Boring or penetrating the earth – With signaling – indicating – testing or measuring – Tool position direction or inclination measuring or...
Patent
1985-08-29
1987-05-19
Novosad, Stephen J.
Boring or penetrating the earth
With signaling, indicating, testing or measuring
Tool position direction or inclination measuring or...
1661175, 175 73, E21B 708
Patent
active
046659951
DESCRIPTION:
BRIEF SUMMARY
This invention relates to an improved method of drilling and to apparatus for carrying out the method.
In drilling it is well known that a borehole tends to deviate from the desired line and therefore it may be necessary to monitor its deviation and to take corrective measures to the inclination of the borehole. Drilling, being primarily a method by which rock samples may be obtained for analysis, tends to be exploratory and inexact. Thus, although borehole deviation may be monitored and controlled by steering, it may also be desired to use the same borehole from which to obtain rock samples from other adjacent areas. In this case the original borehole is branched at an appropriate depth and orientation to avoid the need to drill a new borehole thereby keeping costs to a minimum.
The drill hole inclination angle and azimuth angle are normally monitored either using an electronic data collection system or a one shot system taking measurements at selected stations. Where steering or branching is required this is usually orientated using a wedge clinometer which is aligned exactly within the borehole and which receives a glass vial of hydrofloric acid. A line is scratched lengthwise on the glass vial and on the wedge clinometer and the two lines are aligned before the clinometer is lowered into the borehole. The clinometer is left within the borehole a sufficient time to allow the acid to etch a line on the glass vial and the clinometer is then withdrawn and the orientation of the wedge determined. This method can only orientate a steering or branching wedge relative to the (known) dip of a hole. It is also known to use an electronic magnetic orientation device which is run in the borehole with a logging cable. This method orientates a wedge relative to magnetic north and therefore is unsatisfactory where the rock is magnetised in any way.
Once the exact orientation of the steering or branching wedge has been determined such corrective measures as may be necessary are taken. If it is required to alter the course of a borehole, a wedging assembly is used to steer or deflect the borehole in the desired direction and may achieve a correction of 1 to 11/2 degrees per setting. The most common steering wedging assembly in present use is The Clappison Wedge which tightens against one side of the borehole and prevents rotation during the deflection drilling but which can be removed after use. The deflection drilling involves drilling off the wedge a pilot hole of smaller diameter than the borehole. The pilot hole is then reamed out following the intended direction of deflection and is enlarged to full borehole diameter. The reaming assembly used to widen the pilot hole is then withdrawn from the borehole whereupon drilling is resumed. This procedure can be repeated as desired in order to achieve the necessary angular correcton.
Where a branch is required to obtain samples from areas laterally spaced from the original borehole it is usual to employ a fixed deflecting wedge which remains in the hole to ensure that the drilling operation is conducted down the branch borehole, rather than the main borehole, each time. Previously, this has involved filling or plugging the main borehole back to the branch position and then setting a wedge at the desired orientation which involves several steps each involving running in and drawing out the drill rods.
Therefore in accordance with one aspect of the invention there is provided orientation means for determining orientation within a borehole comprising sensing means for sensing the orientation relative to a predetermined datum, an ultrasonic transmitter arranged to transmit a signal or signals indicative of the sensed orientation, and an ultrasonic receiver for receiving and representing the signal or signals transmitted. Preferably the sensing means is sensing the orientation of a wedging assembly relative to the dip of the borehole, but it may be used to sense the actual hole inclination.
Preferably the sensing means are a plurality of gravity sensitive mercury switches.
The
REFERENCES:
patent: 2401893 (1946-06-01), Williams, Jr.
patent: 3131778 (1964-05-01), Emersen et al.
patent: 3275983 (1966-09-01), Kaneko
patent: 3693142 (1972-09-01), Jones
patent: 3889228 (1975-06-01), Shawhan
patent: 4003017 (1977-01-01), Bailey
patent: 4293937 (1981-10-01), Sharp et al.
patent: 4391336 (1983-07-01), Coon et al.
patent: 4420049 (1983-12-01), Holbert
patent: 4479564 (1984-10-01), Tanguy
Bellamy Norman W.
Braithwaite Richard W.
Gergely Stephen
Smith Graham M.
Encore Drilling Limited
Neuder Willian P.
Novosad Stephen J.
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