Well Test for pumping wells

[amahaminer]

i have a question for oil well producing with sucker rod pump & includes a memory gauge set in XN below down hole pump & the well is producing for one month while the gauges are in hole.

Which is better for build up in this well , whether to POOH w S.Rods then shut well for build up or just to shut the well for build up while the rods are in hole?

[medori]

I believe it would be better to do the build up by just shutting in the SRP to avoid creating any disturbance while pulling the rods out of hole that misses up your pressure build up

[for_lon]

I'm agree with Medori. Sounds better to start the build up with the rods in the well. I think you won't get any advantage by POOH the rods, instead you will be at risk of getting kind of swabbing pressure on your gauges while POOH the the rods that will complicate the PTA interpretation.

I should shut in the well with no disturbance during the BU to get as good data as possible.

[Shakespear]

Take a look at the company named ECHOMETER. I believe they have done work and sell equipment for this.

[vinomarky]

If you simply want reservoir pressure and PI, you can get a pretty good approximation simply by performing a step rate change for a few days. If you need to deconvolve skin from the PI, then yes you'll need a buildup and I would agree with the above that there's no need to POOH.

With the step rate change approach, you will have two rates, and two bottom hole flowing pressures - everything else in the Darcy equation will be the same, so you can explicitly calculate the reservoir pressure (Or simply plot an inflow rate vs Pwf, and extrapolate back to zero rate)

[Shakespear]

Vinomarky

This is the paper that I recall regarding Echometer and well testing as per skin/reservoir pressure.

[link Point to another website Only the registered members can access] I know about this work because I was at the university at the time McCoy was working on this with my professor. However on their website I do not see anything on this subject. Perhaps it is not as reliable as initially was suspected.

[vinomarky]

I'm familiar with this sort of acoustic technology - there are a number of variants around, and we are testing some ourselves.

On plus side, it is real time and installed at surface (makes maintenance easy), while on the negative side downhole conditions (such as slotted liners etc) can make interpreting the echo returns impossible, liquid/gas interfaces can be frothy and uncertain, and liquid column density can be uncertain (need to use approach such as Podio correction if significant gas bubbling through)

Its a useful technology to know about, but not a silver bullet for every situation.