Multi-Scale Nanoindentation For Characterization Of Oil Shales

Studies of the effects of polishing techniques, scale of nanoindentation, and petrophysical properties were conducted on both Woodford and Tuscaloosa Marine Shale. Polishing procedures include both an in-house developed, mechanical sample preparation protocol as well as ion beam milling. The elastic modulus and hardness of each mechanically polished sample was found to have larger value than those that were ion-milled. Additionally, at low loads, the samples resulted in having high standard deviation. This high deviation was found to be significantly reduced by testing at higher loads. The variations in results between mechanically polished and ion beam milled samples is believed to occur due to a higher “peel-out” rate during mechanical polishing that is not a significant factor within the ion beam milling procedure. The level of polishing was analyzed in order to determine the effect of surface roughness on indentation results within both a standard nanoindentation practice as well as atomic force microscope indentation. Nanoindentation tests were conducted on six Woodford Shale samples (each cut from a single core), as well as thirty Tuscaloosa Marine Shale samples (retrieved from drilling mud). For the Woodford Shale, an average of twenty-five indentations was considered. Likewise, for the Tuscaloosa Marine Shale, eighty indentation tests were completed for each sample depth for an end result of 1,200 indentation tests for determining average mechanical properties of the shale play as a whole. In both cases, maximum loads of 350 mN were used in order to negate deviations due to heterogeneity and obtain average mechanical properties of the samples. Thermogravimetric analysis (TGA) is used to correlate mechanical properties to the amount of total organic content as well as composition and shale maturity. For both shale plays, decomposition of light and heavy fractions occurs in the range of 200–300 °C and 420–520 °C respectively. By this process of analyses, it is determined that nanoindentation and atomic force microscopy technologies can be successfully used in the determination of mechanical properties for both core plug samples and drill cuttings alike.

Name thesis:degree_name

M.S. in Engineering Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Civil Engineering

Year dc:date.available

2016

Author dc:creator

• Miller, Zachary N.

Contributors dc:contributor

• Ahmed Al-Ostaz
• Greg Easson
• Hunain Alkhateb

• Atomic Force Microscope
• Nanoindentation
• Shale
• Tuscaloosa Marine
• Woodford
• Nanotechnology

Repository record dc:identifier

https://egrove.olemiss.edu/etd/426

OAI identifier oai:identifier

oai:egrove.olemiss.edu:etd-1425