bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pattern Fracturing: Concept, Simulation, and Case History of Platform-Based Completion and Fracturing Optimization
Authors: Liu Yuan , Li Jian , Lei Qihong , Zhang Tongwu , He Youan , Luo Yin , Ma Fujian , Wang Bo 
Published: September 2023

Abstract
Inspired by the success of North American unconventional resources, many shale oil operators in China adopted the intensive completion and fracturing practice for field development. The intention of the aggressive scheme was to improve individual well productivity as well as the ultimate recovery. Similar to the shale oil counterpart in North America, however, frequent frac hits have been reported in the recent years, and the increase of the engineering parameters has not always increased field productivity. Based on geo-engineering work in Ordos basin, we developed and tested an innovative strategy, pattern fracturing, to solve this issue, and it proved to be an effective and low-cost completion and fracturing optimization method for reservoir management.
Pattern fracturing differs from the previous field practice by dividing pad wells into two groups, each with a distinctive strategy for the job design and execution sequence. One group is defined as energy charger (EC) and the other as reinforced producer (RP). EC wells adapt to the large-volume high-rate fracturing practice to maintain the long-term reservoir pressure. The RP wells adapted to an intensive staging with low-volume low-rate fracturing practice, which aims to create a better near-wellbore flowing environment. EC wells are to be completed earlier than the RP wells, so that the RP well engineering parameters can use the previous monitoring and observation as a reference. Essentially, pattern fracturing is a platform-based reservoir management approach.
Pattern fracturing was evaluated with reservoir simulation for validity and then put into practice in a five-well testing site on platform-A in Ordos basin. The result from the pattern fracturing trial was encouraging. In addition to the lower horsepower consumption, the higher efficiency of job execution, and fewer perceived frac hits from offset wells, the production performance from platform-A showed positive results in both EC and RP wells. This indicates that by assigning the wells into different groups and refining the strategy and design for each of group, there is a good chance of improving the productivity with less cost.
Pattern fracturing is an innovative completion and fracturing optimization approach with reservoir management purposes used in horizontal well groups, particularly fit for the scenario of unconventional resources.
Application of Pulse Hydraulic Fracturing for Tight Oil Reservoir with low frequency
Authors: Shi Xian , Xu Hongxing , Han Lei , Wang Daobing , Ni Hongjian 
Published: September 2023

Abstract
A promising stimulation technique to increase effective permeability is pulse hydraulic fracturing. A particular frequency of fracturing fluid injection causes rock failure and may lead to the formation of a complex fracture network due to cyclic loading. When compared to hydraulic fracturing, pulse hydraulic fracturing has produced better fluid extraction results. Although it would be extremely difficult given the various downhole operating conditions, adopting pulse hydraulic fracturing technology to enhance the fracturing effect of tight reservoirs is an issue that merits consideration. This study developed an experimental setup for triaxial rock that was subjected to cyclic damage at various frequencies and amplitudes. Moreover, this study developed an experimental setup for triaxial rock that was subjected to cyclic damage with low amplitudes. The pulse frequency can be adjusted from 0 to 50Hz, and the pulse pressure amplitude varies from 1MPa to 5MPa. The comparison of rock failure studies under various cyclic loads as well as the impact of various hydraulic pulse parameters and rock characteristics on rock damage were done. According to experimental findings, load amplitude affects rock compressive strength and breakdown pressure differently depending on the rock's qualities. The impact on rock's compressive and tensile strength grows as pulse pressure amplitude increases. The influence on rock fracture pressure increases initially with an increase in hydraulic pulse processing time before tending to stabilize. The compressive and tensile strength of rock samples were reduced by 15% and 12%, respectively, while the drop rate of the breakdown pressure was roughly 18%. Hydraulic pulse has the largest impact on tight reservoirs collected from various levels of the Ordos Basin in China. High fluid pressure is advantageous for quick fracture initiation and propagation, but low fluid pressure might cause the fracture to originate and propagate with a protracted pulse fracturing time. A downhole hydraulic pulse generator is conceived and created based on the experimental findings that the preferred hydraulic pulse frequency is between 18 and 20 Hz. The results of the experiment demonstrate that the generator's performance satisfies the design specifications. Field trials of pulse hydraulic fracturing with low amplitude were carried out in 2 oil wells in a tight reservoir. The actual application demonstrates that the average breakdown pressure was reduced obviously and the average daily production per well increased significantly compared to adjacent wells with similar geological and reservoir conditions.
Innovative Acoustic System for Data Detecting in Open Hole Multi Stage Frac Completions
Authors: Malik Muhammad Usman , Alaithan Monaf S , BoHulaiqa Mugdad M 
Published: September 2023

