Petroleum Geochemistry Division – Characterisation of Liquid & Extracted Hydrocarbons...

GEOTECH provides a comprehensive suite of analyses designed to determine the gross and molecular composition of crude oils and organic matter extracted from sediments. Data can be used to characterise source, maturity and depositional environment as well as for detailed oil-oil and oil-source rock correlations. All analyses and analytical programs can be designed to meet the specific client requirements.

Sediments submitted for hydrocarbon characterisation are generally selected on the basis of Rock Eval data (S1 values in excess of 0.2mg/g are considered suitable). In addition, intervals of particular interest, for example those with reported oil shows, can be analysed.

GEOTECH’s routine analyses for the characterisation of crude oils and sediment extracts include:

Physical Properties of Crude Oils

A range of physical property tests are offered including flammability limits, API gravity, flash point, viscosity, cloud point, pour point, sulphur, nickel and vanadium content and asphaltene isolation. Flammability limits, API gravity and vapour pressure tests characterise liquid hydrocarbons for transport purposes to comply with Dangerous Goods Transport Regulations.

Simulated Distillation (Sim Dis)

Simulated Distillation (Sim Dis) is a chromatographic method widely used to replace conventional distillation methods for control of refining operations and specification testing.

Sim Dis simulates the physical distillation of a hydrocarbon liquid.

In conventional Sim Dis, the system used contains a temperature programmable inlet, a column and a flame ionisation detector. Testing is carried out under constant flow to insure constant response of the flame ionisation detector. At Geotech an AC (Analytical Controls) system is used for characterising petroleum fractions. The system uses an Agilent 6890N gas chromatograph equipped with a programmable temperature vaporiser inlet designed specifically for high temperature analysis.

The American Society for Testing and Materials - ASTM have published several simulated distillation methods some of which are included in the table below: -the four most popular methods are : D2887, D7213, D7169, and high-temperature D6352.

Application	Purpose	Boiling      Range	Boiling      Range
		ºC	ºF
ASTM D2887	Gasoline & Jet Fuel	36-538	97-1000
ASTM D3710	Petroleum Fractions like Naphthas	-260	-500
ASTM D5307	Crude Oil	36-538	97-1000
ASTM D5442	Wax Analysis	302-538	575-1000
ASTM D6352	Lube Oils	174-700	345-1292
ASTM D7096	Gasolines with Oxygenates	-260	-500
ASTM D7169	Crude Oils and Residues	-720	1328
ASTM D7213	Lube Oils	36-615	97-1138