Abstract
This study aimed to evaluate the corrosion properties of J55 carbon steel immersed in CO2/crude oil/brine mixtures present in the wellbores of CO2-flooded production wells. The main corroded position of wellbore was determined and wellbore corrosion law was provided. Corrosion tests were performed in 30% crude oil/brine solution under the simulated temperature (30–80 °C) and pressure (2–15 MPa) conditions of different well depths (0–1500 m). The corrosion behavior of J55 carbon steel was evaluated through weight-loss measurements and surface analytical techniques, including scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction analysis, and optical digital microscopy. Corrosion rate initially increased and then decreased with increasing well depth, which reached the maximum value of 1050 m. At this well depth, pressure and temperature reached 11 MPa and 65 °C, respectively. Under these conditions, FeCO3 and CaCO3 localized on sample surfaces. Microscopy was performed to investigate corrosion depth distribution on the surfaces of the samples.
Highlights
CO2 is internationally recognized as a major greenhouse gas that accounts for approximately
The corrosive medium and environment have been identified as the deciding factors of corrosion rate and morphology
2 -flooded well in Chang-8 Oil Reservoir of a certain block in Changqing Oilfield was taken as an example
Summary
CO2 is internationally recognized as a major greenhouse gas that accounts for approximately65% of the total greenhouse gas emissions [1,2,3]. All countries currently attach considerable importance to environmental issues, global warming caused by CO2. CO2 is used as an oil-flooding agent worldwide because it can effectively reduce crude oil viscosity and residual oil saturation, dissolve gum in reservoirs, and increase permeability and crude oil recovery rate [4,5]. CO2 flooding can reduce CO2 -associated air pollution and greenhouse effects. CO2 corrosion and its control in oil casing and surface transmission pipelines have been important topics in the field of oil and gas exploration. Related studies have focused on the influence of environmental and material factors on corrosion behavior [7,8,9,10,11,12,13,14,15,16]. The corrosive medium and environment have been identified as the deciding factors of corrosion rate and morphology
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
