bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solving Ultra-High Temperature Scale Challenges: A Case Study of Re-Use of Polymer Flooding Waters for Heat Exchangers
Authors: Yue Zhiwei David , Chen Ping , Draghici Vlad , Westerman Megan , Huijgen Martijn , Privitera Angelo , Hazlewood John , Hagen Thomas 
Published: June 2020

Abstract
An oilfield operator relies extensively on heat exchangers (Hexs) to break heavy oil emulsions. A workhorse inhibitor worked reliably to control thermally induced scale precipitation caused by local hard waters. However, an upsurge of scale-related Hexs tubing blockage occurred during a harsh winter that coincided with a breakthrough of enhanced oil recovery (EOR) polymer into some water sources. Through comprehensive lab testing, root causes of the failure were identified. A new product was developed featuring superior tolerance to variable production parameters, especially Hexs temperatures.
Scale inhibitor efficacy is strongly influenced by overall scaling conditions including water chemistry, temperature, pressure, and presence of incompatible chemicals. In this study, scale precipitates collected from Hexs were characterized using environmental scanning electron microscopy techniques. New inhibitor chemistries were screened through thermal aging; then evaluated for inhibition performance by dynamic tube blocking methods at temperatures ranging from 42°C to 171°C. An additional performance test was designed for the final candidate to further investigate adverse impacts from the EOR polymer and incumbent scale product if a dual-product treatment is required throughout the field fluid system.
The incumbent effectively inhibited scale formation at ≤120°C but showed reduced performance at 160°C. This result is consistent with field records indicating most tubing blockages occurred during the coldest days when Hexs temperature was raised to 160°C to increase heat to treat fluids. Meanwhile, it also suffered antagonistic effects from the EOR polymer. A dozen new inhibitor chemistries were studied including polymers and phosphonates. Polymeric inhibitors had higher thermal aging ratings but were less compatible with the waters involved. Ideal candidates must have thermal stability, high-temperature inhibition performance, and applicability to wide ranges of operational conditions, including Hexs temperature, water hardness, bicarbonate, and foreign substances. Thus, a single product can be applied to the entire field and simple dosage adjustments can readily handle most expected scaling risks. The new product passed all the criteria and significantly reduced operating and equipment replacement cost since deployment.
This paper provides a unique scaling challenge that combined ultra-high temperature and EOR polymer influence, and a systematic approach to understanding and resolving the issue.
Prevention of Mineral Scale Deposition Using Dispersants and Inhibitors
Authors: Ko Saebom , Wang Xin , Zhao Yue , Dai Chong , Lu Yi-Tsung , Deng Guannan , Paudyal Samridhdi , Mateen Sana , Kan Amy T. , Tomson Mason B. 
Published: June 2020

Abstract
Scale formation in oil and gas wells commonly occurs, causing not only pipeline blockage, equipment failure, or formation damage during production, trasnsportation, and treatment, but also premature abandonment of wells in serious cases. Although types of mineral scale occurrence depend on the types of ions in water, sulfate and carbonate scales are the most commonly found scales in oil and gas fields. In this study, we investigated a single approach to prevent complex mineral scales from deposition using water-soluble polymer dispersant or the combination of water-soluble polymer dispersant of carboxymethyl cellulose (CMC) and phosphonate inhibitors of diethylene triamine penta(methylene phosphonic) acid (DTPMP) or hexamethylene diaminetetra (methylene phosphonic) acid (HDTMP) in highly saturated solution or high ionic strength (IS) brines. This study shows that CMC effectively prevents sulfate (barite and gypsum) and carbonate (calcite nd iron carbonate) scales from deposition. The particle size dispersed in the presence of CMC remains in nanosize ranges. When CMC was combined with phosphonate inhibitors of DTPMP or HDTMP, sulfate scales were even more effectively controlled, compare to CMC or phosphonate inhibitors by themselves. In the combination of CMC and DTPMP, the majority of barite (&gt; 90%) remained in a size of smaller than 200 nm and the total mass of barite deposition on 316 stainless steel coupon was negligible, as low as 0.079% of total input mass. Gypsum formation was inhibited for at least 6 hours and gypsum particles remained in a size of smaller than 200 nm for 12 hours in the combination of CMC and HDTPM. For calcite, measured induction time was 134 minutes and calcite particles were dispersed for at least 15 hours with its average particle size of 396 nm in the presence of CMC. Iron carbonate particles were well dispersed for 2 hours in the presence of CMC.
An Experimental Determination of Hydrogen Sulfide Scavenging Capacities and Mechanisms in Iron-Bearing Minerals
Authors: Graham Alexander , Salleh Intan , Ibrahim Jamal , Khairuddin Khairunnisa , Singleton Michael , Sorbie Kenneth 
Published: June 2020

