49 research outputs found

    Removing of Formation Damage and Enhancement of Formation Productivity Using Environmentally Friendly Chemicals

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    Matrix acidizing is used in carbonate formations to create wormholes that connect the formation to the wellbore. Hydrochloric acid, organic acids, or mixtures of these acids are typically used in matrix acidizing treatments of carbonate reservoirs. However, the use of these acids in deep wells has some major drawbacks including high and uncontrolled reaction rate and corrosion to well tubulars, especially those made of chrome-based tubulars (Cr-13 and duplex steel), and these problems become severe at high temperatures. Hydrochloric acid (HCl) and its based fluids have a major drawback in stimulating shallow (low fracture gradient) formations as they may cause face dissolution (formation surface washout) if injected at low rates. The objective of stimulation of sandstone reservoirs is to remove the damage caused to the production zone during drilling or completion operations. Many problems may occur during sandstone acidizing with Hydrochloric/Hydrofluoric acids (HCl/HF) mud acid. Among those problems: decomposition of clays in HCl acids, precipitation of fluosilicates, the presence of carbonate can cause the precipitation of calcium fluorides, silica-gel filming, colloidal silica-gel precipitation, and mixing between various stages of the treatment. To overcome problems associated with strong acids, chelating agents were introduced and used in the field. However, major concerns with most of these chemicals are their limited dissolving power and negative environmental impact. Glutamic acid diacetic acid (GLDA) a newly developed environmentally friendly chelate was examined as stand-alone stimulation fluid in deep oil and gas wells. In this study we used GLDA to stimulate carbonate cores (calcite and dolomite). GLDA was also used to stimulate and remove the damage from different sandstone cores containing different compositions of clay minerals. Carbonate cores (calcite and dolomite) of 6 and 20 in. length and 1.5 in. diameter were used in the coreflood experiments. Coreflood experiments were run at temperatures ranging from 180 to 300oF. Ethylene diamine tetra acetic acid (EDTA), hydroxyl ethylethylene diaminetriacetic acid (HEDTA), and GLDA were used to stimulate and remove the damage from different sandstone cores at high temperatures. X-ray Computed Topography (CT) scans were used to determine the effectiveness of these fluids in stimulation calcite and dolomite cores and removing the damage from sandstone cores. The sandstone cores used in this study contain from 1 to 18 wt percent illite (swellable and migratable clay mineral). GLDA was found to be highly effective in creating wormholes over a wide range of pH (1.7-13) in calcite cores. Increasing temperature enhanced the reaction rate, more calcite was dissolved, and larger wormholes were formed for different pH with smaller volumes of GLDA solutions. GLDA has a prolonged activity and leads to a decreased surface spending resulting in face dissolution and therefore acts deeper in the formation. In addition, GLDA was very effective in creating wormholes in the dolomite core as it is a good chelate for magnesium. Coreflood experiments showed that at high pH values (pH =11) GLDA, HEDTA, and EDTA were almost the same in increasing the permeability of both Berea and Bandera sandstone cores. GLDA, HEDTA, and EDTA were compatible with Bandera sandstone cores which contains 10 wt percent Illite. The weight loss from the core was highest in case of HEDTA and lowest in case of GLDA at pH 11. At low pH values (pH =4) 0.6M GLDA performed better than 0.6M HEDTA in the coreflood experiments. The permeability ratio (final/initial) for Bandera sandstone cores was 2 in the case of GLDA and 1.2 in the case of HEDTA at pH of 4 and 300oF. At high pH HEDTA was the best chelating agent to stimulate different sandstone cores, and at low pH GLDA was the best one. For Berea sandstone cores EDTA at high pH of 11 was the best in increasing the permeability of the core at 300oF. The low pH GLDA based fluid has been especially designed for high temperature oil well stimulation in carbonate and sandstone rock. Extensive studies have proved that GLDA effectively created wormholes in carbonate cores, is gentle to most types of casing including Cr-based tubular, has a high thermal stability and gives no unwanted interactions with carbonate or sandstone formations. These unique properties ensure that it can be safely used under extreme conditions for which the current technologies do not give optimal results. Furthermore, this stimulation fluid contributes to a sustainable future as it based on readily biodegradable GLDA that is made from natural and renewable raw material

    Removing of Formation Damage and Enhancement of Formation Productivity Using Environmentally Friendly Chemicals

