Does anyone knows about LCT? what is the function of LCT and how does it work?
I also really appreciate if you can give me more information, maybe some links related to LCT.
Thank you
LCT = Long Connection Test Total like them and they perform them something like this.... 10 minutes circulating before making a connection, 10 minutes with the pumps off while making the connection and a further 10 minutes circulating before continuing drilling. The mud loggers will then monitor gas levels at bottoms up. They are a means of more accurately monitoring connection gas levels or to be more precise increases in connection gas levels.
Now I've worked for Total in various capacities in the past, and thus know how they sometimes come up with some strange ideas, but...
Heck, back when I was a driller, if it took me ten minutes to make a connection and with the pumps shut down, I'd have got my a** run off pdq, or even quicker if it resulted in us getting stuck! And working as company man (even for Total), I'd be raising some serious questions with the people in town if they issued an instruction to perform such a manoeuver.
Maybe they should be looking at changing out their mudloggers, instead. What a waste of time and money. No wonder fuel prices at the pumps in France have increased so dramatically.
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with qualified individuals in these respective fields.
Joined: May 2010 Gender: Male Posts: 824 Location: UK
Re: LCT « Reply #3 on Aug 13, 2012, 1:10pm »
I would think that rather than concentrating on the ECD effect of just turning the pumps off, they could get quicker and more effective results by moving the pipe upwards with the pumps off. The swab effect of setting and getting out of slips during a normal connection will have a far bigger draw-down on BHP than a fortnight of sitting with the pumps off. Also moving the pipe before kicking the pumps in (IF THE HOLE IS STABLE ) reduces the differential sticking risk. Obviously that is something that needs to be assessed on a case by case basis depending on torque and drag, formation stability and whether you feel that you are already too close to balance.
If you are going to take an influx, it is almost certainly going to be as the result of pipe acceleration with the pumps off, that is your worse case scenario and the thing that you should be simulating when you monitor connection gas.
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with individuals qualified in these respective fields.
My name is Prince Jeff Harry, the chief accounting and auditing, Eco Bank Plc, Benin Republic here in Africa.My reason for contacting you is for my urgent need for a foreigner on your location, which can really help me in confidence and perform this great opportunities that have recently occurred in my bank.
If you are interested, contact me through my private email address (princeharry172@yahoo.com), which allows me to give you more information about how we're going to start the claim.
Also you confirm the following information for further details
My name is Prince Jeff Harry, the chief accounting and auditing, Eco Bank Plc, Benin Republic here in Africa.My reason for contacting you is for my urgent need for a foreigner on your location, which can really help me in confidence and perform this great opportunities that have recently occurred in my bank.
If you are interested, contact me through my private email address (princeharry172@yahoo.com), which allows me to give you more information about how we're going to start the claim.
Also you confirm the following information for further details
I would think that rather than concentrating on the ECD effect of just turning the pumps off, they could get quicker and more effective results by moving the pipe upwards with the pumps off. The swab effect of setting and getting out of slips during a normal connection will have a far bigger draw-down on BHP than a fortnight of sitting with the pumps off. Also moving the pipe before kicking the pumps in (IF THE HOLE IS STABLE ) reduces the differential sticking risk. Obviously that is something that needs to be assessed on a case by case basis depending on torque and drag, formation stability and whether you feel that you are already too close to balance.
If you are going to take an influx, it is almost certainly going to be as the result of pipe acceleration with the pumps off, that is your worse case scenario and the thing that you should be simulating when you monitor connection gas.
RT,
Can't agree with you here.
When making a connection, there is no reason (kelly or topdrive rig) to be moving the pipe upwards with the pumps off. So why deliberately try to swab your well in?
'Pumps off' is purely the time when the string's in the slips, and the handling of the new joint (or stand) is taking place. And if the driller's anything more than worthless, he'll have already started the pumps (albeit slowly) as soon as makeup is achieved, and simultaneously (or thereabouts) picking up out of the slips. It can be done. One hand on the makeup clutch, another on the pump rheostat, leg on the brake stirrup (draworks clutch already engaged), and eyes on everything. Probably can't be done with a cyber, though.
Sure, I'm becoming an old-timer, and these new-fangled rigs work slow. But a connection which takes more than a minute and a half is bad news. Certainly, circulate as long as you need to before the connection. If you want to, circulate afterwards (though with a topdrive rig you can't move your pipe much then, other than rotation, but it's a principle, basic, rule to keep the pipe moving). Sit in one place with your pumps off, just so the mudloggers can gather data? Sounds like deliberately asking for trouble, to me.
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with qualified individuals in these respective fields.
Sure, if you pull with the pumps off, you will get a gas response, but there's a reason they don't do that.
Total have been using this a long time (Exxon do a 10-10-10 test).
It's not for use everywhere. I saw Total using it in Kalimantan (Mahakam delta) in 2001 and it was well established there. It's a typical sand/shale continuous deposition environment. They used to use the 'D' exponent and wheelie bits, but there were using PDC bits and needed some way to quantify the overpressure. The ROP with PDC's (and bit life) is much better with the PDC's, so there were willing to take the extra operational time to get an overall more efficient and safer operation. I think that there might be an SPE paper about it.
I must admit, that there were times that I was confused about the results of the tests, but I was drill crew at the time, not company man.
Mahakam is a big play for Total, they have lots of wells and a big database, so the data from the LCT is a big benefit for them.
