JOGMEC (Japan Oil, Gas and Metals National Corporation) was planning for the first offshore production test of methane hydrates in the eastern Nankai Trough off of Japan. The test needs one production well and three temperature monitoring wells to study the dissociation performance of methane hydrate formations. Cementing these types of wells needed to have a specific cementing technology fit for deepwater shallow unconsolidated formations subject to subsidence and methane hydrate-bearing formations.

A project was initiated in 2011 with the objective being to design and qualify a cement slurry system fit for deepwater shallow unconsolidated formations subject to subsidence and methane hydrate-bearing formations. Based on extensive laboratory and full-scale testing, a cement technology was qualified by the service company and approved by JOGMEC to be the optimum solution for this unique project.

This paper will describe the full-scale and extensive laboratory testing used to qualify the cement technology fit for this application and the different stages that create sufficient wellbore stability for the drawdown during the production test. In addition, real-time temperature data interpretation will be presented showing the cement hydration in these wells after placement. Case histories of the three wells will be presented.