Primary cementing practices and compliance in Queensland’s petroleum wells

Abstract

Primary cementing is a crucial aspect of petroleum well construction, ensuring long-term well integrity, preventing fluid migration, and protecting groundwater. In Queensland, Resources Safety & Health Queensland (RSHQ) Petroleum and Gas Inspectorate enforces the Code of Practice for the construction and abandonment of petroleum wells and associated bores in Queensland, which outlines engineering and technical requirements for well construction and abandonment. Between January 2020 and December 2023, industry operators drilled 2541 wells and reported 43 failures to meet primary cementing objectives (FTMCOs), prompting the Inspectorate to conduct industry-wide audits. The audits focussed on compliance with cementing practices, formal safety assessments, slurry design, laboratory testing, verification procedures, and factors contributing to slumping and failure to reach the designed top of cement (TOC). Key findings highlighted gaps in formal safety assessments, a tendency to delegate cement slurry design to contractors without rigorous technical oversight, and inconsistencies in laboratory testing documentation. Additionally, verification procedures were not always aligned with regulatory requirements, and cement losses presented significant challenges towards the slumping and TOC deficiencies. To enhance primary cementing practices, the paper recommends strengthening oversight of cementing contractors’ technical capabilities, improving verification procedures, and ensuring consistent comprehensive risk assessments. Aligning cement verification procedures with regulatory requirements and adopting best practices for mitigating cement losses will improve well integrity and regulatory compliance.