Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Perforations in the wrong place « Thread Started on Aug 11, 2011, 6:14pm »
Many wells are not perforated in the correct interval due to the failure to account for the gun movement that occurs after the surface winch is stopped to fire the gun. When in the well with a perforating gun with a collar locater, the tools are pulled upward to tie into the casing collars for "accurate" depth control. When this is done, there is stretch in the wireline due to drag, fluid viscosity, etc. etc. After ensuring that the gun is in the "correct" position, the surface winch is stopped so the gun can be readied to fire. When the winch is stopped, the gun continues to move upward until all the forces are equalized. This movement has been called "creep". Failure to determine and adjust for creep results in the perforations being higher than planned. In deep wells, especially with thin pay zones, this problem can result in completely missing the pay zone when the gun is fired. If the real perforations are above the pay zone (in the shale), if the well is fracture stimulated, the frac job may experience a hard screenout because the fracture is not as wide as the computer program says it is when the proppant is added to the fluid.
Currently, as best I can determine, none of the perforating companies are determining or adjusting for creep.
Joined: Apr 2005 Gender: Male Posts: 152 Location: M.E. / Asia Pacific
Re: Perforations in the wrong place « Reply #1 on Aug 11, 2011, 11:33pm »
TPLEDGER,
I believe what you stating is true to certain extent but if you log up and into place slowly (consistently)I do not think you will have too much trouble.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #2 on Aug 12, 2011, 12:12am »
That is a very common belief. However, the stretch was in the wireline when logging the collars. Even though you slow down when the gun is positioned to fire, the gun is higher in the well than planned due to the fact that the stretch was then when you tied into the casing collars.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #3 on Aug 12, 2011, 12:17am »
The very first article to appear in the industry journals about this problem was in the January, 2008, issue of World Oil, I believe it is on page 61. Your comments would be appreciated.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #5 on Aug 14, 2011, 12:14am »
I have tried to attached a copy of a brochure from a company that adds radioactive tracers to frac fluids, but the file was too large. On that add is proof that perforations are not always where they are planned. The two middle set of perforations, at a depth of 7,350' and again at 7,000', the radioactive tracer indicates that the perforations are 10 feet higher than the well records indicate. What I can not explain is why the top and bottom perforations are shown to be correctly placed. The point is that creep should always be determined and adjusted for to ensure that the perforations are placed correctly.
Although Schlumberger was granted a patent on creep (author: Peter Fitzgerald) in January, 2009, to the best of my knowledge, no changes have been made in field operations to handle this problem. Reading their patent does not give enough information on how to determine and adjust for wireline creep.
The next time wireline logs are run into the open hole, creep can easily be seen by stopping the logging operation in the middle of a thick shale for about 2 minutes. When logging continues, straight lines will seen on all of the curves. the length of the straight lines shows how far up hole the tools moved while stopped. This is creep.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #6 on Aug 18, 2011, 4:26pm »
On a geologist site, this comment was found:
It was interesting to read a paper on Creep. I am working as logging engineer since last 5 years. I have worked with two major companies but none of them taught me about creep.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #7 on Aug 21, 2011, 6:51pm »
This subject may need to be a new thread, but it is related to this topic: Wireline set packers, bridge plugs, cement retainers, etc. are prone to have much more creep than perforating guns on wireline.
DRILLERS: PACKERS, BP'S OR CR'S THAT HAVE BEEN SET WITH WIRELINE, WHEN YOU MEASURED (TALLY) THE PIPE INTO THE HOLE TO TAG UP ON THE DEVICE, HOW DID YOUR PIPE TALLY COMPARE TO THE WIRELINE SETTING DEPTH? DID THE PIPE TALLY INDICATE THAT YOU NEEDED MORE PIPE TO BE ON THE DEVICE (THIS WOULD MEAN THE DEVICE WAS SET HIGHER THAN PLANNED), OR DID THE TALLY INDICATE YOU HAD TOO MUCH PIPE IN THE HOLE (THIS WOULD INDICATE THAT THE DEVICE WAS SET DEEPER THAN PLANNED)?
Maybe some of you rig supervisors could share your findings on this matter.
Attached is the article from World Oil on wireline creep.
tpledger,
That is a fascinating article, and many thanks for the link. I'll try to be serious,and avoid any facile references to wireline seeming to attract more than its fair share of creepy people...
No, the penultimate part, 'creep confirmation' seems like a good 'checklist' to follow in the field, and worth pasting into one's tally book for quick reference when in the winch unit.
I've posted a couple of comments into your other newly-started thread on this topic, but now I suspect you're searching for some comprehensive statistical data upon which to base a further article. Would that be correct?
You're obviously an expert in this particular field, and it's interesting stuff. Please let us know when you publish your new findings... One is never too old to learn some new things.
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: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #9 on Aug 30, 2011, 4:02pm »
My first job out of college (1960) was with a company called Schlumberger Well Surveying Corp. They made me believe that I would have been fired on the spot if I failed to determine creep and adjust for it when shooting cores or setting FT's in the open hole, or when perforating or setting packers, etc. in the cased hole. As best I can determine, when the wireline companies started using the computer, creep was no longer accounted for in well operations. However, one thing I know, physics does not change, if there was creep in 1960, there is still creep today.
Many wells today are being recompleted from their original zone, and often, this new zone is thin. I am concerned that much oil and gas will be missed because of this creep problem.
However, one thing I know, physics does not change, if there was creep in 1960, there is still creep today.
Many wells today are being recompleted from their original zone, and often, this new zone is thin. I am concerned that much oil and gas will be missed because of this creep problem.
tpledger,
The fact that Slb took a cheap route and adopted Bill Gates' shoddy software hasn't helped at all.
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.