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    Matrix acidizing is used in carbonate formations to create wormholes that connect the formation to the wellbore. Hydrochloric acid, organic acids, or mixtures of these acids are typically used in matrix acidizing treatments of carbonate reservoirs. However, the use of these acids in deep wells has some major drawbacks including high and uncontrolled reaction rate and corrosion to well tubulars, especially those made of chrome-based tubulars (Cr-13 and duplex steel), and these problems become severe at high temperatures. Hydrochloric acid (HCl) and its based fluids have a major drawback in stimulating shallow (low fracture gradient) formations as they may cause face dissolution (formation surface washout) if injected at low rates. The objective of stimulation of sandstone reservoirs is to remove the damage caused to the production zone during drilling or completion operations. Many problems may occur during sandstone acidizing with Hydrochloric/Hydrofluoric acids (HCl/HF) mud acid. Among those problems: decomposition of clays in HCl acids, precipitation of fluosilicates, the presence of carbonate can cause the precipitation of calcium fluorides, silica-gel filming, colloidal silica-gel precipitation, and mixing between various stages of the treatment. To overcome problems associated with strong acids, chelating agents were introduced and used in the field. However, major concerns with most of these chemicals are their limited dissolving power and negative environmental impact. Glutamic acid diacetic acid (GLDA) a newly developed environmentally friendly chelate was examined as stand-alone stimulation fluid in deep oil and gas wells. In this study we used GLDA to stimulate carbonate cores (calcite and dolomite). GLDA was also used to stimulate and remove the damage from different sandstone cores containing different compositions of clay minerals. Carbonate cores (calcite and dolomite) of 6 and 20 in. length and 1.5 in. diameter were used in the coreflood experiments. Coreflood experiments were run at temperatures ranging from 180 to 300oF. Ethylene diamine tetra acetic acid (EDTA), hydroxyl ethylethylene diaminetriacetic acid (HEDTA), and GLDA were used to stimulate and remove the damage from different sandstone cores at high temperatures. X-ray Computed Topography (CT) scans were used to determine the effectiveness of these fluids in stimulation calcite and dolomite cores and removing the damage from sandstone cores. The sandstone cores used in this study contain from 1 to 18 wt percent illite (swellable and migratable clay mineral). GLDA was found to be highly effective in creating wormholes over a wide range of pH (1.7-13) in calcite cores. Increasing temperature enhanced the reaction rate, more calcite was dissolved, and larger wormholes were formed for different pH with smaller volumes of GLDA solutions. GLDA has a prolonged activity and leads to a decreased surface spending resulting in face dissolution and therefore acts deeper in the formation. In addition, GLDA was very effective in creating wormholes in the dolomite core as it is a good chelate for magnesium. Coreflood experiments showed that at high pH values (pH =11) GLDA, HEDTA, and EDTA were almost the same in increasing the permeability of both Berea and Bandera sandstone cores. GLDA, HEDTA, and EDTA were compatible with Bandera sandstone cores which contains 10 wt percent Illite. The weight loss from the core was highest in case of HEDTA and lowest in case of GLDA at pH 11. At low pH values (pH =4) 0.6M GLDA performed better than 0.6M HEDTA in the coreflood experiments. The permeability ratio (final/initial) for Bandera sandstone cores was 2 in the case of GLDA and 1.2 in the case of HEDTA at pH of 4 and 300oF. At high pH HEDTA was the best chelating agent to stimulate different sandstone cores, and at low pH GLDA was the best one. For Berea sandstone cores EDTA at high pH of 11 was the best in increasing the permeability of the core at 300oF. The low pH GLDA based fluid has been especially designed for high temperature oil well stimulation in carbonate and sandstone rock. Extensive studies have proved that GLDA effectively created wormholes in carbonate cores, is gentle to most types of casing including Cr-based tubular, has a high thermal stability and gives no unwanted interactions with carbonate or sandstone formations. These unique properties ensure that it can be safely used under extreme conditions for which the current technologies do not give optimal results. Furthermore, this stimulation fluid contributes to a sustainable future as it based on readily biodegradable GLDA that is made from natural and renewable raw material

    Change in Behavior, Blood Parameters and Pain Score in Response to Different Treatment Strategies in Bull Infected with FMD or LSD

