Joined: Dec 2011 Gender: Male Posts: 228 Location: Alberta
Help With Hydraulics « Thread Started on Mar 22, 2012, 7:58am »
OK so I'm going to ask something that some may think is stupid but I am going to ask because I don't know & the only way to learn is to ask, also I hope others read to learn from it. I have an excel program that is a United Diamond Hydraulic program. I entered in all the data pertaining to this well & it came up with some values, now what do I do with these numbers ha ah. Keep in mind I'm kinda like a relief push just left driller stage...Not a company man OK. Drilling a 156mm Hole with 6 x 8.7 jets in a PDC bit, pumping at 840l/min. Ok TFA:356.68mm*2 Total Flow Area, Is that good & why? I had It explained if you have a wash gun & took your tip off your TFA would increase & your Jet Vel would go down, so imagine trying to clean the cuttings out of the hole with a wash gun with no nozzle. Now bit pressure drop is 1195kpa & that's just the pressure loss across the bit due to the nozzle selection? Ha ha PSI 173.33psi, why psi is that a good range? Then we got Jet Vel at 39.25M/sec...hmmm sounds fast probably good. Also have Bit Hydraulic Power at 16,732watts......watts why watts & how will I ever know if these ranges are acceptable? Then there is a H-S-I of 0.76 that looks a little low Ok what do I need to study to get a better grasp with this, Focusing on my weaknesses to make myself stronger & admitting my weaknesses.
Re: Help With Hydraulics « Reply #1 on Mar 22, 2012, 4:07pm »
sostraightup,
You are breath of fresh air on this site. However, if you're just into Night Push position, I fear from your latest question that you may be enjoying the freedom from the slavery of the brake-handle a bit too much, and spending too much time in the office with your spreadsheets!
I won't try to answer your various questions separately, because they involve detail, and the hydraulics side of things is possibly one of the most complicated part of drilling. But essentially hydraulics all boils down to how much bang you get for your buck. Or footage, rather. It's about cost, and economics. And how much diesel you're burning up to drill that hole.
Because that's what the client is looking at. Cost-efficiency.
Drillstring and bit hydraulics calculations are fiendishly complicated, and I don't consider myself to be an expert. Also, it all depends on the hole you're drilling. For instance, a few years ago in Egypt I found that drilling right close to critical annular velocity around the Bha really helped the ROP in the 12 1/4" section, and also made for a good hole. But the engineers in town were getting kittens about what I was doing, because it didn't fit with their 'modeled' program. Took a few wells before they saw the sense. Hole getting drilled faster, casing going in easier, etcetera. OK, had to increase the cement excess, but cement is cheap.
I like your 'learn something new every day' thread, but in this case, all I would suggest is never to forget the big picture. Oilwell drilling is about making money, and doing so without wasting it. Hydraulics is all about cost per foot. Take a day during your leave-time and go talk with one of your client's engineers about their hydraulics program. But meanwhile, make sure to get outside once in a while to be sure your people are taking care of the equipment!
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.
Re: Help With Hydraulics « Reply #3 on Mar 23, 2012, 6:07pm »
Hey! I wasn't wanting to put your question down. It's simply that it came out of one spreadsheet, so I couldn't give a definitive answer.
Many companies provide 'hydraulics spreadsheets', and they can come up with some wildly differing results. Tread carefully here. While you're out on the rig, I'd suggest you request your hydraulics from the mud-loggers, then compare that with whatever other software you're looking at.
From your previous posts, it's evident that you're a keen young man making your way up the ladder, and asking pertinent questions.
But I'd urge caution regarding hydraulics. As a 'Night Push', the important thing is to make sure that the Client isn't asking the impossible (or uneconomical) of your rig. And also, to establish a good relationship with the client's representative (Co-man), and ask him why he wants such-and-such pump rate, size of nozzles, etcetera. If he doesn't want to discuss it, or says that's what 'town' wants, or can't come up with any explanation, start being wary. A good Co-man will always have space for such stuff, and even welcome it, if he's any good at his job and managing his time.
Some things are best sorted out in the field. Don't be shy. Go bang on that man's office door. He's probably got a better brand of coffee than you, as well.
