Newbie Oil Production Automation Question!

[cmoney]

Hey everyone. This is my first post to the site. I've got some questions on a job I'm looking to do and could use some advice.

Quick background. I've got a couple years in with an automation company that works with oil/gas and water systems. I was hired to work on HMI Programming and handle Communications. I have 15 year ***perience in IT and networking. Picking up the HMI programming was fairly easy for me but I'm starting to get more involved with the programming of PLCS. Plenty of experience with instrumentation like pressure transmitters, tank sensors, switches, flow meters and work a lot with Schneider Clear SCADA and SCADA Packs.

Heres what I'm looking at. A small oil production site with 4-5 producing pumping units. A couple injection pumps for disposing of water. Approximately 6 tanks holding oil and production fluid. All within 1/2 mile radius. The owner is wanting to set up remote access to monitor tank levels, pressures, run statuses and some automated controls that will turn off well sites on high tank levels, send alerts on high/low tank levels, etc.

Keep in mind I don't have a lot of experience with setting something like this up from scratch, but here's what I'm thinking.

I'd like to go with an IP network. Point to multi point to get all the different sites "talking". Probably Ubiquiti or Cambium. Cheap means of communications.

I don't have an office or anything to house a server so looking at the possibility of a Beijer screen for HMI and alarm notifications. Also looking into the Flexy but I need to research it a bit more.

I guess my question is, is IP networking the way to go here? It's cheap! $50 a radio per site. Will I need PLCs at each site to handle the tank level data? Most of the sites I'll need I/O as well as relay outputs to turn off a pump or a motor. I can draw out a diagram if that helps.

I am a little unclear on whether or not I need PLCs at each site or just some sort of remote/IO device that gathers the data and can be sent to a primary PLC that handles the shutoffs, setpoints, etc. Will a Beijer screen and PLC alone (and of course a WAN connection) allow for remote access for monitoring?

I'm new to the PLC world so wondering what would be the easiest to learn on. I'm somewhat familiar with ladder logic but beginner level. I also need to keep cost very low here.

This may be a bit vague so excuse me for that. Let me know what additional information I can provide.

 

[BobB]

You could use a main PLC with Ethernet IP communications built in. You could then use Ethernet IP remote I/O through the radios. You would have to make sure the radios do not drop out or the PLC could go into fault if a remote is lost - all depends how you set it up.
Just doing a job with an Omron CJ2M with an Ethernet IP port and all I/Os are Ethernet I/O - suits the job as remotes are all over the pplace, Wire and fibre though - no radios. Cannot help you there.

 

[cmoney]

No worries on the wireless network and it's reliability. It will be super reliable with way more bandwidth then they'll ever know what to do with.

I was looking at some click PLCs at a u t o m a t I o n d I r e c t . c o m that support Ethernet communications for less than $150. I thought I could use it as the primary as well at each of the other locations. And super affordable solution at that cost.

I did a little reading on the remote I/O. So you are saying use a primary PLC that will talk to the remote IO devices at each of the other sites? Are the remote I/O stations designed to be used in this exact type of setup? I see they have devices with multiple inputs and output relays. Any recommendations on a remote I/O device?

 

[cmoney]

Also looking for low cost tank level sensor suggestions if anyone has them. It's oil/gas so I think I probably better stay with the explosion proof, higher rated instrumentation, correct? For a seimens non contact ultra sonic or comparable brand I'm looking at right around $1,000. I could go pressure transmitter and convert to tank level but this is salt water combined with oil, so I'm afraid my reading will not be accurate enough on 10 or 15 foot tanks.

 

[cmoney]

One of the reasons I'm going IP wireless network is from my experience a serial 900 Mhz transnet runs $500+ plus antenna, cabling, etc. I can go IP for more than 50% savings. Unless anyone has recommendations on other serial radios.

 

[Toine]

Here's a point to keep in mind when selecting remote I/O's.

If you use remote I/O's with ethernet through radio communications, what does the I/O do when the connection drops? Although you can built it pretty reliably, you must assume connection will drop occasionally. Will all inputs and outputs remain in the position they were just before communication went down? Especially relevant for outputs. You may want to build your control system in such a way that outputs go to a fail safe position when communication fails. E.g. pumps off, valves closed. Or pressure release may be safer to turn open. Safe position for each output is to be determined by a good understanding of the systems at hand. I would not use remote I/O's that remain stuck in the last position when communication to the controlling PLC drops. At the very least use something that makes all outputs go low and wire the hardware that is driven by these outputs accordingly (output low = safe position).

