The Characterization of a Tar Sand Sample Using Differential Scanning Calorimeters

In this study, non-isothermal kinetics and a thermal analysis tar sand sample is studied by differential scanning calorimeter and pressurized differential scanning calorimeter. Differential scanning calorimeter and pressurized differential scanning calorimeter curves revealed two reaction regions in the temperature range of 20-600 degrees C. Effect of pressure was also studied in order to see the thermal behavior of a tar sand sample under different elevated pressures. Two different kinetic methods (ASTM and Borchald and Daniels) were used to determine the kinetic parameters of the samples

Paleotemperature analysis of Aliaga (Izmir, Turkey) geothermal field

Mineralogical and organopetrographic analysis were carried out on core samples of four geothermal wells from the Aliaga geothermal field located in western Turkey. Whole rock mineralogy and clay minerals were determined, and thermal maturity of the different levels of the formation was defined by means of vitrinite reflectance measurements. The measured maturity gradients compiled from analytical data for four wells and outcrops ranged from low to very high values

An experimental investigation on the chemical stability of selected formation and determination of the proper type of water-base drilling fluids. Part 1. Descriptive tests

The objective of this study was to identify the descriptive tests for drilling stable holes through the problems of the selected formations. This study was performed on the shale samples taken from 10 wells in which hole instability was encountered to various extents during drilling the Germav formation. A total of 13 formation samples, characterizing the problematic intervals of the 10 wells under consideration, were evaluated. Descriptive tests were used to compare the samples and to determine the samples that should be used for drilling fluid selection tests. Based on the results of these tests it is possible to select the best drilling fluid for the formations studied. Descriptive tests include x-ray analysis, capillary suction time, hot rolling test, linear swelling test and cation exchange capacity test

End effect evaluation in rheological measurement of drilling fluids using Coutte coaxial cylinder viscometer

This paper demonstrates the order of influence of end effects on the application of a theory to determine and correct the end effects in Couette coaxial cylinder rotational viscometers, which are commonly used for the rheological evaluation of drilling fluids. It is found that higher shear stresses are measured due to end effects and, consequently, this error bearing shear stress-shear rate data leads to unreliable predictions of the rheological parameters. Evaluation of the shear stress-shear rate data obtained from various drilling fluids indicates that the flow curve corrected for end effects deviates significantly from the measured curve. A parametric analysis for the rheological models, such as the Bingham plastic, power law, and yield-pseudo-plastic models, is also performed with the parameters of the selected rheological model

An experimental investigation on the chemical stability of selected formation and determination of the proper type of water-base drilling fluids. Part 2. Test results

The objective of this study was to select the proper drilling fluid type and composition for drilling stable holes through the problems of the selected formations. This study was performed on shale samples taken from 10 wells in which hole instability was encountered to various extents during drilling the Germav formation. Both ionic and polymer inhibitions were utilized in formulating the proper drilling for the Germav formation. Ionic inhibition was obtained using KCl and NaCl. Polyanionic polymer (Pac-L) was used for providing the polymer encapsulation. Experimental results indicated that KCl is superior to NaCl in providing ionic inhibition. Both salts lowered the interaction between the drilling fluid and Germav formation, but better results were obtained with KCl. Minimum salt concentration up to 15% yields more inhibitive environment. Polymer inhibition tests indicated that minimum Pac-L concentration required for maintaining the polymer inhibition was about 2 lb/bbl for both systems. In conclusion, KCl/encapsulating polymer system seems to be the most proper water: base drilling fluid available for Germav formation achieving the required wellbore stability. The fluid loss and suspending properties of the proposed system must be controlled using the modified starch and XC polymer

Düşük basınçlı sondaj akışkanlarının karakterizasyonu köpüklü akış uygulamaları

Köpük, yüksek kesinti taşıyabilme, sıkıştırılabilme ve formasyon akışkanını kaldırabilme özelliklerinden dolayı en sık kullanılan düşük basınçlı sondaj akışkanlarından birisidir. Köpük reolojisi üzerine birçok çalışma yapılmıştır. Araştırmacılar, köpük davranışını Power Law ve Bingham Plastik gibi daha önceden tanımlanmış modelleri ele alarak, köpük içerisindeki gaz oranının bir fonksiyonu olarak geleneksel yollardan incelemişlerdir. Ancak, kabarcık boyutu ve kabarcık deseninin köpük davranışında etkili olduğu da bilinmektedir. Köpük, değişik köpük yapıcı kimyasallar kullanıldığında, gaz miktarının aynı olduğu hallerde bile değişik reolojik davranışlar göstermektedir Bu nedenle kabarcık boyutunu ve desenini de dikkate alan daha kapsamlı bir köpük karekterizasyon modeli gereklidir. Görüntü analizi ve bilgisayar teknolojisindeki gelişmeler, kabarcık boyutu ve deseninin gözlemlenebilmesini mümkün kılmaktadır. Bu çalışmada, köpüğün reolojik tanımınının kabarcık boyutu ve desen etkilerini de dikkate alan daha kapsamlı bir model geliştirilmiştir. Analiz için ihtiyaç duyulan reolojik ve görüntü bilgileri, bu çalışma için oluşturulmuş olan ve farklı çaptaki dairesel borulardan meydana gelen bir düzenek yardımı ile elde edilmiştir. Gerek görüntü analizi teknikleri kullanılarak, gerekse hacim eşitleme prensibi kullanılarak hesaplanan duvardaki gerilme miktarları ± %20'lik bir hata payı ile tahmin edilebilmiştir. Sadece görüntü bilgisinin kullanılması ile köpük karakterizasyonunun doğru ve çabuk bir şekilde yapılabilineceğinin mümkün olduğu gözlemlenmiştir

Measurement of heat capacity and thermal conductivity of HDPE/expanded graphite nanocomposites by differential scanning calorimetry

Purpose: In this study, heat capacity and thermal conductivity of nanocomposites formed by high density polyethylene (HDPE) matrix and expanded graphite (EG) conductive filling material were investigated. Design/methodology/approach: Nanocomposites containing up to 20 weight percent of expanded graphite filler material were prepared by mixing them in a Brabender Plasticorder. Two grades of expanded graphite fillers were used namely expanded graphite with 5 μm (EG5) and 50 μm (EG50) in diameter. Heat capacity and thermal conductivity of pure HDPE and the nanocomposites were measured using differential scanning calorimetry (DSC). Findings: A substantial increase in thermal conductivity was observed with the addition of expanded graphite to HDPE. Thermal conductivity increased from 0.442 W/m.K for pure HDPE to 0.938 W/m.K for nanocomposites containing 7% by weight of expended graphite. Heat capacity increases with the increase in temperature for both pure HDPE and the nanocomposites filled with expanded graphite and no appreciable difference in the values of heat capacity were detected due to particle size. Heat capacity decreased with increasing graphite particle content for both particle size, following the low of mixtures. Practical implications: Layers of expanded graphite have become of intense interest as fillers in polymeric nanocomposites. Upon mixing the expanded graphite intercalates and exfoliates into nanometer thickness sheets due to their sheet-like structure and week bonds normal to the graphite sheets. That way they have very big surface area and high aspect ratio (200-1500) what results in a formation of percolating network at very low filler content. The nanoparticles usage results in significant improvement in thermal, mechanical, and electrical properties of polymers even with very low loading levels compared with microparticles. Originality/value: To see the effect of conducting fillers on thermal conductivity and heat capacity two different sizes of expanded graphite were used. © International OCSCO World Press