The rock melting approach to drilling

Conference · Wed Sep 01 00:00:00 EDT 1993

OSTI ID:10185682

Cort, G E; Goff, S J; Rowley, J C; Neudecker, Jr, J W; Dreesen, D S; Winchester, W

During the early and mid-1970`s the Los Alamos National Laboratory demonstrated practical applications of drilling and coring using an electrically-heated graphite, tungsten, or molybdenum penetrator that melts a hole as it is slowly pushed through the rock or soil. The molten material consolidates into a rugged glass lining that prevents hole collapse; minimizes the potential for cross-flow, lost circulation, or the release of hazardous materials without casing operations; and produces no cuttings in porous or low density (<1.7 g/cc) formations. Because there are no drilling fluids required, the rock melting approach reduces waste handling, treatment and disposal. Drilling by rock melting has been demonstrated to depths up to 30 m in caliche, clay, alluvium, cobbles, sand, basalt, granite, and other materials. Penetrating large cobbles without debris removal was achieved by thermal stress fracturing and lateral extrusion of portions of the rock melt into the resulting cracks. Both horizontal and vertical holes in a variety of diameters were drilled in these materials using modular, self-contained field units that operate in remote areas. Because the penetrator does not need to rotate, steering by several simple approaches is considered quite feasible. Melting is ideal for obtaining core samples in alluvium and other poorly consolidated soils since the formed-in-place glass liner stabilizes the hole, encapsulates volatile or hazardous material, and recovers an undisturbed core. Because of the relatively low thermal conductivity of rock and soil materials, the heat-affected zone beyond the melt layer is very small, <1 inch thick. Los Alamos has begun to update the technology and this paper will report on the current status of applications and designs for improved drills.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10185682
• Report Number(s): LA-UR-93-3191; CONF-940126-2; ON: DE93040162
• Resource Relation: Conference: Energy-sources technology conference and exhibition,New Orleans, LA (United States),23-26 Jan 1994; Other Information: PBD: [1993]
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
02 PETROLEUM
03 NATURAL GAS
04 OIL SHALES AND TAR SANDS
ROCK DRILLING
TECHNOLOGY ASSESSMENT
ROCKS
MELTING
CLAYS
ALLUVIAL DEPOSITS
SAND
BASALT
GRANITES
PENETRATORS
422000
020300
030300
040300
MINING AND UNDERGROUND ENGINEERING
DRILLING AND PRODUCTION
DRILLING, PRODUCTION, AND PROCESSING
DRILLING, FRACTURING, AND MINING