Shale gas has recently become one of the most important hydrocarbon sources in North America. Despite of the development of economic methods to exploit the resources, formation evaluation still includes many principal questions; one of them is about total reserve. As shale's organic matter does not only play as a hydrocarbon generation factor but also as a storage factor, being able to estimate total porosity (both organic and inorganic porosity) is crucial to answer the question about total reserve. One of the biggest unknown, yielding big error in the estimation is kerogen or organic density. The experiment combining low pycnometer grain density (LPP) measurement and TOC measurement provides a new approach to measure organic density. Organic density is clearly a function of thermal maturity. It increases with increasing maturity. With %Ro< 2%, kerogen density has different trend for different type of kerogen. Type I&II 's density ranges from 1.2 to 1.6 g/cc; type II density is from 1.4 to 1.6 g/cc; and type III's density ranges from 1.6 to 1.8 g/cc. However, when maturity level reaches dry gas window, there is only one trend for all various kerogen types. The results from the experiment agree well with measures from different techniques. The advantages of this technique allow measuring both kerogen and mineral true grain density, and potentially measured k – as inverse weight fraction of organic carbon to organic matters. Kvalue seems to be a good independent local indicator of thermal maturity.
A New Approach to Measure Organic Density
Dang, Son T., Sondergeld, Carl H., and Chandra S. Rai. "A New Approach to Measure Organic Density." Paper presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, Denver, Colorado, USA, August 2014. doi: https://doi.org/10.15530/URTEC-2014-1921752
Download citation file: