DFDP-2 @ 635 m, packer tool

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

Doug Schmitt, Dierdre Mallyon, and Alex Pyne take a moment from packer tool testing. 28/11/14. Photo B. Celerier. 

Drilling has been going smoothly over the last few days. We reached 635 m depth at breakfast time. 

We will continue this phase of drilling until the team analysing rock cuttings tell us we are near the fault. Then, we will put steel casing (pipe) into the hole and cement the annulus (gap between rock and steel), to secure a foundation for deeper operations.

In the meantime, we are also mobilising and testing tools for the next phase. A new tool for imaging the borehole wall at high temperatures arrived this morning from Europe, and a packer tool was tested on site.

Water circulating through packer tool. Photo B. Celerier.

A packer is a rubber element that inflates to seal and isolate a section of the borehole. It is then possible to pump water down the pipe that is inside the packer and inject water into the isolated section of rock. The process works in reverse too: you can produce a small amount of fluid out of the rock from an isolated section of borehole.

Why do we want to do packer experiments? 

(1) To determine how easily fluid can move through the rock; and 

(2) to collect fluid for analysis. 

When combined with other data, we can also use this tool to evaluate the stress state of the rock, which is interesting for us earthquake scientists.

Checking the packer tool works OK. Photo B. Celerier.

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

DFDP-2 @ 547 m, drilling equipment

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

DFDP-2 drill site from the bridge over Whataroa River.13/11/14. Photo R. Sutherland. 

Exploration can present logistic challenges, because any trip into the unknown may hold surprises. In the case of our drilling experiment, the challenges we face include: having the right drilling equipment; attracting and sustaining a strong team of people for many months; and extracting scientific results from challenging underground conditions (e.g. the high temperatures that we have already encountered).

Obtaining and maintaining the right drilling equipment has proven tougher than expected and we are now several weeks behind schedule.

The current drilling method we are using breaks the rock into small pieces (cuttings) and creates a 215 mm diameter open hole. It is a similar method to that employed by the petroleum industry, but we are drilling into a much harder rock than they typically encounter. Hard rocks similar to our site are commonly drilled by mineral explorers (e.g. gold miners), but they usually collect rock cores and drill a much smaller (<125 mm) and shallower hole. It is hard to find a drilling company with such overlapping experience. The NZ contractors we have on the job (Webster Drilling and Eco Drilling) have been very helpful and are learning with us.

This video shows you what the business end of our open hole drilling gear looks like:


We reached 547 m depth last Wednesday (17/11/14), but progress was slow and equipment was damaged. A decision was made to remove all drilling equipment from the hole, send it to Christchurch for a makeover, and obtain new specialised drill bits. The new roller-cone drill bits have hardened points to shatter the rock, but they need several tons of weight on them to be effective.

We hope to start drilling again tomorrow.

Photos of different (used) drill bits: 
(A) Coring drill bit with industrial diamonds for hard rock
 – the hole in the middle is where rock core enters; 
(B) PCD, Poly-Crystalline Diamond, bit for an open hole;
(C) Roller-cone bit designed for soft rock (damaged bit).

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

DFDP-2 @ 520 m, geothermal resource?

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

Happy to be drilling again. Onsite shift scientists under some of our flags.16/11/14. Photo R. Sutherland.

What a great team we have at the DFDP project. About 120 scientists from 12 countries are involved in DFDP-2, and more than half of them have been working with us here onsite already.

We started in August and won’t be finished until Christmas. It’s a long time away from families and friends, but the team here has great morale. It will take at least a year to make systematic lab analyses of samples, and then another two years to do specialised analyses. It really is a big job.

We are making steady progress and passed 520 m at breakfast today (17 Nov.). We are drilling a 212 mm diameter hole on our way towards the fault, sampling and analysing rock cuttings as we go.

Geothermal conditions in the borehole have turned out to be one of the most popular talking points amongst scientists and locals. We have made 9 temperature logs of the borehole. When not cooled by circulating fluids, the borehole is at about 85°C at 500 m depth. This is about 70°C hotter than at the surface. For an average location in New Zealand, or on most other continents, the temperature increase would be about 12°C. The geothermal gradient – the rate of temperature increase with depth – is six times normal. The hot conditions underground are of scientific interest, but are also a challenge for sensitive instruments.

Is there a commercial geothermal resource here?

Our main focus is earthquake science, but there is a reasonable possibility that we have discovered a significant resource in the process.

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

DFDP-2 Calamity resolved! Mostly.

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

A lovely morning at the site. 13/11/14. Photo R. Sutherland.

Successful fisherman, Richard. 
Photo: R. Sutherland 13/11/14

Yesterday, after it was clear that the drill had snapped and been left at the bottom of the hole (489 m depth), the drillers flew into action, quite literally. They went up to New Plymouth in their plane, obtained a fishing tool, got it back to our site, deployed it, attached to the lost drill, pulled it back to the surface, and took it apart. This was all complete by 4 a.m! It was an impressive effort.

The drill bit was damaged, but still in one piece. The bearings were broken. It was also badly worn, so must have been cutting a hole that was at least one cm too narrow. We think this explains the damage to the bottom stabiliser, but are still piecing together the facts.

Our next challenge is to check the integrity of all components and obtain new stabilisers. We hope to be drilling again very soon.

