Laboratory evaluation on temporary plugging performance of degradable preformed particle gels (DPPGs)

Summary Preformed-particle gels (PPGs) have been applied for reducing excessive water production caused by fractures in reservoirs. A portion of the fractures existing in reservoirs is composed of a void part and a fracture tip. The PPG placement behavior and plugging performance could be mainly affected by the fracture tips. A fracture with a tip, called a “partially open fracture” in this paper, was designed to investigate the placement and water-plugging performance of PPG. Cylindrical sandstone cores were used to manufacture partially open fractures. Pressure data of PPG injection, post-gel water breakthrough, and stable injection were analyzed to investigate the PPG propagation and plugging performance with respect to water. Experiments with different PPG placing pressures were conducted to explore the effects of pressure on PPG water-plugging performance and dehydration. In the fractures with tips, the PPG injection pressure increased rapidly, and could reach any designed pressure with continued injection after gel filled the fracture. By setting the PPG placing pressure at 500, 1,000, and 2,000 psi, the blocking efficiency to water showed a growth with the increase of placing pressure. The reswelling experiments show that PPG samples dehydrated when exposed to a high pressure difference between fracture and porous rock. Moreover, the placed PPG dehydrated relatively evenly along the fracture. Some gel particles were found whitening and reducing the capability of reswelling at the placing pressure of 2,000 psi. Scanning-electron-microscope (SEM) images indicated that the distinct 3D network of the PPG was compressed or damaged in the whitish sample. In addition, a discussion about PPG dehydration and fracture-tip extension is provided. In general, this study experimentally characterized PPG placement and plugging performance with respect to water in the fracture with tips. The PPG dehydration and fracture extension in PPG treatment, which have not drawn much attention in the literature, are investigated in this paper.

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Performance Evaluation of Degradable Temporary Plugging Agent in Laboratory Experiment

Journal of Energy Resources Technology ◽

10.1115/1.4047311 ◽

2020 ◽

Vol 142 (12) ◽

Cited By ~ 2

Author(s):

Shun Liu ◽

Tiankui Guo ◽

Zhenhua Rui ◽

Kegang Ling

Keyword(s):

Large Scale ◽

Fracture Initiation ◽

Laboratory Evaluation ◽

Stimulated Reservoir Volume ◽

Closure Stress ◽

The Core ◽

Fracture Complexity ◽

Basic Performance ◽

Initiation Pressure ◽

Plugging Performance

Abstract Temporary plugging fracturing is an effective way to enhance the fracture complexity and increase the stimulated reservoir volume (SRV) of unconventional reservoirs. The performance of temporary plugging agents (TPA) directly affects the success rate of temporary plugging. Currently, laboratory evaluation of the plugging effects of the TPA is rarely reported, and there are no industrial standards on laboratory evaluation of TPA plugging. In this study, two new experimental methods were used to evaluate a novel particulate TPA. The plugging performance of the TPA to the core end face and the propped fractures was measured through displacement experiments of cores, and the applicability of its basic performance to the temporary plugging fracturing was verified. Furthermore, the large-scale true triaxial simulation experiment of temporary plugging fracturing was carried out to confirm the influence mechanism of different factors on fracture propagation during temporary plugging. Finally, the influence rule of different types of combinations of TPA and placement patterns on the plugging was obtained based on laboratory evaluation of the conductivity. The results show that the novel TPA causes effective temporary plugging on the core end face and the propped fractures and has the strong plugging performance, and the TPA solubility in the carrying fluids decreases with the increase in the TPA concentration. The basic performance of the TPA meets the requirements of temporary plugging fracturing. If the proppants and 20% fibers are placed within the fracture in the mixed pattern, the fracture is initiated along the direction of the horizontal maximum principal stress. The preset fracture reduces the fracture initiation pressure. The fracture complexity is closely related to the placement pattern of TPA and proppants. If the preset fractures are filled by the uniform mixture or the plug of the 20/40 mesh or 20/80 mesh particulate TPA (4%), fibers (1%), and proppants, the fracture initiation pressure significantly increases, and the complex fractures are formed after fracturing. Effective plugging cannot be formed only by mixing the fibers with the proppants, and the uniform mixture of the proppants and 4% particulate TPA and the 6% particulate TPA at the front end of the fracture form a temporary plugging belt, achieving effective plugging. The fibers improve the conductivity under the low closure stress, and it has a certain effect of temporary plugging under the closure stress above 30 MPa. The research results provide the design consideration for creating the complex fracture by temporary plugging.

