The use of MWD for turbodrill performance optimisation as a means to improve rate of penetration

Conference · Mon Oct 01 04:00:00 EDT 1984 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:5982689

de Bruijn, H J; van Dongen, J C.M.; Kemp, A J

Field tests have been carried out to monitor the performance of turbodrills driving poly-crystalling diamond compact (PDC) bits. Separate tests, using mud pulse MWD tools, involved measuring the rotational speed of the bit and measuring downhole torque. The results show that turbodrills are not always operated at the manufacturer's claimed maximum efficiency, resulting in disappointing rates of penetration. Based on the observed reduction in turbodrill run-away speed from the manufacturer's value it is estimated that thrust bearing friction can consume up to 50% of the net turbodrill power output. In 8 1/2 inch hole improvements in rate of penetration of up to 100% could be obtained using the measured bit rotational speeds to monitor power output of the turbodrill. However, it was difficult to control bit rotational speed from the weight on bit at the low average weights on bit necessary for present PDC bit designs. It was apparent that measuring downhole torque has limited field application because no distinction can be made between true reactive torque at the bit and additional torque from the turbodrill's thrust bearings and stabilisers. The possible effect of flowrate variations through the turbodrill during negative mud pulses was investigated using a flowloop. This proved to be insignificant.

• Research Organization: Koninklijke/Shell E and P Laboratorium
• OSTI ID: 5982689
• Report Number(s): CONF-8410154-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE13000
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
BEARINGS
CRYSTALS
DEPTH
DESIGN
DIMENSIONS
DRILL BITS
DRILLING
DRILLING EQUIPMENT
DRILLS
EFFICIENCY
EQUIPMENT
FIELD TESTS
FLOW RATE
FRICTION
MACHINERY
MONITORING
MOTION
MWD SYSTEMS
OIL WELLS
OPTIMIZATION
PERFORMANCE TESTING
POLYCRYSTALS
PULSES
ROTARY DRILLS
ROTATION
TESTING
TORQUE
TURBODRILLS
TURBOMACHINERY
VELOCITY
WEIGHT
WELL DRILLING
WELLS