Abstract
The injection of sea water for the pressure support of oil fields is commonly associated with the biogeneration of hydrogen sulfide (H2S) by sulfate reducing bacteria and/or archaea (SRB/SRA). H2S is extremely toxic and corrosive, as well as providing a source of sulfide ions for the formation of iron, zinc and/or lead sulfide scale. However, H2S production is rarely, if ever, associated with seawater breakthrough and its retardation can be linked to a number of mechanisms.
Certain minerals (e.g. siderite, FeCO3, and/or iron oxides, FexOy) may react with produced H2S and retard its progress towards the producer wells. This is a generally beneficial effect but it is difficult to quantify and it is generally estimated from direct matching to the field appearance of H2S. Alternatively, H2S retardation factors are based on correlations with the mineralogy of the field and these are rather unreliable, since few experimental results have been published. In essence, this quantity (the H2S retardation factor) is more of a "matching parameter" rather than being truly predictive.
Candidate mechanisms for sulfide scavenging by iron-bearing minerals have been experimentally identified and scavenging capacities have been determined for siderite FeCO3 in modified static adsorption tests and in dynamic pack floods, for aqueous-only systems. The effects of changing several conditions were studied, including temperature, initial pH and grain size.
A combination of dissolution/precipitation and surface displacement mechanisms were identified in the static bottle tests and further confirmed during the dynamic sand/siderite and crushed-core pack floods. ESEM-EDX and particle size analyses established the presence of mobile FeS (&lt;100 µm) in the column after the flood had reached completion, confirming the bulk precipitation of FeS from dissolved Fe2+. Bringing together these two mechanisms allowed for the rationalisation of the observed scavenging profile, with reference to the Ksp of siderite. By further understanding the mechanisms of H2S scavenging experimentally, it will be possible to incorporate these into field-prediction models.
The absolute values obtained for the 8 wt% siderite packs were 1.03 and 1.74 mg/g at 25 and 96°C, respectively. Crushed core packs yielded significantly higher values of 5.76 and 5.80 mg/g at 25 and 96°C, respectively, which have been hypothetically attributed to the presence of iron-bearing clays in the core samples.
Correlating Calcium Carbonate Scale Risk with Field Experience Data
Authors: Ramstad Kari , Sandengen Kristian , Mitchell Anthony Frank , Moldrheim Erlend 
Published: June 2020

