the slickline toolstring. It took five upward strokes, up to 100,000 lbs, to release the slickline toolstring from the plug's fishing neck. The ring of the fishing neck sheared from isolation plug.
Following the base function test, equipment was mobilized offshore. The heavy duty overshot was installed on the fish using Slickline. Electric wireline hydraulic stroking tool was then rigged up on electric wireline, run-in-hole, and latched onto the overshot. After two strokes of up to 100,000 lbs, the slickline toolstring released cleanly from the fishing neck of the plug (similar to the base function test). Following successful fishing operation, the plug was successfully retrieved and well was brought back to production. Using the electric wireline hydraulic stroking tool allowed to perform the job rigless, in a cost effective, safe and time-controlled manner.
Novel Techniques to Optimize the Fishing Process of WL Cable and Bha for Plug & Perf
Authors: Naso Luciano Andres , Zambon Matias Nahuel , Goñi Lucas , Ureta Matias Ezequiel 
Published: March 2022

Abstract
One of the most challenging Coiled Tubing (CT) operations is the fishing of Wireline (WL) components. In Vaca Muerta (Neuquen, Argentina), the shale activity has been increasing over the recent years with more than 1,000 hydraulic fracs per month, pushing the operational limits to achieve new records, bringing new unplanned operational issues.
After eight plug and perf stages completed in well A, a wireline BHA got stuck at 16,433 ft. After several attempts to retrieve the cable by activating the electrical and mechanical disconnect devices, it was decided to use a cable cutter which did not reach the target depth. Due to this event, four elements were left in the well: the cable cutter, 5,938 ft of cable with cable head, and lower part of BHA.
The recovery plan was to fish the cutter, pull out the wireline cable by breaking the mechanic release device, and then fish the BHA. The highest risk of this job was losing the horizontal section of the well if the cable broke during the fishing process, due to the well pressure and complex conditions.
For this reason, a new operation plan was designed and executed, that included the combination of wireline and Coiled Tubing services with an innovative rig up and fishing technique. These changes allowed to optimize the job to 5 operating days with only one wireline run and three CT runs. No damage was caused on the well and completion operations were resumed as planned.
Field Application of Slickline Fishing Well Intervention Technology in Ultra-Deep HTHP Gas Reservoirs
Authors: Liu Huifeng , Ding Mingming , Li Cheng , Ling Zongfa , Yuan Zebo , Liu Qi , Qin Zhengli 
Published: March 2022

Abstract
Kelasu gas field in Tarim Basin is characterized by ultra-deep (6500-8000m), ultra-high temperature (160-19°C) and ultra-high reservoir pressure (110-136MPa). The wellhead pressure during production is also as high as 80-100MPa. Rigless well intervention is always difficult to perform because of the high well control risks. Slickline testing, electric line testing and optical fiber monitoring have all been tried, but problems like breaking of slickline, loss of signal, falling of instruments into well, etc. were encountered.
A slickline fishing technology has been used for bottom hole well surveillance in this area with many optimizations on the instruments. Grease injection sealing assisted by packing sealing is used to reduce friction of slickline and to guarantee well safety during operation; a choke tube stabilization device is invented to deal with the eccentric wearing of slickline and choke tube; self-supporting lever together with 8 anchor ropes are used to stabilize the blowout prevention tube assembly to withstand the high wind in the mountainous area; grease collection device is used to avoid the discharge of grease into the environment.
The technology has been successfully used in more than 70 wells in Kelasu gas field. The interventions include production testing, pressure built up (PBU) testing and well interference test. The maximum setting depth of the manometer reaches 7189 m. The highest wellhead pressure during testing reaches 90 MPa. Longest pressure survey time comes up to 52 days. No surface or downhole problems have been encountered and all the required data have been acquired. The wells were not killed during the intervention so the reservoir is well protected. Well interference tests were conducted in Keshen 8 block using this technology. The results showed very good interwell connectivity and suggested that well spacing should be enlarged. The development program of this block was adjusted accordingly and it turned out that the expected production rate was achieved with 4 less wells. Besides, the drilling thickness of the target formation was reduced from 200m to 130m and the same well productivity was also obtained.
Now the slickline fishing bottom hole pressure survey technology has been extensively used in the ultra-deep HTHP wells in Kuqa Foreland Area. It has been field proven for simple operating, less cost and formation protection. It can be used anytime in the life cycle of a well to evaluate the reservoir dynamic data, to deploy new wells and to optimize the production system of existing wells.
Nonlinear association between changes in fasting plasma glucose and the incidence of diabetes in a nondiabetic Chinese cohort
Authors: Huang Chenghu , Ren Chenhong , Xuan Xiuping , Luo Yi , Peng Caibi 
Published: March 2022

