The wellbore cement additive, gilsonite, a solution to leaky gas wells
A faulty cement sheath in a wellbore can result in gas migration from the formation to surface, which can leak and emit into the atmosphere. In attempt to combat this issue, we set out to investigate a natural cement additive, Gilsonite. The origin of Gilsonite is crystalized hydrocarbon located from fractures deep inside the subsurface and is likely responsible for its potential affinity towards light hydrocarbons that may be manipulated towards specific design goals of the wellbore cement. This research first investigates the additive’s mechanical and petrophysical properties while incorporated in a cement matrix and then investigates its potential affinity towards the uptake of hydrocarbons in order to postulate potential gas migration prevention applications. Specifically, Microindentation was performed on natural Gilsonite samples and compared to neat cement in order to postulate its potential mechanical integrity. Then Helium-Gas Porosimetry and Liquid-Pulse Decay Permeametry was conducted on three varying levels of Gilsonite-enriched cement cores before and after exposure to Natural Gas to determine its feasibility as a cement additive. These experiments lead to the discovery that the exposure to Natural Gas resulted in a decrease of the permeability of the Gilsonite-enriched cores, which implicates potential gas migration mitigation.
Publication Source (Journal or Book title)
52nd U.S. Rock Mechanics/Geomechanics Symposium
Didier, A., Radonjic, M., & Du, H. (2018). The wellbore cement additive, gilsonite, a solution to leaky gas wells. 52nd U.S. Rock Mechanics/Geomechanics Symposium Retrieved from https://repository.lsu.edu/geo_pubs/1527