Hydrocarbon Engineering

March

2017

HYDROCARBON

ENGINEERING

in the water phase after boiling and is discharged

with effluent water, and the MEG that remains in

the crude as a contaminant, ultimately devaluing

the product. Regularly assessing the efficacy of the

regeneration unit is therefore vital, in order to

minimise these losses by ensuring the highest MEG

recovery rate possible and the best price for the

crude.

Historically, gas chromatography (GC) has been

the industry accepted technology for measuring

methanol and MEG in oil and water. Operators have

grown confident in the methodology and accuracy

of GC performed in controlled laboratory

environments, but its practicality is limited offshore.

The complex hardware needs specialist staff to run

it, and requires significant maintenance costs

alongside the already high CAPEX, though the

greatest limitation is the unsuitability for use out

with a stable laboratory environment. Transportation

of samples onshore can often mean that an operator

waits weeks for a result, increasing the cost of

testing and potentially reducing the value of the

result. Critically, in this fast paced sector, it prevents

the operator being able to act on knowledge gained

from these tests before the product arrives at its

destination.

LUX Assure has developed a new solution to

address the limitations of GC analysis for MEG and

methanol. The OMMICA

kit range has been

supplied to oil and gas operators, refineries and

chemical testing companies globally for onsite

analysis, where it has facilitated informed,

evidence-based decision making.

Case study: applying innovation

The following case study illustrates how the

deployment of the OMMICA technology at the

Statoil Mongstad refinery in Norway, allowed for

fast, accurate results to be obtained on cargo fluids

prior to entry to the refinery.

The Mongstad refinery was receiving crude from

a newly commissioned oil installation in the

North Sea, which utilised continuous injection of

MEG to prevent hydrate formation during start up.

At this time, the MEG regeneration units were

undergoing the associated period of stabilisation,

and greater than usual quantities of MEG were

being lost into the oil stream, at high cost to the

producer. These losses were impacting downstream

activities and, although the specific values of MEG

were unknown, it had led to unwillingness from the

refinery to accept cargo shipments suspected of

containing excessive levels.

To accept these shipments, Statoil Mongstad

needed to analyse the arriving crude within a short

timeframe in order to make decisions regarding the

requirement for additional washing and processing

of the cargo crude. Once the need for testing was

established, a suitable method was required. In this

scenario, GC analysis would have been impractical,

given the delay in obtaining results it could have

meant making critical decisions with incomplete

information. The refinery required an adaptive

system, which could be implemented simply and

efficiently.

Statoil Mongstad purchased a number of

OMMICA kits and all the equipment required for

the analysis – including a spectrometer, rotator

oven, centrifuge and pipettes – and was able to

carry out multiple, simultaneous testing of MEG

within the oil phase quickly, without requiring large

volumes of additional training or a complex

extraction process.

Statoil Mongstad was able to obtain the results,

in the timeframe required, using a cost efficient

method. The company gained confidence that the

incoming crude was within specifications and could

be processed without increasing risk to sensitive

components within the process. The Mongstad

refinery used OMMICA for analysis on all shipments

from the installation during the MEG regeneration

unit stabilisation phase, avoiding any potential

problems at the refinery. Samples from the cargo

tankers were also later analysed using the

traditional GC method. When the results from this

testing were received, the data showed a strong

correlation, giving the team further confidence that

the reliability and accuracy can be achieved using

the technology onsite and in near real time.

Reflecting on the data, the GC and OMMICA

methods produced a less than 20% difference when

analysing non-identical samples in independent

laboratories across a wide range of concentrations.

The result from this testing supported Mongstad

refinery’s decision to implement testing using this

technology on future suspect shipments of crude

coming in from a variety of locations, across a range

of scenarios. This method has been endorsed by

Statoil Mongstad, for use in analysing incoming

crude oil for MEG content. The company envisages

a variety of benefits at refinery level – saving time

and money usually lost through demurrage, storage

of the product whilst waiting for the result and

eliminating additional ‘just in case’ processing steps

to ensure received cargo crude is within the

required MEG concentration.

Conclusion

Looking into the future, the path for the oil and gas

sector may not be as clear as it once was. The

recent downturn has presented the sector with

fresh challenges and companies are being forced to

respond. The industry has always relied on

experienced personnel and cutting edge

technology, but now it must look forward, with

increased adaptive capacity, as well as the

development and the adoption of innovative

technology.