Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : thermal stability


Potential of Ethylhexyl Ester Oil to Enhance Drilling of HTHP Wellbores

Lina Jassim; Robiah Yunus; Suraya Abdul Rashid; Amar Salleh

Engineering and Technology Journal, 2018, Volume 36, Issue 1C, Pages 30-37
DOI: 10.30684/etj.36.1C.6

Ester-based drilling fluids have been accepted as an alternative to mineral oils in drilling applications and currently being utilized to drill oil or gas wells around the world. However, the ester-based fluids have deficiencies that limit its ability to carry and transfer drilled solids, stabilize the wellbore and drill the extended reach wells. Several approaches have been considered to overcome the ester limitations. Thus, the main aim of this study is to overcome these limitations by developing the high performance ester-based green drilling fluids for deep and ultra-deep wells. The low-pressure technology was applied in the synthesis of the ester to minimize ester hydrolysis and thermal instability issues during the drilling operation. The rapid ester synthesis involved the 2-ethylhexanol and vegetable oil-based methyl esters C12 in the presence of sodium methoxide as the catalyst. Performances of 2-EH ester-based drilling fluids behaviour was assessed under different hot rolling temperatures (121, 149, 177, and 200oC) for 16 hours. The rheological properties in terms of low shear rate of 6 and 3 rpm were superior which verified that these ester-based muds could be used in deep and ultra-deep wellbores without sagging, pipe sticking and unbalanced wellbore problems.

Improvement, the Performance of Polyurethane (PUR), Y-290 Resin as Coating of Oil Pipeline by Using Multi-Walled Carbon Nanotubes (MWCNTs)

S.A. Awad; E.M. Khalaf

Engineering and Technology Journal, 2017, Volume 35, Issue 8, Pages 845-848
DOI: 10.30684/etj.35.8A.10

In this study, polyurethane epoxy-Y290 (PUR-Y290) as a matrix material was reinforced by 1%MWCNTs. Polyurethane is a thermoset polymer and using for several applications particularly as coatings of gas and oil pipeline. Polyurethane uses as a liquid coating against the corrosion, and that is caused by the direct exposure for long periods of UV irradiation and humidity. The nanocomposites were prepared by adding 1wt% MWCNTs to polyurethane and mixed by using an ultrasound mixer. Polyueethane-1%MWCNTs composite sample was exposed to accelerate weathering (UV irradiation coming from sunlight, moisture, and salt water spray) during the exposure to different durations 6 months, 12 months and 24 months. Exposed and unexposed samples were investigated and evaluated by thermal and mechanical tests.It was found that the incorporation 1.0%wt of MWCNTs filler, enhanced the thermal stability and improved the mechanical properties during the exposure for long-term life to accelerated weathering conditions, compared with polyurethane coating without MWCNTs filler. These results indicated that polyurethane (liquid coating) nanocomposites have a higher resistance to environmental condition and give more protective against corrosion of oil pipelines and applied as coatings by spray method to protect the oil pipeline surfaces from environmental conditions.

Thermogravimetric Analysis on PVA / PVP Blend Under Air Atmosphere

Nadia Azeez Betti

Engineering and Technology Journal, 2016, Volume 34, Issue 13, Pages 2433-2442
DOI: 10.30684/etj.34.13A.6

Films of poly vinyl alcohol (PVA) /poly vinyl pyrrolidone (PVP) blends have been prepared by solution casting method with different ratios of each other (100/0 , 80/20 , 60/40 , 50/50 , 40/60 , 20/80 , 0/100) to investigate their thermal stability comparing to correspondent pure polymers by using thermogravimetric analysis (TGA) under air atmosphere. It was found that PVA and PVP films show two decomposition steps while PVA/PVP blend films show three decomposition steps except the film of the ratio (20/80) that shows four decomposition steps .It was also found that blending decreases the temperature ranges at which the first and the second decomposition steps of PVA and PVP occur. It was found that blending PVA with PVP has significant effect on weight loss at first decomposition step of PVA by increasing it as the ratio of PVP increases. It was also found that blending PVA with PVP has significant effect on weight loss at second decomposition step of PVA by decreasing it as the ratio of PVP increases. It was found that the weight loss at third decomposition step of PVA/PVP blend films increases as the ratio of PVP increases . According to TGA thermograms under air atmosphere, PVA , PVP and PVA/PVP blend films show almost the same total weight loss which means of same thermal stability.

The Effect of Cesium Chloride on Thermal Properties of Poly (Vinyl Alcohol)

Nadia Azeez Betti

Engineering and Technology Journal, 2016, Volume 34, Issue 12, Pages 2193-2206
DOI: 10.30684/etj.34.12A.3

Poly (vinyl alcohol), PVA for short, films doped with different concentrations of cesium chloride(CsCl) (0% , 2% , 4% , 6% , 8% , 10% , 12% , 14% ,16% ) were prepared by solution casting method to study the effect of this salt on thermal properties of PVA by using thermogravimetric analysis (TGA) .It was found that the dopedPVA films with concentrations(14% and 16%) of CsCl aremore thermal stable than PVA while doped PVAfilms with concentrations ( 4% and 6%) of CsCl are less thermal stable than PVA and the dopedPVA films with concentration of ( 2% , 8% , 10% and 12%) are almost as thermal stable as PVA. Fourier transform infrared spectroscopy (FTIR) was also used to investigate complexation between CsCl and PVA and was foundthat the doped PVA films with concentration (2% , 4% , 6% and 8%) of CsClshowno significant shifts in wave numbers of the characteristic bands of PVA while doped PVA films with concentrations (10%, 12% ,14% and 16% ) of CsClshow a significant shifts to a higher values in wave number of stretching vibration of (-OH) comparing to PVA indicating well complexation between CsCl and PVA.