Project Overview

A prospective buyer engaged SPD to conduct an independent well integrity due diligence assessment of a large onshore oil and gas field ahead of a proposed acquisition. The field comprised several dozen producing, shut-in and suspended wells across multiple reservoir horizons, some with construction histories spanning more than three decades. The acquiring operator needed a clear, independent picture of the integrity status of the existing well stock — the liabilities it was inheriting, the remediation costs it would need to carry, and the risks that could affect the field’s long-term production potential.

Key Challenges

• Data room limitations — well records held by the vendor were incomplete and inconsistently archived; cementing records, casing inspection logs and workover reports were missing or partial for a significant proportion of the well stock
• Mixed well stock — wells of widely varying age, construction standard, completion type and operational status, from recently drilled producers to wells shut in for over a decade
• Undisclosed integrity issues — preliminary data review indicated several wells had known annular pressure anomalies and unresolved barrier failures not prominently disclosed in the vendor’s information memorandum
• Time pressure — acquisition timelines are fixed; robust investment-grade assessment required within a compressed programme without physical access to the field

SPD’s Approach

SPD deployed an experienced well integrity team to work through the vendor data room systematically, reviewing all available well construction records, cementing reports, completion diagrams, mechanical integrity test histories, annular pressure records, workover reports and production histories for every well in the asset.

A standardised assessment framework was applied consistently across the well stock, classifying each well against a defined barrier status matrix aligned to recognised well integrity standards. Where records were incomplete, SPD applied conservative engineering assumptions and clearly flagged each data gap. The output was a well-by-well integrity register, an aggregated liability assessment with costed remediation ranges, a prioritised 12-month action list, and an executive summary structured for direct use in the acquisition negotiation process.

Results & Value Delivered

• Hidden liabilities uncovered — material number of wells with undisclosed barrier failures, unresolved annular pressure anomalies and deferred workover programmes identified
• Remediation costs quantified — well-category-level cost estimates gave a credible, defensible liability figure for price negotiation
• Price adjustment secured — due diligence findings provided the evidential basis for a meaningful purchase price adjustment
• Regulatory exposure identified — wells with compliance risk under current regulations flagged for pre-completion planning
• Day-one action plan delivered — prioritised 12-month post-acquisition workover and monitoring programme