Estimation on organic carbon content of source rocks by logging evaluation method as exemplified by those of the 4th and 3rd members of the Shahejie Formation in western sag of the Liaohe Oilfield

2012 ◽  
Vol 31 (4) ◽  
pp. 398-407 ◽  
Author(s):  
Luofu Liu ◽  
Xiaoqing Shang ◽  
Ping Wang ◽  
Yongqiang Guo ◽  
Weili Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Evaluation Method ◽  
Source Rocks ◽  
Organic Carbon Content ◽  
Liaohe Oilfield ◽  
Shahejie Formation ◽  
Western Sag

scholarly journals Geophysical Prediction Technology Based on Organic Carbon Content in Source Rocks of the Huizhou Sag, the South China Sea

2017 ◽  
Vol 24 (s2) ◽  
pp. 4-13 ◽  
Author(s):  
Wei Yang ◽  
Xiao-xing Gong ◽  
Fei-fei Peng
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Linear Relationship ◽  
Assessment Method ◽  
Seismic Inversion ◽  
Source Rocks ◽  
Seismic Facies ◽  
Organic Carbon Content ◽  
Seismic Attribute ◽  
Regional Prediction

Abstract Due to the high exploration cost, limited number of wells for source rocks drilling and scarce test samples for the Total Organic Carbon Content (TOC) in the Huizhou sag, the TOC prediction of source rocks in this area and the assessment of resource potentials of the basin are faced with great challenges. In the study of TOC prediction, predecessors usually adopted the logging assessment method, since the data is only confined to a “point” and the regional prediction of the source bed in the seismic profile largely depends on the recognition of seismic facies, making it difficult to quantify TOC. In this study, we combined source rock geological characteristics, logging and seismic response and built the mathematical relation between quasi TOC curve and seismic data based on the TOC logging date of a single well and its internal seismic attribute. The result suggested that it was not purely a linear relationship that was adhered to by predecessors, but was shown as a complicated non-linear relationship. Therefore, the neural network algorithm and SVMs were introduced to obtain the optimum relationship between the quasi TOC curve and the seismic attribute. Then the goal of TOC prediction can be realized with the method of seismic inversion.

Evaluation of shale gas potential of Cambrian Jiulaodong Formation in Wei-201 well block in Sichuan Basin, China

2016 ◽  
Vol 4 (2) ◽  
pp. T123-T140 ◽  
Author(s):  
Julius Kwame Borkloe ◽  
Renfang Pan ◽  
Jineng Jin ◽  
Emmanuel Kwesi Nyantakyi ◽  
Jianghui Meng
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Gas Storage ◽  
Source Rocks ◽  
Gas Content ◽  
Brittleness Index ◽  
Organic Carbon Content ◽  
Gas Potential

The Cambrian Jiulaodong Formation of the Wei-201 well block in the Sichuan Basin was investigated for shale gas potential. In the subsurface, the thermally mature formation attained a stable thickness of 234 m encompassing an area of approximately [Formula: see text] and representing a potential gas resource. The total gas content measurements from canistered samples was more than the estimated total gas storage capacity of the free gas, absorbed gas, and gas dissolved in water and in oil. The canister gas content ranged between 0.971 and [Formula: see text] and averaged [Formula: see text]. The average estimated gas in place was 2.5 billion cubic meters for the formation in the Weiyuan area. Reflectance measurements for thermal maturity range between 2.60% and 3.06% and average 2.84%. The results of our total organic carbon content (TOC) content analysis conducted on the core shale samples indicate that the TOC content of the formation ranges from 0.87% to 3.57% and averages 2.2%. The mineral composition of marine mudstone formation of the Jiulaodong shale is relatively consistent. Brittle mineral content increases with organic carbon content and is approximately 32%–43%, of which quartz content is 29%–40% with a very low amount of clay mineral as the mixed layer. The amount of illite-smectite ranges from 0% to 1% and the brittleness index range from 37% to 62% and average 57.1%. The Cambrian Jiulaodong Formation ha very good petroleum-source rock potential due to its average TOC content of greater than 2%, average canister gas content of [Formula: see text], good type I kerogen, high maturity with average 2.84% of source rocks that are characterized by a fairly high abundance of organic matter increasing from top to bottom and a large thickness of 234 m. Natural fractures, cracks, and pores developed in the Jiulaodong Formation also provide space for shale gas storage, and its average brittleness index is greater than 57%, which is good for fracability.

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