Method of detecting collars using computerized pattern recognition
AssigneeWestern Atlas International, Inc.
InventorsSteven B. Easton, Norman R. Carlson, James C. Barnette
Life of this patent
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Abstract
A method of determining the location and dimensions of collars present along a section of casing. An inspection instrument is passed through the casing section generating an electromagnetic wave which permeates the casing. The phase shifted electromagnetic wave is detected by a receiver and a data string comprising the degree of phase shift present at each point along the casing section is created. The data string is processed to identify the location of collars present along the casing section. Upon the identification of a collar, a series of pattern recognition interrogations are used to confirm the collar location and to determine the collar's dimensions.
Claims15
A method of determining the location of collars present in a casing section under inspection by passing an inspection instrument through said casing and submitting the outputs of said inspection instrument to a process of analysis comprising the steps of:
- a. deriving, from said outputs of said inspection instrument, responses forming a data curve;
- b. selecting a point of said data curve;
- c. selecting a survey interval of said data curve such that said point is within said interval;
- d. summing the responses of said data curve located within said survey interval;
- e. comparing the summation of said responses of said data curve within said survey interval to a first reference value;
- f. determining from said comparison whether a collar is located at said point;
- and
- g. repeating steps (b) through (f) for each point of said data curve.
A method of determining the location of collars present in a casing section under inspection by passing an inspection instrument through said casing and submitting the outputs of said inspection instrument to a process of analysis comprising the steps of:
- a. deriving, from said outputs of said inspection instrument responses forming a data curve;
- b. selecting a point of said data curve;
- c. selecting a survey interval of said data curve such that said point is within said interval;
- d. summing the responses of said data curve within said survey interval;
- e. comparing the summation of said response, of said data curve within said survey interval to a first reference value;
- f. making an initial determination from said comparison of whether a collar is located at said point;
- g. examining said survey interval for said point if an initial determination of a collar at said point has been made, for a first and second responses of a first predetermined polarity within said survey interval of magnitude exceeding a second reference value;
- h. comparing the magnitude of said two responses of a first predetermined polarity;
- i. determining the separation distance between said first and second responses of a first predetermined polarity;
- j. comparing said separation distance to a separation distance reference value;
- k. examining said survey interval for a first response of a second predetermined polarity (located between said two positive responses) of magnitude exceeding a third reference value;
- l. examining said survey interval for a second response of said second predetermined polarity (located between the upper boundary of said survey interval and the closest of said positive responses) of magnitude exceeding a fourth reference value;
- m. examining said survey interval for a third response of said second predetermined polarity (located between the lower boundary of said survey interval and said closest of said positive response) of magnitude exceeding said fourth reference value;
- n. making a final determination of whether a collar is located at said point;
- o. designating the section of said data curve between said second and third responses of said second predetermined polarity as a collar interval;
- p. selecting a next data point along said data curve outside of said collar interval;
- and
- q. repeating steps (c) through (p) for said next data point.
A method of determining the location of collars present in a casing section under inspection comprising the steps of:
- (a) passing an inspection instrument through said casing section;
- (b) generating a first electromagnetic wave;
- (c) detecting a second electromagnetic wave;
- (d) comparing said first and second electromagnetic waves;
- (e) deriving a first measurement from said comparison of said first and second electromagnetic waves;
- and
- (f) analyzing said first measurement to determine the location of collars.
Dependencies are inferred from the claim text.