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    Foot and mouth disease and lumpy skin disease of cattle is a common disease on commercial cattle farms which associated with changes in behavior, blood parameters, pain related behaviors and pain scale measurements, but little is known about this effect. The objectives of the present study were to test 2 hypotheses. First, investigate these changes; second, explained the effect of different treatment strategies (analgesic with Flunixin meglumine) or non-analgesic on lameness and pain scale. 125 bull cows were enrolled in the study based on visual observation of abnormal behavior the present study was done in Assiut governorate in Egypt was divided in three groups, which 25 clinically healthy bull (control group), FMD clinically infected group (25 analgesic + 25 non-analgesic and LSD (25 analgesic + 25 non analgesic). Obtained data illustrated that; there are significant increase physiological parameters (rectal temperature, heart rate and respiratory rate), lying behavior and total pain scale, while, there are significant decrease in feeding, drinking, rumination and standing behaviors, activity of exploration and activity of body care which may be corrected by Flunixin using. Conclusion: Flunixin injection may help in decreasing the negative pain behaviors and physiological changes caused by LSD or FM

    POLYMORPHISMS OF PFCRT AND PFMDR-1 GENES AND CHLOROQUINE RESISTANCE OF P. FALCIPARUM IN WAD MEDANI (CENTRAL SUDAN)

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    Introduction: Malaria parasite resistant to Chloroquine poses severe and increasing health problems in tropical countries. Monitoring the drug resistance by implementing the molecular markers may be essential to overcome the problem, therefore this study aims to assess the Chloroquine resistance of Plasmodium Falciparum parasite in central Sudan, using molecular markers. Methods: One hundred and seventy six patients were confirmed P. falciparaum positive. Sixty-four were selected and only forty patients completed the follow-up. In vivo sensitivity assay was used accompanied with standard regimen of Chloroquine phosphate. DNA was extracted from blood on filter paper (day 0) and was used to amplify two genes P. Falciparum transporters gene Pfcrt and multi-drug resistant gene-1 Pfmdr-1. Results: Among forty patients, 54% responded to Chloroquine regimen with adequate clinical response (ACR), however, 46% showed treatment failure. All treatment failures were treated with Artemether or Quinine. The amplification of Pfcrt gene (n, 18) and Pfmdr 1 gene (n, 29), had shown that 72% of Pfcrt T76 were mutant allele, 22% were K76 wild-type, however, only 5% were mixed alleles T/K. while Pfmdr 1 gene (n, 29) revealed that 55% were wild genotype N 86, 38% were mutant Y 86, and 7% were mixed alleles Y/ N 86. Conclusion: The high frequency of the mutant Pfcrt 76T gene among P. Falciparum isolates was consistent with in vivo study supports the hypothesis that Pfcrt 76T gene could be used as predictive marker for Chloroquine susceptibility in epidemiological surveys

    Placental pouch closure: a novel, safe and effective surgical procedure for conservative management of placenta accreta

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    Background: Placenta accreta spectrum (PAS) has become a global problem secondary to the high rate of cesarean delivery (CD). The current study presents an effective surgical procedure (placental pouch closure) for uterine preservation in patients with PAS. Methods: We applied this procedure in sixty cases at a tertiary university hospital between September 2017 and January 2019. We included women who were diagnosed as PAS based on preoperative ultrasound and Doppler evaluation, and who had the desire for uterine preservation. Results: The procedure was successful in almost all cases; the uterus was conserved 98.33 % of participants, with no associated severe maternal morbidities or mortality. In all cases, no additional surgical procedures were needed. The mean blood loss was 1263 ml, and the mean number of units of blood required for transfusion was 2.31 units. Conclusion: Identifying and meticulously closing the placental pouch is a novel surgical procedure for conservative management of PAS. In well-selected cases with the availability of facilities and expertise, the technique could have a place as a safe and effective surgical technique in women presenting with placenta accreta who desire uterine preservation. Trial registration number: NCT03241849. Registered on August 8, 201

    Surgical Complications of Arteriovenous Fistula as Permanent Vascular Access in Patients with End Stage Renal Disease at Gezira Hospital for Renal Disease and Surgery. Revisited

