Find leak/hole on a submerged pipeline in dirty water using Infra-Red 1

[daddy12]

I need an infra red detecting equipment for my submarine instrument. My instrument is submarine robot that suppose to searched for leaks from pipelines submerged in dirty underwater condition. My thought is that the infra red would be developed from the hot oil leaking from the pipeline and be detected. The temperature of the pipeline or the exiting plume should be quite different from the surrounding water so that identifying the leaking hole on the pipeline should be easy. The problem is that I cannot find an infra red system that operates underwater. My problem is to lcate the point on the pipeline surface where the leak is occuring. Diver or working ROV cannot see in thsi water. What should I do?

 

[BigInch]

Water is an efficent adsorbent of all things IR.

Assuming you mean a pinhole leak, you might have more luck with sounic detection, or an actual temperature probe of some kind?

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso

 

[brimmer]

I think some of the ROV's are equiped mith multiple technologies these days to detect leaks - optic systems with black light for flourescense techniques, acoustics (hydrophone) to lsiten for leaks, hydrocarbon detection sensors, temperature sensors for differential temperature measurement techniques, MEG sensors.

Something like a SmartBall from Pure Technologies would most likely work if you can lauch and receive it in the pipeline.

 

[IRstuff]

Water pretty much absorbs anything remotely IR.

Seems to be pretty late to the party.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[BigInch]

What party? Where? When?

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso

 

[IRstuff]

"What party? Where? When?"

Seems to me that it's all but over, given the number of hits I got for "leak detect rov"

Just to recap, the market already has:
> laser leak detector
> sniffer leak detector
> acoustic leak detector
> fluorescence leak detector

http://www.ngoilgasmena.com/article/Subsea-leak-detection/

Admittedly, I didn't see an ORV with ALL the sensors...

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[daddy12]

Thank you so much for the contributions.
I am a diver and do work with ROVs too but I still need help here. This is a real problem not theory.
-If the pressure is not much and the not a pin hole, there may not be enough acoustic to trace the hole.
-Sniffer and Scanning system means that the ROV operator directs his ROV to sniff or scan the section of interest. BUT THIS IS DIRTY WATER, HOW WILL THIS HAPPEN? THE OPERATOR SEES NOTHING ON THE SCREEN. If an answer can be found here, scanning can be a way out.
-I found this IR pix in the internet. If IR is absorbed in the water, what does the pix really show. See attachment.
- I was actually thinking of away of tracing the hole through the plume...but how will the ROV swim through the plume without a trace for the operator to follow. ROV is a machine. The brain is with the operator. If the operator can not see to push his joy stick, ROV is useless.

I am just struggling with thoughts. Help out please.

 

[MikeHalloran]

I'm thinking that if the ROV could _find_ the surface of the pipe, and maintain station against it, e.g. by powering into it with V-shaped locators, or clamping onto it somehow, then it should be possible for the ROV to use what would possibly be its _third_ arm to mechanically scan the volume adjacent the pipe with a conductivity or temperature probe, mapping the volume.

That would have to be done 'open-loop', i.e. with the arm knowing limb lengths and joint angles and calculating and controlling the probe tip position, without operator or joystick involvement.

Scanning at coarse resolution should find the general location of the plume, which could be mapped at finer resolution in a second step, perhaps with operator guidance, using a computer display of the mapped points with false color for temperature or conductivity, maybe even in 3D, given current toy technology.

Assuming the arm and probe are sturdy enough to not be blown off or subsantially displaced by the leak flow, and recognizing that the process of mechanically scanning a volume has to be slow, it could still work.


I can't, er, see, any imaging technology work in opaque water, except maybe acoustic imaging, but I don't know if you can get the resolution you'd want with acoustics.




Mike Halloran
Pembroke Pines, FL, USA

 

[daddy12]

It appears to me that underwater visibility has relative definition. Mr A with good eyesight in water would see better than Mr B with no so good eye vision. Does this make sense?
Is there any tool to measure underwater visibility?

 

[StoneCold]

Here is an idea for you. You can be the judge if it is a good one.
If you can get the ROV to straddle the pipe, attach a plastic sheet to the ROV like a drag line with weights at the bottom.
Introduce a gas into the pipeline. Focus the camera of the ROV so that it is looking at the Plastic sheet. Back the ROV along the pipeline. When you pass over the bubbling spot the bubbles will travel up the drag line sheet and go past the camera. Then you have found the basic area of the leak. Sounds good on paper. Currents and other real world items might cause some problems.
I guess you could also cover a 40ft or 80ft section of the pipe with a larger half pipe with seals on the end and a vent in the middle. Then just watch the temp etc at the hole in your pipe.

Both ideas try to take a three dimentional problem and make it into a one dimensional one.

Regards
StoneCold

 

[hydrac]

I've only been in the ROV industry a short time, so I could be a bit off.
I think that IR was used by research vehicles right after Deepwater Horizon, and I'm pretty sure that I've seen IR underwater before. Maybe FLIR makes something?
If not, all you would really need is some kind of material with the same thermal properties as water. I know that hydrophones are potted in "acoustically neutral" material, so it transmits sound at the same speed as water. There must be a "thermally neutral" potting available.
Otherwise, if you could get something attached to the pipeline, so that it was near the surface, a regular temperature sensor should do the job

 

[daddy12]

StoneCold, so you believe that it IR is not absorbed by water. If this is true, it appears then that IR could be able to give us trace.

How do I get an IR system to try?

 

[StoneCold]

Daddy12
I did not say anything about IR, hydrac did.
I was just trying to solve your problem with bucket and a hose from Home Depot.
My way may not be elegant but it will determine the location of the leak.

Regards
Stonecold

 

[daddy12]

I switched the names.Sorry man. I have a baby ROV and will try the plastic ideology. I will let u know what the progress.

 

[IRstuff]

The Gulf oil spill was monitored above sea level with airborne or satellite infrared:

http://www.spacemart.com/reports/NASA_Captures_Night_Infrared_View_of_Gulf_Oil_Spill_999.html

Thermal infrared can't pentrate water. Near infrared can, up to a point, but there's no thermal sensitivity there.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[daddy12]

Thanks for the clarification IFstuff.
Can I get near infra red system that can be used in water? I expect that for this to be applicable in my case, the ROV will carry the near IR stuff in water.

 

[BigInch]

No. The satellite monitored difference in IR adsorbtion between water and the oil slicks, but as seen only at the ocean surface.

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso