I have a further question in my mind. Don't know if the inquiry has yet asked it.
Wiper plugs (for the initial casing cement job). I have run tapered strings before, but that was 7 5/8" x 7". We even had some doubts there. Once did a 9 5/8" x 7", but with just one joint of 9 5/8" below the hanger before the crossover to 7".
But such a depth of 9 5/8" before the taper down to 7"? Were these 'special' plugs designed for these different diameters? Do such items exist?
AK
An excellent question. WE often run Casing with Tapered strings e.g. 10 3/4" X 9 5/8". Plugs pass through both!! Other than that, I have no knowledge.
Alcor,
Without wishing to state the obvious, but nevertheless doing so, a plug which will pass through 7" will naturally fit through 9 5/8". Just like your own 10 3/4" x 9 5/8" strings. But do they have a 'seal' in the larger diameter? Especially when the cement slurry density (as in the DWH case) is very different from that of the displacement fluid, and foamed as well?
Just speculative questions, to which I have no answers in my own head.
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.
Now if you are viewing this horizontally, it is quite plain to see that the Black WOB mirrors the red SPP to an extent, indicating reduced buoyancy due to circulation of severely gas cut mud at the bottom - do not confuse this gas with the red gas line as this red gas line trace is lagged gas from an earlier time, not the gas that is affecting the mud's ability to buoy the string weight. This is a time based chart, not a depth based one.
Even so, the magnitude of the gas line does mirror the SPP to an extent starting from 20:12 HR, because SPP is directly proportional to pump speed and pump speed will define the height of returned mud level in the possum belly, which in turn will influence how effectively the gas trap in the possum belly is sucking gas to the gas detectors.
At 21:12 the red gas line flat-lines on the baseline, 3.5 min (possibly time it takes for gas sample to travel from possum belly along gas lines to detector) after pumps are stopped, albeit SPP does not fall to zero. I believe this is because returns were diverted and shakers/possum belly by passed ie: gas readings drop to baseline....mud level in possum belly too low for suction.
It is with a very heavy heart that I present my perspective of these chart trends especially from here on. At 21:42 hr this "thing" forces itself into an empty trip tank (florescent green line). I don't know if this happens via a fill up valve or fluid is raining down ? As everyone would have noticed, SPP increases from here on.
At 21:46:30 even the flow-in (blue) shows a blip that peaks at 100 gpm lasting about 40 seconds with pumps off since about 21: 30hr. What caused this ? I'll stop here as the rest is too violent to describe if a close look at all parameters toward the end with correlation is done.
However looking back in time, I cannot figure why the SPP dropped between 21:36 - 21:38+ . Something arrested it for a couple of minutes and then gave way. Was the manifold-bypass-valve actuated to further energize rams ? Where from ? Drillers console ?
It is obvious as several members have suggested previously these guys were struggling for quite a while. Where were the generals all that while. ? This is something I will very closely pay attention to during the Inquiry.
Good reading PJ, but I still am not sure the crew realized the danger they were in. I can see the driller manipulating pump strokes (possibly changing pump) starting from 2108 hrs when confusion started. From this time SPP and Riser flow show anomalies and only at 2130 hrs decision is taken to stop pumps. From 2130 hrs on, I can't figure what was happening. May be panic, may be flow checking prior to call the generals.
I insist: the fact that OIM and Company Reps are still alive make me believe the crew didn't understand the problem was serious and never called them.
I have a further question in my mind. Don't know if the inquiry has yet asked it.
Wiper plugs (for the initial casing cement job). I have run tapered strings before, but that was 7 5/8" x 7". We even had some doubts there. Once did a 9 5/8" x 7", but with just one joint of 9 5/8" below the hanger before the crossover to 7".
But such a depth of 9 5/8" before the taper down to 7"? Were there 'special' plugs designed for these different diameters? Do such items exist?
AK
Yes Davis Lynch have a chart which shows the upper and lower limits of their wiper plugs. I reckon others will.
An excellent question. WE often run Casing with Tapered strings e.g. 10 3/4" X 9 5/8". Plugs pass through both!! Other than that, I have no knowledge.
Alcor,
Without wishing to state the obvious, but nevertheless doing so, a plug which will pass through 7" will naturally fit through 9 5/8". Just like your own 10 3/4" x 9 5/8" strings. But do they have a 'seal' in the larger diameter? Especially when the cement slurry density (as in the DWH case) is very different from that of the displacement fluid, and foamed as well?
