The Inter-M Pulse (IMP) is an instrumented mooring link designed to measure mooring line tension in realtime.
The link is able to measure the load and acoustically transmit the information to a single receiver in the water underneath the floating unit. A set of tension/compression strain gauges transforms minuscule link deformations into electrical signals, which are interpreted by a calibrated linear co-relation with tension. The equipment was developed to be used in water depths ranging from 50 up to 3000 meters.
It is well known that the maximum tension in a mooring line is located on the top end of the catenary.
However, considering operational issues, it is not feasible to install the IMP in this location. The equipment does not pass through the fairlead or any similar interface between mooring line and offshore unit; additionally, the harsh conditions in the splash zone mean that this is not a desirable region to position the sensor and the acoustic transmitter.
For this reason, the Inter-M Pulse should be installed at the optimum position to measure the critical tension.
An engineering technique called Design of Experiments (DoE) is widely used in different industries but not often applied in the oil and gas industry. This paper uses the DoE approach to study the influence of different factors in the mooring line measurement and the optimization of Inter-M Pulse location.