Study and Field Testing on the Top Cementing Technology of Screen Pipe Free from Drilling and Fishing

Top cementing technology with conventional screen pipes can combine advantages of the screen pipe and liner cementing, but internal accessories need to be removed upon completion of cementing operations. To improve the top cementing efficiency of the screen pipe, the internal and external pipe string structure was optimized with a rubber cup packer and a sliding sleeve staged collar. They were used to replace the blind plate and differential-pressure type staged collar in the top cementing with conventional screen pipe. The internal pipe string was moved to achieve setting, cementing, circulation and other process operations and all the residual accessories were brought out when the internal pipe string was lifted after cementing. Thus, the blind plate and staged collar would not be retained in the casing and the diameter could meet requirements for follow-up operation to avoid drilling and fishing after cementing. At the same time, screen pipe completion of different composite casings could be performed by adjusting the sizes of rubber cup packers. This technology has been used for field tests in Well X in the offshore cooperation block of Bohai Bay to complete top cementing operation with φ177.8 mm liner +φ139.7 mm screen pipe. The well can be directly put into production after waiting on cement setting. Without the need for plug drilling, the drilling time can be effectively minimized.