Monday, August 2, 2010

How much mud, and how long is the first undamaged casing length ?

I still think if they have problems with mud being lost to any leaks in the bore, they can apply Faraday waves into the fluid to prevent the structure of the mud from " breaking " the gelled structure it may have established as it settles. It would provide much higher surface friction throughout the structure of the mud, ie: the face friction. The face between the casing and the mud would overall exhibit a higher overall " grab " factor due to random shifting particle positioning , ie:average face-friction gradient. 13ppg mud can exhibit density and weight changes up to 15ppg in localized pockets, it's: the reason I have been writing about binary fluids, aside from a personal interest. Muds are /can be, binary fluids, Non-Newtonian fluids, Newtonian fluids, etc, etc,

If and when they get hydrostatic equalibrium in a certain section of the bore above the first damaged area, but the mud cannot exert enough face tension against the casing walls, then it will start to loosen and disseminate into the oil flow it is trying to compress. It will be lost into the same areas that any mud will be lost to. If they apply Faraday wave...they can make the mud " stick " to the casing more than it normally would.

                                                              Just a theory.

" A 18,000 column of 13 ppg mud will exert a bottom hole pressure of about 12,200 psi. Original reservoir pressure was 11,900 psi. But remember when they are pumping the mud the effective mud weight (ECD) could approach 14 ppg to 15 ppg. "

" The Calculation for hydrostatic pressure (HP) is weight of mud in ppg X 0.052 X True Vertical Depth.

The depth of the well is ~18,000 feet below sea level so ~13,000 feet of well.

The hydrostatic pressure will therefore be 13.2 X 0.052 X 13000 = 8923 psi. This will result in an overbalanced well assuming well integrity since the surface pressure is currently ~7,000 psi. "

                                                            Here's what it looks like

" Figure 1a (based on a government document) shows that the upper part of the well bore is protected by three strings of casing (36-, 28-, and 22-inch) and cement down to 7,937 feet (measured depth below sea level). A fourth string of 16-inch casing extends nearly from the well head to where it is cemented at 11,585 feet, but it is apparently hung inside the 22-inch casing at 5,227 feet, leaving a gap of 160 feet. The 16-inch pipe has a burst rating approximately equal to the current shut-in pressure of 6,900 psi (80% of rating), but the 22-inch pipe does not meet this standard. "

Drilling companies are required to "bake" any hydrogen in casing sections before reusing them in a drilling operation. It's standard. Otherwise the metal becomes embrittled. That's why I have been mentioning possible " stress cracking " as a possibility leading to a structural failure. Seeing all the sloppy practices from these guys come to light over the past 3 months...makes me wonder if they skipped this crucial step as well. I was asking about this 2 months ago at the Drum, but for some strange reason...they didn't know what I was talking about...even though it's common knowledge in the drilling industry.

I have my fingers crossed, But I think they can do it.


                          And one more

...but I think lower, much lower amplitude than the last

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