Just speculative questions, to which I have no answers in my own head.
AK
Where did you find the slurry density? The cement was displaced with 14 ppg. The N2 is usually incorporated to equilibrate the MW the hole was drilled with. I assumed that the slurry was +/- 14.0 ppg. If it is different I missed that in my reading.
Without wishing to state the obvious, but nevertheless doing so, a plug which will pass through 7" will naturally fit through 9 5/8". Just like your own 10 3/4" x 9 5/8" strings. But do they have a 'seal' in the larger diameter? Especially when the cement slurry density (as in the DWH case) is very different from that of the displacement fluid, and foamed as well?
Just speculative questions, to which I have no answers in my own head.
AK
Where did you find the slurry density? The cement was displaced with 14 ppg. The N2 is usually incorporated to equilibrate the MW the hole was drilled with. I assumed that the slurry was +/- 14.0 ppg. If it is different I missed that in my reading.
Holdril,
I didn't. I simply ASSumed that the slurry (and spacers) were displaced with the mud currently in circulation. (Though now there seems to be some question as to whether that was 14 ppg or 16 ppg).
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.
Where did you find the slurry density? The cement was displaced with 14 ppg. The N2 is usually incorporated to equilibrate the MW the hole was drilled with. I assumed that the slurry was +/- 14.0 ppg. If it is different I missed that in my reading.
Holdril,
I didn't. I simply ASSumed that the slurry (and spacers) were displaced with the mud currently in circulation. (Though now there seems to be some question as to whether that was 14 ppg or 16 ppg).
AK
There is no question in my mind. The reports to the hearing and the official drawings show 14.0 ppg. As to the chart the straight line is indicative of the Mud weight not being recorded. The fluid being pumped was seawater which allowed the well to come in. The top kill at 5000 feet has a very good chance of success. 16.8 ppg KWM will get it. All they need is luck.
I didn't. I simply ASSumed that the slurry (and spacers) were displaced with the mud currently in circulation. (Though now there seems to be some question as to whether that was 14 ppg or 16 ppg).
AK
There is no question in my mind. The reports to the hearing and the official drawings show 14.0 ppg. As to the chart the straight line is indicative of the Mud weight not being recorded. The fluid being pumped was seawater which allowed the well to come in. The top kill at 5000 feet has a very good chance of success. 16.8 ppg KWM will get it. All they need is luck.
Holdril,
No way. "All they need is luck?". If that's what BP's counting on, the operation's doomed from the outset.
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.
Now if you are viewing this horizontally, it is quite plain to see that the Black WOB mirrors the red SPP to an extent, indicating reduced buoyancy due to circulation of severely gas cut mud at the bottom - do not confuse this gas with the red gas line as this red gas line trace is lagged gas from an earlier time, not the gas that is affecting the mud's ability to buoy the string weight. This is a time based chart, not a depth based one.
Even so, the magnitude of the gas line does mirror the SPP to an extent starting from 20:12 HR, because SPP is directly proportional to pump speed and pump speed will define the height of returned mud level in the possum belly, which in turn will influence how effectively the gas trap in the possum belly is sucking gas to the gas detectors.
At 21:12 the red gas line flat-lines on the baseline, 3.5 min (possibly time it takes for gas sample to travel from possum belly along gas lines to detector) after pumps are stopped, albeit SPP does not fall to zero. I believe this is because returns were diverted and shakers/possum belly by passed ie: gas readings drop to baseline....mud level in possum belly too low for suction.
It is with a very heavy heart that I present my perspective of these chart trends especially from here on. At 21:42 hr this "thing" forces itself into an empty trip tank (florescent green line). I don't know if this happens via a fill up valve or fluid is raining down ? As everyone would have noticed, SPP increases from here on.
At 21:46:30 even the flow-in (blue) shows a blip that peaks at 100 gpm lasting about 40 seconds with pumps off since about 21: 30hr. What caused this ? I'll stop here as the rest is too violent to describe if a close look at all parameters toward the end with correlation is done.
However looking back in time, I cannot figure why the SPP dropped between 21:36 - 21:38+ . Something arrested it for a couple of minutes and then gave way. Was the manifold-bypass-valve actuated to further energize rams ? Where from ? Drillers console ?
It is obvious as several members have suggested previously these guys were struggling for quite a while. Where were the generals all that while. ? This is something I will very closely pay attention to during the Inquiry.
