Selected highlights are given below:

In terms of consultancy, FEESA has continued providing Flow Assurance services to two major BP projects in Angola: Block 31SE (PAJ) and Block 31MW.  Both these projects envisage the development of multiple oilfields located in deepwater Block 31 offshore Angola.

The Block 31SE project is in the Select (or Pre-FEED) phase of design.  We used our software Maximus to perform various thermal hydraulics studies of the integrated production systems.  Working in conjunction with the BP reservoir team, a Maximus deliverability model was developed to forecast production rates.  This model was then benchmarked against independent predictions from a Nexus model of the system and good agreement was shown.

In addition, a Wax Management study was performed to investigate options for developing a lower temperature potentially waxing field.  This investigation included an analysis of electric heating using the electrically heated pipeline option in Maximus.  Also, Maximus was used to predict the phase diagram including both regions of wax and hydrate formation.  Figure 1 shows a predicted phase diagram with a typical pT path from the reservoir to the reception facilities.

In parallel with the Maximus Flow Assurance studies, we have also undertaken transient analysis to investigate shutdown, restart and slugging avoidance.

Figure 1, Phase Diagram & pT Path

The Block 31MW project is in the Appraise (or Conceptual) phase of design.  Here, we have developed a Maximus Integrated Production Model (IPM) to investigate novel development options and the impact these might have on deliverability and Flow Assurance.  In particular, the Maximus model was used evaluated subsea separation, subsea boosting and riser-base gas-lift.  The model was configured to predict drilling schedules for different production system arrangements and different FPSO sizes.

Recently, FEESA has also performed a benchmarking exercise for the Xodus Group in Perth, Western Australia.  This involved the development of a Maximus Integrated Production Model (IPM) for a gas field development located in Australian territorial waters (see Figure 2).  This model was used to investigate the deliverability of various options, including different pipeline sizes and routes and two potential offshore compression locations.  The investigation produced considerable insights regarding production system configuration and well allocation.

Figure 2, Maximus IPM for Australian Gas Field Development

 

On the software development front, there have been several incremental developments to Maximus .  These are listed as follows:

• Control Choke Compressors and Pumps. These new objects offer hybridised functionality allowing these devices to act as chokes when there is sufficient supply pressure to meet a target rate but then switching on pressure boosting when the pressure has declined and the target cannot be met.
• New Plotting Options. Maximus’ Dynamic Plotter (the user-configurable plotter created and updated at runtime) has been improved offering both stack plots (see Figure 2) and stepping line plots.
• Microsoft Vista Maximus’ has been ‘ported’ to the Microsoft Vista OS and integrity tested.  Testing has gone well and FEESA is now able to offer Maximus for Vista.
• Transmissibility Connectors. Maximus’ connector object has been modified to allow connectors to be specified in terms of transmissibility.  This feature allows Maximus’ reservoir tank model to be coupled to aquifers and for communication between tanks.