Abstract
The importance of data accuracy cannot be overstated, especially in the oilfield where every second counts. It is important to know exactly what is happening down the hole and act quickly in case of emergencies. However, the importance of data accuracy goes far beyond just decision making as it improves productivity. A pioneering project in the middle east has utilized a new acoustic monitoring technology to improve data accuracy in open hole multi-stage frac operations.
An innovative acoustic monitoring system has been developed in order to have an additional layer of acoustic and pressure data to detect and confirm events in real time. This technology utilizes sounds and pressure data to verify what is happening downhole. The system is very compact and can typically be rigged up and ready to acquire data in less than two hours. Pressure transducers installed in the treatment line and the ball injector line collect and display data in real time. The system collects data at a very high rate as data shows pressure in 10,000 samples per second compared to the conventional pressure sensor which shows pressure in 3 samples per second.
The new acoustic monitoring system proved to be a success as it shows clear indications of balls launching from the surface, balls landing on the seat and shifting of sleeves. The trial test well included five stages, only three of which were stimulated. Each stage utilized a single-entry port and was flanked by two open hole packers, one on each side in 5.875in open hole. In the first stage, the acoustic monitoring system successfully showed the pressure drop and captured an acoustic signature during rupturing the disc of the hydraulic valve. In the second and third stages, the system showed clear acoustic signatures during ball launching, ball landing on seats and sleeves shifting. In addition, the system also captured clear pressure indications during shifting of sleeves. This data cleared any doubts that could have occurred during the frac operation in multi-stage fracturing and saved a lot of time that could have been wasted reaching a decision on whether sleeves have been shifted or not. The new acoustic monitoring system improved the overall efficiency of the operation by capturing all events and hence increases the confidence of the operator in the downhole tools.
The successful completion of these trial tests shows how critical having reliable data on a timely basis. It includes a number of multi-stage frac technologies with an additional layer of acoustic monitoring which allowed operator to see in real-time downhole operation changes within equipment. This new acoustic monitoring technology proves to be beneficial especially in cases where pressure signatures are not clear. Having reliable data that explains the situation downhole would improve the visibility and help decision makers to act or react quickly.
Thermochemical Fluids: A Promising Technology to Enhance Breakers Performance and Ultimate Cleanup of Frac Fluids
Authors: Al-Taq Ali Abdullah , Aljawad Murtada Saleh , Alfakher Basil Mansour , Aldarweesh Sajjad Seed 
Published: September 2023

Abstract
Cleanup of fracturing fluids is an imperative key in the success of the whole fracturing operation. Breakers, one of the main fracturing fluids additives, are commonly used to degrade polymers and thus provide better cleanup. Encapsulation of the breakers is a common practice used to avoid premature viscosity reduction of fracturing fluids, allow the placement of elevated breaker concentrations within the proppant pack, and permit a controlled release of the active material after the proppant is placed. Lack of sufficient release of active material from the encapsulated breakers will negatively impact the outcome of the cleanup process and ultimately the outcome of the fracturing treatments in enhancing oil/gas well productivity. Lab tests conducted on guar gum-based fracturing fluids showed that the release of active material from the encapsulated breakers was directly proportional to temperature.
Thermochemical fluids (TCFs) of interest in this study were ammonium chloride (NH4Cl) and sodium nitrite (NaNO2). The reaction of the TCFs is associated with generation of huge amounts of heat and nitrogen gas. The amounts of heat and nitrogen gas generated from the TCFs were found to be dependent on the TCFs volume and concentration. According to laboratory testing, the heat produced by the TCFs reaction has a tendency to dramatically reduce the viscosity of fracturing fluids from a few hundreds to a few centipoises. Also, the generated nitrogen is expected to reduce the well hydrostatic pressure and ultimately enhance the cleanup process. The TCFs reaction is triggered either by acid or heat.
This paper studies in detail the reactivity of TCFs in terms of concentration and volumes using a closed PVT cell and a high temperature high pressure (HTHP) autoclave system. The effect of heat generated by TCFs reaction on the reduction of fracturing fluid's viscosity was investigated using the HTHP filter press.
Integration of Fracturing Memory Production Logging Tool (MPLT) with Multistage Smart Tracer Program for Hydraulic Fracturing Stimulation and Flowback Efficiency Assessment
Authors: Al Raisi O. , Al Yaaribi A. , Kurniadi S. D. 
Published: September 2023