Good reading PJ, but I still am not sure the crew realized the danger they were in. I can see the driller manipulating pump strokes (possibly changing pump) starting from 2108 hrs when confusion started. From this time SPP and Riser flow show anomalies and only at 2130 hrs decision is taken to stop pumps. From 2130 hrs on, I can't figure what was happening. May be panic, may be flow checking prior to call the generals.
I insist: the fact that OIM and Company Reps are still alive make me believe the crew didn't understand the problem was serious and never called them.
Good reading PJ, but I still am not sure the crew realized the danger they were in. I can see the driller manipulating pump strokes (possibly changing pump) starting from 2108 hrs when confusion started.
21:08 - pumps off but SPP still up @ 1000 psi likely due to differential caused by displacement with Sw. Blue flow out drops to zero.
21:08 to 21:10 – returns finish trickling from flow line and possum belly level drops.
21:10 to 21:14 - gas readings flat-lines to zero and remain so till the end of chart. Pit vol change drops to minus 50 bbl . SPM=0, Flow out = 0. But SPP>1000psi. Yeah I know, we all can read charts, so bear with me.
21:14 to 21:18 – pumps ON but no flow out ! I speculate returns bypassed shakers because gas readings still flat at zero and diverter actuated which is why zero FLOW OUT , but riser flow commences at 21:16 hr.
21:18 to 21:20 -Pumps off., but riser flow continues and SPP now holding @ 1500 psi, flow out zero.
21:20 to 21:30 Pumps on but it appears SPM varies for these 10 minutes. Possibly to cater for diverter tolerance limits or the gas pressure is influencing SPM by speeding it up while driller is trying to keep it constant manually. Note the hikes in SPM for this 10 minute period appear less deliberate or human when compared to the SPM step downs from 20:50 to 21: 10. Magnify your pdf.
21:30 –Pumps off
21:30 – 21:34 . Having diverted gas for the past 16 min, the well is shut in ? and SIDPP observed. However IF this happened , ie : space out, hang off on rams and Shut-in, the black WOB and red HKL should straight line from where it is at, but this does not appear to be the case
21:34 - 21:36:30 – SPP stabilizes and perhaps SIDPP is ascertained for kick control
After 21:36:30 under magnification it appears that pressure in the SP was bled down from about 1700 psi to 700 psi. Under magnification this not appear to be a leak. The jagged trace alludes to human in control.
21:38+ hr Pressure shoots up from 700psi to 1000 psi in a straight uniform rate that appears to me to be of non-human cause. Stop bleed ?
3 other points to ponder : - the blue flow in blip 21:46:30 hr - the change in block position in the last 2 to 3 minutes by 2 to 3 ft. - the red SPP spike at 20:24 hr at which time riser flow commences.
What's your take on these points Marco ?
From this time SPP and Riser flow show anomalies and only at 2130 hrs decision is taken to stop pumps. From 2130 hrs on, I can't figure what was happening. May be panic, may be flow checking prior to call the generals.
I can’t figure things out as a whole either but all indications indicate, to my experience, that situation was being handled by a crack drilling crew. I believe we are the ones who are confused considering the very limited amount of data we have to infer or interpret.
I insist: the fact that OIM and Company Reps are still alive make me believe the crew didn't understand the problem was serious and never called them.
According to the 60 minutes witness the Companyman overrode the TP during a meeting pertaining to shut in procedures. To my knowledge shut in procedures are the client’s call.
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.
Reuters: Schlumberger says its crew left Horizon day of fireSAN FRANCISCO, May 19 (Reuters) - Schlumberger Ltd (SLB.N), the world's largest oilfield services company, said on Wednesday it had a crew on the Deepwater Horizon that departed only hours before the explosion and fire that engulfed the rig.The company, which had not previously revealed its work on the Horizon, said in an emailed statement that it performed wireline services for BP Plc (BP.L) on the rig in March and April, completing the last services on April 15 and leaving a crew on standby in case any more were needed.
"On the morning of April 20, 2010, BP notified the Schlumberger crew that it could return to its home base in Louisiana," Schlumberger said in a statement, which a spokesman for the company confirmed by phone.The crew departed the rig at about 11:00 a.m. on April 20 on one of BP's regularly scheduled helicopter flights, Schlumberger said. The explosion occurred at about 10:00 p.m. that night, and the rig sank two days later, which led to a massive oil spill off the Gulf Coast. [ID:nN19188461] (Reporting by Braden Reddall, editing by Bernard Orr)
[This story was developed from 2 posters at theoildrum.com as follows:]http://www.thomhartmann.com/forum/2010/05/smoking-gun-bps-deep-horizon-messI expect this to lead to a few days of breaking news. The truth is most welcome.Here's how story developed from 2 key persons at theoildrum.com asking that rumors be investigated and, if not clearly denied, pursued.
