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Permalink Reply by Sandbar on February 7, 2014 at 18:29

        I'm curious about this too, Glenda. Does anyone have much insight on this?

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Permalink Reply by Skip Peel - Mineral Consultant on February 8, 2014 at 2:47

All wells decline from their first day of production excepting short term circumstances such as flow back of frac water and proppant.  Choke size (orifice diameter) is generally increased as formation pressure decreases over time.  The DT-1 test reports above would look normal if most recent two entries are typos and should read 24 instead of 4.  Operators do occasionally adjust chokes for a number of reasons that may or may not appear obvious.  With Haynesville Shale wells for example an operator may choke back wells on a shared gathering system when they start production from a new well.

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Permalink Reply by Joe Aldridge on February 8, 2014 at 3:44

Glenda,

We really need more info. Do you have any more info about well FTP and amount of production during these periods?

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Permalink Reply by Glenda Simmons on February 8, 2014 at 9:37

RPT DATE	LUW CODE	GAS PROD(MCF)
11/1/2013		28042
10/1/2013		25568
9/1/2013		29707
8/1/2013		33530
7/1/2013		35162
6/1/2013		21431
5/1/2013		34303
4/1/2013		34123
3/1/2013		36940
2/1/2013		36074
1/1/2013		38700
12/1/2012		42769
11/1/2012		44156
10/1/2012		48443
9/1/2012		50059
8/1/2012		54950
7/1/2012		59180
6/1/2012		62485
5/1/2012		70120
4/1/2012		74476
3/1/2012		85923
2/1/2012		93452
1/1/2012		109613
12/1/2011		132241
11/1/2011		172412
10/1/2011		224577
9/1/2011		243319
8/1/2011		297000
7/1/2011		285588
6/1/2011		367458
5/1/2011		382137
4/1/2011		265186
3/1/2011		10856

   The chart shows the well's gas production.

   Please tell me what a FTP is. Thank you.

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Permalink Reply by Joe Aldridge on February 8, 2014 at 12:05

Glenda,

It looks like the choke size is a typo. I would guess that it should be a 14/64 not the listed 4/64. That would be my guess. 

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Permalink Reply by jim weyland on February 8, 2014 at 11:04

ms. simmons,

FTP is flowing tubing pressure.

think of a choke as valve that can be totally closed or totally opened or set somewhere in between.  with a  0/64" choke setting. in that condition the well is shut-in. a gauge on the well head would shown a pressure, shut-in tubing pressure. this is sometimes called SITP. in shut-in conditions, one will see the highest pressures of all choke positions. if you were to open the choke as wide as it goes, 64/64" you would obtain the lowest FTP. and at a 32/64" choke the FTP would be somewhere between the SITP and the FTP at 64/64" choke. note, in my very limited experience,

chokes are most times set below, usually well below, one/half choke. 

note: all wells have their highest pressures when they're new. over time, the well depletes and pressures decline, both FTP and shut-in pressure. 

other than when shut-in or certain special circumstances, the prudent well operator will set the choke at all times to obtain the highest rates of flow consistent with: 1) not damaging the well, and 2) obtaining maximum ultimate recoveries of oil and gas from the well.

those factors are why you'll see the varying choke settings over time and the varying FTP's and varying well flow rates.

the above really isn't my area of expertise, if i even had one. there's a whole lot of very smart and knowledgeable folks on the board that i'm sure could tell you a lot more and in a better fashion

jim weyland.

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Permalink Reply by Bill McDaniel on February 9, 2014 at 15:20

Does anyone know what a choke of '80' indicates?  CHK seems to like to put it in the column of their latest entry.  It may mean 'I don't know', 'You don't need to know', or 'get lost rookie-trust us'.

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Permalink Reply by Glenda Simmons on February 14, 2014 at 7:50

Thank you all for the very helpful replies. The information is very enlightening. 

Glenda

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Permalink Reply by Bill McDaniel on February 14, 2014 at 13:29

Hey folks.  If anybody reads what I asked, don't answer it.  I got to searching around and found the tons of discussions that were way old, although I'm not sure that anybody nailed down the definition.  Thanks

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