water injection pump issue 1

[johngladstone]

Dears ,

i looking for your help my manager give me task to determine the size of booster pump suitable to pumping water into water injection pump multistage operate with 55 KW electrical motor to raise the pressure from 500-800 PSI to make injection into well .

this is first time i dealing with this subject ,kindly i looking for your help to give me any text papers any any advise to put the parameters in the consideration to make the subject successful .

Thanks in advance .
Br
John gladstone .

 

[TD2K]

http://www.pumpfundamentals.com/goulds residential pump guide.pdf

Start on page 20.

 

[johngladstone]

DearTD2K
I appreciate for your quick response but I need how can determine the proper type of booster pump size as pressure and flow rate to be contnous supply into water injection pump for oil christmas tree

 

[LittleInch]

You need to know flow rate, liquid density, inlet pressure or head and outlet pressure or head. You also need to guess an efficiency for your pump (70% is a good start). If you don't have this information you can't work anything out.

Then look up "power calculation for pump" or better still call a pump vendor or fill out a data sheet and send it to a pump vendor with that critical information I listed above. That gives you shaft power. You then need to factor in motor efficiency (say 90%) to get electrical power required.

Why has your manager given you this task without asking or knowing if you are capable of doing it? Far better to be honest with him/her and say that you need some guidance or teaching on how to do it. You could get this horribly wrong if it is assumed you know what you are doing when clearly you don't.

Get the data above, work it out then come back to the forum to see if you got it right.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[TD2K]

Booster pumps are centrifugal pumps and are intended to supply the necessary suction pressure for the high pressure injection pumps. They 'usually' aren't very high head pumps. You need to understand the system that the pump(s) are installed in and the flow/pressure requirements of the high pressure injection pumps to be able to specify them.

As LittleInch said, your manager should not have given you this assignment without a better explanation and direction to you. You're going to get frustrated, they aren't going to get what they want.

 

[johngladstone]

Dears
Actually the system will be water injection pump system for christmas tree .the system required as follows
Discharge pressure of water injection pump must be 500-800psi to get this the section pressure must reach 80psi with continues flow rate .
Because when we start the system the water injection pump was evacuate the line within milisecond .so I looking to get better booster pump can give continues and higher flow rate to guarantee water injection pump was operate properly continously.
Please advise is there any reference
To guide me I will appresiate

 

[LittleInch]

Now we're starting to get somewhere.

Be an engineer and sketch your system, scan it and post it here with pressure, flow, line size, distances etc marked on it. Or post the P & ID

From your posts my understanding is that there is an existing pump which has an inlet pressure of about 80 psig and an outlet of 500 to 800 psig as water injection. You're having problems on pump start. This sounds to me like there is no flow control to slow down the main injection pump? Is there any control valve between the pump discharge and the well head?

Please describe your system and how you start this pump.

The issue is probably that your injection pump is starting too fast and running off the end of the curve before the pressure from the well rises. By the way a pressure output range of 500 to 800 psig is a lot.

Maybe a PD type pump would be better.

I await more data with interest.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[SNORGY]

Also sounds to me like you want to take a look at your startup and shutdown logic. You want to start the booster pump first and, on shutdown, shut the booster pump down last. The 80 psig on the booster pump discharge is unusual to me. I usually like to arrive at the injection pump suction at around half of that pressure. If your injection pump is multistage, can you add one more stage and reduce the booster head requirement? Otherwise you are probably going to want to look at additional startup controls on the booster, if not already present. To run a pump up to 80 psig, even with soft start or VFD, prior to ramping up the injector pump, would be pretty hard on the system.

 

[DubMac]

Sorry Johngladstone but you have no business selecting this pump; even with the help of the experts on this forum. The best thing you can do for your boss, your company, and maybe your career, is to call in Sales Engineers from Sulzer, Goulds, and Flowserve to advise you on this.

You haven't even mentioned a flowrate, although i imagine it is probably too large to consider a PD pump. What type of bearing arrangement would you like? What type mechanical seals would it require? Have you thought about materials of construction? Wear rings?

People on this forum are very knowledgeable and helpful, and I recommend you keep using it. For this problem however, you can make a very expensive "beginners mistake". Do the right thing: go call a Pro and let them make a selection for you and explain it to you at the same time.

 

[Artisi]

DubMac A star for such good advice. To the OP, use your engineering skills to make a good engineering selection based on the advice / selection from competent engineers- more mileage for you than making a stuff-up.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[GHartmann]

My goodness, maybe I am obtuse, but I don't understand the system being designed.

