Austin Freeman & John Brandell, Halliburton Services
A recently developed hydraulically operated (HO) stage cementer has proven beneficial in cementing both vertical and horizontal wells. Although the tool was developed primarily to aid in cementing highly deviated and horizontal wells, its application in any situation calling for a stage cementer can be beneficial. 1. In operations where a free-fall opening pluq (bomb shaped) is normally used, the waiting time for free fall to the plug seat is eliminated, saving rig time and allowinq for continuous circulation of the hole. These cementers can be opened immediately, which is beneficial in those applications in which first stage cement is brought above the cementer. 2. If a displacement plug (pump down style) is normally used, the need is eliminated for excess cement in the casing to ensure that the first stage is not over-displaced, saving drill out time after cement is set. In this configuration, a positive check of float equipment for secure holding can be made. The cementer is designed to monitor annulus pressure and internal pressure. When internal pressure reaches a predetermined level above annulus pressure at the tool, the cementer opens and circulation begins for the second stage. The cementer is closed by a conventional closing plug. This paper presents discussion of HO stage cementer operation, options available with the cementers, job design , and results of actual job conduct using these methods.