What is the purpose of a cement bond log?
What is the purpose of a cement bond log?
A log that uses the variations in amplitude of an acoustic signal traveling down the casing wall between a transmitter and receiver to determine the quality of cement bond on the exterior casing wall.
What is a cement bond log test?
A cement bond log documents the evaluation of the integrity of cement work performed on an oil well. A sonic tool is typically run on wireline by a service company that detects the bond of the cement to the casing and formation via a principle based on resonance.
What is CBL VDL log?
Cement bond logs (CBL) and variable density log (VDL) are one of the vital logging techniques used to evaluate cement-casing-formation bonds before the well testing or execution of the production operation in the well. The logging techniques provide a clear view of the quality of cement bonds with casing and formation.
What is CBL in drilling?
A cement bond log (CBL) is a means to determine the integrity and quality of a cement bond. After a borehole is drilled, the casing is lowered and cement slurry is injected into the annulus between the casing and the borehole wall.
What do you use to bond concrete to concrete?
QUIKRETE® Concrete Bonding Adhesive (No. 9902) permanently bonds new concrete, plaster, and stucco to existing concrete, plaster, and stucco. Eliminates the need for roughing the surface before the application.
In what principle cement evaluation is based on?
The main objective of the cement evaluation process is to evaluate the hydraulic isolation of the cement sheath. The main principle of cement bond log (CBL) tools is to send an acoustic signal inside the casing and measuring the acoustic impedance of the cement between the casing and the formation.
What is a radial bond log?
The radial cement bond tool (CBL) utilizes a single ceramic transmitter, an eight segment receiver at 3ft. spacing to accurately measure the quality of the cement job in a cased hole well environment. The segmented receiver provides a good indication of cement channeling behind the casing.
What is VDL in drilling?
Variable Deck Load (VDL) VDL includes any item of weight that is not included in the lightship of the basic vessel. Lightship is the basic weight of the MODU, including all equipment considered permanent. This includes: Drawworks.
How do you evaluate cement?
The colour of cement gives an indication of excess lime or clay and the degree of burning.
- RUBBING. Take a pinch of cement between fingers and rub it.
- HAND INSERTION. Thrust your hand into the cement bag and it should give cool feeling.
- FLOAT TEST.
- SMELL TEST.
- PRESENCE OF LUMPS.
- SHAPE TEST.
- STRENGTH TEST.
How is the precision of gamma ray log measurements determined?
Hence, like all nuclear tools, the raw measured quantity in a gamma ray log is counts. This means that the precision of gamma ray log measurements is determined by Poisson statistics. The precision is the square root of the total number of counts recorded at a given depth.
How do acoustic logs measure cement quality?
Acoustic logs do not measure cement quality directly, rather, this value is inferred from the degree of acoustic coupling of the cement to the casing and to the formation. Properly run and interpreted, cement-bond logs (CBL) provide highly reliable estimates of well integrity and zone isolation.
What is a gated system in cement logging?
Cement-bond logging tools use gated systems to measure the specific parts of the acoustic waveform needed for the primary bond-amplitude measurement. Gates are time periods during which measurements are made—they can be either of the following:
What are the tools used in gamma ray spectroscopy?
Conceptually, the simplest tools are the passive gamma ray devices. There is no source to deal with and generally only one detector. They range from simple gross gamma ray counters used for shale and bed-boundary delineation to spectral devices used in clay typing and geochemical logging.
