In 1998, there was a 24% decrease in the success rate of liner cementing that resulted in 11 repair jobs to correct primary-cement-job failures. On the basis of an analysis of the failed jobs, it was determined that most problems were caused by flaws in the displacement system. The most common causes of failure were the piston effect between the liner displacement plug and the seal bore and inadequate sealing during plug latch-in. Because of changes made to liner-hanger designs used for 7 5/8-in. intermediate and 5 1/2-in. production strings, approximately U.S. $1.5 million for repairs to primary cement jobs was saved.