Memory cement bond logging apparatus and method
AssigneeProbe Technology Services, Inc.
InventorsRonald E. McDaniel, Tony M. Small, Dwight A. Bloomfield
Life of this patent
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Abstract
A method and device are shown for detecting the characteristics of a cement annulus between a casing in a borehole and the surrounding earth formations in a slickline cement bond logging operation. An acoustic logging tool is utilized which produces a pure signal downhole. The received acoustically transmitted energy produces electrical signals indicative of both the amplitude of the received energy and variable density log data. Both the amplitude data and the variable density log data are captured in memory downhole by the use of a time amplitude matrix which stores a limited number of data points for producing a cement bond log at the well surface.
Claims15
A method for detecting the characteristics of a cement annulus between a casing in a borehole and the surrounding earth formations in a slickline cement bond logging operation, the method comprising the steps of:
- lowering an acoustic logging tool within the borehole to a desired depth, the acoustic logging tool having at least an acoustic transmitting transducer, a primary acoustic receiving transducer and a longitudinally spaced secondary acoustic receiving transducer, the acoustic logging tool being suspended within the borehole by means of a slickline extending to the well surface;
- generating a pulse of acoustic energy from the transmitting transducer at a first point along said casing and transmitting said energy along said casing;
- receiving the acoustic energy transmitted along the casing with the primary receiving transducer at a second point along the borehole longitudinally spaced from the first point and producing an electrical signal representative thereof;
- receiving the acoustic energy transmitted along the casing with the secondary receiving transducer at a third point along the borehole longitudinally spaced from the first and second points and producing an electrical signal representative thereof;
- collecting data based upon the electrical signals and storing the data so collected in memory carried down hole by the logging tool;
- generating additional pulses of acoustic energy at timed intervals as the acoustic logging tool is moved within the borehole between known depths and storing the data collected in memory;
- retrieving the logging tool to the well surface and producing a cement bond log based upon the memorized data.
A method for detecting the characteristics of a cement annulus between a casing in a borehole and the surrounding earth formations in a slickline cement bond logging operation, the method comprising the steps of:
- lowering an acoustic logging tool within the borehole to a desired depth, the acoustic logging tool having at least an acoustic transmitting transducer, a primary acoustic receiving transducer and a longitudinally spaced secondary acoustic receiving transducer, the acoustic logging tool being suspended within the borehole by means of a slickline extending to the well surface;
- generating a pulse of acoustic energy from the transmitting transducer at a first point along said casing and transmitting said energy along said casing;
- receiving the acoustic energy transmitted along the casing with the primary receiving transducer at a second point along the borehole longitudinally spaced from the first point and producing an electrical signal representative thereof;
- receiving the acoustic energy transmitted along the casing with the secondary receiving transducer at a third point along the borehole longitudinally spaced from the first and second points and producing an electrical signal representative thereof;
- collecting data based upon the electrical signals and storing the data so collected in memory carried down hole by the logging tool;
- generating additional pulses of acoustic energy at timed intervals as the acoustic logging tool is moved within the borehole between known depths and storing the additional data collected in memory;
- retrieving the logging tool to the well surface and producing a cement bond log based upon the memorized data;
- and
- wherein each pulse of acoustic energy so generated down hole is a nearly pure sonic signal free from interactions with the logging tool itself.
Dependencies are inferred from the claim text.