Why don't you pull with the pumps off? Pulling speed will be different depending on who is driving, what rig it is and the mud properties is use. They are drilling thru overpressure, so the MW will be going up in stages.
The LCT test described by perferador, I suppose, takes some of that into account.
To use this technique, you have to be in the right drilling environment and have some sort of data set (or be prepared to take the time to build up a dataset) of gas responses.
It is a 'fingerprinting' technique, but cannot be used for all applications.
There are some good HPHT fingerprinting techniques that are applicable to any well, but there are some absolute bull541t techniques that someone wrote into a programme that has been copied by lots of other operators and no one has the balls to junk them.
What's the questions doing in the completions section anyway. I was going to post an answer similar to Pereradors one, but I thought LCT might be some completion widget/practice I'd never head of.
Thanks for the clarification. Maybe my initial reply to Perforador's post was a (typical) knee-jerk reaction. Because I was imagining that this procedure was being done at every connection, which would make no sense at all. If however it's a test made every ten stands or something like that, maybe it's understandable, in a way.
However, I feel that the acronym is slightly misleading. It seems that an LCT is rather like circulating for a geological sample, except here it's to get a good sample of gas for analysis, to add to the logging data. Not quite the same as getting a firmer handle on connection gas as such. Because the only good way to keep track of connection gas trends is to ensure that connections are made (if possible) the same way and within the same time window consecutively. And with the 'pumps off' time being as constant as possible. Like that, the connection gas spikes can be compared, and are following handling and surface timing conditions which are more or less consistent. Change those conditions, and you'll get a different sort of gas spike which doesn't fit into the trends which one is (hopefully) tracking. But keep the surface properties the same, and any changes you see will (probably) be an indicator of changing downhole conditions.
By the way, I wasn't saying one doesn't pull with the pumps off, during a trip. But I can see no good reason to do so during a connection, unless it's to do some sort of test such as this. Very occasionally I've seen (or indeed myself given instructions to do so) the pipe reciprocated once with the pumps off, when the hole appears to be getting tight, and one wants to be sure about its condition before proceding with the connection. But it's unusual.
The point about the difference between drilling with a PDC bit or a roller-cone in respect to 'd' exponent is quite valid, of course. 'D' exponent should be monitored, but it's a fickle and frequently untrustworthy thing. A PDC bit generally couldn't care less about the mud weight nor mud / pore pressure differentials for instance, unlike a roller-cone, where chip holddown effects (or their opposite) may be observed, or something like that, and directly impact on ROP. In certain formations cuttings size and shape will tell you plenty with a PDC, but of course that's nothing to do with gas sampling.
AK
PS Not quite sure what the original question was doing in the 'completions' section either, unless there's more than one sort of LCT! (Lousy Coiled Tubing maybe?)
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with qualified individuals in these respective fields.
Joined: May 2010 Gender: Male Posts: 824 Location: UK
Re: LCT « Reply #9 on Aug 14, 2012, 9:51am »
One technique that I have seen is the use of 'dummy connections'. At least once per stand, maybe more if there are concerns about approaching overpressure, you go through the motions of making a connection, off bottom, set slips, pumps off and on, out of slips etc. It means that you have more data when it comes to looking at your connection gas trends, but it also means that you have more control over the timing than in a proper connection, so you can get some of the consistency that SD2 is talking about, making trend analysis even more precise. Sure it takes time, but if you are in a tight PP-MW-FG window you need to keep on top of things all the time. Keeping an eye on the swab surge effects using a PWD gives you a fine tuning of what the hole is actually seeing when you do the dummy connection.
As a side benefit I suppose, picking up every 45ft also gives the driller more feedback on drag.
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with individuals qualified in these respective fields.
Yes, and I think there was some considerable discussion about 'dummy connections' elsewhere on this site in the past. In many circumstances it's a valuable procedure to use, in order to avoid drilling yourself into an untenable situation.
There does seem to me to be a slight difference between a 'dummy connection' and this LCT thing, though, which suggests that they're not quite the same beast. The first simulates a connection before it's made, or even halfway down the stand, whereas the latter involves making the connection, but deliberately taking a long time over it.
Which sounds very counter-intuitive to me, but now having had it explained I can see the purpose, though it's not something I'd want to do on a willy-nilly 'programmed' basis without being completely sure it wouldn't cause greater problems than the acquired data might help to resolve in the future.
Information or opinions are solely provided for educational and/or discussion purposes on an informal public forum and should not be interpreted as a recommendation for a specific treatment plan, course of action or product/ service. Use of any of this information does not replace consultations with qualified individuals in these respective fields.
The Driller’s Club is constructed around many oil field forums that allow drilling and oil field oriented people to ask and answer questions relating to subjects within the industry. Membership is free and you can pick your own user name
![[image]](http://www.drillfloor.com/the%20driller%27s%20club.jpg "[image]")
![[Search This Thread]](http://images.proboards.com/search2.gif "[Search This Thread]")
![[Share Topic]](http://images.proboards.com/new/buttons/share.png "[Share Topic]")
![[Print]](http://images.proboards.com/buttons/print.gif "[Print]")
Author
![[avatar]](http://images.proboards.com/avatars/baby.gif "[avatar]")
Logged
![[avatar]](http://www.tellumo.co.uk/brent%20storm%20100.jpg "[avatar]")