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Tetracycline-resistant pneumococcal infection. Incidence, clinical presentation, and laboratory evaluation

Archives of Internal Medicine ◽

10.1001/archinte.123.4.388 ◽

1969 ◽

Vol 123 (4) ◽

pp. 388-393 ◽

Cited By ~ 1

Author(s):

O. J. Bizzozero

Keyword(s):

Clinical Presentation ◽

Pneumococcal Infection ◽

Laboratory Evaluation ◽

Infection Incidence

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Clinical features and outcome of acquired haemophilia A

Hämostaseologie ◽

10.1055/s-0037-1619050 ◽

2010 ◽

Vol 30 (03) ◽

pp. 156-161 ◽

Cited By ~ 9

Author(s):

R. Gheisari ◽

B. Bomke ◽

T. Hoffmann ◽

R. E. Scharf

Keyword(s):

Respiratory Diseases ◽

Care Center ◽

Treatment Algorithm ◽

Early Death ◽

Underlying Disease ◽

Pulmonary Sarcoidosis ◽

Relative Increase ◽

Laboratory Evaluation ◽

Haemophilia A ◽

Acquired Haemophilia

SummaryWe have performed a monocenter study on 29 consecutive patients with acquired haemophilia A who were referred for diagnosis and treatment to the Düsseldorf Haemophilia Comprehensive Care Center between March 2001 and February 2010. Patients, methods: 18 men (age: 44–86 years) and 11 women (age: 20–83 years). For laboratory evaluation, a standardized staged protocol of aPTT, FVIII : C activity and concentration, mixing studies with patient and normal plasma, and quantification of inhibitor titers (Bethesda assay) was used. Diagnostic work-up included elaborate examinations for any underlying disease. Results: In 18 (62%) of the 29 patients with acquired haemophilia A, an underlying disorder was identified, including 9 patients with respiratory diseases (31%), 7 patients with autoimmune disorders (24%), one with malignancy, and one with postpartum state, while in 11 patients (38%) acquired haemophilia A remained idiopathic. Haemotherapy of bleeding, suppression or elimination of the inhibitor, and induction of immunotolerance to endogenous FVIII:C were performed according to a treatment algorithm. Predefined clinical endpoints were control of bleeding, eradication of the inhibitor, complete or partial remission (CR, PR), relapse, or early death (≤30 days). Of the 29 patients in total, 22 individuals achieved CR (76%), three had PR, one relapsed, and three died within 30 days (one of acute myocardial infarction while on anti-haemorrhagic treatment, one of sepsis while on immunosuppression due to active acquired haemophilia A, one of lung bleeding in association with pre-existing pulmonary sarcoidosis). Conclusion: This monocenter study demonstrates that control of life-threatening bleeding, eradication of the inhibitor, and induction of tolerance to endogenous FVIII have significantly improved the clinical outcome of acquired haemophilia A. Our data also suggest a shift in underlying disorders associated with acquired haemophilia A, whereby, in comparison to published studies, a relative increase in the proportion of patients with respiratory diseases is present.

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Laboratory Evaluation and Clinical Characteristics of 2,132 Consecutive Unselected Patients with Venous Thromboembolism – Results of the Spanish Multicentric Study on Thrombophilia (EMET*-Study)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655986 ◽

1997 ◽

Vol 77 (03) ◽

pp. 444-451 ◽

Cited By ~ 163

Author(s):

José Mateo ◽

Artur Oliver ◽

Montserrat Borrell ◽

Núria Sala ◽

Jordi Fontcuberta ◽

...

Keyword(s):

