GEOPHYSICAL METHODS OF ASSESSMENT OF WELL CEMENTING QUALITY
Dmitry F. Novokhatsky – PhD in Engineering, professor, OJSC “NPO “Burenie”,
Alexander V. Krivoshey – PhD in Engineering, professor, OJSC “NPO “Burenie”,
Key words:cementing quality; geophysical surveys; quality coefficient; density of contact with pipe string and rocks; density of cement bond; cementing of casing string , eccentricity.
The article describes a method of casing cementing quality using geophysical survey techniques: cement bond logging, acoustic cement bond logging, selective gamma-gamma ray logging, downhole gamma ray density fault detection. Provided are formulas for calculation of cementing quality coefficient based on cement bond logging data: density of contact with cement bond and casing Кc, rock Кr, integrated coefficient of quality of density of contact with casing and rock; there is an example of assessment of quality of centering in a particular interval and wellbore as a whole, Кeco. There are examples of grading of cementing quality using the K coefficient. The qualitative assessment of the quality of cementing and centering is based on desirability function that is widely used for experimental data processing.