9 replies to this topic

[Himanshu Sharma]

Dear All,

I would like to discuss a pretty unusual (at least to me ) raw water system where in we have to pump out water from a well that’s approximately 1500 Meters deep, over that an additional head of 150 meters is required with a huge flow rate to cater to entire refinery.

Is anybody aware of type of pumps being available for these kinds of services?

Is there any other method like Gas injection in Crude well is applicable here??

[Art Montemayor]

You have a formidable problem.

By not giving us basic data such as the required flow rate, you limit our comments and recommendations.

For the service, as described, the only type of pump I can think of is an electric-submersible type. However, these types of pumps are limited to a maximum flow rate that may fall short of your requirements. I would guess you are contemplating a flow rate well in excess of 1,000 gpms.

Considering the depth you cite, I would not consider a shafted, deepwell turbine type of pump that has the motor drive at grade. I don't believe anyone would consider the length of the shaft bearings required.

Note: This is NOT a suction lift problem. No pump could "lift" this depth!

[Himanshu Sharma]

Thanks for the kind reply Sir !

i asked this while trying to calculate the costing inputs for various source of raw water available(water is real scarce nearby),my intention was to check that if this alternative is technically feasible or not !!!

I am yet to estimate the entire flow rate requirement for entire refinery complex,will come up with the figure in a day or two

However since this will cater to a whole 7.5 MMTPA refinery i anticipate the flow rate to be much larger than the range specified.

After a fair amount of research on INTERNET i could come up with the idea of ESP and some vendors claim that they can provide up to 64000 bpd or more for a depth range of 10000 ft.

being specific i am aware for these kind of systems been used in Oil wells ,are the same been ever used for water !!!

[Art Montemayor]

Himanshu:

You are not giving specific basic data. For example, you don’t tell us if you are proposing supplying cooling water for an oil refinery on a once-through basis or as make-up to cooling water towers. You don’t even give a “guesstimate” figure.

Your figure of 64,000 BPD of oil is equal to 1,867 gpm. That may well be what you need as cooling water tower make up. You should make a calculation on what that flow of water at 2,450 psig discharge (the pressure head the submerged electric pump has to overcome) will require for an electric motor horsepower. That will give you an idea of the size of motor, the size of the well diameter , and whether the idea is feasible or not.

Bear in mind that it is being assumed that the dynamic water level of the deep-deep well is not going to fluctuate deeper while the pump is working (which is not true). You will have to first drill well(s) that prove that the water is there. Then you will have to verify and confirm that the dynamic water level can be trusted to go no lower than is required – while pumping at rated capacity, year-round. All this work and investment has to be done prior to starting the detailed engineering on the refinery in order to justify the basis of using such a system. This is a big, infrastructure front-end engineering investment.

I know that electric submersible pumps can be used because I've used such pumps in hot crude oil production on an Ecuadorean project. The idea works. But, as I've said, the type of pump is limited to a certain capacity and you require an ability to drill the required well diameter for the pump's motor.

[Zauberberg]

Why would you consider 1.5km deep Well for water supply purposes? It sounds like a scientific experiment and certainly not as the way of providing reliable cooling water supply. Whichever technology you employ, my guess is that you will need a lot of additional facilities just for providing the required water quality before sending it to the cooling tower - separation, stripping, chemical injection, who knows what else.

I would say that even if you are based deeply in the Saudi desert, looking for supplying sea water to the plant would be a less costly and less risky option.

[Himanshu Sharma]

@Zauberberg

Sir ,

with due respect i would like to contest your statement,many a times i ridiculed an idea because it was not conventional and was not sounding 'right' as per my Process Engineer's Mindset.

but recently i carried out a number of feasibility studies(Conceptualizing +costing) ,many of them had an unusual outcome that surprised everyone including me...

Just want to study this idea,as an engineer i should be able to provide facts and figures even if i have to conclude that 'this idea is not feasible'

as for the present case the water quality from well is amazingly good as compared to sea water in terms of TDS,acidity etc,you may save good amount of capital investment in terms of admiral brass!!!

@Art,

sir,

Your post not only enriches technical side of the argument but the presentation part too !

It was a holiday here ,could not get the figures for flowrate.

This will be a recirculating water system,
water is available at much shallower height but this is the design case for the pumping operation.

[Himanshu Sharma]

Sir/s

Sorry for this late addition of data

Water Flow rate required is about 2000m3/hr.

water is available at 1km depth but pump has to be designed to take suction up to 1.5 km depth.

Any idea how to deal with this problem,considering only this alternative !!!

[Art Montemayor]

Himanshu:

I believe I already told you my idea of how to deal with this problem, so I won’t repeat myself.

9,000 gallons per min is a formidable makeup water rate. You will require various wells to justify this type of flow rate, I suspect.

Since a picture is worth a thousand words, I am attaching a set of photos of the type of pump I have described. The file is very large, even though I have compressed it.

Attached Files

•  Electric Submersible Pumps.zip   6.38MB   41 downloads

[kkala]

A few additional comments on the issue are following.
1. Environmental
If understood well, intent is to transfer 2000 m3/h of water from a depth of 1000 - 1500 m to the globe surface through a well. It seems this is a normal well, not a tunnel connected to an underground cavity (full of water). There is serious doubt that statuary authorities would permit this installation, negatively affecting arrogation of neighboring land (I heard of similar event with Coca Cola company in India few years ago). Concerning Greece, underground water level was statistically at 8 m depth (October), but cases of drilling from a depth up to 300 m have been recently reported with much anxiety, since sea water intrudes into the underground land (replacing mild water) and desertification starts. Probably investigation of this matter is of first priority, to exclude the well alternative in case of no permit. Authorities may ask for an environmental impact study, then services of an experienced geologist will be needed.
2. Technical (supposing environmental matter has been settled)
- Air injection could have been an option to examine, in case that the water is in an underground cavity of impermeable walls, strong enough to withstand a pressure in excess of 150 kgf/cm2. Present case does not seem so.
- Water flows to the well through natural underground channels etc. Their flow capacity must be higher than the flow rate to the earth surface, as pointed out by Art Montemayor (constant well level, post Sept 1st). Chances that their capacity is higher than 2000 m3/h seems remote. Again an experienced geologist can advise.
- As said in previous posts, submersible pumps could be a solution (though used in wells of much shorter depth)

[kkala]

Referring to Environmental issue, following views were traced in work place , which may not be precise but not far from reality (concerning Greece).
1. Normal wells have quite a limited depth. In agricultural areas a lot of water is needed, then "deep" drilling is applied, after a permit by authorities to ensure neighboring wells are not affected.
2. By "deep" drilling we mean depth up to 180 m. Deeper drilling is considered financially unattractive, since water transferred by trucks gets cheaper (but have heard of deeper drilling).
3. The above does not mean that aquifer depth is 180 m, it is much less; water is found at this depth at flow rates high enough (not so high as 2000 m3/h).
4. Deeper drilling is realized for geological research.