Novel Cementing Technology for Deep Water Development Wells in South China Sea

In South China Sea Block X, a deep water promising gas reservoir more than 100 billion m3 was discovered. Unlike onshore or shallow water wells, cementing operations in deep water development wells face tougher challenges. Low temperature and shallow hazards limit conventional cement slurries, especially when these issues coexist. Besides, temperature prediction and oil-based mud (OBM) removal also add to the complexity of the cementing operations. A novel cementing technology for deep water development wells has been developed in order to ensure long-term isolation. This paper will describe in detail how to design the cement slurry parameters, how to apply the hydrate decomposition simulation, how to predict the temperature and how to remove the OBM. With the novel technology, cementing operations in Block X have been successfully carried out for 11 wells, achieving the desired objective of well bore integrity. Cement bond logging (CBL) evaluation has shown excellent bonding result. This successful cement operation helped to establish record for the biggest deep water gas field in South China Sea.