Elemental Inorganic Analysis is an important tool for the field and petroleum geologist in the field or lab to characterize and identify petroleum or gas bearing formations. Drill cuttings and mud, as well as cores can be analyzed directly onsite using portable or mobile instrumentation. Collected materials can be brought to a laboratory and measured on bench top or floor standing instrumentation.

Drill coresXRF spectrometry allows for the non destructive analysis of solids, liquid samples for elements ranging from F to U with a dynamic range from ppm to dual digit weight %. Analysis can be done on the unprepared sample (e.g. drill core), homogenized powder sample from washed drill cuttings or fused beads and pressed pellets from substrate rocks. The application requirements in terms of elements, point of analysis as well as time to result define the suitable instrumentation.

On-site characterization and non destructive analysis on cores can be performed with the TRACER series Handheld XRF units.

More excitation power for lower detection limits on prepared drill cuttings in a mobile lab is available by using the S2 PUMA direct excitation EDXRF.

Analysis of drill cuttings for majors and traces in the lab can be performed ideally with the floor standing S8 TIGER Series 2 WDXRF using either custom calibrations or the GEO-QUANT applications.

Using a small spot XRF source (25 microns) and the mapping on the fly approach implemented in the M4 TORNADO it is possible to image drill cores simultaneously for all elements from Na down to U!

The mineralogical composition of the sediment or formation studied offers much more information than the elemental information. It enables pinpointing of potential reservoirs and host formations:

Mineralogical phase identification and quantification by X-rays (XRD) can be used in a mobile laboratory or traditional laboratory setting. It is more accurate and easier to use than optical point counting methods on thin sections or powders. XRD distinguishes minerals having the same or similar chemistry and compared to mapping techniques it easily analyzes also the ultra-fines fraction of minerals. A major advantage over element sensitive scanning electron microscopy is the rather simple and quick sample preparation.

Drill cuttings only need to be washed and powdered for analysis by XRD. The measurement itself is fast and takes just a few minutes, including sample preparation. XRD not only allows the identification of minerals from major to accessory phases with DIFFRAC.EVA. XRD also offers standardless and even automatable quantification using the NEXT generation Rietveld approach. Furthermore, non-crystalline phases may be quantified with this approach. 

The analysis of drill cuts can be done in a mobile lab using BRUKER’s benchtop D2 PHASER. In a lab setting the D8 ENDEAVOR or D8 ADVANCE are used. Cores and thin or mounted polished sections may be analyzed by micro XRD using BRUKER’s unique 2 dimensional VANTEC 500 detector on a D8 DISCOVER.

During the oil production process on off-shore platforms large amounts of waste water are accumulated. In order to assure an environmentally safe waste dump the quality of the waste water is regulated by law. Therefore special parameters like the total hydrocarbon content have to be determined. The current standard measurement technique is based on the gas-chromatography (GC)-analysis of a pentane extract of the waste water. Due to the fact that pentane is highly flammable and forms explosive gas-air mixtures, it´s not advisable to be used on oil platforms. Hence the waste water sample needs to be transferred to a mainland lab by helicopter. Obviously this form of water analysis is very costly and time consuming.

As an alternative to this GC-based measurement procedure, FT-IR based methods have already been established and used. Their mayor drawback is the need of C-H free extraction solvents like carbon tetrachloride (CCl 4) or tetrachloroethylene (C2Cl4).In contrast the ALPHA II based method is a very effective approach for the fast screening of waste water samples, however it does not replace the OSPAR GC-based method when official results are required. It uses a simple extraction method with a small amount of the less harmful solvent chloroform. Since the chloroform extraction is not prone to emulsification as is the case with pentane, there is no need to add salt or to centrifuge the extract. With the exception of a filtration using a disposable syringe filter, there is actually no need for a further treatment of the extract. Subsequent to this easy step, the extract can be measured directly at the oil platform with an ALPHA II spectrometer in combination with a liquid flow through cell. Compared to the GC-analysis it’s not necessary to transport the sample to a mainland lab and therefore the measurement procedure is very fast and cheap. The complete test including sample preparation, measurement and analysis takes less than 10 minutes. When using the intuitive and easy to use OPUS-LAB software even an untrained person is able to get reliable results immediately.