Abstract
Calcium carbonate (CaCO3) scale formation in production wells and process systems is a well-known challenge in the oil and gas industry. Various strategies are selected to prevent scale formation (proactive, e.g. by scale inhibitors) or to remove scale when it has formed (reactive, e.g. by acid treatment), depending on the severity of the problem and the complexity of the production system. Lack of access for remedial actions may be a limiting factor in subsea and unmanned installations and scaling may represent a larger risk of production losses or system failures.
The scale management strategy and design of new wells during field development are based on thermodynamic calculations, kinetic studies and field observations. Experience has shown that wells with high temperature and high pressure drops are more prone to downhole calcium carbonate scaling.
Field experience has been collected and systemized based on operations of oil and gas-condensate fields in the North Sea and Norwegian Sea. The observations have been compared to thermodynamic calculations and aligned to kinetic modelling, defining the critical saturation ratio (SRCaCO3) for scaling. The result is a graphic which has proved to be a powerful tool in planning of new wells and is described in this paper.
The Oseberg field in the North Sea is producing from oil and gas-condensate wells at various reservoir temperatures (98-128°C). The field comprises platform and subsea production systems and one unmanned wellhead platform. Seawater has been injected for pressure support in some areas, while gas injection or depletion are the driving forces in other segments. The CaCO3 scale potential and management strategy have been evaluated for new wells in a field life perspective. Risk of production losses and maximizing cost benefit are key selection criteria, and the variety of wells requires individual solutions. The paper discusses the need for downhole continuous injection of scale inhibitor, compared to batch scale inhibitor squeeze treatments and/or acid treatments. Guidelines for optimum operation of these wells to avoid scaling are presented.
A Rigorous Procedure to Predict Coupled Carbonate and Sulfide Scales in Different Field Scenarios
Authors: Ness Giulia , Sorbie Kenneth S. 
Published: June 2020

Abstract
The prediction of pH-dependent scales such as carbonates and sulfides presents unique challenges because their formation is strongly related to the three phase partitioning of the acid gases (CO2 and H2S). A rigorous procedure is required to ensure proper modelling of the hydrocarbon phases, in order to derive the correct data input for the software from available field data. Using this input, reliable scale prediction calculations may then be run using either integrated or separate PVT and scale prediction software. Although some carbonate scale prediction methods have been published in the past, these methods are field and software specific, and they do not provide a general procedure for carbonate and sulfide scale predictions in oil and gas wells. Operators also have in-house proprietary procedures, but these are not publicly available and hence cannot be used or critically reviewed by the wider upstream chemistry community.
This work presents an improved version of the original Heriot-Watt scale prediction workflow previously published in 2017 (Verri et al., 2017). The authors show how this previous procedure is intrinsically general, but requires modifications depending on specific field variables such as oil type, topside vs reservoir data availability or the use of integrated or separate PVT and scale prediction software.
The workflow is built on three general calculation blocks which apply to all field scenarios, as follows: 1. defining a total PVT feed; 2. modelling the water chemistry leaving the reservoir; 3. running scale prediction calculations throughout the system. After describing the general carbonate and sulfide scale prediction procedure in details, this paper also looks into the specific calculation steps required in different scenarios for variable oil type, sample availability (topside vs downhole), software choice (integrated vs separate PVT and aqueous phase models), EOR, reservoir souring, artificial lift, and HP/HT/HS.
This is a truly general approach to carbonate and sulfide scale predictions which the authors hope will provide a widely available, useful tool to anyone performing field prediction studies for pH-dependent scales. In addition, a worked example is presented in Appendix 1 where the "correct" answer is known, and the workflow is demonstrated to be rigorous in that it recovers this correct answer. This data can be used to test any other procedures for rigorously predicting carbonate and sulfide scales from field data.
Numerical Simulation to Study Scale Formation on SSV Valves
Authors: Poletto V. G. , De Lai F. C. , Ferreira M. V. , Martins A. L. , Junqueira S. L. 
Published: June 2020

Abstract
This work provides a preliminary study of solids adherence on the surfaces of a sliding-sleeve valve (SSV), aiming to mimic inorganic scaling process. SSVs assembled in production sites subjected to water flooding might suffer from scale deposits of barium sulphate. Scaling may result in production stops, production restriction and also heavy workover jobs, reducing project profitability. The simulation of the scaling formation process allows the observation of fouling hotspots and, shortly, it can become a powerful tool to increase the valves reliability in scaling-prone scenarios. In the present problem, a four-way coupled CFD-DEM technique simulates the liquid-solid two-phase flow considering the solids particles as precipitated of barium sulfate crystals. The Discrete Element method allows the evaluation of inter particles interactions, such as collision, friction and adhesion, accounting for relevant phenomena such as particulate agglomerates build-up and particles adhesion on surfaces. The fluid-particle interaction forces arise from the simulation of the flow field through CFD. The main motivation is to analyze the influence of particle granulometry over the fouling process, keeping constant the scale index. The size distribution follows a normal distribution and reducing the mean dimension (smaller particles) results in more particles within the domain. The increase in the number of particles stimulate the formation of particulate agglomerates, which adhere on the grooves and holes of the SSV. Furthermore, agglomerates of tinier particles are less permeable, which accentuates the increase of the pressure drop in the valve.
A Systematic Investigation of Barite and Zinc Sulfate Scale Inhibition in a Produced Water Stripper
Authors: Lu Haiping , Patenaude Tyler , Watson Bill , Gu Zhening , Locklear Jay 
Published: June 2020

