Sustainable Energy Technologies Seminar
"Cementitious Materials for Geothermal Wells"
Presented by Tatiana Pyatina
Thursday, November 7, 2013, 11 am
ISB 734 2nd Floor Seminar Room 201
Geothermal wells arguably present the most severe conditions to which well cements are exposed. The failure of wells in several geothermal fields has been directly attributed to cement failure (Nelson and Guillot "Well cementing" 2nd Ed., 2006). The talk will give an overview of three projects that address different challenges of well cementing in general and those of geothermal wells more specifically. The first project focuses on new cementitious materials that withstand temperatures of more than 300oC, resist significant thermal shocks in chemically aggressive environments, while providing subterranean zonal isolation and carbon steel casing corrosion resistance. The second project formulates and develops unusual, self-degradable cements that plug fractured formations to cure fluid losses during well drilling and degrade when the well is put into production. Finally, we will discuss some essential organic cement additives (set retarders), that allow the necessary time for cement placement in a well before the cement hardens; their fate in highly alkaline cement environments at elevated temperature and their effect on mechanical properties of the set cement.