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.
Re: Help With Hydraulics « Reply #4 on Mar 24, 2012, 1:50am »
sostraightup,
spreadsheets and even stand alone hydraulics programs are as good as the formulae used to determine various outputs and also the accuracy of inputs.
You need to get to know how reliable that particular hydraulics program is and also its weakness where applicable.
Once I get all the various reports ex: mud, drilling etc , I input what I see on these reports into the program, ex: MW, PV , YP, bit /hole size, nozzles, SPM and so on. Look at the drilling data or screen trends to make sure these values are indeed what they say they are.
Then I compare the calculated SPP to the actual SPP. If both values don't tally it is safe to tweak stuff like SPM, PV and YP by +/- 1.0 ..but with MW ONLY +/- 0.01 ppg depending on the accuracy limits of the mud balance.
The idea is not to make the hydraulics report look pretty or a perfact match but to pin point blatant mismatches and ask why ? Could it be a lousy program, or erroneous pump efficiency/output figures ? Is the mud engineer a very creative character ? does the companyman actually watch the guy perform some of the tests ? or is he another creative character who says the mudmen know what they are doing -that's what we pay them for. Could the pressure drop past downhole turbines provided by service engineers be too approximate (frequently they are because the lazy fellows use ball park internal diameters). Things like hole volume are empirical unless you are running a downhole caliper.
Most of the time you will also locate the source of such major mismatches to badly calibrated instrumentation ex: down the mudman calibrate the balance with fresh or seawater ? Is the standpipe pressure reading as it should ? Do you need to ascertain a proper mum pump efficiency using the trip tank..provide that too has been calibrated properly.
You can also use the hydraulics program to predict expectations for a depth you have not yet drilled, and then wait and see what you really get when the bit gets there.
By the way I second what AK mentioned about consultation with dubious or unapproachable BS artist client reps. I have great respect for the ones who say " I don't know...can you show me or explain".
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: Dec 2011 Gender: Male Posts: 228 Location: Alberta
Re: Help With Hydraulics « Reply #5 on Mar 24, 2012, 4:25am »
The company reps out here are very informative & answer any questions I have. AK I was not being sarcastic in my last statement & really do appreciate & value your guy's opinions & statements. I am working my way up & even from the tome I have joined this site I feel that I am growing more & more everyday. I like the idea about checking pump eff through the trip tank, never thought or heard of that before, So just start with a volume in the tank, pump x amount of strokes & compare the gain in volume I would guess? Sounds pretty easy & a good way of checking efficiency.
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 company reps out here are very informative & answer any questions I have. AK I was not being sarcastic in my last statement & really do appreciate & value your guy's opinions & statements. I am working my way up & even from the tome I have joined this site I feel that I am growing more & more everyday. I like the idea about checking pump eff through the trip tank, never thought or heard of that before, So just start with a volume in the tank, pump x amount of strokes & compare the gain in volume I would guess? Sounds pretty easy & a good way of checking efficiency.
Doing that you will get 100% efficiency. Pumps lose efficiency when the pressure is high and the valves are not closed quickly enough to ensure 100% of the volume is displaced. Also, under high pressure the elastomers may deform. Efficiency, is a 'fudge factor' that can be used to adjust for observed phenomena. The history of pump efficiency takes us back to steam powered pumps where the stroke was not fixed length.
Re: Help With Hydraulics « Reply #8 on Mar 24, 2012, 5:15pm »
Woho! Steady on here guys!
A personal opinion, but I have never seen pump efficiency tested using the trip tank. By definition, the trip tank is of relatively small volume. That won't do the trick. Testing pump efficiency is usually done over a period of time during the rig acceptance. And using a large-volume tank. Using the trip tank (commonly 30 - 50 bbl capacity) won't meet the nut. Simply getting the pump up to speed will throw the calculations wildly out.
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.
does the companyman actually watch the guy perform some of the tests ? or is he another creative character who says the mudmen know what they are doing -that's what we pay them for.
The day I get a company rep watching me do a mud check is the last day I go to that rig. It's not that I don't do the checks or lie about the results, it's that a mud check requires a lot of interpretation. Two people will always interpret something differently, and that's where trust issues come in.