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.
KABOOM ! Schlumberger confirmed they were there to do CBL and left hours before DH exploded.
Pupjoint, where did you see they were there to do a CBL or you make that up? All I saw was last services were completed 15 April and crew kept on standby until 20 April. Doesnt mean they were there to run a CBL.
Re: Cause of Blowout/Fire on Horizon « Reply #85 on May 20, 2010, 1:29pm »
MW indeed, definitely was a forced value - i.e. user input. Normally while drilling ECD sensitive formations, MW is taken from in and out and input as frequently as conditions dictate. While cased and cemented MW monitoring would stop.
The black line "Riser Flow" would be booster pumps flow rates.
The red line "Pit Vol Chg" from 20:14 to 20:34 actually read +50bbls then +150bbls then +250bbls, +350bbls, +450bbls, +510bbls. Hard to say what went on there as we need to know how the pump room was lined up.
From 20:34 I believe crew monitoring Pit Vol - signs of steady gain. Mud transfer 250bbls out of active started at 21:10? Need info on Pit Vol indicator setup.
From the beginning, IMO, WOB is "zeroed" at pumps-off and with drill-string filled with SW. With SW exiting the stinger at 20:18 - corresponding drop in circulating pressure (red-line SPP) and WOB (U-tubing?). By 20:52, SW completely filled up the annulus. 21:14 wellbore influx (quite possibly already present inside the 7" CSG), with circulation resuming, now worked its way up the annulus making the drillstring bouyant - pressure build-up + density?
Alarms most certainly went off at 20:58-21:00 when Flow-out (blue line) increased by about 300+gpm
At 21:08 with pumps-off and SPP remaining 1k and rising must have set off more red-flags.
Block height (blue line) did not move at all during this time - otherwise could give indications of spacing out? Untill the last minute where movement could be seen ...
Gas cut mud this late in the well? This is puzzling don't you think?
Should be able to work out where the influx came from by studying the WOB and knowing exactly where it was "zeroed" with what fluid in the string? Was it from the 7" shoe or hanger seal?
KABOOM ! Schlumberger confirmed they were there to do CBL and left hours before DH exploded.
Pupjoint, where did you see they were there to do a CBL or you make that up? All I saw was last services were completed 15 April and crew kept on standby until 20 April. Doesnt mean they were there to run a CBL.
Carlton,
you will need to go to the source to see it. Put your glasses on. Links were provided, use them to check first, before you accuse me of making things up.
If I want to make things up I know a good company where I can do it professionally ie: " make things up as we go", and get paid millions for it,..... not do it here for free.
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 red line "Pit Vol Chg" from 20:14 to 20:34 actually read +50bbls then +150bbls then +250bbls, +350bbls, +450bbls, +510bbls. Hard to say what went on there as we need to know how the pump room was lined up.
X/fer BPs expensive displaced OBM w/sw
From 20:34 I believe crew monitoring Pit Vol - signs of steady gain. Mud transfer 250bbls out of active started at 21:10? Need info on Pit Vol indicator setup.
Yep . Stop x/fer to observe pits ...maybe.
From the beginning, IMO, WOB is "zeroed" at pumps-off and with drill-string filled with SW. With SW exiting the stinger at 20:18 - corresponding drop in circulating pressure (red-line SPP) and WOB (U-tubing?).
We can get top to btm lag time from this if circ w/sw commenced at this time 20:02 hr. However prior to 20:02 hr SPP=1500psi and was bled to give corresponding blue flowout of 300 gpm at the same time.
By 20:52, SW completely filled up the annulus. 21:14 wellbore influx (quite possibly already present inside the 7" CSG), with circulation resuming, now worked its way up the annulus making the drillstring bouyant - pressure build-up + density?
Alarms most certainly went off at 20:58-21:00 when Flow-out (blue line) increased by about 300+gpm
At 21:08 with pumps-off and SPP remaining 1k and rising must have set off more red-flags.
Block height (blue line) did not move at all during this time - otherwise could give indications of spacing out? Untill the last minute where movement could be seen ...
