Infographic: Relief Well Reaches 8000 Foot Depth

BP has released an infographic showing the current state of the Relief Well, the “final solution” in resolving the Gulf Oil leak caused by the Deepwater Horizon, that shows the current progress (As of yesterday) as well as the proposed design of how they plan to intersect the previous pipe.

When will BP open its books to explain its $77,000 contributions to Hussein?

When will the Hussein’s Department of the Interior open its books to show why they allowed BP an EXEMPTION from environmental studies because an oil spill was “unlikely”?

Do you want to know why Hussein and BP are not being raked over the coals daily by the media? Because BP and Hussein are friendly—VERY friendly with each other.

If this were a Bush White House and, say, an Exxon oil well, you’d hear day by day accounts of their closeness.

Been a while - but I worked for Schlumberger for a few years so I can speak to the basics. These days they have sortof a GPS in the drill that allows them to help direct where things are going. They do need a minimum amount of depth before kicking things at an angle. They used to do that by placing what they called a shoe to help start the deflection - with the steerable gear they have now not sure if the shoe is still needed. It could be that there are other high pressure regions above the main blow out that they want to ensure are properly addressed prior to targeting the previous pocket.

In any case once they are in the old hole, they won’t be as concerned with using too heavy a mud and overpacking or washing out the producing formation in the hole, so they will weight up the mud as heavy as they can in order to gain control of the old hole and then they’ll send down a cement slurry to plug it for good.

In order to control both wells (the relief well and the uncontrolled well, they have to be able to introduce heavyweight drilling fluid at a depth which will provide enough pressure to stop flow from the reservoir.

The extra depth gives a taller fluid column in the relief well, and that translates into more pressure against the producing formation to hold the oil in the formation. If they tried to intersect at too shallow a depth they would encounter a significant risk of having two uncontrolled wells and another disaster.

In addition, the rock layers deeper are often more conducive to directional steering, enabling the directional drillers to do a more precise job.

For starters, they have the survey data from the original wellbore: that gives the position of the wellbore within a few inches at most relative to the position of the relief well wellhead. From there, survey tools are used to measure the azimuth and angle of the drill string along the relief wellbore as it is drilled, which enables the directional drillers to steer the relief wellbore toward the existing and uncontrolled wellbore.

There are a couple of technologies out there, one which uses pads which push the lower part of the drill string over in the intended (target) direction, the other uses a mud motor, which is bent a specific number of degrees (usually 2 or less) and which uses the flow of drilling mud through the mud motor to rotate the drill bit. Both technologies permit the wellbore to be steered by knowing which way the tools are aimed, that determined by MWD (measurement while drilling) survey tools contained in the drill string--the data relayed to the surface by a pulser in the drill string and pressure transducers at the surface which pick up the pulses which are decoded by the MWD computers to give the information as to azimuth and inclination of the tools.

The series of surveys show the progress of the wellbore, and with a specific target, it is a matter of working out the math and steering the drill bit to the target.

Believe it or not, that is a bit simplified, and good directional drillers will compensate for variations in tool response which come with variations in geology.

On all the wells I have worked, we get the best results when the MWD, Directional Drillers, Geologists and engineers work together as a team. I'm sure BP has the best available people they know for the job, people with experience in the area.

As far as tapping into the existing wellbore, if they can hit the casing, they can mill into it, cutting a hole in the casing. From there, it is a matter of having heavy enough mud (drilling fluid) in the wellbore to provide pressure to control the relief well, and to be able to introduce that mud into the other wellbore to control the 'wild' well also. Once controlled, then they can 'set' a plug in both the cased wellbore and the open (relief) well and let the heavy drilling fluid hold it and the produced fluid in place.

In the event the problem might be a flaw in the cement job, then the formation fluid will be channeling up the outside of the casing, and remediation may be more tricky, but will involve basically the same process: introducing heavy drilling fluid to control the well, and then setting a cement plug to maintain that control and remediate the cement job by filling the channel. The latter would be a more difficult situation.

The weight of the drilling fluid should be sufficient to hold the oil in the currently producing well long enough for the cement plug to harden, and once the wellhead situation is remediated, the well could be produced by drilling out the cement plug, or simply plugged and abandoned in favor of drilling new wellbores with even more substantial safety precautions.

Now that the characteristics of the area are better known, the hazards can be better dealt with.

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