I had a retort that I could not get calibrated correctly, but I knew it always reported the water right and the oil a percent and a half low (in a typical 95/5-ish OBM). After years of running it I could not get that extra oil out but I knew it was there and corrected for it on my mud reports. Do you think a company rep would trust me more after reporting a different number than what we both saw in the mud check, even though the reported number is closer to the truth? There's nothing for me to gain in that situation.
Re: Help With Hydraulics « Reply #10 on Mar 24, 2012, 6:50pm »
It would probably be a good idea to log the actual retort result, the compensation factor and the final number. It would also probably be a good idea to bring it to the company man's attention so that every one is on the same program.
A personal opinion, but I have never seen pump efficiency tested using the trip tank. By definition, the trip tank is of relatively small volume. That won't do the trick. Testing pump efficiency is usually done over a period of time during the rig acceptance. And using a large-volume tank. Using the trip tank (commonly 30 - 50 bbl capacity) won't meet the nut. Simply getting the pump up to speed will throw the calculations wildly out.
AK
Too right AK, my mistake, the trip tank can be used to ascertain or fine tune surface line volume but for pump out put, can we instead use returns/flow out to the active by circulating once we tag TOC inside casing, in which case we are dealing with a finite or calculable volume ?
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.
Re: Help With Hydraulics « Reply #12 on Mar 24, 2012, 6:59pm »
skr,
I quite agree with you, even if I work as one of those hated ogres who go under the name of 'company-man'.
Don't put up with being micro-managed!
However, I have come across instances (fortunately only twice) where I knew I was being deliberately lied to, the evidence being wildly differing reports coming from the derrickman, the loggers, and the mud engineers themselves.
So I went and did a mud-check myself on both occasions. Basic stuff, not the whole nine yards, and while the mud engineer was in bed, but it became obvious that the client I was working for (and thus myself) were being ripped-off, that the properties being reported were untrue, and now I understood a bit more about why we were having difficulties drilling.
Underhand stuff, maybe, but necessary. Those mud engineers didn't come back, once the discrepancies were reported and acted upon.
Far too often, there is the cry 'blame it on the mud!', and nine times out of ten that's untrue. But just once in a while it is, and that has to be investigated.
A good relationship and honest communication between the mud engineer and the client rep is primordial for drilling a good hole, not only because it's technically so important, but also mud cost usually represents a significant part of the overall well budget. Which may go a long way to explaining why so many 'company-men' are ex-mud engineers!
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.
does the companyman actually watch the guy perform some of the tests ? or is he another creative character who says the mudmen know what they are doing -that's what we pay them for.
The day I get a company rep watching me do a mud check is the last day I go to that rig. It's not that I don't do the checks or lie about the results, it's that a mud check requires a lot of interpretation. Two people will always interpret something differently, and that's where trust issues come in.
I had a retort that I could not get calibrated correctly, but I knew it always reported the water right and the oil a percent and a half low (in a typical 95/5-ish OBM). After years of running it I could not get that extra oil out but I knew it was there and corrected for it on my mud reports. Do you think a company rep would trust me more after reporting a different number than what we both saw in the mud check, even though the reported number is closer to the truth? There's nothing for me to gain in that situation.
Totally understood valid points particularly that part about interpretation and later on, oil percent, but my post was referring to mudmen who don't know what hydrostatic pressure means ? ...definitely not mudmen of your caliber.
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.
Re: Help With Hydraulics « Reply #14 on Mar 24, 2012, 7:10pm »
PJ,
Don't know where you're question's coming from, but a mud engineer who doesn't understand hydrostatic pressure???? Luckily I've never encountered that. What's that Barite for? Just to make the mud look like mud, and give it a nice colour? Frightening.
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.
Don't know where you're question's coming from, but a mud engineer who doesn't understand hydrostatic pressure???? Luckily I've never encountered that. What's that Barite for? Just to make the mud look like mud, and give it a nice colour? Frightening.
AK
Frightening ?...too right mate and it was a true wildcat ! Re:Barite (I asked him the same question) Answer: You tell us how much you want to mix and we'll do it as per client requirements !!!!