Thanks for this observation. We can rule out space out occurring for the period covered by this last 2 minute chart. In other words they could have had contingency to space out prior to time when this chart began.
Gas cut mud this late in the well? This is puzzling don't you think?
Appreciate you pointing this out. I could be wrong here with regard to the cause of loss of string buoyancy. It could be the SW relative to OBM weight causing the WOB to fluctuate with SPP.
Should be able to work out where the influx came from by studying the WOB and knowing exactly where it was "zeroed" with what fluid in the string? Was it from the 7" shoe or hanger seal?
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.
21:08 - pumps off but SPP still up @ 1000 psi likely due to differential caused by displacement with Sw. Blue flow out drops to zero.
21:08 to 21:10 – returns finish trickling from flow line and possum belly level drops.
21:10 to 21:14 - gas readings flat-lines to zero and remain so till the end of chart. Pit vol change drops to minus 50 bbl . SPM=0, Flow out = 0. But SPP>1000psi. Yeah I know, we all can read charts, so bear with me.
21:14 to 21:18 – pumps ON but no flow out ! I speculate returns bypassed shakers because gas readings still flat at zero and diverter actuated which is why zero FLOW OUT , but riser flow commences at 21:16 hr.
So, if diverter was actuated at 21:14, it is because the crew recognized the gas already in the riser. I didn't listen to the 60 minutes but whatever conflict might have arised between OIM and Company man, at this stage any of them and most likely both should have been present on the floor (as well as the subsea eng, another good soul among survivals.
21:18 to 21:20 -Pumps off., but riser flow continues and SPP now holding @ 1500 psi, flow out zero.
21:20 to 21:30 Pumps on but it appears SPM varies for these 10 minutes. Possibly to cater for diverter tolerance limits or the gas pressure is influencing SPM by speeding it up while driller is trying to keep it constant manually. Note the hikes in SPM for this 10 minute period appear less deliberate or human when compared to the SPM step downs from 20:50 to 21: 10. Magnify your pdf.
It looks like they are boosting the gas up the riser. I supposed they weren't conscious of that because after only 10 minutes, seeing SPP fluctuation, the shut pump off again.
21:30 –Pumps off
21:30 – 21:34 . Having diverted gas for the past 16 min, the well is shut in ? and SIDPP observed. However IF this happened , ie : space out, hang off on rams and Shut-in, the black WOB and red HKL should straight line from where it is at, but this does not appear to be the case
As stated below, string was already in position for closing BOPs place before starting displacement as they weren't obliged to a precise depth with the stinger.
21:34 - 21:36:30 – SPP stabilizes and perhaps SIDPP is ascertained for kick control
After 21:36:30 under magnification it appears that pressure in the SP was bled down from about 1700 psi to 700 psi. Under magnification this not appear to be a leak. The jagged trace alludes to human in control.
I agree SPP drop was a human manipulation but still seems strange to me that driller did it on his own without OIM orders or, alternatively, that OIM gave this order from his office. If it was a stabilized SIDPP which is the reason for a bleed off if not calling for more gas to come or accelerating its expansion?
21:38+ hr Pressure shoots up from 700psi to 1000 psi in a straight uniform rate that appears to me to be of non-human cause. Stop bleed ?
Stop bleeding and pressure came back to its natural value?
3 other points to ponder : - the blue flow in blip 21:46:30 hr Gas bubble point? - the change in block position in the last 2 to 3 minutes by 2 to 3 ft. Buoyancy effect due to the gas came out from crude kick? - the red SPP spike at 20:24 hr at which time riser flow commences. Debris or the system? I'd not wonder to much on it.
What's your take on these points Marco ?
From this time SPP and Riser flow show anomalies and only at 2130 hrs decision is taken to stop pumps. From 2130 hrs on, I can't figure what was happening. May be panic, may be flow checking prior to call the generals.
I can’t figure things out as a whole either but all indications indicate, to my experience, that situation was being handled by a crack drilling crew. I believe we are the ones who are confused considering the very limited amount of data we have to infer or interpret.
I insist: the fact that OIM and Company Reps are still alive make me believe the crew didn't understand the problem was serious and never called them.
According to the 60 minutes witness the Companyman overrode the TP during a meeting pertaining to shut in procedures. To my knowledge shut in procedures are the client’s call.
Shut in procedure should have been established in advance with the called Bridging document that merges and agrees the common procedures between contractor and client. In any case, in such events, the ultimate word is OIM's.
