scholarly journals Zwitterionic Polymer P(AM-DMC-AMPS) as a Low-Molecular-Weight Encapsulator in Deepwater Drilling Fluid

2017 ◽  
Vol 7 (6) ◽  
pp. 594 ◽  
Author(s):  
Xin Zhao ◽  
Zhengsong Qiu ◽  
Yongjun Zhang ◽  
Hanyi Zhong ◽  
Weian Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Drilling Fluid ◽  
Low Molecular Weight ◽  
Deepwater Drilling ◽  
Zwitterionic Polymer

scholarly journals Low-molecular-weight, fatty-acid esters as potential low-temperature drilling fluids for ice coring

2014 ◽  
Vol 55 (68) ◽  
pp. 39-43 ◽  
Author(s):  
Huiwen Xu ◽  
Lili Han ◽  
Pinlu Cao ◽  
Mingyi Guo ◽  
Junjie Han ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Fatty Acid ◽  
Butyl Acetate ◽  
Drilling Fluid ◽  
High Viscosity ◽  
Fatty Acid Esters ◽  
Low Molecular Weight ◽  
Drilling Fluids ◽  
Cold Environments ◽  
Acid Esters

AbstractA challenge for future deep-ice coring in central Antarctica is to identify an appropriate inert drilling fluid with no undesirable physical or chemical characteristics. The drilling fluids currently in use (kerosene-based fluids with density-increasing additives, ethanol and n-butyl acetate) are not intelligent choices for the future from safety, environmental and some technological standpoints. Recently proposed drilling fluids based upon ESTISOL™ have high viscosity at low temperatures, which severely limits their application in cold environments. This paper presents our research into the application of low-molecular-weight, fatty-acid esters (FAEs), substances commonly used in the fragrance and flavoring industries. According to available data, selected FAEs are not hazardous to human health. Considering density requirements alone, ethyl butyrate and n-propyl propionate best meet our present needs. The viscosities of these two chemicals are also the lowest among studied FAEs, not exceeding 4 mPas at temperatures down to −60°C. Both compounds are highly volatile, and insoluble in water. Such properties are attractive, but the applicability of FAEs to deep, cold, ice drilling can be evaluated only after field-based, practical experiments in test boreholes.

Investigation and Application of New Polyamine Salt Inhibitor

2012 ◽  
Vol 518-523 ◽  
pp. 594-597
Author(s):  
Hong Wei Zhang ◽  
Feng Jiang Zuo ◽  
Ye Tian ◽  
Dong Min Jia ◽  
Yan Mei Liu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Drilling Fluid ◽  
Organic Salt ◽  
Low Molecular Weight ◽  
Drilling Fluids ◽  
Inhibition Ability

A new kind of polyamine salt inhibitor (code name BH-JAI) with low molecular weight, was synthesized and evaluated in the lab. The tests showed that BH-JAI could suppress the hydration and dispertion of reactive claystone effectively, compatible with organic salt or KCl water drilling fluid, and could play its role of inhibition even at temperature as high as 200°C. The field tested in 5 wells suggested that the new polyamine salt could enhance the inhibition ability of drilling fluids obviously, and reduce downhole complex accidents such as sloughing and tight hole efficiently.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment

Venous thromboembolism in a general hospital. An update with low molecular weight heparin prophylaxis

VASA ◽  
2007 ◽  
Vol 36 (1) ◽  
pp. 17-22
Author(s):  
Schulz ◽  
Kesselring ◽  
Seeberger ◽  
Andresen
Keyword(s):  
Molecular Weight ◽  
Pulmonary Embolism ◽  
Venous Thromboembolism ◽  
Low Molecular Weight ◽  
Trauma Patients ◽  
Vte Prophylaxis ◽  
Vein Thrombosis ◽  
Patients At Risk ◽  
Hospital Stays ◽  
Event Rates

Background: Patients admitted to hospital for surgery or acute medical illnesses have a high risk for venous thromboembolism (VTE). Today’s widespread use of low molecular weight heparins (LMWH) for VTE prophylaxis is supposed to have reduced VTE rates substantially. However, data concerning the overall effectiveness of LMWH prophylaxis is sparse. Patients and methods: We prospectively studied all patients with symptomatic and objectively confirmed VTE seen in our hospital over a three year period. Event rates in different wards were analysed and compared. VTE prophylaxis with Enoxaparin was given to all patients at risk during their hospital stay. Results: A total of 50 464 inpatients were treated during the study period. 461 examinations were carried out for symptoms suggestive of VTE and yielded 89 positive results in 85 patients. Seventy eight patients were found to have deep vein thrombosis, 7 had pulmonary embolism, and 4 had both deep venous thrombosis and pulmonary embolism. The overall in hospital VTE event rate was 0.17%. The rate decreased during the study period from 0.22 in year one to 0,16 in year two and 0.13 % in year three. It ranged highest in neurologic and trauma patients (0.32%) and lowest (0.08%) in gynecology-obstetrics. Conclusions: With a simple and strictly applied regimen of prophylaxis with LMWH the overall rate of symptomatic VTE was very low in our hospitalized patients. Beside LMWH prophylaxis, shortening hospital stays and substantial improvements in surgical and anasthesia techniques achieved during the last decades probably play an essential role in decreasing VTE rates.

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