Abstract
Oilfield scale deposition is a common problem causing production deferment, safety issues, and equipment damage. This paper presents the laboratory testing data and some field data for barium sulfate (barite) and zinc sulfide (ZnS) scale control. It demonstrates possible synergetic scale inhibition effects and successful field implementation based on laboratory results in a produced water stripping system. Literature shows barite scale can be effectively prevented by phosphonate inhibitors and polymer inhibitors. Effective ZnS scale inhibitors are not commercially available, so dispersants are commonly used to suspend the ZnS scale particles in production fluids carrying the particles through the system without deposition.
Ten scale inhibitors were evaluated for this system: Product A (combination of phosphonate inhibitor and ZnS dispersant); Product B (polymer inhibitor), Product C (polymer inhibitor), Product D (chelator), and Product E (chelator), Product F (phosphonate inhibitor + polymer inhibitor), Product G (phosphonate inhibitor + polymer inhibitor), Product H (phosphonate inhibitor + polymer inhibitor), Product I (phosphonate inhibitor + polymer inhibitor), and Product J (phosphonate inhibitor). Aerobic bottle tests, anaerobic bottle tests, and kinetic turbidity tests evaluated the potential scale risk at various scaling conditions including ∼3,000 mg/L SO42-, 1.1-78 mg/L Ba2+, 0.56 -5.6 mg/L Zn2+, 25-250 mg/L H2S, and pH (3.2-7.5). Product F (phosphonate/dispersant) prevented barite and ZnS most effectively in lab testing but was incompatible with the process system, so Product G, the second best performer, was field trialed. Product C prevented barite scale formation at low dosage and eventually prevented ZnS formation at very high concentrations.
Next Generation On-Site Scale Inhibitor Analysis - Surface Enhanced Nanotechnology Detection
Authors: Murugesan Sankaran , Ahoor Danika , Souza Lauren , Liu Ya , Heath Stephen 
Published: June 2020

Abstract
Scale control and inhibition is very important for maintaining flow assurance of oil production. Several specialty chemicals are used to delay, reduce or prevent scale deposition and, in particular, polymers and phosphonate-based chemicals have been used extensively. The accurate and precise topside measurement of scale inhibitors plays an important role in assessing the efficiency of scale squeeze and continuous-chemical injection treatments. At present, numerous techniques exist for scale inhibitor (SI) analysis but each method has its own limitation and often these methods give results of either total chemical content or elemental analysis without details of chemical speciation. Furthermore, most techniques often lack the ability for on-site analysis on fresh produced water samples, which yields the potential for quick and more accurate and precise information due to minimal sample degradation.Nanotechnology-based Surface Enhanced Raman Spectroscopy (SERS) developed as the next-generation method to fill the gap in speciation of phosphonates and to determine low concentrations of different scale inhibitor chemicals in produced brines in a timely and cost-effective manner.Particular focus is placed upon the individual and mixed analysis of a novel phosphonate and Deta Phosphonate (DETPMP) respectively. Development of this method with handheld instrumentation provides better detection and quantification of scale inhibitors in the field and reduces time and cost compared to sending samples to off-site laboratories for data collection.
Laboratory colonization by Dirofilaria immitis alters the microbiome of female Aedes aegypti mosquitoes
Authors: Adegoke Abdulsalam , Neff Erik , Geary Amie , Husser Montana Ciara , Wilson Kevin , Norris Shawn Michael , Dharmarajan Guha , Karim Shahid 
Published: June 2020

