Mehanical integrity of CO2 injection wells : master's thesis

Kaptiranje i geološko skladištenje CO2 predstavlja jedan od načina smanjenja ispuštanja stakleničkih plinova u atmosferu. Za utiskivanje CO2 koriste se postojeće ili se izgrađuju nove bušotine. Glavni čimbenik pri utiskivanju CO2 za geološko skladištenje je dugotrajno održavanje unutarnje i vanjske mehaničke cjelovitosti utisne bušotine. Zbog svoje agresivne prirode, CO2 uzrokuje koroziju zaštitnih cijevi i bušotinske opreme, te degradaciju cementnog kamena. Kako bi se održala dugotrajna mehanička cjelovitost bušotine, veoma je važno pri konstrukciji bušotine odabrati materijale otporne na koroziju i specijalne cemente koji ne reagiraju s CO2. Pri odabiru utisnih bušotina bitna je analiza rizika podzemnog skladištenja CO2. Kao ulazni podaci u analizi rizika služe analitički i numerički modeli propuštanja CO2 kroz kanal bušotine. U radu su prikazani analitički modeli elementa kanala bušotine i sustava kanala bušotine. Modeli su razvijeni korištenjem izolacijske učinkovitosti kanala bušotine koja može poslužiti kao kriterij za odabir utisne bušotine.Abstract: Capture and geological storage of CO2 is one of the ways to reduce greenhouse gases in the atmosphere. Existing or new wells are used for injecting of CO2. The main factor of the carbon and capture process is a long-term maintenance of internal and external mechanical integrity of the injection well. Due to its aggressive nature, CO2 causes corrosion of casing and drilling equipment, and degradation of cement. To maintain long-term mechanical integrity of the well, it is very important during the construction of wells to choose resistant materials to corrosion and special cements that do not react with CO2. Risk analysis of underground CO2 storage is important before defining injection wells. Analytical and numerical models of leakage through the well are used as input data in risk analysis. This thesis contains analytical models of wellbore element and wellbore system. Models were developed using wellbore sealing efficiency wellbore indeks. Wellbore sealing efficiency can be used as a ranking criteria for the selection of injection well