Volumetric requirements for foam and mist drilling operations

Journal Article · Sat Feb 01 04:00:00 EST 1986 · SPE (Society of Petroleum Engineers) Drill. Eng.; (United States)

DOI:https://doi.org/10.2118/11723-PA· OSTI ID:5373152

Okpobiri, G A; Ikoku, C U

State-of-the-art foam and mist drilling suggests a need for predictive models for volumetric requirements that properly account for frictional losses caused by the solid phase in solids/foam slurry flow, settling velocities of such solids, and pressure drop across bit nozzles during foam flow. The objective of this paper is to fulfill this need. A model that predicts pressure drop across bit nozzles for foam and mist and minimum volumetric requirements for foam and mist drilling operations is presented. It accounts for the compressibility of foam but assumes negligible pressure losses resulting from friction and change in elevation and for the frictional losses caused by the solid phase, pressure drop across bit nozzles, and particle-settling velocity. This technique offers a high degree of flexibility in the selection of wellhead injection pressures and volumetric injection rates. Field application of this work can be accomplished by two primarily graphical methods that depend on compressor specification: variable-backpressure and constant-backpressure schedules. Charts are presented for 7.875- and 9.00-in. hole sizes, and for 0.500-, 0.75-, and 1.00-in. cutting sizes. Penetration rates range from 30 to 90 ft/hr. Results indicate that volumetric requirements increase with increasing hole size, depth, and particle size. Increases in penetration rate cause only minor increases in volumetric requirements. All foam-drilling and well-cleanout operations can be accomplished within the laminar flow region with adherence to 0.55 minimum bottomhole and 0.96 maximum annular foam quality. Annular backpressures greater than atmospheric pressure are needed to maintain a bottomhole foam quality of 0.55 or more while reaching reasonable depths. To maintain constant depth as backpressure increases, however, both wellhead injection pressure and gas injection rate must be increased, and liquid flow rate decreased.

• Research Organization: Univ. of Tulsa
• OSTI ID: 5373152
• Journal Information: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States) Vol. 1:1; ISSN SDENE
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ATMOSPHERIC PRESSURE
COLLOIDS
COMPRESSORS
DEPTH
DIMENSIONS
DISPERSIONS
DRILL BITS
DRILLING
DRILLING EQUIPMENT
EQUIPMENT
FLOW RATE
FLUID FLOW
FLUID MECHANICS
FLUIDS
FOAMS
FRICTION
GASES
GRAPHS
LAMINAR FLOW
MATHEMATICAL MODELS
MECHANICS
MIXTURES
NATURAL GAS WELLS
NOZZLES
OIL WELLS
PARTICLE SIZE
PARTICLES
PNEUMATICS
PRESSURE DROP
SIZE
SLURRIES
SOLIDS FLOW
SPECIFICATIONS
SUSPENSIONS
TWO-PHASE FLOW
VAPORS
VOLUME
WELL DRILLING
WELLHEADS
WELLS