American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the 49th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Texas, Oct. 6–9, 1974. Permission to copy is restricted to an abstract of not more than 300 words. illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.
A new casing-inspection log, in combination with other logs, provides for detailed evaluation of in-place well casing. The new Pipe Analysis Log employs separate tests o the total casing wall and of the inner surface. Together, these two measurements permit detection, with a high degree of resolution, of small defects and corroded areas in the pipe, and also provide the ability to discriminate between defects on provide the ability to discriminate between defects on the inner and outer walls of a single string of casing. This was not possible with just the wall-thickness information provided by the older low-frequency Electromagnetic Thickness Tool. Using the data from the new log along with the older wall-thickness measurement it is also possible to detect and locate severe corrosion or defects in the outer casing of a double string,
The following information bearing on the condition of the casing is now available from cased-hole well logs:
location of small defects or corroded areas, and discrimination between inner- and outer-walldefects (from the Pipe Analysis Log);determination of casing-wall thickness (from the Electromagnetic Thickness Tool); detection of gas accumulation behind casing in gas-storage wells(from Gamma Raj? and Neutron logs); detection of gas flow (from the High Resolution Thermometer); determination of top of cement (from Cement Top Locator); and evaluation of casingbonding (from Cement Bond Log-Variable Density Log.).
Example logs of the -new casing-inspection tool, selected from an extensive test program and nine months of commercial application, are presented. Comparisons are made of the results from the new tool with defects observed in the pipe when out of the well.