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    Background: Vascular access (VA) is a mainstay to perform an efficient hemodialysis (HD) procedure. Objectives: To evaluate the surgical complications of AV fistula as permanent vascular access in a patient of end stage renal disease (ESRDS) at Gezira hospital for renal diseases and surgery (GHRDS). Methods: Retrospective, prospective cross sectional hospital based study, done in 237 patients with end stage renal disease who underwent arteriovenous fistula.In 206 patients of the study sample done retrospectively and 31 patients of the study sample done prospectively,and they were followed for 1year. Study was conducted from September 2010 to September 2016. Data was collected using questionnaire.  Results: Sixty eight percent of study sample were males, with 42% above 50 years and 0.8% less than 10 years. Most of the patients (52.3%) were diagnosed as ESRD from the first presentation, 43.5% were diagnosed as chronic renal failure (CRF) on regular followup, while the minor rest of the patients were due to acute renal failure(ARF) which progressed to end stage renal disease.The complications rate was 32.8% (n=82), perioperative complications were 9.3% (n=22) represented as infections 3.8% (n=9), bleeding 3.0% (n=7), stenosis 1.7% (n=4), thrombosis 0.8% (n=2). The late complications were 23.18% (n= 60) the commonest was pseudo aneurysmal 19.4% (n=46) followed by venous HTN 0.8% (n=2) and steal syndrome 0.4%(n=1), skin necrosis 0.4%(n=1), idiopathic stop function 2.1% (n=5), thrombosis 0.4% (n=1). Conclusion: Permanent arteriovenous fistula is the best option for haemodialysis in patients with end stage renal disease. The commonest complication was puncture site pseudo aneurysm

    Variants of CTGF are associated with hepatic fibrosis in Chinese, Sudanese, and Brazilians infected with Schistosomes

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    Abnormal fibrosis occurs during chronic hepatic inflammations and is the principal cause of death in hepatitis C virus and schistosome infections. Hepatic fibrosis (HF) may develop either slowly or rapidly in schistosome-infected subjects. This depends, in part, on a major genetic control exerted by genes of chromosome 6q23. A gene (connective tissue growth factor [CTGF]) is located in that region that encodes a strongly fibrogenic molecule. We show that the single nucleotide polymorphism (SNP) rs9402373 that lies close to CTGF is associated with severe HF (P = 2 × 10−6; odds ratio [OR] = 2.01; confidence interval of OR [CI] = 1.51–2.7) in two Chinese samples, in Sudanese, and in Brazilians infected with either Schistosoma japonicum or S. mansoni. Furthermore, SNP rs12526196, also located close to CTGF, is independently associated with severe fibrosis (P = 6 × 10−4; OR = 1.94; CI = 1.32–2.82) in the Chinese and Sudanese subjects. Both variants affect nuclear factor binding and may alter gene transcription or transcript stability. The identified variants may be valuable markers for the prediction of disease progression, and identify a critical step in the development of HF that could be a target for chemotherapy

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Noninvasive ventilation in COVID-19 patients aged ≥ 70 years—a prospective multicentre cohort study

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    Funding Information: COVIP study did not have any funding. Publication of this article was funded by the Priority Research Area qLife under the program “Excellence Initiative – Research University” at the Jagiellonian University in Krakow (06/IDUB/2019/94). Publisher Copyright: © 2022, The Author(s).Background: Noninvasive ventilation (NIV) is a promising alternative to invasive mechanical ventilation (IMV) with a particular importance amidst the shortage of intensive care unit (ICU) beds during the COVID-19 pandemic. We aimed to evaluate the use of NIV in Europe and factors associated with outcomes of patients treated with NIV. Methods: This is a substudy of COVIP study—an international prospective observational study enrolling patients aged ≥ 70 years with confirmed COVID-19 treated in ICU. We enrolled patients in 156 ICUs across 15 European countries between March 2020 and April 2021.The primary endpoint was 30-day mortality. Results: Cohort included 3074 patients, most of whom were male (2197/3074, 71.4%) at the mean age of 75.7 years (SD 4.6). NIV frequency was 25.7% and varied from 1.1 to 62.0% between participating countries. Primary NIV failure, defined as need for endotracheal intubation or death within 30 days since ICU admission, occurred in 470/629 (74.7%) of patients. Factors associated with increased NIV failure risk were higher Sequential Organ Failure Assessment (SOFA) score (OR 3.73, 95% CI 2.36–5.90) and Clinical Frailty Scale (CFS) on admission (OR 1.46, 95% CI 1.06–2.00). Patients initially treated with NIV (n = 630) lived for 1.36 fewer days (95% CI − 2.27 to − 0.46 days) compared to primary IMV group (n = 1876). Conclusions: Frequency of NIV use varies across European countries. Higher severity of illness and more severe frailty were associated with a risk of NIV failure among critically ill older adults with COVID-19. Primary IMV was associated with better outcomes than primary NIV. Clinical Trial RegistrationNCT04321265, registered 19 March 2020, https://clinicaltrials.gov.publishersversionpublishe

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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