We are expanding! We are going to start providing our unique services in Indonesia. To celebrate this we will host a free conference and Gas Chromatograph (GC) training event in Jakarta Indonesia. Both conference and training will be hosted in the following location:
Event location: Padang Room, The Westin Jakarta
Address: Jl. HR Rasuna Said Kav. C-22, Jakarta, Indonesia, 12940
Conference: 18 July 2018
GC Training: 19-20 July 2018
During the conference we will introduce our product as well as our company capabilities in to Indonesian market. The conference agenda will be as follows:
- Background of i-Vigilant
- GCAS software introduction
- Discussion of case studies that we have found such as:
- Error of £300K /month was found due to calibration error
- Error of £6 Million /year was found due to heavy end drop out
- Potential error was identified 2 months prior to actual error happened. The early error indication helped minimise downtime
- Error identification in calibration gas concentration
- No objection letter from OGA UK (Oil and Gas Authority in UK) for the use of dual level calibration method on GC maintenance
- Discussion on i-Vigilant support model
- Discussion about GC maintenance practices in Indonesia:
- What is the current maintenance regime
- Is there room for improvement
- QA session
We will then go into the training of analysing GC data with the help of our unique GCAS software with patented “near live” uncertainty technology. The training will be conducted at the same place between on 19-20 July 2018. Below is the agenda of our training:
We would like to invite GC end users in Indonesia and the region around for this event. Lunch will be provided as well as dinner on the last night of the event. This event will be presented in Indonesian language. Please contact us at firstname.lastname@example.org to book for your place. We look forward to seeing you there.
So we have set the GC into a healthy state earlier. We know it’s healthy as we tried the all possible valve and event timing and find optimum point for valve timing. What we do after this exercise is to set the healthy calibration result as a footprint. This footprint is the one to be used for reference for any future data comparison. The following is the footprint that is taken from 20/6/2018 11:31.
Once we have a healthy footprint, it is now time to monitor the health of the GC. To get more data in faster, We have set the GC to calibrate every 6 hours. This way we can see the GC performance based on the calibration result. Up to this time when this is written, we have already done 30 calibrations. Based on this 30 calibration data, we can determine the uncertainty of the GC. We won’t explain the procedure to get the uncertainty of the GC here, however this is a very powerful tool to ensure health of the GC. By monitoring the calibration result of the GC, we will know the natural variation of the calibration result. Therefore, at any single point in time, we would expect the uncertainty of the CV measurement to be on a certain range. When the uncertainty start to increase, we know that the GC is having a problem or begins to have a problem. On our case here with the “LIVE DEMO” GC, based on the uncertainty trend we know that the GC is healthy. The following is the uncertainty trend of the GC after 30 calibrations.
Now that we know that the natural variation of the GC will result in uncertainty of around 0.103%, we can then set an alarm limit. As there is no standard talking about this, we currently set the limit to around 0.005% higher than the highest detected uncertainty so far. Therefore we set the alarm limit at 0.108%. The uncertainty trend with the limit will now show as follow:
Performing this removes the need of monthly repeatability test as we are performing an automatic “reproducibility test” by looking at the calibration result and interpret this as an uncertainty value of the CV calculated by the GC. When the GC starts to drift, the uncertainty will start increasing and we will get an early warning of fault with the GC. The following trend shows an actual case where the rise of the uncertainty flag an issue around 2 months prior to the actual failure happen on the GC.
On another case, we also found that there’s a sudden increase of uncertainty as shown below:
Because of the sudden increase in uncertainty, GCAS flags up the operator by raising an alarm. We can then dig deeper on what’s causing the issue. From the RF trend, we then identified that the problem came from propane response factor as shown below:
We can then take an appropriate action before mis-measurement actually happened. The increase in uncertainty only impacted the accuracy of the GC by small amount and by rectifying the issue before the issue becomes big we have managed to avoid a potential failure or mis-measurement on the GC.
We just did C6+ GC configuration to show how to configure GC from scratch. In this instance the original GC was a C7+ GC. We then did all the changes required to make it a healthy C6+ GC.