Venous Thrombosis ◽

Odds Ratio ◽

Protein C ◽

Protein S ◽

Laboratory Evaluation ◽

Clinical Factors ◽

Recurrent Thrombosis ◽

Heparin Cofactor Ii ◽

Crude Odds Ratio ◽

History Of

SummaryPrevious studies on the prevalence of biological abnormalities causing venous thrombosis and the clinical characteristics of thrombotic patients are conflicting. We conducted a prospective study on 2,132 consecutive evaluable patients with venous thromboembolism to determine the prevalence of biological causes. Antithrombin, protein C, protein S, plasminogen and heparin cofactor-II deficiencies, dysfibrinoge-nemia, lupus anticoagulant and antiphospholipid antibodies were investigated. The risk of any of these alterations in patients with familial, recurrent, spontaneous or juvenile venous thrombosis was assessed. The overall prevalence of protein deficiencies was 12.85% (274/2,132) and antiphospholipid antibodies were found in 4.08% (87/2,132). Ten patients (0.47%) had antithrombin deficiency, 68 (3.19%) protein C deficiency, 155 (7.27%) protein S deficiency, 16 (0.75%) plasminogen deficiency, 8 (0.38%) heparin cofactor-II deficiency and 1 had dysfib-rinogenemia. Combined deficiencies were found in 16 cases (0.75%). A protein deficiency was found in 69 of 303 (22.8%) patients with a family history of thrombosis and in 205/1,829 (11.2%) without a history (crude odds ratio 2.34, 95% Cl 1.72-3.17); in 119/665 (17.9%) patients with thrombosis before the age of 45 and in 153/1,425 (10.7%) after the age of 45 (crude odds ratio 1.81, 95% Cl 1.40-2.35); in 103/616 (16.7%) with spontaneous thrombosis and in 171/1,516 (11.3%) with secondary thrombosis (crude odds ratio 1.58, 95% Cl 1.21-2.06); in 68/358 (19.0%) with recurrent thrombosis and in 206/1,774 (11.6%) with a single episode (crude odds ratio 1.78,95% Cl 1.32-2.41). Patients with combined clinical factors had a higher risk of carrying some deficiency. Biological causes of venous thrombosis can be identified in 16.93% of unselected patients. Family history of thrombosis, juvenile, spontaneous and recurrent thrombosis are the main clinical factors which enhance the risk of a deficiency. Laboratory evaluation of thrombotic patients is advisable, especially if some of these clinical factors are present.

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88. A Laboratory Evaluation of a Personal Air Sampling System for Airborne Enzymes

10.3320/1.2758995 ◽

2006 ◽

Author(s):

A. Panepinto ◽

M. Emley ◽

R. Hunt ◽

I. Christie

Keyword(s):

Air Sampling ◽

Laboratory Evaluation ◽

Sampling System ◽

Personal Air Sampling

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178. Laboratory Evaluation of Ventilated Shrouds for Mortar Grinding

10.3320/1.2765695 ◽

2001 ◽

Author(s):

W. Heitbrink ◽

D. Watkins

Keyword(s):

Laboratory Evaluation

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Sheehan's syndrome: clinical and laboratory evaluation of 80 cases

Endocrine Abstracts ◽

10.1530/endoabs.56.p788 ◽

2018 ◽

Author(s):

Emna Elfaleh ◽

Ibtissem Oueslati ◽

Melika Chihaoui ◽

Meriem Yazidi ◽

Fatma Chaker ◽

...

Keyword(s):

Laboratory Evaluation ◽

Sheehan’S Syndrome ◽

Sheehan's Syndrome

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Laboratory evaluation of the etiology of pathological vaginal dischurge

HEALTH OF WOMAN ◽

10.15574/hw.2019.140.64 ◽

2019 ◽

pp. 64-68

Author(s):

O.A. Burka ◽

◽

T.M. Tutchenko ◽

Keyword(s):

Bacterial Vaginosis ◽

Crucial Role ◽

Inflammatory Process ◽

Vaginal Discharge ◽

Vulvovaginal Candidiasis ◽

Diagnostic Methods ◽

Laboratory Evaluation ◽

Aerobic Vaginitis ◽

Laboratory Confirmation ◽

Vaginal Secretions

Pathological vaginal discharge is one of the most common complaints in women of all ages. Today, gynecologists are increasingly faced with a problem when, in the absence of laboratory confirmation of vulvovaginal candidiasis, bacterial vaginosis and STIs, women complain of discomfort caused by vaginal secretions. Causes of pathological vaginal discharge can be infectious and non-infectious processes and their combinations. The article analyzes the causes of the difficulties of diagnosing the of pathological vaginal discharge ethiology, demonstrates how the application of adequate volume of modern laboratory diagnostic methods in combination with understanding the multifaceted components of the inflammatory process plays crucial role in finding out the etiology of pathological vaginal secretions and the choice of optimal therapeutic tactics. Key words: pathological vaginal dischurge, vaginal microbiota, vulvovaginal candidiasis, bacterial vaginosis, aerobic vaginitis, cytolytic vaginosis.

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