[QUOTE=dell;40517]27182,
I would be most interested in looking at the way the same group recorded the same data for the day before, and a random date in March. If the same kind of record, grrr, complain about yet more corner cutting, even in data collection/recording etc. If different…[/QUOTE]
Sorry if this is a bit long…
[B]Mud Logging Data[/B]
[B][I]Some quick background[/I].[/B] It’s usual for mudloggers to have numerous sensors monitoring different parameters associated with the drilling operation. (probably 20 to 30 in total). The idea being to have an independant monitoring system to the rig’s own sensors. Data from these sensors is recorded realtime at a frequency of less than 1 minute intervals. (don’t know how this logging unit was set up), and is stored on the mudlogging unit computer on the rig.
It is usual to have at least 2x sensors on the choke manifold one monitoring kill line and one choke line pressures. Plus, one on each mud pump recording strokes (ie volume pumped which =flow in), 2x on the gumbo-box/flow-line out monitoring Flow Out and Gas Units and several monitoring various pit levels. There are numerous other sensors as can bee seen from the charts.
How accurate is the data that’s recorded depends on when and how often the sensors are calibrated and checked. It should be done regularly at least every day.
How accurately does the data match the data recorded by the rig’s own sensors… it should match closely but there will be differences in values.
Outside of the mudlogging unit that data is displayed on a screen in at least 2 or 3 places around the rig… Company Man office, Driller’s shack and Toolpushers office. What data gets displayed depends on what that individual wants to see. The mudloggers have numerous standard display formats, or you can have your own format showing just a subset of the data. Scales can also be adjusted as you wish. There are too many sensors to display on one screen all at once, so there would be various subset displays depending on what operation/sensors you wanted to monitor.
[B][I]Data back to town[/I][/B]. As above, bp also had a screen in town. How much of the real time data set do they have and is it stored on their computer also, I don’t know, but logic would say yes. Like wise it appears Halliburton in town also have a full data set. (reason behind this is the initial 2 hour log was presented by Halliburton to the senate committee, and I believe the 14 hour log was presented by bp to the USCG committee/MMS). Maybe someone with a mudlogging background can answer this better.
[B]
[I]Who owns that mudlogging data?[/I][/B] [B]dell[/B] can most likely answer this better than I can, but bp’s contract with halliburton would have a clause in it somewhere with words to the effect that “all data collected on the well belongs to bp”.
So back to the charts…
one quick interesting comparison. Right hand most column on both logs shows “Cem Pump Press” (Cement Pump Pressure). On the initial 2 hour log, that column was blank. On the 14 hour log there is a black/dark green? data trace.
On the 2 hour log there are 2 headings “Choke Press #1” & “…#2”. Are these choke and kill line pressure sensors? Strangely they are not shown on the 14 hour log.
On both logs only “Pit Vol Chg” is shown. No indication of what pit sensors were combined to give this total reading, and also no readings from individual pits.
Lots of other data is not shown which possibly could be shown.
Is the data that’s presented being sensored?? Draw your own conclusions.