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 day I get a company rep watching me do a mud check is the last day I go to that rig. It's not that I don't do the checks or lie about the results, it's that a mud check requires a lot of interpretation. Two people will always interpret something differently, and that's where trust issues come in.
I had a retort that I could not get calibrated correctly, but I knew it always reported the water right and the oil a percent and a half low (in a typical 95/5-ish OBM). After years of running it I could not get that extra oil out but I knew it was there and corrected for it on my mud reports. Do you think a company rep would trust me more after reporting a different number than what we both saw in the mud check, even though the reported number is closer to the truth? There's nothing for me to gain in that situation.
Totally understood valid points particularly that part about interpretation and later on, oil percent, but my post was referring to mudmen who don't know what hydrostatic pressure means ? ...definitely not mudmen of your caliber.
Oh yeah I know, I just wanted to put that in there so that when sostraightup is a company rep, and I'm still checking mud, he doesn't think back to this thread and start supervising my mud checks.
Re: Help With Hydraulics « Reply #17 on Mar 25, 2012, 5:42am »
skr,
Sups are there to supervise. This entails some level of spot checking vital figures, not just take every thing as gospel be it depth, MW, volumes, pressures, what ever - that's a major portion of his job.
It is impossible to micromanage every aspect of any report, but that's why we have these reports decimated to several others up the chain of command including people in town to double check what might get past their man on the rig.
But once they know the persons who fill out reports are proven reliable they mostly leave them to their own space and some level of reliability is built. Errors can be made even by experienced personnel due to various reasons such as stress, fatigue and penny pinching - which in my opinion is the mother of most causes when it comes to stuff ups.
I doubt very much sostraightup is going to breath down any ones neck when/if he gets to supervisor levels but I'm sure stuff like mudmen not knowing what hydrostatic pressure is or what well control is (refer: Mudman Macondo Inquiry - the guy said he did not have any knowledge of well control with words to that effect) has to become part of his awareness...the sooner the better short of poisoning his mind.
Its 2012 and that good old trick of sending mud sacks on palettes that sag in the middle is still alive and well. If simple stuff like this let alone erroneous or even bogus cut-n-paste reports and logs...yes logs....get past a supervisor, vendors will see him as a gold mine.
Ambulance chasers in the guise of HSE, have added a new dimension to how we go about our jobs these days with CYA clauses to fall back on when all else goes pear shaped.
The vast majority of oilfield personnel these days reckon well control is something that occurs when a kick is taken and the BOP is closed. This a very dangerous misconception because they need to know that as soon as we step on a rig where a well has been spudded we are in a well control situation ie: Primary Well control which by the way was the obvious mind set back in the 80Ss and to a lesser and lesser degree during the 90s.
We all know that the driller is the one that makes the decision to shut-in a well however this fact has been misconstrued by other parties who partake in primary well control.
Ex: Connection gas, increasing in magnitude, for the past 48 hr totally ignored: when such parties are questioned as to why they did not alert the rig floor or other supervisors of early signs of a kick or abnormal pressure or if questioned what if we take a kick/blowout as a result of their don't-ask-don't -tell policy ..the answer invariably that it is the drillers responsibility to shut-in the well.. in other words I won't be blamed if a real kick was imminent.... it not my problem my rear-end won't get burnt.
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: Dec 2011 Gender: Male Posts: 228 Location: Alberta
Re: Help With Hydraulics « Reply #18 on Mar 25, 2012, 7:05am »
For me reliability is built on tests minor at first & as worker proves this "skill" to me the tasks become more & more important. One thing I have noticed especially with the newer workers, is when you send them to do a task & you notice that it has taken longer for them to return & you know is taking longer than it should. 9 times out of 10 they are doing something completely different then you have asked. That is why the whole communication issue is so important at all levels. You know who is reliable by not being let down & by the past tasks weather they are good or bad...just sayin.
A personal opinion, but I have never seen pump efficiency tested using the trip tank. By definition, the trip tank is of relatively small volume. That won't do the trick. Testing pump efficiency is usually done over a period of time during the rig acceptance. And using a large-volume tank. Using the trip tank (commonly 30 - 50 bbl capacity) won't meet the nut. Simply getting the pump up to speed will throw the calculations wildly out.
