Naturally flowing oil well diagnostic

[ahmedj9579]

Dear Pet people,
we got an oil well producing naturally for more than one year then the well start prodducing like a cycle (production naturally, shut in for build up due to lose of naturally flowing then re-open the well to produce for a while).
We plan to perform a static pressure measurement then a flowing measurement (including a surface production test).
We doubt about an increase in WC for the lose of naturally flowing.
Please is there any procedure or steps to follow to analyse the phenomena and find solution to bypass this shut in period? (keep the well flowing all the time)
Regards

[ahmedj9579]

please help....

[ivan_aljeburi]

Do you have water in production ?Is the reservoir pressure good enough to provide a natural flow? My advice to you is to run a multi rate test with with 3 different chokes and record a bottom hole flowing pressure. And then shut the well for build up test. This is necessary in order to obtain data for a well problem analysis.
Try to check the reservoir permeability,skin and reservoir pressure from PBU. Afterward try to estimate your IPR curve using several models (PI, Vogle, Fetkovich..). Making all these analysis will help you to get a better picture of your well and predict WC


Best regards

[ivan_aljeburi]

Do you have water in production ?Is the reservoir pressure good enough to provide a natural flow? My advice to you is to run a multi rate test with with 3 different chokes and record a bottom hole flowing pressure. And then shut the well for build up test. This is necessary in order to obtain data for a well problem analysis.
Try to check the reservoir permeability,skin and reservoir pressure from PBU. Afterward try to estimate your IPR curve using several models (PI, Vogle, Fetkovich..). Making all these analysis will help you to get a better picture of your well and predict WC


Best regards

[ahmedj9579]

the reservoir pressure is good enough (strong aquifer), we got also another problem that the bubble point is very close to reservoir pressure. we already try the test that you propose and we conclude that the best choke to use is 28/64"(moderate GOR and continuously production) .but after more than one year, and with the same choke we produce for some days then the well died.we need to close it before reopened it.
In term of practical analysis, i propose to RIH gauges , to record static and several days of flowing pressure with the same choke size. that we already used before the problem appear. once the well died, we reopened with another choke size.my question here is how can i analyse the problem when i retrieve the data from the gauge?

[ahmedj9579]

the reservoir pressure is good enough (strong aquifer), we got also another problem that the bubble point is very close to reservoir pressure. we already try the test that you propose and we conclude that the best choke to use is 28/64"(moderate GOR and continuously production) .but after more than one year, and with the same choke we produce for some days then the well died.we need to close it before reopened it.
In term of practical analysis, i propose to RIH gauges , to record static and several days of flowing pressure with the same choke size. that we already used before the problem appear. once the well died, we reopened with another choke size.my question here is how can i analyse the problem when i retrieve the data from the gauge?

[ivan_aljeburi]

Is there any neighboring well that can affect this well ? i'm a little bit confused..did your WC increased over time ? i thought you might have loading problem, but as the reservoir pressure is high it could not be possible. Try to record pressure gradient while passing down in dynamic conditions at let say 100m for 5min and then do the same thing in static conditions so you can see is there any water in the column. When you retrieve DHMG, try see if you BHFP is increasing over time .. i suppose you should install gauges as much long as you can so you can see the pressure profile . Pressure transient analysis is highly required. If you want send me the previous pressure data so i can take a look at it

Regards

[ivan_aljeburi]

Is there any neighboring well that can affect this well ? i'm a little bit confused..did your WC increased over time ? i thought you might have loading problem, but as the reservoir pressure is high it could not be possible. Try to record pressure gradient while passing down in dynamic conditions at let say 100m for 5min and then do the same thing in static conditions so you can see is there any water in the column. When you retrieve DHMG, try see if you BHFP is increasing over time .. i suppose you should install gauges as much long as you can so you can see the pressure profile . Pressure transient analysis is highly required. If you want send me the previous pressure data so i can take a look at it

Regards

[drwho]

check your GLR, not GOR. once your well starts producing water, make sure that your GLR is sufficient to unload the water; otherwise the water will act as kill fluid and kill the well. regardless of how high your reservoir pressure is, if your GLR is low, the well will not flow. have you seen any water well (where there is no gas) flow to the surface by itself without a pump? Consider putting the well on artificial lift - gas lift, esp, rod pump, etc....

[ahmedj9579]

thank you. actually what we did is we RIH a memory Gauge and record static pressure, we leave the gauge and we open the well using 28/64" and we record all the rates on surface and flowing pressure. the well still producing now (let's say since 4 days). we plan to keep recording all data with the same choke size (because we succeed to keep the well flowing for more than one year without any shut in using this choke size) until further losing of naturally flowing.
@ drwho, how can i estimate if my GLR was enough to unload the fluid or not?.currently, i'm monitoring data that i received from the field.
regards

[ahmedj9579]

thank you. actually what we did is we RIH a memory Gauge and record static pressure, we leave the gauge and we open the well using 28/64" and we record all the rates on surface and flowing pressure. the well still producing now (let's say since 4 days). we plan to keep recording all data with the same choke size (because we succeed to keep the well flowing for more than one year without any shut in using this choke size) until further losing of naturally flowing.
@ drwho, how can i estimate if my GLR was enough to unload the fluid or not?.currently, i'm monitoring data that i received from the field.
regards

[drwho]

Use PROSPER, PIPESIM, WELLFLO or any NODAL analysis software. make sure you use flowing gradient to build your VLP curve. then sensitize on the GLR until the two curves do not intersect. at this time you know your estimated minimum GLR. alternatively, if you have any well in the field shut in due low GLR, then you have an idea.