GEOPHYSICAL METHODS OF ASSESSMENT OF WELL CEMENTING QUALITY
Dmitry F. Novokhatsky – PhD in Engineering, professor, OJSC “NPO “Burenie”,
postmaster@npoburenie.ru postmaster@npoburenie.ru;
Alexander V. Krivoshey – PhD in Engineering, professor, OJSC “NPO “Burenie”,
postmaster@npoburenie.ru postmaster@npoburenie.ru.
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.
Изложена методика оценки качества цементирования обсадных колонн геофизическим методами: ОЦК, АКЦ, ГГК-СГДТ. Приводятся расчетные формулы для определения коэффициента качества цементирования на основе данных АКЦ, СГДТ: плотности контакта цементного камня с колонной Кк, с породой Кп, интегрального коэффициента качества плотности контакта с колонной и породой; дана оценка качества центрирования отдельного интервала и в целом колонны Кэко. Приводится градация качества цементирования по коэффициенту К. Количественная оценка качества цементирования и центрирования основана на функции желательности, широко используемой при обработке экспериментальных данных.
GEOPHYSICAL METHODS OF ASSESSMENT OF WELL CEMENTING QUALITY
Dmitry F. Novokhatsky – PhD in Engineering, professor, OJSC “NPO “Burenie”, postmaster@npoburenie.ru
Alexander V. Krivoshey – PhD in Engineering, professor, OJSC “NPO “Burenie”, postmaster@npoburenie.ru
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.
