An Investigation of Hydraulic-Fracturing Applied to Marine Gas Hydrate Reservoirs

Abstract

Abstract Engineers have been struggling to harvest natural gas from the marine hydrates through drilling wells in the past two decades. The harvesting process has not been successful due to engineering problems such as wellbore collapse and sand production. This study proposes to use frac-packing method to address the wellbore collapse and sand production issues to break through the bottleneck of commercial production of natural gas from marine gas hydrates. An analytical model was developed to describe sequential initiation and simultaneous propagation of multiple vertical fractures in horizontal wells for frac-packing gas hydrate reservoirs. Result of sensitivity analyses with the models indicates that to frac-pack horizontal gas hydrate wells for solid-production control, increasing injection rate and flow behavior index of fracturing fluid will create more friction and thus more resistance to flow in large fractures, promoting the creation of more short fractures, and thus larger treated reservoir volume for higher gas production rate and gas recovery.