Chapter 14 - Drilling of gas hydrate reservoirs: recent technological developments and solutions to drilling problems

Abstract

For a long time, gas hydrate–bearing sediments were considered a problem during the drilling of conventional wells. Moreover, the plugging of the wellhead on the seafloor was a big problem, and with chemicals, it is essential to prevent gas hydrate formation in the wellhead. However, later it was understood that methane hydrates include an enormous amount of natural gas; so after the 2000s, the number of drilling activities targeting the data collection and/or gas production test in gas hydrate reservoirs has increased (i.e., Canada, United States, Japan, China, and Korea). In these drilling operations, several drilling problems were observed, and it was solved with the experiences gained and technological innovations. This chapter aims to evaluate the recent developments in gas hydrate drilling. The future trends of the drilling of commercial gas hydrate production wells and observation wells are discussed.