10th March 2017
For this interview, we had the honor to converse with Mr. Alexey Slesarev from Diascan Transneft, CIVA user in the Oil & Gas sector.
Your Company, Diascan Transneft, is specialized in Oil and Gas and performs NDT inspections for this sector. As a CIVA client, could you tell us why you decided to use simulation for your inspections?
We decided to use simulation for ultrasonic inspections for the two main reasons.
First is the need for the development of scanning plans for various pipeline wall thicknesses, pipeline diameters and speeds of inline inspection tools for ultrasonic phased arrays. It’s necessary to calculate the delay law for certain refraction angles, so that a specified area of a pipeline wall is covered by an ultrasonic beam with an amplitude not lower than -6 dB with respect to the maximum. I use beam computation for this purpose. I also evaluate the time of flight of echo signals.
The second reason is the ability to simulate echo signals from relatively complex shaped flaws. It takes much time to produce specimen, even with simple flaws like notches or side drilled holes, let alone complex shaped flaws. I am intending to use inspection simulation mode for such simulations.
What are the specificities of NDT in this sector?
The specificities of inline inspection (pigging) compared to both manual ultrasonic NDT and automatic ultrasonic tube testing machines are:
- The inability to control the position of the ultrasonic probe relative to welds and flaws, in order to search for the maximum level of echo signal, and thus use an amplitude sizing technique;
- The inability to slow down the inline inspection tool in order that a more thorough inspection of welds and flaws could be done;
- The inability to accurately calibrate ultrasonic probes, because of relatively great variations of oil temperature and composition in the course of an inspection.
Which extra function would you like to see in the next CIVA version?
In next CIVA versions, I would like to be able to use some kind of programming language to have full control over the simulation process, as well as the export and import of signals. I need to link CIVA with MATLAB in order to perform complete simulations of ultrasonic inspections, including the processing of received echo signals, flaw detection and adaptive change of the delay law.
Another problem is that it’s not possible to set different signal shapes for different elements of a phased array probe. Different elements of real ultrasonic phased arrays transmit signals with slightly different shapes, durations and amplitudes. It’s important for us to evaluate the effect of such differences on the beam parameters and the amplitude of echo signals.
I would also like to be able to create a graph that shows the local orientation of the beam at each calculation point by means of color rather than arrows. It would allow me to quickly evaluate the size of a zone where the local orientation differs from the required refracted angle by not more than a certain value. With the current CIVA version, I need to hover the cursor over a certain arrow to see the angle of the local orientation at a certain point, and it takes me too long to find out the size of the zone where the amplitude of the echo signal from the flaw with a specified orientation is appropriate.
Do you tend to increase the use of modelling in the future?
Regarding an increase of usage of our CIVA products, I hope that in the future we will use them more extensively, particularly for the purpose of simulating parasitic echoes from elements of inline tool construction.
Do you already use Simulation for other applications than NDT?
We are going to use MATLAB to simulate digital signal processing. That’s why it’s very important to me that it will become possible to link CIVA with MATLAB via some kind of CIVA programming language in the next CIVA version.