Method and apparatus for forming boreholes

Patent · Tue Dec 17 04:00:00 EST 1985

OSTI ID:5700531

Burton, J A; Elkins, H L; Goodhart, M E

A method and apparatus is disclosed for deviated hole drilling upwardly and outwardly from beneath a shallow hydrocarbon formation pay zone. A large diameter vertical hole is first formed as by drilling below the pay zone. A first casing having a directional window provided in its wall is cemented in the large diameter hole. One or more casings are then provided in the borehole below the first casing. A carriage assembly loaded with drilling tools for drilling upwardly and outwardly is then lowered by means of a working drill string and landed within the first casing. The carriage assembly has a first passage in fluid communication with the drill string. The drilling tools are loaded within a second passage of the carriage assembly. The top opening of the second passage is below the directional window when the carriage assembly is landed and angularly oriented in the first casing. A drill string extends from the drilling tools through the bottom of the carriage assembly and into the cased hole below the first casing. A stripper packer assembly at the lower end of the carriage assembly prevents the incoming high pressure mud from entering the second passage of the carriage assembly. The drilling tools comprise a mud pressure driven motor for turning a drilling bit. A weight-on-bit assembly provides force to the drilling bit against the face of the borehole being drilled. A bent sub causes the drilling to be deviated outwardly while drilling upwardly.

• Assignee: Hydril Co.
• Patent Number(s): US 4558750
• OSTI ID: 5700531
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
BOREHOLES
CAVITIES
DESIGN
DIRECTIONAL DRILLING
DRILLING
DRILLING EQUIPMENT
DRILLING FLUIDS
EQUIPMENT
FLUID MECHANICS
FLUIDS
HYDRAULICS
MECHANICS
NATURAL GAS WELLS
OIL WELLS
PERFORMANCE
WELL CASINGS
WELL DRILLING
WELLS