Abstract
In Burhaan west field, Oman, the contribution of zones in multistage fracturing is critical information during well evaluation. Although many methodologies are available to evaluate zonal contribution, all have some disadvantages, particularly in application to tight gas wells; therefore, an integrated surveillance is required to confirm the result. Understanding the zone contribution provides a greater understanding of the reservoir and geological features and promotes a successful fracturing result.
The development strategy of tight gas often requires close-to-real-time post-fracturing performance following multistage fracturing due to the shut-in period limitation of the fractured wells. The result is important to improve the target reservoir development strategy of the entire field. A chemical tracer in combination with a memory production logging tool (MPLT) was selected as a solution to this challenge. A unique oil and water tracer pair was pumped during the main treatment of the stage for post-fracturing flow profile mapping assessment. In addition, a sampling campaign was initiated to identify potential communication and crossflows. The memory production logging tool was then run to provide the flow confirmation of each zone.
The overall process decreased the operational time and the learning curve and refined geological assumptions without sacrificing the effectiveness of the fracture treatment in terms of conductivity and gas recovery. The tracers’ data integration with the MPLT data helped to improve the target reservoir development approach and provided a continuous performance flow profile for the long term. The data were used to optimize the 3D fracture modeling and design, achieve the best flowback strategy, and significantly enhance the understanding of the reservoir geology for the field. In addition, analysis of the chemical tracers over several months provided insight into the continuous flow profiles leading to optimizing fracturing performance and design strategy in the field on a regular basis, based on the updated result.
Since the Burhaan Northwest high-pressure high-temperature gas wells are being completed with multistage cemented fracturing designs rather than openhole stimulation, a chemical tracer in combination with the memory production log played a key role in delivering zone contribution data. Results of the work include documentation of the step-by-step planning and surveillance setup of the zone contribution in combination with the outcome achieved and the usefulness of the data.
Cemented Multi Stage Fracturing Completion System – An Alternative to Open Hole MSF and Plug and Perf
Authors: Rodoplu Rasim Serdar , Malik Ataur R. , Hababi Ali H. , Al-Mohanna Khalid S. 
Published: September 2023

Abstract
Open Hole Multi Stage Fracturing (OH MSF) completion system technologies and Plug and Perf (P&P) technique are being utilized with the goal of increasing hydrocarbon production for years. However, due to unfavorable open hole well conditions, increased number of stages and limitations of open hole packers under challenging HPHT environments, some of OH MSF completions planned are converted to cemented liners. P&P is the only option for multi stage fracturing in the event of cemented liner completions. This paper discusses if cemented MSF can be an alternative to OH MSF completion systems as well as P&P and expands the technology portfolio for multi stage fracturing.
The new cemented MSF completion system consists of a cementable hydraulic frac port opened by applying pressure in the first stage and multiple cementable fracturing ports for the next stages that are opened by dropping activation balls during rig-less fracturing operations. Stage zonal isolation is not dependent on mechanical, swellable or metal expandable packers and relies on cement behind the completion. Zonal isolation can be achieved with cement in the absence of gauged hole. The deployment of the lower completion is much less sensitive to the washed out or over gauged hole condition than that of an OH MSF system. Moreover, cement on the annulus ensures integrity of stage isolation while minimizing liner deformation and maximizing full well accessibility after multi-stage stimulation treatments.
This was the first time a 15k psi pressure rated cemented multi-stage fracturing completion system was successfully deployed and stimulated through in the area. The implementation had qualified and field-tested the novel completion methodology which resulted in successful multi-stage stimulation operations. Production rate was enhanced in the well completed with the cemented MSF when compared with offset wells having OH MSF and P&P completions. The novel system without isolation packers and less string stiffness was easy to deploy and allowed for precise frac initiation point through continuous cement behind the liner. Compared to P&P, the cemented MSF system maximized the operational efficiency and cost saving by eliminating the need of wireline perforation and frac plug milling with CT.
To address the challenges encountered in deploying OH MSF completions, cemented liner and P&P operations, it was necessary to develop a new completion strategy providing commercial production rates comparable to results achieved from OH MSF completions. This paper seeks an answer to whether cemented MSF completion system can be an alternative to OH MSF systems or P&P technique. Successful implementation of a cemented MSF completion that utilizes cementable sleeves capable of withstanding high fracturing pressures and harsh environments improves attending tight formations in an efficient and cost-effective manner and diversifies the efforts in exploiting tight HPHT formations.
Greater physical fitness (Vo2Max) in healthy older adults associated with increased integrity of the Locus Coeruleus-Noradrenergic system
Authors: Plini Emanuele RG , Melnychuk Michael C. , Andrews Ralph , Boyle Rory T. , Whelan Robert , Spence Jeffrey S. , Chapman Sandra B. , Robertson Ian H. , Dockree Paul M. 
Published: September 2023

