Use of MWD for turbodrill performance optimization as a means to improve ROP

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · SPE (Society of Petroleum Engineers) Drill. Eng.; (United States)

OSTI ID:5247678

deBruijn, H J; Kemp, A J; vanDongen, J C.M.

Field tests were carried out to monitor the performance of turbodrills driving polycrystalline-diamond-compact (PDC) bits. Separate tests with mud-pulse measurement-while-drilling (MWD) tools involved measurement of the rotational speed of the bit and downhole torque. The results show that turbodrills are not always operated at the manufacturer's claimed maximum efficiency, resulting in disappointing rates of penetration (ROP's). On the basis of observed reduction in turbodrill runaway 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 an 8 l/2-in. (21.6-cm) hole, improvements in ROP of up to 100% could be obtained by use of the measured bit rotational speeds to monitor power output of the turbodrill. It was difficult to control bit rotational speed from the weight on bit (WOB), however, at the low average WOB's necessary for current PDC bit designs. It was apparent that the measurement of 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 stabilizers. The possible effect of flow-rate variations through the turbodrill during negative mud pulses was investigated with a flow loop. This proved to be insignificant.

• Research Organization: Koninklijke/Shell E and P, Rijswijk
• OSTI ID: 5247678
• Journal Information: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States) Vol. 1:4; ISSN SDENE
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
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42 ENGINEERING
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
BEARINGS
CARBON
CRYSTALS
DIAMONDS
DRILL BITS
DRILLING
DRILLING EQUIPMENT
DRILLING FLUIDS
DRILLS
ELEMENTAL MINERALS
ELEMENTS
EQUIPMENT
FIELD TESTS
FLOW RATE
FLUIDS
MACHINERY
MINERALS
MONITORING
MOTION
MWD SYSTEMS
NATURAL GAS WELLS
NONMETALS
OIL WELLS
OPTIMIZATION
PERFORMANCE TESTING
POLYCRYSTALS
PULSES
ROTARY DRILLS
ROTATION
TESTING
TORQUE
TURBODRILLS
TURBOMACHINERY
VELOCITY
WEIGHT
WELL DRILLING
WELLS