The Secret at Waitangi Hill

The Secret at Waitangi Hill

“East Coast oil helped save New Zealand’s whales!” asserted David Francis, as the Ute jolted, bouncing me off my seat on the steep dirt farm track. Sporting a bushy beard that added bulk to his wiry frame; ‘Rockdoc’ is the unquestionable geological guru of the East Coast Sedimentary Basin, having literally spent more than my lifetime, 27 years, studying the hydrocarbon potential in only these hills. In the East Coast from then on, it was cheaper to; “…drive a horse cart up this hill and scoop up the oil, than to harpoon a whale!” he said with a crackle of laughter. The discovery of the kerosene rich oil; so light that it could be directly burnt, forever removed the dependence on whale blubber oil for street lighting in the town of Gisborne. However there was one problem, oil could never been commercially exploited, even though geologically this was a perfect setting for an oil accumulation. We were driving to the top of the hill where a crew of 9 had assembled from all over New Zealand, and we were hoping to make history.

Under the dim light of my sheep-shearing tin shed room- our makeshift camp; I ferreted through the paraphernalia of literature authored and collected by Dave; I found out that oil exploration in the 19^th century had that little to do with policy; but more lunacy. The rare moment of success was not because of deep design, but simply because of blunder and blind chance. However meagre, this was enough to surge expectation and rope in eager investors to allow a gambler to poke yet another hole in the ground.

Back then, prospectors did not deliberate on the subsurface geological structure or reservoir Formations. Almost all the wells had been “sunk in the obvious place”; either, on the hill top or near surface oil seeps. With no 4-wheerlers or quad bikes, access to the top would have been a horrendous whenever it rained, as the Lower Tertiary clay Formations on the hillsides made life slushy-slippery for the horses and bullocks that carted rig equipment up. As drilling technology was at its infancy, a wooden timber lined shaft would then have to be hand-dug to as deep as one could get, usually about 30-60m. And the conditions were tough. It was cold and slushy for the men working at the bottom of the shaft, with only a Davy lamp strapped to their head for illumination. A winch tethered to the miner, was not only used to haul shoveled dirt up or down the shaft, but it also was a lifeline. The stench of oil, gas and mud at the bottom would have been un imaginable- a beggaring description really, and blowouts (catastrophic explosions as a result of encountering unexpected high pressure gas/oil) during shaft sinking seemed to have occurred in almost every well account I read! You were in for more than a double-whammy if you were miner; if the sparks from the miner’s pick didn’t “ignite the seams of shallow gases”, the naked flame in the Davy lamps most often definitely did! But very often gases escaping at the surface were ignited by the coal fired boilers of the steam powered pumps! Setting the dreams of many a prospector, investor and unlucky miner alike, in “…a spectacular fire fountain displays of burning oil and gas…” There was no record of how many lives were lost.

After “bedrock” was struck, drilling would proceed with a ‘cable tool’- a steel bit with a chisel-shaped cutting edge strung by a cable. The tools were alternately lifted and dropped, cutting the rock by repeated blows of the bit. With common citations of “…caving caused abandonment”, “…pipes got stuck…” or even a very vivid description of how “…tools blew out of the hole”, meant that success didn’t come that easily or often. Of the wells that finally did get ‘shows’, often “half a gallon” or “a little black oil” was all that was sometimes collected. The only “successful” well, drilled in 1909, produced 37bbls on the first day, petering off, before being abandoned a week later. Inexplicably enough, here I was standing 5m from that well, Waitangi-1, drilled to a modest 433m that had taken an arduous 19 months; only because in 2009, some oil company spurred on by reading these same preserved reports, letters and transcripts that I was reading, decided to try their luck at striking, hopefully more than just 1 pot of black gold!

“OIL..!” I exclaimed, as a honey hued liquid trickled down my arm as I squeezed a fistful of earth. With the exception of a brown horse, no sheep stirred when I yelped with child like exuberance! I was standing by a 4m diameter of brownish black patch. Not in my wildest dreams would I have thought, that one day I would see, least in a green paddock in the middle of New Zealand; an oil seep! A black gooey mush of oil and mud, with puddles that shone bright orange, sputtering and hissing with a constant stream of bubbling gas; it all reminded me of thriving molten lava pool. In fact the only eruption taking place; was of exhilaration from within me. I was a child in a sandpit; watching the unending stream of gas bubbles explode up close, tasting, smelling, even lighting it (there was a ‘small’ fireball) and, of course, not forgetting to click a squillion photographs in between. Though the grass had died in the oily earth, I was dumbfounded to see startled frogs jumping out of the oily mud when I tried walking (…err should I say I sank) on its surface. There were several other smaller seeps along the fault, but not as spectacular as the “mother seep”, bubbling and seeping just as they have been doing in the last 140 years since it was rediscovered by white man. And then it dawned on me; we sure would find oil; Waitangi hill was the crest of a faulted anticline, however not by any stretch were we going to drill “a gusher” with so much oil already seeping to the surface along the flanks of the faults.