Abstract

Physical activity (PA) is a key component for brain health and Reserve, and it is among the main dementia protective factors. However, the neurobiological mechanisms underpinning Reserve are not fully understood. In this regard, a noradrenergic (NA) theory of cognitive reserve (Robertson, 2013) has proposed that the upregulation of NA system might be a key factor for building reserve and resilience to neurodegeneration because of the neuroprotective role of NA across the brain. PA elicits an enhanced catecholamine response, in particular for NA. By increasing physical commitment, a greater amount of NA is synthetised in response to higher oxygen demand. More physically trained individuals show greater capabilities to carry oxygen resulting in greater Vo2max – a measure of oxygen uptake and physical fitness (PF). In the current study, we hypothesised that greater Vo2 max would be related to greater Locus Coeruleus (LC) MRI signal intensity. As hypothesised, greater Vo2max related to greater LC signal intensity across 41 healthy adults (age range 60-72). As a control procedure, in which these analyses were repeated for the other neuromodulators’ seeds (for Serotonin, Dopamine and Acetylcholine), weaker associations emerged. This newly established link between Vo2max and LC-NA system offers further understanding of the neurobiology underpinning Reserve in relationship to PA. While this study supports Robertson’s theory proposing the upregulation of the noradrenergic system as a possible key factor building Reserve, it also provide grounds for increasing LC-NA system resilience to neurodegeneration via Vo2max enhancement.
Fatigue life analysis of a composite materials structure using allowable strain criteria
Authors: Turbin Nikolai , Shelkov Kirill , Ivanov Yuri , Chashin Nikolai 
Published: September 2023

Abstract
In the current research, a method for estimation of the durability of a structure based on an integrated calculation of static and fatigue strength according to the criterion of allowable strain is presented. The proposed technique is demonstrated for the upper stringer panel of the wing design. In the course of calculations, several combinations of design service goals, levels of allowable strains, and levels of cyclic stresses were considered. As a result, the relative values of stiffness degradation and the required safety ratios of static strength were obtained.
POP-Brominated Flame Retardants in plastic childcare products and toys: a scoping review protocol
Authors: Mlelwa Rebecca , Rother Hanna-Andrea 
Published: September 2023

Abstract
Background
Brominated Flame Retardants (BFRs) are hazardous chemicals banned globally in 2009 under the Stockholm Convention due to their toxic effects. POP-BFRs cause adverse environmental and health impacts, including endocrine disruption, cancer, reproductive effects and neurobehavioral and developmental disorders in children. Children have unique vulnerabilities that put them at a higher risk as compared to adults. Emerging literature suggests that POP-BFRs are increasingly found in consumer products, including those used for and by children. The rising problem is attributed to toxic recycling practices within the circular economy and exemptions introduced by the Stockholm Convention's conference of parties to allow the recycling of POP-BFRs in waste electrical and electronic equipment (WEEE). The recycled products are thus contaminated with legacy POP-BFRs. The presence of POP-BFRs in childcare products and toys is a big concern considering children's unique vulnerabilities. While the scope of this problem is not fully known, we aim to summarise the global evidence on the extent to which plastic childcare products and toys are contaminated with legacy POP-BFRS to inform decision-making.
Methods
Our scoping review will follow a methodology recommended by Arksey and O'Malley. Peer-reviewed and grey literature will be retrieved from electronic databases and other relevant sites. Two reviewers will screen titles and abstracts based on the inclusion and exclusion criteria, followed by a full-text review. Data will be extracted and grouped according to the study settings, types of samples, levels detected and classes of POP-BFRs, and quantitatively presented using frequency counts. A narrative description will be used to summarise and discuss the evidence and any gaps identified in the current literature.
Discussion
Information about potential exposures that children face is essential for making informed decisions, yet such information is often insufficient or lacking. Our intention is to synthesize the evidence to inform decisions. Findings will be disseminated through publishing in scientific journals, media for the public, policy briefs for decision-makers and presentations at professional meetings.
Scoping review registration:
The protocol is registered with the Open Science Framework (https://doi.org/10.17605/OSF.IO/7KDE5).
Vedolizumab-associated Nasopharyngitis in the Treatment of Inflammatory Bowel Disease: A Systemic Review and Meta-analysis of Randomized Placebo-controlled Trials
Authors: Liao Zicheng 
Published: September 2023

Abstract

Vedolizumab is a new biologic therapy that selectively inhibits α4β7 integrin in the gut to alleviate inflammation, making it a promising treatment option for inflammatory bowel disease. This meta-analysis investigated the correlation between vedolizumab treatment and nasopharyngitis incidence, as well as the effect of different formulations on nasopharyngitis occurrence. Six randomized, double-blind, placebo-controlled clinical trials demonstrated that the incidence of nasopharyngitis adverse events in the vedolizumab group was higher than that in the placebo control group, and the intravenous formulation group had a higher incidence than the placebo group. However, subcutaneous administration did not increase the incidence of nasopharyngitis adverse events. Vedolizumab may be a promising treatment option for inflammatory bowel disease, but the potential risk of nasopharyngitis should be considered, especially for intravenous formulation.