Same but other way around for inputs: if communication drops, assume the input is in non-safe position and react accordingly. Make sure you show communication drops to an operator, preferably log when connection is not monitored continuously and coms may go down and come up again before the next operator look at the system.

 

[DwSoFt]

I'd recommend in this scenario you use an RTU at each site. I wouldn't trust a shutdown to a network. Unless of course the tanks are at a central location away from.the pumps. Then a failsafe network.may be the way to.go. You are familiar with the scadapacks already so why not use them?
Nothing wrong with having an IP network for the data gathering and if it's cheaper why not.
As far as the central point. Does this client have more that could be added later to this or is this everything they have. If it's very small a standalone HMI polling all the sites may be pretty nice as long as if u need it to send data from.one rtu to another it can.

 

[cmoney]

i gotchya. Now I'm seeing how the remote IO devices will function in the event of a network drop and how that could be a disadvantage.

At a couple of these locations all I will be doing is gathering data. So nothing but a tank sensor.

I'm thinking what I may look at doing is a simple PLC at each location. It will be connected Ethernet and talking to the level transmitter, pump, pressure transmitter, etc. at $125 for a basic click plc that's fairly inexpensive for a controller IMO. Then have local controls at each site and not worry about the remote IO problem of the network going down or packet loss type of scenario.

In the world of PLCs can I mix and match controller manufacturers when using Ethernet communication?

 

[DwSoFt]

Scadapacks with the Ethernet port talk Modbus TCP. Your hmi or scada software needs to support Modbus TCP. If you want the local.plc to poll the data directly from the scadapack it needs to as well. For modbus TCP on allen bradley I use the Prosoft in rack cards. But if you don't need it direct then it's not needed. Long as the HMI/scada supports it. It's all about what you want to do.

EDIT
The click plc is a nice alternative. Just make sure it is not anywhere near production equipment as I don't believe it is rated Div2 such as RTUS are

 

[cmoney]

I'd recommend in this scenario you use an RTU at each site. I wouldn't trust a shutdown to a network. Unless of course the tanks are at a central location away from.the pumps. Then a failsafe network.may be the way to.go. You are familiar with the scadapacks already so why not use them?
Nothing wrong with having an IP network for the data gathering and if it's cheaper why not.
As far as the central point. Does this client have more that could be added later to this or is this everything they have. If it's very small a standalone HMI polling all the sites may be pretty nice as long as if u need it to send data from.one rtu to another it can.

I'm beginning to see why I may want to go with RTUs at each site. I mentioned Schneider scada packs that I have experience with. From my experience, the scada packs are pricey! I'm sure a scada pack 100 or the next step up that supports Ethernet is going to be close to a $1,000 correct? Are the mpdocons a cheaper alternative?

For the central point, this will be it for this specific field but there are plenty of other production sites in the area that could be brought onboard if the price is low enough. One thing I thought about was a tower install at this location which would IP relay this field data to a local HMI server stored in an office. Then we could bring future sites into the same HMI system

I know with clear scada I could throw in a WAN cell router and poll the network remotely. But there again, clear scada licensing is several thousand dollars + server costs. But that is one option.

 

[DwSoFt]

Yes they aren't cheap that's for sure but as my.edit said they are DIv2 rated unlike the click. This allows the cabinet to be on the outside of a production building vs all on its own away from everything. Just something to consider. Honestly if you.arent doing gas measurement with the scadapack as well then it may be overkill. But maybe that could be a future option as well. LOL

 

[cmoney]

I'm somewhat familiar with the rating on the hardware. Should I be looking at going with the div2 class rating on all the equipment so install, including PLCs, pressure transmitters and tank level sensors?

 

[cmoney]

I'll be dealing with h2s gas as well as oil so the div2 is something I definitely need to factor in

 

[cmoney]

Any other div2 PLC more affordable alternatives you can suggest?

 

[DwSoFt]

Is gas metering a possibility? what is currently metering the gas, a chart recorder?
Id Hate to recommend a PLC if it is a possibility, but if its not then a cheap plc will be the cheapest option.

I believe some of the AutomationDirect PLCs may have the div2 rating, just trying to look that up right now.

As far as the instruments, they should be at least div2, maybe even div1 if its at the wellhead or inside a building.

Again, if the cabinet is 10ft+ from any gas venting source or building it could be general class. sometimes this means that if you put a small tower up for communications, the cabinet is mounted on the tower. up here though this leads to very cold equipment lol.