HRGWD: The insights you need when it really counts

HRGWD is an innovative process and workflow that allows for the detection, collection and quick analysis and interpretation of potential oils, condensates and gases from drilled reservoir sections using organic extraction (Soxhlet) of plugs, cuttings and/or core reservoir samples. And with the correct logistics, operations managers will have previously unimagined insights in hand in time to guide their on-site drilling decisions.

This revolutionary technology leverages special Soxhlet extraction used for the cleaning of plugs/cores/cuttings in petrophysical studies (e.g., microscopy mineralogy, permeability and porosity analyses, etc.) in order to optimize drilling efforts. The extracted fluids can be quickly used for HRGWD analyses, while the cores and plugs are totally cleaned and ready for future petrophysical studies.

We should also highlight Optimum’s (Stratum Reservoir, BTI and BPS) proprietary extraction/liquid chromatography methods, which optimize hydrocarbon fraction/small and large diamondoid molecule recovery to a level never previously imagined.

HRGWD has proven very successful in petroliferous basins in Brazil, especially when extracts have complex fluid mixtures composed of uncracked and cracked oils and condensates. 

The results allow for the identification and quantification of heavy oils, light oils, condensates and fluid mixtures in well sections while drilling is still ongoing. In addition, origin, thermal and biodegradation stages, oil quality, oil mixing, hydrocarbon fractionation and, most importantly, oil cracking stage can be quickly deciphered.

These data are critical to better understanding the petroleum system in the well and characterizing and predicting the oil/condensate/gas potential of the reservoir before the end of drilling and logging operations. Meanwhile, HRGWD is also a key tool in identifying the various hydrocarbon compartments in the reservoir and water/oil/condensate/gas contact.

Via analysis of organic extracts of reservoir rocks containing oil/condensate from a particular well section, calibration curves based on measured oil properties versus molecular ratios can be constructed. These ratios are determined via high resolution gas chromatography (GC) and/or gas chromatography-mass spectrometry (GC-MS), chromatography-mass spectrometry-mass spectrometry (GC-MS-MS), quantitative diamondoids analyses (QDA), compound specific isotope analyses of biomarkers (CSIA-B) and quantitative extended diamondoids analyses (QEDA).

Once suitable calibration curves have been constructed, oil properties can be indirectly determined throughout an entire well via analysis of core and/or cutting extracts. The analyses can be quickly performed on plugs, cores and cutting composite samples, providing important insights to enable successful exploration evaluations before the end of drilling/logging operations.

See some examples below!

Geochemical analyses of cutting samples while drilling in a well in the Campos Basin illustrating examples of the results of HRGTWD in two well reservoir section from the post-salt.
Geochemical data of oil extracts taken from cutting samples while drilling in the well depicted in Figure 1, showing correlation with data from produced oils near the drilling site. The data allows the construction of calibration curves aimed at indirectly predicting the geochemical properties of extracted oils.
Geochemical analyses of cutting samples while drilling in an Orange Basin well section in offshore Namibia. The GC and GC-MS traces of terpanes (m/z 191) showing biomarker ratios against depth (m) suggest the presence of at least two oil types in the drilled sedimentary section.
Geochemical analyses of cutting samples while drilling in the Orange Basin in offshore Namibia. The GC-MS traces of diasteranes and steranes (m/z 217 and 259) showing biomarker maturity and source ratios against depth (m), taken as an example, confirms the presence of at least two oil types in the drilled sedimentary section. It is important to mention that the Dia/TPP ratio of the deeper samples suggest mixed marine and lacustrine oils.
Plot of C29 sterane biomarker versus diamondoid concentration (e.g., ppm of 3+4 methyldiamantanes) of reservoir extracts from a pre-salt section of the Santos Basin indicating the presence of mixed black oil with highly cracked oils originating from very deep source rock pods. In this case, the very high diamondoid number suggested a long-distance migration pathway for the condensate fraction mixed with the black oil sourced inside the oil window.

Share this post

Select your currency


Sign up for our newsletter to receive the latest insights and exclusive studies from our experts