RESULTS AND POWER GENERATION IMPLICATIONS FROM DRILLING INTO THE KILAUEA IKI LAVA LAKE, HAWAII
In November 1959 eruption at Kilauea Iki, Hawaii produced a lava lake over 300 feet deep in the volcanic crater; it contained about 100 million metric tons of molten lava. The knowledge gained is valuable to the engineering of equipment to study, and to recover power from, molten rock that might be formed by deep underground nuclear explosions or surface lava flows that might be trapped in man-made craters. The objectives of the experiment were to obtain knowledge of the drilling problems encountered while probing into hot and even molten lava; and, if drilling was successfully completed into the melt, to obtain samples and to study the thermal environment of interest to volcanology and to power recovery studies. After drilling only 19 feet, the crust of the lake was pierced; it was then possible to make temperature measurements in the melt and to collect samples of the molten lava and gases. Completion of the experiment demonstrated the feasibility of drilling into hard rock formations at temperatures up to 850 deg C using standard coredrilling equipment and compressed air to cool the drilling tools and remove the cuttings. Using a mixture of water and air as the coolant, it is possible to drill with standard equipment into rock at temperatures exceeding 1050 deg C. The major drilling problems encountered were: (1) excessive chipping and wearing of the bits resulting from the hardness of the material, high temperatures encountered in the hole, and vibration of the small drill rig from use of air as the coolant; (2) inadequate compressed air circulation to properly remove heat when temperatures exceeded 850 deg C; and (3) binding of threads on the drill string caused by thermal expansion and contraction of the couplings. Binding of the threads on the drill string was overcome by use of powdered graphite as a lubricant for the couplings. Selection of more suitable drilling equipment, such as drill rig, bits, and air supply, would help overcome the vibration and heat problems. The Kilauea Iki lava lake is a significant energy source, estimated to contain about 2 x 10/sup 9/ kilowatt- hours of recoverable energy. The drilling experience indicates that pipes could be pushed deep into the fluid melt, making it possible to field-test power generation schemes and to measure many of the melt properties. Difficulties would be encountered in the selection of materials to withstand corrosion at temperatures up to 1250 deg C and in the possibility of equipment becoming bound in the melt by strong convection currents or excessive buildup of viscous lava on the pipes. A few simple corrosion experiments were performed to aid the design of equipment for measuring various properties of molten lava and equipment for testing power recovery schemes. On the various metals tested, air attack was more severe than melt attack. The most serious problems would apparently be from the attack of steam on pipes at such high temperatures. (auth)
- Research Organization:
- California. Univ., Livermore. Lawrene Radiation Lab.; California. Univ., Mercury, Nev. Radiation Lab.
- DOE Contract Number:
- W-7405-ENG-48
- NSA Number:
- NSA-15-025743
- OSTI ID:
- 4012993
- Report Number(s):
- UCRL-6374
- Country of Publication:
- United States
- Language:
- English
Similar Records
Drilling into molten rock at Kilauea Iki
Cooling of Kilauea Iki lava lake