fluid levels cbm wells

[rv13]

what would be the normal procedure to obtain a fluid
level in a cbm well - using the echometer and a belief in the accuracy of the information

thank you

 

[zdas04]

Basically there isn't one. Mr Rowland at Echometer would disagree with me (he does that several times a year), but the assumptions he makes and the ones I make are different.

I'm assuming that you have some sort of pump in your well and you are flowing gas up the tubing/casing annulus. In that case, flow as low as 10 MCF/d through a water column will stir up the surface so much that you simply cannot get a reliable, repeatable liquid level.

I've seen people put downhole pressure gauges to try and work it out, and the values change hundreds of times per hour.

My first question to you would be "Why do you need to know the fluid level?" If it is to ensure that a pump has adequate NPSH, then downhole gauges might work for you. If it is to reduce the BHP to start initial production, then you're pretty much out of luck.


David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

"It is always a poor idea to ask your Bridge Club for medical advice or a collection of geek engineers for legal advice"

 

[rv13]

thanks for the information
it is a little of both - mainly for information

i wonder if i can get a refund on all this expensive
echo-meter equipment?? kidding

 

[zdas04]

A lot of people swear by fluid shots. The guys that shoot fluid shots for a living will always do one and take it as gospel. I always want them to shoot 5 shots in a well and it is unusual for the results to be within 100 ft of each other. One guy charges by the shot (not the well) so when I say I want 5 shots he charges 5 times his normal rate. When I ask "which shot is right?", he usually backs off his charge.

David

 

[rv13]

as a former owner/operator of a mid-size production/drilling comapny that was started by grandfather
in the early in the early 20's, i like you can attest to the lack of professional experience of the younger generations and a dependence just on technology (
shortage of experienced talent)

we are a consulting engineering company that specializes in the mechanical efficienies of of surface and downhole equipment. we use my 40+ years of production engineering experience and analysis of data to improve performance and reduce costs - does not matter where the incremental income comes from just so it goes in the owners pocket.

i have learned how my success could have been enhanced had i done a better job of gathering this type of data and more importantly used it. there is not operation out there that
can not be improved - problem is convincing the operator to
get past his ego.

thanks for your advice - not much experience with cbm
or tight reservoirs

dws

 

[DrillerNic]

Knowing your liquid level in a CBM well is pretty important (at least for our ones) to see if you have managed to get the water level below the coal seams, and thus are beginning to dewater them.

We tried echometers with varying degrees of sucess, and now use fibre optics for our fluid level, backed up with an open chemical injection line that the prod tech guys inject air down - the pressure needed to push the fluid out of the bottom of the chemcial injection line can be measured and the fluid level backed out.

 

[rv13]

thanks

for the info - can you explain a little more on the fiber
optics equipment and their procedure for the chemical slip stream line

have a nice weekend