Subsea Compressors Sim

Dynamic simulation study of a subsea wet compression unit (phase 1).

Client: Renowned European Petroleum company


The job described in this outline regards the development of a simulation model of wet gas compressors, well tubing and pipeline dynamics.
On the whole, the main goals of the job are:

  • to optimize design,
  • to tailor and understand tests,
  • to help defining operational procedures,
  • to pretune control systems parameters.

In particular, the main goal of Phase 1 of the job was to study the effects of transients on the combined system. The response time of the control system with flow recirculation valves was one of the concerns. Moreover, the objective of the first delivery was to establish a basis for the selection of the necessary response time and type of the recirculation valves, as emerging from the following main operational scenarios:

  • Driver Trip (ESD)
  • Process disturbances
  • Emergency operation and faults, namely the fail closing of the isolation valves or the fail opening of the subsea unit by-pass header valves.


Input data received from the Client

Plant drawings and geometry (P&ID, sketches, 3D drawings)

Reference operational conditions (PFD and H&MB)

Control system logic description

Compressors datasheets

Valves and equipment technical specifications

Main technical activities performed by S.A.T.E.

Model equations implementation in the SIMULINK® environment

Control system tuning

Simulations and data analysis by means of COMPSYS software

Identification of the causes leading to compressors surge during some of the operational scenarios

Output delivered to the Client

Technical documentation: Final report including the model description, results analysis, remedies recommendations (in particular recommended changes on the implemented compressors control logic)


The main competences that were needed to perform the job are in the following fields:

  1. Turbo-compressor physics, thermodynamics and fluid dynamics
  2. Compressors control systems implementation and tuning
  3. Data processing and analysis
  4. Advanced use of the MATLAB/SIMULINK® environment
  5. Advanced use of the proprietary simulation software COMPSYS