Everyone on site is now familiar with what a bottom-hole assembly (BHA) looks like. If you want to watch an explanation of the various parts and what they do, see our youtube video:


https://www.youtube.com/watch?v=A6gLpzR8mlI

Comparison of broken drill bits. The bit recovered today (left) is badly worn and the bearings are loose. The bit dropped previously (right) has broken teeth and has cones jammed together. Photo R. Sutherland. 13/11/14.

Broken pin with stripped thread. This is the top of the recovered piece of BHA. Scratches visible at the top of the photo are from the fishing operation. 
Photo R. Sutherland 13/11/14.

Driller, Paul, is standing next to the fishing tool and a part of the recovered bottom section of the BHA. The drill collars beneath are part of the upper BHA. 
Photo R. Sutherland 13/11/14.

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

DFDP-2 @ 489 m: Calamity! Again!

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

Fresh snow in Whataroa. Drill site is up the valley on right of photo.
12/11/14. Photo R. Sutherland.

Misfortune struck in the early hours of Wednesday morning. Drilling progress had slowed the previous day, and then it totally stopped. We had reached 489.5 m depth.

The drill was removed from the hole and we got a surprise: the drill bit was missing. So was the bottom 7.5 m of the bottom-hole-assembly (BHA).

Steps to recover the lost BHA piece are in motion. We know how to fish it out from our last experience.

Crossover (left) with stripped thread and a broken fragment inside.
It should look like the male thread on the right.
Note the stabiliser just above it.
12/11/14. Photo R. Sutherland.

Worn stabiliser. 12/11/14. Photo R. Sutherland.

Close-up of stripped thread and broken fragment still engaged.
12/11/14 Photo R. Sutherland

 The loss was caused by equipment failure: a broken thread. It is the same section of drill collar that bore the full impact when the BHA was previously dropped to the bottom of the hole, so it may have had a weakened thread. However, there are also signs that drill bit failure contributed to this incident.

The science team noted anomalies in the hours before the incident. Steel shavings were collected (damage to stabiliser and bit?) and traces of hydrocarbons detected (grease from the threads?). The bottom stabiliser is badly worn at its base, suggesting the hole was not in gauge (it was too narrow). It seems that the drill bit may have started to fail at least 8 m before BHA separation occurred.

Wireline logging is underway. It will help us understand the state of the hole and what happened.

We hope to be drilling again in a few days.

These little fellas really didn't care about our woes. They are always happy to see us.
Photo R. Sutherland

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

DFDP-2 @ 430 m: Drilling hole again

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

It certainly took longer to get drilling again than we had hoped, but we are now making steady progress. We started drilling again at 7 pm last night and passed 430 m depth this morning.

The delay was caused by annoying fragments of metal that were still in the borehole after we had recovered the main BHA.

Fishing tool with a strong magnet inside it covered in fine metal shavings 9/11/14.
Photo: R. Sutherland.

The most elusive object was a weight that normally resides at the bottom of the winch rope (just below the flag, see photo of the new one). It was eventually retrieved using a strong magnet in a steel pipe (see photos).

Fishing tool with our last catch. 9/11/14. Photo: R. Sutherland.

The BHA and a nice new tricone drill bit were installed yesterday and we are now making good progress. The science team and drillers are very pleased to have put the dropped BHA drama behind them.

Flying the flag again 10/11/14. Photo: R. Sutherland

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

Happy drillers

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

Broken drill bit recovered from the lost BHA. 5/11/2014 Photo R. Sutherland.

Happy drillers: Luke Valour (left) and Tony Lyons (right). 5/11/14 Photo: R. Sutherland.

Was it great to see that smashed up drill bit finally recovered? Yes it was!

It took longer than we thought to get everything on deck, but finally the fish was landed, cleaned, and checked. The drill bit was a write-off (see photos), but the other components were surveyed by an engineer (who arrived by helicopter) and they are apparently undamaged — they are very solid steel.

Minor fishing operations continue as we recover remaining small fragments, but we are nearly there. We will collect wireline logs tonight. Tomorrow, a new drill bit will arrive, and a new BHA configured. We have an engineer’s report into the original winch failure and repairs will be complete tomorrow.



Hail on us, sunshine everywhere else. 4/11/14 Photo: K. Sauer

Check out our new video... Minerals and Alpine Fault drilling

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.

Landing the fish

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

Photo: R. Marx.

The BHA — 7400 kg of steel — was lost to the bottom of the hole over a week ago. The weather packed up shortly afterwards. It was a pretty grim week to be a scientist or a driller in Whataroa. But, the science and weather forecasts are good.



Photo: R. Marx.

The drillers have been fantastic. They methodically and calmly worked at the problem, systematically cleaning out loose materials and deconstructing the top of the lost BHA. It is amazing how they can picture and even feel what is going on 324 m underground. Over the last 10 days they have recovered wire rope, a shackle, a piece of wet rag, the top and then the bottom of the heavy steel hauling plug. They grabbed stuff with all sorts of special tools and even lifted the whole assembly by 5 m at one point. The mood has steadily improved.

This morning, just as the hail set in, they successfully latched onto the top of the BHA. By lunch time, the top of the ‘fish’ was visible at the surface. Tomorrow morning it will be landed. Then there will just be some minor bits of trash to clean up. Hopefully we will be drilling again by Thursday.



Drillers landing the fish. Photo: R. Marx.

Primary funders of the DFDP-2 project are: the International Continental Scientific Drilling Program (ICDP), the Marsden Fund of the Royal Society of New Zealand, GNS Science, Victoria University of Wellington, and the University of Otago.