The Geochemical Characterization of Adsorbed/Occluded Hydrocarbons Inside Solid Bitumen in the Kuangshanliang Area of the Northwestern Sichuan Basin and Its Significance

Abstract

The geochemical characterizations of adsorbed and occluded components of solid bitumen in the Kuangshanliang area of northwestern Sichuan Basin were studied by comparing the results of conventional extraction and mild oxidative degradation. The results indicate that the solid bitumen originated from Sinian-Cambrian ancient oil reservoirs. The main source of the parent material is lowerorder aquatic deposited in a high-sulfur anoxic marine environment. Exposed solid bitumen suffered from severe biodegradation, altering the tricyclic terpane/pentacyclic terpane and (pregnane + homopregnane)/regular sterane ratios as compared to the earlier parent material.

Determination of the series of even carbon numbered n-alk-1-enes trapped inside geomacromolecules

“…From the Cambrian solid bitumens of northwestern Sichuan Basin, the trapped even carbon numbered n-alk-1-enes ranged from C 16 eC 22 , with the ratios of -ene/-ane <1 except for C 22 -ene/-ane (Cheng et al, 2013).…”

“…However, recent studies have shown that a series of even carbon numbered n-alk-1-enes are present in the trapped fractions of asphaltenes (Yang et al, 2009;Zhao et al, 2010Zhao et al, , 2012Tian et al, 2012) and solid bitumens (Cheng et al, 2012(Cheng et al, , 2013. They may be stable in these geomacromolecules owing to the protection afforded by the matrix, which inhibits transformation of the trapped n-alk-1-enes during later geochemical processes.…”

Thermal Evolution of Adsorbed/Occluded Hydrocarbons inside Kerogens and Its Significance As Exemplified by One Low-Matured Kerogen from Santanghu Basin, Northwest China

“…15,46,47 Detection of n-alk-1-enes from the occluded fraction shows that the hydrocarbons within the structure of kerogen have been well protected from the impact of the later geochemical depositional processes. Lower relative concentration and no distinct odd-over-even predominance (OEP) for the alkanes in high-temperature stage suggested that the disappeared even-carbon-number n-alk-(1)-enes may have been combined with some active groups of kerogen macromolecular structure but not evolved into the even-carbonnumber n-alkanes.…”

“…The occluded component can be well preserved by the macromolecular structure, thus reducing the transformative effects of later geochemical processes and thereby preserving the earlier organic geochemical information. 10−12 Researches have shown that mild oxidative treatment of asphalt and solid bitumen with H 2 O 2 can properly release the occluded compounds, which have been found useful in the study of organic matter with depleted soluble fractions, 13 oil (bitumen)−source correlation, 14,15 identification of mixed-source reservoirs, 16−18 and hydrocarbon accumulation and evolution. 19 Because kerogen as an important geological macromolecule, studies concerning the adsorbed and occluded fractions of kerogen will be helpful in understanding its structural characteristics and evolution features.…”

The features of the through-hole by picosecond pulse laser helical drilling on alloy

“…One of the most efficient and accurate drilling technologies namely helical drilling was reported [8] .It was reported that a combination of picosecond laser with an optimal parameter setup and helical drilling method has been proposed to gain microholes with different shapes on stainless steel. Precision drilling with picosecond laser maybe a better method to obtain the high-quality holes with the optimal adjustment of parameters such as average power,repetition rate,and focal position [9] . Although there are many studies [10,11] demonstrate the helical drilling was a good choice for machining microholes on the workpiece,however the detail research about the evolution of the hole by picosecond laser drilling was absent.…”