We geologists are like detectives really. In this case the presence of oil was never in question; we could see it. But where exactly was it coming from? And how thick was the horizon? It’s groping in the dark really, if you are standing at the surface trying to speculate with only a basic 2D seismic survey and a scanned copy of the only surviving tattered handwritten ‘Waitangi-1 Geological Report’ drafted by “a school inspector with significant geological knowledge”. Since there were no compulsions to submit relevant reports, drill cuttings, lithological logs or anything else, information about these older wells is very sketchy. So a Stratigraphic Core from surface to our target depth, planned a little deeper than the original well Waitangi-1, was what we reckoned would surely take us past the oil bearing sandstone; the core giving us a true visual of the geological structures-the faults, joints, bedding, lithology thickness and even the porosity and permeability of the reservoir for future drilling. Invaluable information that will get a ‘Rocdoc’ terribly excited about.

“... terrific gas pressures were suddenly encountered. It showered me with mud and blew the tools out of the well…”I was peering down the original surviving casing stump of Waitangi-1, 101 years after that fateful day. Incredibly oil reached the brim of its hollow cylinder stump, still vivaciously gurgling and bubbling. I dipped a branch into it… a honey coloured watery liquid dripped. I closed my eyes and licked a finger rub of it… an intoxicating riot of colours exploded, a mix of pleasant blooming sensations streamed in my mind. It was a virgin elixir, straight from the earth –pure ‘Te Karaka Tea’!

The condition, that we modern day explorer’s endured, even during late summer was harsh. My fingers numb with cold, as needling rain and icy wind sprayed Waitangi hill like a dart gun. Yet the aged rig pump monotonously chugged along and the crew unflinchingly toiled along providing me core after core to log and describe. Some porous sandstone cores fizzed as I opened the core-barrel, myself privileged to allow the stratified rock and gases to see the surface for the first time in 34 million years! When some of the sandstone streamed with ‘free oil’, we were excited as it was a sign that the ‘pay-zone’ was not too far away. And then suddenly without warning, at 3am on a nippy night, there was fountain of mud shooting a few feet out of the pipe. The 4 of us on the shift froze out of fear-a blowout! I can remember the chill run down my spine as the alarm in the driller face caught my eye, as the two roustabouts simultaneously scattering as flammable gas filled the air and showered us with an emulsion of oil- water- mud and sand. What seemed like ages, actually took the swift driller a few seconds, to shut the valves of the BOP (Blow Out Preventer). My heart was at this moment beating in my mouth, but I tried to mask it, ticking through a mental checklist of things I had to do in such an emergency. Satisfied the rig-site was safe; the driller gingerly released the valve of the diverter, diverting the explosive ‘wet gases’ away from the rig site. It escaped from the mouth of the pipe with a bone chilling whistle that was shrill in the night air, so loud that it sounded like a jet plane taking off! We immediately realized the pressure was too great to be released, and so we quickly ‘Shut-In’ the well again. A few hours later the site was buzzing with opinions on how best to ‘kill the well’. Yet it took 2 days before the well was ‘killed’ and we ready to core again. But she wasn’t going to be cowed down that easily it seemed. Before long, she was bubbling again. We tried our best, using our collective experience and ingenuity, but she soon was beginning to start frothing and belching like an angry monster. Within a few hours the well was ‘flowing’, like the effervescence of a freshly uncorked bottle of champagne. “Our gods are angry” remarked Tama, the Maori roustabout. I was nervous, and I had enough experience in the oilfield to stay clear and enough sense put on my running shoes. This was a lethal cocktail-a froth of flammable gas, oil and water, luckily they understood that they were now playing with a ticking time bomb. It was only a few hours and things were getting out of hand remarkably quickly. With a lot of lives and reputations at stake, finally they decided it would be in the best interests to abandon the well; leaving the card table while we could with all the winnings of the data we had already collected. Pumping a thick slurry of cement, we plugged and abandoned the hole as per regulation. We all were sorely disappointed, but it was the right thing to do.

And so 120 years on, we too left bloodied nose, but not without a fight. I bet they are planning another spar at Waitangi hill; with a better rig and better equipment! Till then, Waitangi hill will still keeps her most precious secret closed inside, hopefully only till next summer.