Monday, December 8, 2014

892 m, decision time, steel casing

Rupert Sutherland, GNS Science and Victoria University of Wellington
John Townend, Victoria University of Wellington
Virginia Toy, University of Otago


The view downstream. It is 600 m to the bridge. 4/12/14.  Photo J. Townend.
We reached a very important decision point today. At 8 a.m. this morning at 892 m depth, we decided to stop drilling and to cement casing into the hole. A bunch of things now have to happen so that we are ready to start the collection of rock core.

We first have to clear the borehole of rock chips and cool it by circulating mud. The mud emerges at 52°C. How hot would it be if we weren’t drilling? We will know in the next week or so.

Before we cement PWT steel casing (5.5 inch = 140 mm diameter pipe) into the hole, we will use wireline tools to log the hole. This is our last look at the borehole wall before steel and cement get in the way. Logging will start about midnight tonight.

New PWT casing is ready to go. Photo J. Townend.

The process of putting casing in the hole is fairly complicated. It has to get down and around the J-bend in one piece. The bottom of the hole is now 250 m horizontally towards the road bridge and away from the drill site (see our last blog). Next, we have to run another smaller steel pipe next to it – this is going to be a tight fit. Then, we have to insert a fibre optic cable down the second pipe. Finally, we have to pump 25 cubic metres of cement down the inside and back up the outside of the casing without it leaking into the rock or setting hard before we are finished.

If all that happens without a hitch, then we will be hoping to collect our first core this weekend.

View from the geologists’ cage.  J. Townend.



7 comments:

  1. Hi, thanks for the interesting blog! Such an amazing project. I am a veteran of the Christchurch sequence, 10000 odd shakes...7.1 slammed into that old volcanic rock...daily it was breaking up...lava tubes collapsing...got too much had to head north to the outrageous city of sales and second hand goods. i worked on the Wahapo power scheme in the early 1990's..I was there when the top fell off Mount Cook. I stayed in Whataroa, they were milling native trees back then...is the sawmill still operational in Whataroa?

    so last night I wrote a poem...about the project...hope you like it Rupert!

    Fucking the fault lines.

    downtown...the hypodermic needle...reaches for the sky
    ....seen from the huaraki gulf...
    it is a fault zone...between....
    piercing below the cloud line...
    the roulette players push on...
    is it red?
    or is it black?

    others jump

    ...in the other island the hypodermic needle pushes towards the fault zone
    at 635 meters...it's time to fix the diamond cutter for a sharper hole

    it is hot down there 80 degrees C - no time to ask why
    ...push on toward the fault...through the schist overhang...
    lets drop a line down and survey the hole....

    it is 825 below..... and the fault is 300 years young
    such an intrusion....
    it is a private matter between schist and granite
    punchering the fault with a needle may cause a blow-out on the Whataroa river flats....
    blown- out- veins.... below the snow line...

    scientists meeting in the sky city convention centre...discuss fault lines..
    the temperature, the fluid pressure - what are the signs of rupture?

    it's about to go with a magnitude 8.0...birds will be silent monetarily...
    pipes and bridges, roads and streams, chimneys and hill sides...

    while downtown.... we gamble the days away..

    the cathedral is full of pigeon shit...the urban minors found it...
    what to do with it?

    ReplyDelete
  2. flanges such as weld neck flange & socket weld flange also require specifying the pipe schedule. This ensures the pipe bore will match the bore of the weld neck or socket weld flange. check out tiz
    Neck flange

    ReplyDelete
  3. Really a wonderful flange, it easy for connecting pipes, valves, pumps and other equipment to form a piping system
    Slip on flange

    ReplyDelete