Abstract
Background: Limited data show that changes in fasting plasma glucose (FPG changes) are related to the incidence of type 2 diabetes (T2D). We aimed to correlate FPG changes with incident diabetes and evaluate FPG changes as a marker to screen participants at high risk of T2D in China.Methods: A total of 116,816 individuals were followed during a median follow-up of 3.10 years by secondary analysis in a nondiabetic Chinese cohort. The turning points were derived from a receiver operating characteristic curve. Hazard ratios (HRs) were evaluated by Cox proportional hazards models.Results: A total of 2669 cases of T2D were identified (788 women and 1881 men). The age-standardized incidence of diabetes was 12.87 per 1000 person-years (women: 11.04; men: 14.69). A nonlinear relationship between FPG changes and incident diabetes is shown by the fitting curves. The curves were categorized into three stages by two turning points (-0.04 and 1.25 mmol/L) and conformed to the hook-like pattern: an initial decrease (stage-1), then a transient sharp elevation (stage-2), followed by a slow increase (stage-3). HRs per SD of FPG changes on incident diabetes varied with stage: stage-1: 0.16 (0.12, 0.23), stage-2: 0.20 (0.15, 0.28) and stage-3: 0.22 (0.16, 0.31). Compared with stage-1, the HR in stage-3 was significantly higher at 28.05 (23.99, 32.79), while the increase in stage-2 was slight at 2.16 (1.79, 2.61), and the HR in stage-3 rose to 30.09 (25.02, 36.19).Conclusions: FPG changes had a strong correlation with the incidence of T2D and was a steady indicator that was used to distinguish the participants at high risk of diabetes.
Isolation, morpho-physiological and molecular characterization, phylogenetic analysis of Trichoderma asperellum in Bangladesh
Authors: Mahmud Hyat - , Uddin Sheikh Afsar , Hossain Ismail - , Monjil M S , Hossain Mohammad Delwar 
Published: March 2022

Abstract
The experiment was conducted at four laboratories, Bangladesh Agricultural University, Mymensingh to identify T. asperellum and its characterization was obtained from the rhizosphere of 49 different crops in 109 different locations in Bangladesh. Fifteen isolates of 88 isolates in T. asperellum were characterized on morphological and physiological features. TR27 and TR45 were grown and sporulated at 40°C except all the isolates of 35°C. As the increasing pH value mycelial growth of all the isolates was reduced. Molecular characterization in four isolates of (TR27) Sadar, Moulvibazar (Rice), (TR45) Sadar, Mymensingh (Sweet gourd), (TR70) Chapra, Chapai Nawabganj (Sesame) and (TR85) Nayanpur, Lalmonirhat (Maize) were studied at ITS and TEF region nucleotide sequencing among 15 isolates of T. asperellum, and the morphological characterization at ITS and tef1 nucleotide sequencing was assimilated with molecular characterization. Isolates of TR45, TR70 and TR85 were found with 98% homology and TR27 exhibited 88% against their respective closest isolate. Isolates of TR27 and TR85 marked their respective nearest homology (96%), while TR45 showed 99%, and 93% homology was signified with TR70 in TEF sequences. Isolates of TR45, TR70 and TR85 were identified as T. asperellum of 100% bootstrap value and TR27 isolate was also recognized with 72% bootstrap value in the phylogenetic tree. In phylogenetic analysis, tef1 extended better differentiation among the Trichoderma isolates within and among the groups of closely related species than rDNA of the ITS region in reflecting wider variability in the isolates while a higher transversion ratio and evolutionary divergence were defined.
Neuroprotective of Metformin on ischemic brain injury in rats
Authors: Lv HaiXia , ruan cailian , Yu Yong , Wang Lijun 
Published: March 2022

Abstract
Ischemic brain injury is a disease with high incidence rate, high disability rate and high mortality rate. The insufficiency of cerebral blood supply makes cerebral ischemia and hypoxia, leading to severe oxidative stress, severe inflammatory reaction and ultimately irreversible brain tissue damage or apoptosis.Metformin(Met,Abdominal inject,20 mg/kg,28days)is a guanidine derivative extracted from goats and is the first choice for first-line treatment of type 2 diabetes.In this study, the rat model of middle cerebral artery occlusion(MCAO) reperfusion injury and the hippocampal HT22 cell oxygen glucose privatization / reoxygenation (OGD/R) cell model were used to observe the effects of Met on the morphology of hippocampus, Nrf2, apoptosis factors, oxidative stress factors and inflammatory factors after CI/RI in rats ,it was further revealed that Met by using LY294002 antagonist, a specific kinase (phosphoinositide-3 kinase,PI3K) phosphoinositol-3 kinase, regulates the PI3K/Akt/Nrf2 signaling pathway in role in CI/RI.