FACTORS CAUSING POOR CEMENTING QUALITY IN SLIM HOLE AND SOLUTIONS

Poor cementing quality is a common problem in the slim hole due to its small clearance and uneven distribution of cement slurry, it can also cause the reduction of casing collapsing strength. Factors causing the poor cementing quality are investigate by finite element simulation calculating and physical modeling test, and such tool and technologies as casing centralizer, time-delay cementing technology, back-inserting hydraulic liner hanger are developed. Compared with the conventional cementing technology in the same condition, good cementing quality improved by 29%. This technology effectively improved the cementing quality in the slim hole and expanded the life of casing.