However, one thing I know, physics does not change, if there was creep in 1960, there is still creep today.
Many wells today are being recompleted from their original zone, and often, this new zone is thin. I am concerned that much oil and gas will be missed because of this creep problem.
tpledger,
The fact that Slb took a cheap route and adopted Bill Gates' shoddy software hasn't helped at all.
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.
Yup. And all Windows 98, 2000, XP, Vista, Windows 7, etc., is riding on the back of an ancient operating system called MS DOS, which made the great 'philanphropist's' fortune. And which has become the curse of the business world.
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: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #13 on Aug 30, 2011, 8:36pm »
Hearsay has it that the wireline companies are using software developed by Ceribus (unsure of spelling). Their type of software is also used by many coiled tubing units.
I don't know much about this software. The only time I come across it is at the planning stage, when they are worried about maximum available overpull on the cable and it we need to plan for a wireline capstan.
I think they can also model 'tool lift' to get the correct toolstring weight for PLT's.
I am aware of creep, but I don't know what the e-line companies SOP's say about it.
Wireline, like the rest of the oilfield, has problems due to lack of experienced personnel.
Yup. And all Windows 98, 2000, XP, Vista, Windows 7, etc., is riding on the back of an ancient operating system called MS DOS, which made the great 'philanphropist's' fortune. And which has become the curse of the business world.
AK
When IBM had decided to produce a Personal Computer ('PC' is a term coined by IBM), they decided on having an open architecture machine (the guts are accessible and customizable through expansion slots) and as many off-the-shelf components as possible in order to get it into the market ASAP. CPM was owned by Digital Research, so some top guys from IBM in New York made an appointment to see the guys at DR (in San Francisco, I think). When the IBM guys arrived at DR after having flown across the country, the main person with whom the meeting was set up was out flying his private plane, and the other partner sent his wife to the door to tell the IBM folk that they were not interested! After some discussion, one of the IBM guys said he had heard of a guy named Bill Gates in Seattle who was very intelligent and experienced in MS Basic language and in operating systems, like Apple DOS.
They went up to Seattle after making an appointment with Bill Gates. They showed him the CPM manual and Bill already had one. They wanted an operating system for the Intel 8086 (?) with basically the same front end as CPM. Bill Gates said they could do the job. He discovered that Seattle Computer was working on an OS for the Intel chip and so contracted them to continue their coding but to have a similar front-end to CPM. The rest, as they say, is history.
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.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #16 on Sept 1, 2011, 4:42pm »
I am so sure that creep is a major problem that is being ignored by the industry, I am willing to make this offer: if your company will provide transportation and cover all expenses, I am willing to supervise, AT NO CHARGE FOR MY TIME, the perforating of a deep well with a casing gun on wireline. I will provide the necessary proof of the amount of creep and how far off depth the perforations would have been if creep was not determined. Please let me know if you and your company are interested.
I suggest that your perforating companies be contacted and asked what they know about creep and how they compensate for it when perforating. WARNING: do not be surprised if they do not know about creep or even that it exists. I will be greatly surprised if they know how to find creep and compensate for it. Please post your findings about this issue.
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #18 on Sept 14, 2011, 10:31am »
I am currently in a class in Bangkok with two ex-Schlumberger wireline engineers who are now working for Chevron. Neither one of them knew anything about creep and had no idea how to find it.
I am currently in a class in Bangkok with two ex-Schlumberger wireline engineers who are now working for Chevron. Neither one of them knew anything about creep and had no idea how to find it.
Not surprising. A similar type of engineer, claiming 5 years field experience, thought we had TD'ed the well after after set and cement 13 3/8" casing. Some can't even tell the difference between imperial and metric L keys and frequently drop tools into the hole and keep quite about it, not realizing there are several ways to detect this.
Some don't even know how to hold tools like spanners or screw drivers . There's masses of good talent available the world over, young and old , but it beats me where (or why) they get these clowns from. Meanwhile the few experienced hands who have to shoulder it all, burn out rapidly. It is a pity to watch top notch quality gone to the dogs.
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: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #21 on Sept 18, 2011, 8:41pm »
I am glad to say that almost all the service company hands that I have worked with have a great desire to do a good job and try hard to please. However, there are times when their training is lacking in some areas. I have had service company hands that knew how to make their company's equipment work, but sometimes lacked the knowledge of what they were doing could cause problems with the job being performed - again- lack of training.
Re: Perforations in the wrong place « Reply #22 on Sept 18, 2011, 9:59pm »
Perforators.org is an oil field well construction organization dedicated to the advancement of oil field jet perforation technology. On this site you will find their meeting agenda's, presentations given at past meetings, registration for upcoming meetings (active two months prior to meeting).
They have a forum, however no-one seem to use it, there is also a list of links with all the meeting they have held since 2009 including the 2011 seminar, I'm sure you will fins much of what they have discussed interesting, I did
Joined: Aug 2011 Gender: Male Posts: 68 Location: Broken Arrow, Oklahoma, USA
Re: Perforations in the wrong place « Reply #23 on Sept 20, 2011, 5:05pm »
Thanks for the link, Leonard. I went to their web site but could not find how to become a member. I would like to get a thread like this one on their site to see what information they might have.
Re: Perforations in the wrong place « Reply #24 on Sept 21, 2011, 10:33pm »
you might try sending an email to the following people.
Mark Brinsden : Mark.Brinsden(at)shell.com Kent Folse : kcfolse(at)marathonoil.com
use the normal email sign instead of the (at)
It looks to me as though not to m,any people use it in fact it was cleaned up back in May and there has only been one post since and that the admin asking people why they are not using it?
the main problem with such forums is everyone know who's who and therefore will not post in fear of looking bad
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