The fluid-compensated cement bond log
Simulations of cement bond logging (CBL) have shown that wellbore fluid effects can be segregated from sonic-signal response to changing cement strengths. Traditionally, the effects have been considered negligible and the CBL's have been interpreted as if water were in the wellbore. However, large variations in CBL's have become apparent with the increasing number of logs run in completion fluids, such as CaCl/sub 2/, ZnBr/sub 2/, and CaBr/sub 2/. To study wellbore fluid effects, physical and numerical models were developed that simulated the wellbore geometry. Measurements were conducted in 5-, 7-, and 9 5/8-in. casings for a range of wellbore fluid types and for both densities and viscosities. Parallel numerical modeling used similar parameters. Results show that bond-log amplitudes varied dramatically with the wellbore fluid acoustic impedance-i.e., there was a 70% increase in signal amplitudes for 11.5 lbm/gal (1370-kg/m/sup 3/) CaCl/sub 2/ over the signal amplitude in water. This led to the development of a fluid-compensated bond log that corrects the amplitude for acoustic impedance of various wellbore fluids, thereby making the measurements more directly related to the cement quality.
- Research Organization:
- Schlumberger Offshore Services, New Orleans, LA
- OSTI ID:
- 5247586
- Journal Information:
- SPE (Society of Petroleum Engineers) Format. Eval.; (United States), Vol. 1:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
03 NATURAL GAS
36 MATERIALS SCIENCE
CEMENTS
DENSITY
VISCOSITY
NATURAL GAS WELLS
CEMENTING
SONIC LOGGING
OIL WELLS
AMPLITUDES
CALCIUM BROMIDES
CALCIUM CHLORIDES
DATA ANALYSIS
DISPLACEMENT FLUIDS
IMPEDANCE
MATHEMATICAL MODELS
QUALITY CONTROL
RESERVOIR FLUIDS
SIGNALS
STRUCTURAL MODELS
WATER
WELL CASINGS
ZINC BROMIDES
ALKALINE EARTH METAL COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
BUILDING MATERIALS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHLORIDES
CHLORINE COMPOUNDS
CONTROL
FLUIDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
MATERIALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
WELL LOGGING
WELLS
ZINC COMPOUNDS
ZINC HALIDES
020300* - Petroleum- Drilling & Production
030300 - Natural Gas- Drilling
Production
& Processing
360603 - Materials- Properties