Re: Cause of Blowout/Fire on Horizon « Reply #91 on May 20, 2010, 6:07pm »
Thanks Marco for your interp, I have no problem meshing it with Emparri's and mine.
To condense all 3 interps and arrive at some major reference points I summarize as follows:
20:18hr : As per Emparri's input we have SW exiting OE stinger - an SPP apparent momentary spike of about 300 psi shortly follows. I am still not going to let go of this spike but will get back to it later.
21:08 hr : increase in flow-out noticed and pumps shut down. I believe we have all out of respect for the crew on the rig floor, have not over looked being mindful that this was a floater.
21:14 hr: Open diverter , and pump by passing shakers.
21:46 hr: Blowout.
All in about close to 6 minutes for the Companyman, OIM and Subsea Engineer to react from kick detection to divert . Perhaps they were at the remote BOP control panels struggling hard doing their part to save the day perhaps they just freaked out like 99% of us might do if/when caught by surprise, perhaps they realized what they dreaded or hoped would not happen or could happen or may happen, happened ! ?
I have listen to, again, the statements made by witness James, Chris Choy and the Electronics Engineer (60 minutes). As I have mentioned previously , temporal sequence gets distorted when we are in panic mode but the 60 minutes witness has the best recall of temporal sequence. The main trigger for all 3 witnesses was the hissing to whooosh sound. This must have been the diverter in action. The was also a news report of a lady who worked with catering , if I recall correctly and as per her description of events there was time between hearing the hissing sound to the first explosion.
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: Cause of Blowout/Fire on Horizon « Reply #92 on May 20, 2010, 6:48pm »
I have one question that make me crazy since day 1: if the situation was rekon to have became very critical and all "generals" were busy somewhere else but the rig floor, how come the Crane op and Dch foreman were still around? What were they assisting for?
Re: Cause of Blowout/Fire on Horizon « Reply #93 on May 20, 2010, 7:54pm »
Speculation here: At least one and possibly two of the Crane Operators were in the cranes per witness statements.
Is there a possibility that they were getting ready to switch to the mud hose that went to the boat out to take mud back on? As in dropping the rig mud intake hose?
With kicks going left and right, picking up the mud hose or personnel baskets, for evacuation, are the only two things I can come up with right off.
Pupjoint, where did you see they were there to do a CBL or you make that up? All I saw was last services were completed 15 April and crew kept on standby until 20 April. Doesnt mean they were there to run a CBL.
Carlton,
you will need to go to the source to see it. Put your glasses on. Links were provided, use them to check first, before you accuse me of making things up.
If I want to make things up I know a good company where I can do it professionally ie: " make things up as we go", and get paid millions for it,..... not do it here for free.
If the question had been asked more politely the answer would have been KABOOM made it up. A CBL in cement 22 hours old, tells you nothing. As we know they were moving the DWH off. Another rig was coming in to install the completion. The CBL/USIT would have been done then. If they wanted to know the effective TOC with wire line, a sensible move, they could have ran a thermal log. It is obvious that Schlumberger where only on board as a contingency. Nobody has said the cement job experienced losses, so we can reckon the TOC was as planned.
Did they set a cement plug at bottom as it says in the drawing ? or it is just the shoetrack ?
During the inquiry it was revealed that they RIH with DP and cement stinger, set a bottom cement plug. Then pulled back to displace mud to seawater from +/- 8,300 The answer is; the bottom plug is there and was tested with pressure and a inflow test.
Does anyone know if BP is still looking at using it?
As can be seen on the above youtube video of lowering the cofferdam, the problem was not one of gas hydrates, but of the outlet being too small, resulting in the cofferdam becoming pressurized. As could be expected, the oil had no where to go but around the bottom - the sea floor is not a high pressure device. No doubt that with the oil hitting sea water at approximately 40 defF the viscosity would have increased substantially as well adding to the problem.
The cofferdam can work if the outlet is increased. What would then be required is a cap / inverted funnel to match up which would allow for the oil to be directed up a large pipe .
Artificial lifting the oil would be necessary to further reduce the pressure drop otherwise the oil will just spurt out the bottom again. This could either be in the form of an ESP or jet pump and is certainly workable at 5200'. The jet pump would probably be the best solution since sea water could be used as the power fluid.
These are simple technologies that can be easily deployed. I hope BP is taking advantage of their artificial lift people to work solution as well.
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