<Drumbeat: August 2, 2009 The Oil Drum Drumbeat: August 3, 2009>

44 comments on Drilling through Rock

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mcain6925 on August 2, 2009 - 2:16pm Permalink | Subthread | Parent | Comments top

One question that persists is how does the broken rock (chips and dust) get out of the hole?

Please, Heading Out, don't make us wait too long before you write about the glories of mud ("Talk dirty to us, big guy!).

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Heading Out on August 2, 2009 - 5:42pm Permalink | Subthread | Parent | Comments top

It is already up on Bit Tooth which is my own site. As we used to do back when these started, Gail and I feel that these Tech Talks will probably continue on Sundays, since they are slow days for other news, and thus these don't get in the way of other things.

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Substrate on August 2, 2009 - 10:33pm Permalink | Subthread | Parent | Comments top

Ok...someone has to do it...

What a boring post!

I'd always wondered how those tri-cone bits actually did any good. For some reason I'd always imagined that it chewed the rock to death rather than tapping on it to death. Wouldn't last very long trying to chew with brute force, but that seems like the strategy of the diamond bit. A step backwards, supported by advances in materials technology?

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Heading Out on August 3, 2009 - 9:34am Permalink | Subthread | Parent | Comments top

The old style bits that were raised and dropped were still used in some applications into the 1950's - I have an NCB film of the shaft sinking at one of the mines where they started off using it. They were putting in a freezing ring around the shaft area to prevent water coming into the shaft while it was excavated, but they could not drill the holes straight enough with the original system. (They were going down less than 2,000 ft).

When they switched to rotary drilling with the tri-cones not only were the holes drilled a lot faster, but they were much more accurately drilled.

I'll have a couple of posts on directional drilling before long, and talk a little more about other methods of drilling. Diamond drilling helps you get through harder rock faster in some cases than you can achieve with the tri-cones.

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R W Reactionary on August 3, 2009 - 10:24pm Permalink | Subthread | Parent | Comments top

I suspect you know this, but for those who do not, cable tools are still used on a limited basis for certain specialized applications. Deeping out an open hole completion by a few feet to obtain a higher rate of fluid entry (while avoiding the potential for drilling mud related problems) is one of the more common.

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mcain6925 on August 3, 2009 - 9:35am Permalink | Subthread | Parent | Comments top

The Bit Tooth site won't accept my TypePad id, so I'll mention this here. You might want to add a paragraph about blowout prevention. I recall the guy who taught the "practical" mud class at UT-Austin many years ago telling stories about failing to increase mud density quickly enough in response to rapid pressure changes, eg, when drilling into an unexpected geopressured brine reservoir.

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Heading Out on August 3, 2009 - 9:49am Permalink | Subthread | Parent | Comments top

Thanks - there is actually a post on borehole pressures and some of those issues in the works - last time I did the series it came two weeks after the mud post. However I may put in a couple of posts on EROI of drilling before we leave bits and the bottom of the hole, this time around. But with your indulgence we will get there in time.

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44 comments on Drilling through Rock

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