A methodology was invented to detect the unknown API gravity of oils/oils in HCFIs/oil condensates using fluid inclusion techniques coupled with microscope-based fluorescence emission spectroscopy. The API gravity (American Petroleum Institute’s gravity) is a commercial value indicator of petroleum (HCFIs). A diode laser emitting at 405 nm was used for the study. We have derived an arithmetic equation y = y0 (x0−x)t ± 1 for determining the unknown API gravity based on fluorescence emission ratio at F620/F560. With the use of a laser as an excitation source it is possible to specifically target the fluorophores that have absorption at this wavelength within the HCFIs. The precise determination of API gravity of oils in HCFIs at the time of drilling itself leads to the estimation of the quality of oils in a basin that gives an impetus for further exploration activities in petroleum industry. In general, 40% of the exploratory wells may end up as a dry well and the patented invention can help to determine the quality of minute quantities of oil detected by means of fluid inclusion studies and determination of API gravity values using a non-destructive micro-spectrometric technique could lead to further exploration in adjoining areas areas of such dry & abandoned wells...
Patentee Info: Dr. V. Nandakumar, Dr. J. L. Jayanthi
National Centre for Earth Science Studies
Patent No. 315456 dated 03/07/2019