Here’s a quick steps of what we’ve done on this exercise:
- We changed the component data table to C6+ GC component data table:
- We then changed the event timing step by step where initial RF trend looks like this:
- To an optimised GC with final RF trend that is set as footprint as follows:
- After this exercise we currently do the following:
- long term repeatability test using the same test gas
- Calibration every six hours to demonstrate the GC uncertainty monitoring
- Up to now, the repeatability have been showing very good result, the following is the CV trend so far between 20/6/2018 12:49 – 22/6/2018 12:00 (2 std deviation of +/- 0.011% which is much better than stated repeatability tolerance of this GC of 0.05%)
- This is the first step of GC configuration, the next step is to monitor the performance of this GC. On next post, we’ll post about the monitoring of this GC using the near live uncertainty method. This GC is on 24/7 and we’ll be calibrating it every 6 hours to demonstrate how to monitor the GC uncertainty value based on its calibration results.
If you want to get a step by step analysis file including the chromatograms of this exercise, this is available in our web-based support system. Please be in touch with me and i will be happy to give you access. You can also be involved by discussing this as well as give advise on what you want to try next on the GC and we can simulate the issue. The web based support system looks like below where you can all add comment etc.
Please leave a comment if you have any query, or alternatively you can send me an email to request access or if you have any other queries to email@example.com.
Also for our Indonesian colleague, we will do free conference and training between 18-20 July 2018. This exercise can be used as a discussion points for our conference and training. So please be in touch for your free account to our support system to gain access to the detail off this exercise.
I’m so happy, we’ve done the first GC surgery. Hopefully this is the first one among many. I thought it was great, but i look forward to hearing what people are saying about it. I have to apologise to few of the people that try to attend and failed. There are few technology glitches where WebEx only allowed maximum 25 people to login at the same time. Because of the issue we have now upgraded our WebEx to ensure that we are capable of hosting 100 people in the same room through a better service more suited for a webinar.
For the people who missed the surgery, I have made a recording of the presentation and can be accessed on the above link. We do have few questions that came up from this surgery. Here are some of the questions:
Q1: Does atmospheric pressure affect the response?
Q2: What happens if you have to change a column?
Q3: Typical traps to avoid when optimising GC’s? i.e, in your experience most regular types of failure?
Q4: Are all GCs the same in terms of the diagram that you showed?
We have created a GC Surgery group in Linked in, and to begin with we’ll discuss this four questions. And if anybody want to talk about any other GC issues, for instance how does a flow diagram looks like on other GC other than Daniel, and other type of GC such as the C9+ and the C10+ etc, please feel free to post a question in the surgery forum which I hope can be an environment for us all to share our experience on the GC field.
The next GC surgery will be on the 8th of March, we’ll discuss about how to interpret GC calibration data. I look forward to see as many people as possible there. This time we’ll make sure that everybody will fit in the room as we have upgraded our WebEx to cover more people :).
I’m just really excited to say that I’ll be presenting series of GC surgery using WebEx. It’s free for everybody to register. Detail can be seen in i-Vigilant website News section: http://www.i-vigilant.co.uk/news/detail/gc-surgery.
everybody is welcome, from people who don’t know anything about GC, just want to learn something new, or even GC experts who maybe able to share some of their experiences. We have been having great response, and I hope that a lot of people will join us.
The first session will be an introduction to GC. We’ll analyse GC flow diagram as well as look at how time events are configured in a GC. This course will be based on Daniel GC, but of course most of the principle can be applied in other GCs. This will be happening on 23/2/2016 at 2 pm UK time.
If you have any questions or just want to be in contact, you can comment to this post or send me an email at Anwar.Sutan@i-Vigilant.com.
i-Vigilant Technologies Ltd was founded in 2012. We are an innovative technology company dedicated to provide high quality consultancy and services to the oil and gas industry. Based in Aberdeen, Scotland, i-Vigilant provides Gas Chromatography maintenance and consulting, training and condition based monitoring software as well as flow measurement consultancy services.
Our mission is :
(1) Maintain GC accuracy throughout the year by:
• Providing expert system to predict failure
• Providing uncertainty calculation to quantify performance of the GC
(2) Develop technician competency in GC maintenance and troubleshooting
We will use this blog to extend our mission and get the industry to find out about our innovation as well as many discussions on our GC surgery sessions.