PCG is assisting clients to progress through stage gate reviews on their way to sanctioning multi-billion dollar projects.
Increasing capacity without increasing capex
An onshore CSG development had significant capital expenditure investment in compression facilities. PCG helped demonstrate how changing operating parameters at the field compression station could alter the output of the field.
A field compression station (FCS) in a large onshore CSG to LNG development is required to transport CSG long distances.
An FCS is supplied with gas from many wells (100+).
As the FCS consists of a number of compressor units (e.g. 20 MMscf/d compressors), altering capacity is done in large step changes.
Working with the development engineers at a Queensland based gas company, PCG modelled the optimal suction pressure by month for an FCS over the life of the field.
The model considered each well’s production curve and connection date, the FCS discharge constraint, the hydraulic constraint, the compressor operating envelope and the compressor power requirements.
CSG wells experience peak production rates very quickly and then production drops off rapidly. Compressors are required to meet the initial peak production rate, but as well production diminishes, compressor utilisation drops off.
We found that through managing the suction pressure at the FCS over time, gas can be produced at a rate in excess of the nominal capacity – significantly improving project economics.
The optimisation tool was handed over to the developments team to assist with capital requirements assessments on new fields.
It was also used by Operations teams for trialling on existing facilities.
Theoretical improved production rates – managing suction pressure by month