AK
Makes sense what you are sayin AK, how much efficiency are you really going to lose with no pressure in a small volume tank. The pump will more than likely lose more efficiency at higher pressures not pre charge pressures
Re: Help With Hydraulics « Reply #20 on Mar 25, 2012, 5:44pm »
By the way, 'sostraightup', going back to your hydraulics question, there is an excellent pice of software called 'Mudware' which was developed by M-I, the mud company. They used to give it out free, and probably still do. It has a useful hydraulics calculator in it. The software was updated a few years ago an put in a CD format. But I personally still prefer the old original MS-DOS version, which is plain and straightforward, but an invaluable tool to have on one's hard drive.
It's not too big a file, and I can email you a copy via PM if you want.
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.
Re: Help With Hydraulics « Reply #21 on Apr 11, 2012, 3:00am »
AK,
Do you know how reliable these calculators are? Do you use them often in the industry? I'm a student at Texas A&M and we have to do the hydraulic calculations long hand as well as use the mudware software for a particular assignment. I'm getting some crazy answers from mudware... for example when weighing up from 10 to 12.5 ppg w/ barite mudware says I need 132 sx of barite and I calculated longhand that I need 219. Maybe i'm doing the calculation wrong or the formulas used are different but I have lab tomorrow so Ill post back whats going on.
Joined: Jun 2003 Gender: Male Posts: 933 Location: PERTH WESTERN AUSTRALIA
Re: Help With Hydraulics « Reply #22 on Apr 11, 2012, 3:58am »
What formula do you use for Long Hand? Also what is the pit volume? Do you want to keep volume the same or allow for pit volume gain due to volume of weight material? Sx of Wt material/bbl = (14.70 * (MW2 – MW1))/(35 –MW2) Sx/bbl = (14.70*(12.5-10))/(35-12.5)=1.63sx/bbl
Mudware Provides the same answer, i.e. 163 sx/100 bbl if the pit volume is allowed to increase. Alternatively 147 sx if you initially jet 9.98 bbl
Re: Help With Hydraulics « Reply #23 on Apr 11, 2012, 10:16pm »
Thanks for the info holdril,
turns out I was using the formula for variable volume when I was using the mudware "constant pit volume" section ... half the problem is the professor doesn't tell us where these formulas come from so its hard to figure out what exactly you're doing. For example I just found out 35 is the density of barite in ppg.
anyways, Upon recalculation, I found 131.94 sx of barite are required for the weigh up; which is exactly what mudware said, so its pretty dang reliable I would say.
calculation: (constant pit V)
Given: Mud tank: l=12' w=6' h=9' drawdown=2' ... =89.76bbl cap
for cons. V: need to start w/ 89.76(35-12.5)*(35-10)^(-1) =80.78 bbl .... =8.98 bbl to jet
for amount of barite: 1470(12.5-10)*(35-12.5)^(-1) =163.33 sx/100bbl
(163.33/100)*80.78 = 131.94 = 132sx
another question I have is what does a sack measure? volume or mass? is a sack of cotton smaller than a sack of hematite? or are they the same size (volume) with different weights?
Joined: Jun 2003 Gender: Male Posts: 933 Location: PERTH WESTERN AUSTRALIA
Re: Help With Hydraulics « Reply #24 on Apr 12, 2012, 12:27am »
A sack is not an oilfield measure, it has been complicated by HS&E limits on weight. Originally a sack of cement was a cubic foot, +/- 94 lb. This was part of a plan to allow volumetric mixes of concrete. The sack of Barite was 100 lb. What a good man could lift. The Sack of Wyoming Bentonite was 50 lb. The 100 lb sack was too big to get ones hands around it. 35 is the ppg of Barite. Likewise 1470 is the lbs of Barite in a bbl. Calculations should be done in lb. That way there is no confusion. Cheers
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Ok what do I need to study to get a better grasp with this, Focusing on my weaknesses to make myself stronger & admitting my weaknesses.
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