Material Selection Analysis for Well Design Candidate for CCS/CCUS Project

Abstract

As the world in ambition to limit the increment of global temperature not reaching as high as 1.5˚C, Production and consumption of oil and gas currently account for over half of global greenhouse gas emissions associated with energy use. Carbon sequestration is one of crucial element of clean energy transition since this technology contributes to both directly reducing emissions in high energy intensity economic sectors and removing CO2 to balance emissions that cannot be avoided.

Making the opportunity of Indonesia’s G20 Chairmanship, PERTAMINA leads the opportunity to establish the carbon sequestration project in nation. With the spirit of synergy and collaboration with partners, technical aspect and technologies are being studied and simulated in order to help decision makers to decide appropriate action and affordability of carbon sequestration project.

It is important to understand not only the subsurface structure of the field itself but well integrity to ensure that CO2 will able to inject and stays underneath for the intended period of storage take a critical consideration not only in safety but cost parameter. Material including casing, tubing and or other tubular goods points on how will the well last. This paper will using case study method by analyzing and mitigating corrosion of well material. As corrosion as material may degrade with time depending on the downhole temperature, pressure, stress conditions, and formation fluids. CO2 is very corrosive when it encounters aqueous environment and driven by high pressure, temprature, flow rate, and pH, will react with cement and steel resulting in carbonation which can lead to steel rusting. In addition to rusting, it has possibilities to form cracks on well structure and cause the leakage of CO2.

In consequence, several factors had to be considered, including the choice of material. Selection of wellbore material play an important role in reducing the risk of corrosion. Strarting with the evaluation of corrosion causes (from partial pressure of CO2), low life cycle cost, design (including impact of water’s and gasses’ like SOx, NOx, O2, and H2S appearance), availability, mechanical and physical properties of material. The results of this study are well design and materials that should have been used, based on the case study that had been done. By utilizing ferrous or non ferrous metal, and selection of composite and polymer are alternatives to decrease the possibilities of corrosion. Additionally, corrosion caused by the presence of sulphur gasses can be avoided by using a protective layer like iron sulphide film. Regardless of the wellbore material, well needs to be on steady state condition in order to maintain well and CO2 condition.