Abstract
Background: The ability of blood feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered with, or enhanced by, the arthropod’s native microbiome. Mosquitoes transmit viruses, protozoan and filarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Dirofilaria immitis , a mosquito transmitted by filarial nematodes of dogs and cats, is vectored by several mosquito species including Aedes aegypti . Methods: In this study, we investigated the impact of D. immitis colonization on the microbiome of laboratory reared female A. aegypti . Metagenomic analysis of the V3-V4 variable region of the microbial 16SRNA was used for identification of the microbial differences down to species level. Results: We generated a total of 1068 OTUs representing 16 phyla, 181 genera and 271 bacterial species. Overall, in order of abundance, Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were the most represented phylum with D. immitis infected mosquitoes having more of Proteobacteria (71%) than uninfected mosquitoes (56.9%). An interesting finding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes, suggesting a possible endosymbiotic relationship, and has been previously shown to indirectly compete for nutrients with fungi on domestic housefly eggs and larva. While D. immitis colonization has no effect on the overall species richness, we identified significant differences in the composition of selected bacteria genus and phylum between the two groups. We also reported distinct compositional and phylogenetic differences in the individual bacteria species when commonly identified bacteria were compared. Conclusions: In conclusion, this is the first study to the best of our knowledge to understand the impact of a filarial infection on the microbiome of its mosquito vector. Further studies are required to identify bacteria species that could play an important role in the mosquito biology. While the microbiome composition of A. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host.
Pre-hospital delay in patients with myocardial infarction: an observational study in a tertiary care hospital of northern Bangladesh
Authors: Rafi Md. Abdur , Sayeed Md. Zahidus , Sultana Papia , Aik Saw , Hossain Golam 
Published: June 2020

Abstract
Background: Delayed hospital presentation is a hindrance to the optimum clinical outcome of modern therapies of Myocardial infarction (MI). This study aimed to investigate the significant factors associated with prolonged pre-hospital delay and the impact of this delay on in-hospital mortality among patients with MI in Northern Bangladesh.Methods: This cross sectional study was conducted in December 2019 in cardiology ward of a 1000-bed tertiary care hospital of Bangladesh. Patients admitted in the ward with the diagnosis of myocardial infarction were included in the study. Socio demographic data, clinical features and patients’ health seeking behavior was collected in a structured questionnaire from the patients. Median with interquartile range (IQR) of pre hospital delay were calculated and compared between different groups. Chi-square (χ²) test and binary logistic regression were used to estimate the determinants of pre-hospital delay and effect of pre-hospital delay on in-hospital mortality.Results: 337 patients was enrolled in the study and their median (IQR) pre-hospital delay was 9.0 (13.0) hours. 39.5% patients admitted in the specialized hospital within 6 hours. In logistic regression, determinants of pre-hospital delay were patients age (for <40 years aOR 2.43, 95% CI 0.73-8.12; for 40 to 60 years aOR 0.44, 95% CI 0.21-0.93), family income (for lower income aOR 5.74, 95% CI 0.89-37.06; for middle income aOR 14.22, 95% CI 2.15-94.17), distance from primary care center £5 km (aOR 0.42, 95% CI 0.12-0.90), predominant chest pain (aOR 0.15, 95% CI 0.05-0.48), considering symptoms as non-significant (aOR 17.81, 95% CI 5.92-53.48), referral from primary care center (for government hospital aOR 4.45, 95% CI 2.03-9.74; for private hospital OR 98.67, 95% CI 11.87-820.34); (R2= 0.528) and not having family history of MI (aOR 2.65, 95% CI 1.24-5.71). Risk of in-hospital mortality was almost four times higher who admitted after 6 hours compared to their counterpart (aOR 0.28, 95% CI 0.12-0.66); (R2 =0.303).Conclusion: Some modifiable factors contribute to higher pre-hospital delay of MI patients, resulting in increased in-hospital mortality. Patients’ awareness about cardiovascular diseases and improved referral pathway of the existing health care system may reduce this unexpected delay.