The objective is to understand Flow leak Detection In Subsea Pipelines by designing and developing an experimental setup capable of collecting sensor measurements to examine the potential of using statistical monitoring techniques. The ability to detect a micro-leak is also of interest. The current proposed setup will be initially designed to be used with air as the working fluid.
An eventual plan for this project is to extend this setup for use with other fluids, including multiphase. A second eventual goal is to simulate subsea conditions by developing an aquarium to submerge the pipeline under so that leak behavior can be observed and studied under these conditions.
There were two initial suggestions provided by the Pilot Multiphase in charge of experimental design. The proposed approach for simulating the leak involved the utilisation of a 1mm drill-bit to create a perforation in the pipeline. However, a number of concerns arise with this method. Without a means of closing the hole, it is impossible to obtain sensor measurements under no leak conditions.
A suggestion was then provided to cap the 1 mm hole using a screw cap. Unfortunately, these do not exist. Obtaining measurements during the transition from leak to no leak conditions in this hypothetical scenario poses a significant challenge. Therefore, a decision was made to model the leak using a much safer alternative, with a high precision regulating stem tip needle valve. This should allow the engineer running the apparatus to adjust the leak size as desired.
Since Swagelok was chosen for tubing, the needle valve was selected from the same company, in order to make it easier to find appropriate fittings to connect the needle valve to the rest of the setup. The needle valve model selected was “Stainless Steel Integral Bonnet Needle Valve, Regulating Stem”. This item is not available in Qatar and will have to be shipped. As the chosen needle valve is ½ in, and the selected Swagelok tubing is ¾ in, a reducer and appropriate fittings are required in order to connect the two pieces of equipment.