Measurement of Wax Appearance Temperature of an Offshore Live Crude Oil using Laboratory Light Transmission Method

Author(s):  
Emmanuel Uba ◽  
Kingsley Ikeji ◽  
Mike Onyekonwu
2020 ◽  
Vol 1202 ◽  
pp. 127239 ◽  
Author(s):  
Jaber Taheri-Shakib ◽  
Ali Shekarifard ◽  
Ezatallah Kazemzadeh ◽  
Hassan Naderi ◽  
Mahyar Rajabi-Kochi

2018 ◽  
Vol 22 (4) ◽  
pp. 2487-2509 ◽  
Author(s):  
Ashley R. Pales ◽  
Biting Li ◽  
Heather M. Clifford ◽  
Shyla Kupis ◽  
Nimisha Edayilam ◽  
...  

Abstract. The vadose zone is a highly interactive heterogeneous system through which water enters the subsurface system by infiltration. This paper details the effects of simulated plant exudate and soil component solutions upon unstable flow patterns in a porous medium (ASTM silica sand; US Silica, Ottawa, IL, USA) through the use of two-dimensional tank light transmission method (LTM). The contact angle (θ) and surface tension (γ) of two simulated plant exudate solutions (i.e., oxalate and citrate) and two soil component solutions (i.e., tannic acid and Suwannee River natural organic matter, SRNOM) were analyzed to determine the liquid–gas and liquid–solid interface characteristics of each. To determine if the unstable flow formations were dependent on the type and concentration of the simulated plant exudates and soil components, the analysis of the effects of the simulated plant exudate and soil component solutions were compared to a control solution (Hoagland nutrient solution with 0.01 M NaCl). Fingering flow patterns, vertical and horizontal water saturation profiles, water saturation at the fingertips, finger dimensions and velocity, and number of fingers were obtained using the light transmission method. Significant differences in the interface properties indicated a decrease between the control and the plant exudate and soil component solutions tested; specifically, the control (θ= 64.5∘ and γ= 75.75 mN m−1) samples exhibited a higher contact angle and surface tension than the low concentration of citrate (θ= 52.6∘ and γ= 70.8 mN m−1). Wetting front instability and fingering flow phenomena were reported in all infiltration experiments. The results showed that the plant exudates and soil components influenced the soil infiltration as differences in finger geometries, velocities, and water saturation profiles were detected when compared to the control. Among the tested solutions and concentrations of soil components, the largest finger width (10.19 cm) was generated by the lowest tannic acid solution concentration (0.1 mg L−1), and the lowest finger width (6.00 cm) was induced by the highest SRNOM concentration (10 mg L−1). Similarly, for the plant exudate solutions, the largest finger width (8.36 cm) was generated by the lowest oxalate solution concentration (0.1 mg L−1), and the lowest finger width (6.63 cm) was induced by the lowest citrate concentration (0.1 mg L−1). The control solution produced fingers with average width of 8.30 cm. Additionally, the wettability of the medium for the citrate, oxalate, and SRNOM solutions increased with an increase in concentration. Our research demonstrates that the plant exudates and soil components which are biochemical compounds produced and released in soil are capable of influencing the process of infiltration in soils. The results of this research also indicate that soil wettability, expressed as (cos θ)1∕2, should be included in the scaling of the finger dimension, i.e., finger width, when using the Miller and Miller (1956) scaling theory for the scaling of flow in porous media.


2006 ◽  
Vol 77 (4) ◽  
pp. 044301
Author(s):  
Cesar Cab-Cauich ◽  
Juan J. Alvarado-Gil ◽  
Olga L. Leaños-Castañeda

Author(s):  
Dongmin Zhang ◽  
Lixin Zhang ◽  
Lianfeng Huo ◽  
Shujie Zhi ◽  
Xin Ouyang ◽  
...  

A new type of nano-material based hybrid pour-point depressant with significant efficiency has been developed and successfully used in industrial application. For Daqing crude oil, a typical high waxy Chinese crude, with 80–100g/t new pour-point depressant and 58–65°C thermal treatment temperature, the wax appearance temperature of the Daqing crude oil can be decreased by 3–4°C. The viscosity/pour-point reduction, shearing resistance, and fluidity at low temperature of the modified crude with new type of pour-point depressant is much better than the effect of using traditional ethylene-vinyl acetate (hereinafter referred as “EVA”). Therefore the safe shutdown time for a pipeline is dramatically increased which not only enhances the safety of the pipeline operation but also significantly saves the energy consumption of the pipeline company. Besides, the reheating temperature can only be greatly reduced to 35°C. The relationship between the crystal structure of the nano-material based pour-point depressant and the type of the waxy crude, together with its influence on the crystal form/wax appearance temperature of the waxy crude by using X ray diffraction (hereinafter referred as “XRD”) and Polarizing microscope (hereinafter referred as “POM”)are studied.


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