Are you saying you have a multistage injection pump with 80 psi suction / 500-800 psi discharge and 55 kW motor

That would be a fairly small flow


You won't get anywhere without a flow (pretty basic pump concept) plus inlet and discharge head of required duty

(what is booster pump suction pressure?)

Right now we do not have enough information to be helpful

 

[rotw]

You could visit KSB website they have an online selection tool.
However given your limited knowledge I suggest you do NOT select a pump and present it to your boss as the solution.

Instead you could try running the online tool ; this will help you to familiarize with what type of input is needed by the guy who will select/size the pump for you but also you pick up a pump and go to its catalogue.

Big frustration from pumps application engineers is to see non consistent / incomplete data in a request for quote.

http://www.ksb.com/ksb-en/KSB-EasySelect/

You need to know the head, flow as minimum.
I also suggest to read upfront some basic theory of pumps

http://en.wikipedia.org/wiki/Centrifugal_pump

"If you want to acquire a knowledge or skill, read a book and practice the skill".

 

[SNORGY]

I assume by "section pressure", you intended to type "suction pressure".

720 psi is about 1660 ft differential head.
QxHxSG/(3960x.65) = 73.75 hp at about 114.4 USGPM with a pump efficiency of 0.65. (~26 m^3/hr).
That takes a standard 400 barrel tank from approximately full to approximately empty in somewhere between 2 and 2.5 hours.

I've seen more, I've seen less...anyway...

Taking 114.4 USGPM from say 9 psig to 80 psig (assuming a tank static head height of 20.79 ft) is 71 psi differential.
71 psi differential is about 163.7 ft. I like to be a bit left of BEP with a booster, so let's say the efficiency on the booster pump, somewhat left of BEP, is 50%, just to be conservative.

QxHxSG/(3960x0.5) = (114.4)(163.7)(1.0)/(3960)(0.5) = 9.5 hp

So, maybe get a 10 hp pump. As a check, assume you wanted to do this with one pump with an efficiency of 65%.

QxHxSG/(3960x0.65) = (114.4)(791*2.31)(1.0)/(3960x0.65) = 81.2 hp; you appear to have 73.75 hp (55 kW), so the 10 hp booster makes sense.

 

[johngladstone]

Dears ,
really i appresiate for whole of you ,i make system layout to clarify the point ,please see the attach .

Br
Osama A. Nasher

 

[LittleInch]

John / Osama,

Your sketch doesn't really add much, apart from wondering why you have two sets of filters, but the key was in your previous post


This is to do with your starting sequence and how you control flow from the pump and has nothing to do with the booster pump.

Fix this problem first then worry about the pump later.

This is like having two cars which have the same maximum speed following each other. if at the traffic lights the first one is more powerful and sets off like a Grand Prix racer, then the second won't keep up and will fall behind. Both need to start more gently and move off together.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[rotw]

Had same reaction as LittleInch when I saw your sketch: it does not add more to your input.

I suspect the injection pumps have a design already known (for instance these pumps exist already) and may have high NPSH requirement so the booster pumps are added to satisfy the NPSH requirement of the pumps located downstream.

If it is the case then I would have a look at the performance curves of the injection pumps and starting from there I would define going backward what the requirement of the booster pumps are ...

But of course at this point, it is just guessing and speculating...

"If you want to acquire a knowledge or skill, read a book and practice the skill".

 

[itdepends]

I would suggest checking the OP's post history before attempting to help further, these are from some of his other threads. I don't see any evidence of formal training or attempt to preload/prelearn what he's asking about

Dears
Is there any website avilable can found any spare part required for any model of gensets???????

i am seeking for excell sheets for mention master mastinance plan for diesel generators and pumps in the process area .can some one help me to get this excell sheet

i am looking for your help ,is there pssible to give me any pdf , document explain the practical way to understand ASME standard and how we make practical calculation of Flanges rating , Gasket size and pipe size??

can i know the schedule require for greasing of bearings for motors and pumps when it is operate 24 hr per day and when it is shutdown for six month??

As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"

 

[Artisi]

And some complain about students asking questions - maybe posts like this should be given the same treatment.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[DubMac]

I would like to build a small 20HP pump rocket to go to moon. Can someone please design for me and explain how and why it works?? I would also like all applicable specifications and a complete spare parts list.

 

[Artisi]

DubMac
You posted in the right forum, we can do anything plus it comes F.O.C

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)