Downhole control of deviation with steerable straight-hole turbodrills

Journal Article · Tue Mar 01 00:00:00 EST 1988 · SPE (Society of Petroleum Engineers) Drill. Eng.; (United States)

DOI:https://doi.org/10.2118/14769-PA· OSTI ID:7244364

Gaynor, T M

Advances in directional drilling have until recently been confined to issues that are peripheral to the central problem of controlling assembly behavior downhole. Examples of these advances are measurement while drilling (MWD) and the increasing use of computer assistance in well planning. These were significant steps forward, but the major problem remained. Changes in formation deviation tendencies led to trips to change bottomhole assemblies (BHA's) to cope with the new conditions. There is almost no direct control of deviation behavior. The steerable straight-hole turbodrill (SST) addresses this problem directly, allowing alteration of the well course without the need to trip. The availability of such a system radically changes the way in which directional well planning may be approached. This paper describes the equipment used and the equipment's construction and operational requirements. It discusses the capabilities and current limitation of the systems. Field results are presented for some 300,000 ft (91 500 m) of deviated drilling carried out over 2 years in Alaska and the North Sea. A series of four highly deviated wells totaling 35,000 ft (10 700m) with only three deviation trips is included. The SST is the first deviation drilling system to achieve deviation control over long sections without tripping to change BHA's. Bits and downhole equipment are now more reliable and long-lived than ever, therefore, deviation trips are becoming a major target for well cost saving.

• Research Organization: Neyrfor Ltd. (GB)
• OSTI ID: 7244364
• Journal Information: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States), Vol. 3:1
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
TURBODRILLS
CONTROL SYSTEMS
DIRECTIONAL DRILLING
ROCK DRILLING
COMPUTER CALCULATIONS
COST BENEFIT ANALYSIS
DRILL BITS
MWD SYSTEMS
NATURAL GAS WELLS
OIL WELLS
ORIENTATION
PLANNING
DRILLING
DRILLING EQUIPMENT
DRILLS
EQUIPMENT
MACHINERY
ROTARY DRILLS
TURBOMACHINERY
WELLS
020300* - Petroleum- Drilling & Production
030300 - Natural Gas- Drilling
Production
& Processing
990220 - Computers
Computerized Models
& Computer Programs- (1987-1989)