Lesson learned from the assessment of planned converted CO2 injection well integrity in Indonesia - CCUS project

The risk of CO2 leakage from carbon capture, utilization, and storage (CCUS) wells and geological storage sites must be properly assessed before the implementation of CO2 injection. According to ISO 27914 and ISO/FDIS 27916, the design and construction of an injection well needs to guarantee safety and ability to contain the stored CO2 over a long-term period. However, these standards alone were inadequate to evaluate the well integrity due to the need to specify criteria, duration of measurement, and range of measurement parameters of the available tools according to industries' best practices. The methodology used in the study adapted applicable and readily-available international standards, field experiences, and lessons learned that could be used to support the construction of new and/or the conversion of existing oil and gas wells into CO2 injection wells. This study focused on Jepon-1 in Gundih field, Indonesia, an abandoned oil and gas well. Its actual conditions, well integrity, capabilities of the equipment used in the workover and logging operations, and its limitations in checking the conditions of various crucial aspects of integrity, were evaluated. The results showed that the application of the international standards could not fulfill all the detailed requirements of integrity evaluation of the JPN-1 well due to its particular condition and situation. Other field experiences needed to be adapted, improved, and incorporated in the integrity evaluation of this well. Additionally, longer duration of measurement and more accurate and sensitive logging evaluation tools, combined with temperature logging tools, are required to detect leakage that could not be identified by the commercial tools used in this well. The result of this well integrity study will be used as a fundamental basis for constructing CCUS well regulations by the Government and stakeholders.

In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration

In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH₄(HCO₃) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250-570 µm; as evidenced by µCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical non-congruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH₄ (HCO₃), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.