drilling costs to plummet, page-7

I had another look at the CKK page and there wonder machine, to me its atributes are quick erection, small crew and compact lease area. All valuabe savings in the costs of drilling a well. In on one of there photos just happens to a rotating head, can't tell if this is intentional or just good luck, so they have the capacity for managed pressure drilling. This is the pracitice where GDY took a 100bbl+ kick and lost their last drilled hole, Jokel #2 I believe or something similar.

The web site mentions air drilling and water hammer drilling, which can be used in the upper hole. It appears tripping speed is an advantage, though it appears to be a single derrick and for 10000ft/ 3000m, that is a lot of pipe to lay out side ways each trip, compared to racking back in triples in the derrick. This would be compounded in PTR's wells with very hard rock formations and repeated bit trips. Though PAX drilling in soft sedimentery rock only needed one trip per casing section.

But the big or should I say the little number that stood out was 154t hook load. The is the working load of the lightest weight handling gear for casing that Varco make, and is never used in open hole to my experience.

Just to put things in perspective 5" casing which is definately slim hole, range from 13 lb/ft to 24 lb/ft, as geothermal is normally high pressure and corrosive and as its a round number I will take 20lb/ft. So at 10000ft we 200,000lb hook load, add in your top drive and a safety factor for drag and it is a one way trip. In other words it would be risky to plan to pull this string if you had hole problems.

They state it is possible to run 10 3/4" casing as your completion casing. 10 3/4" casing starts at 40lb/ft and go to 65lb/ft. You definately are not going to run that to 10000ft.

Now there is a way to case / line your hole to depth with this low hook load, and that is as PAX did, by running telescopic liners. This works until unexpected over pressured formations are found, as per PTR, and full casing strings are required.

My conclusion still stands, a good tool for quick access slim hole exploration, but under gunned for large bore high pressure, high volume production of geothermal fluids. As for a previous comment of more small bore holes would be better than one large bore. Then think of it this way, double the dia and quadruple the cross sectionial area.