Oil & Gas Documentation Standards

Technical Guide • Intermediate • 2 min read

Audience: Financial Modellers • Financial Model Auditors • National Oil Companies
Last Reviewed: July 2026
Updated: Version 1.0

Executive Summary

An oil and gas financial model requires documentation beyond standard model documentation practice: a clear reference to the specific reserve engineering report and its version, citation of the actual fiscal or commercial contract terms modelled, the source and date of the price deck used, and evidence of the decommissioning financial security in place. This guide sets out these documentation requirements, so a model's technical and commercial basis remains traceable and independently verifiable after the fact.

Key Takeaways

✓ An oil and gas financial model requires documentation beyond standard practice, reserve report reference and version, contract citation, price deck source, and decommissioning security evidence.
✓ Reserve report reference should identify the specific reserve engineering report, its effective date, and version, so the model's production and reserve basis can be independently traced back to its technical source.
✓ Contract citation should identify the specific fiscal or commercial contract clauses the model's formulas are built to replicate, not merely a general statement that a production sharing contract or tariff agreement applies.
✓ Decommissioning security evidence should document the specific financial security mechanism in place and its current funding status, supporting verification that the provisioning obligation is genuinely backed.

Objective¶

This guide sets out the documentation an oil and gas financial model requires beyond standard model documentation practice, within Oil & Gas Financial Modelling.

Reserve Report Reference¶

The model should document a clear reference to the specific reserve engineering report it is built on, including its effective date and version, so the production and reserve basis, addressed in Upstream Financial Models, can be independently traced back to its technical source at any point after the model is built, rather than referring only generically to "the reserve report."

Contract Citation¶

The model should document the specific fiscal or commercial contract clauses its formulas are built to replicate, the cost recovery ceiling percentage, profit split thresholds, or tariff calculation methodology actually in the contract, rather than a general statement that a production sharing contract or tariff agreement applies. This citation is what allows a reviewer to verify the model's fiscal waterfall, addressed in Fiscal Regime Modelling, against the actual contract terms.

Price Deck Source¶

The model should document the source and date of the price deck used, whether a market forward curve or a bank-defined price deck, so a reader can assess whether the price basis remains current or requires updating, consistent with the practice addressed in Oil Price Scenario Analysis.

Decommissioning Security Evidence¶

The model should document the specific decommissioning financial security mechanism in place, sinking fund, parent company guarantee, or letter of credit, and its current funding status, supporting verification that the provisioning obligation addressed in Decommissioning Cost Models is genuinely backed rather than a notional figure in the model alone.

Common Documentation Gaps¶

Referring to "the reserve report" without a specific version and effective date, preventing reconciliation against a later technical update.
Citing a fiscal regime generically rather than the specific contract clauses the model's formulas replicate.
Omitting the source and date of the price deck used, leaving a reader unable to assess whether the price basis is current.
Documenting a decommissioning provision without evidence of the actual financial security mechanism backing it.

Continue Reading¶

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Frequently Asked Questions

What documentation does an oil and gas financial model need beyond standard practice?

A clear reference to the specific reserve engineering report and its version, citation of the actual fiscal or commercial contract clauses modelled, the source and date of the price deck used, and evidence of the decommissioning financial security in place.

Why does the reserve report reference need to include a version and effective date?

Because reserve reports are updated periodically, and a model documented only as being based on "the reserve report" without a specific version and date cannot be verified against the correct technical source when a later update supersedes an earlier one.

What should contract citation include?

Identification of the specific fiscal or commercial contract clauses the model's formulas are built to replicate, cost recovery ceiling percentage, profit split thresholds, tariff calculation methodology, not merely a general statement that a production sharing contract or tariff agreement applies.

Why is decommissioning security evidence a documentation requirement?

Because the decommissioning provisioning obligation addressed in Decommissioning Cost Models is only meaningful if backed by an actual, verifiable financial security mechanism, and documenting the specific mechanism and its funding status supports confirming that backing exists.

References

Society of Petroleum Engineers, World Petroleum Council, American Association of Petroleum Geologists, Society of Petroleum Evaluation Engineers — Petroleum Resources Management System (PRMS 2018)

Oil & Gas Financial Modelling

Oil and gas financial modelling is the practice of building financial models across the four structurally distinct segments of the hydrocarbon value chain, upstream exploration and production, midstream transport and processing, downstream refining and petrochemicals, and LNG, each governed by different revenue mechanics, contract structures and risk drivers. This page is the hub for the Knowledge Centre's oil and gas financial modelling content: industry structure and segment definitions, the financial KPIs the sector is measured against, the investment lifecycle from exploration through decommissioning, and how this domain builds toward asset and project-level models, commercial and investment analysis, and governance and assurance practice as it expands.

Upstream Financial Models

Upstream financial models project revenue and debt capacity from a depleting reserve base using a production decline curve rather than a steady-state or growth volume forecast common to most other industries. This guide sets out how upstream models are structured around exploration and production economics, reserve categories, decline mechanics, fiscal terms, and the reserve-based lending structures that finance the segment, the foundational technical grounding this domain's asset-level and commercial analysis content builds on.

Decommissioning Cost Models

Decommissioning cost models estimate and provision the mandatory end-of-life obligation to plug wells and remove oil and gas infrastructure, an obligation that should be funded progressively across the production life rather than treated as a single terminal-year cost. This guide sets out how decommissioning cost is estimated, the funding mechanisms, sinking funds, parent company guarantees, and letters of credit, regulators typically require, and why timing and discounting of the liability matter to how it is represented in a financial model.

Oil & Gas Model Validation

Validating an oil and gas financial model requires procedures beyond general model validation practice: reconciling the model's decline and reserve assumptions against the current reserve engineering report, independently replicating any reserve-based lending borrowing base calculation, and verifying fiscal regime waterfall mechanics against the actual contract terms. This guide sets out these procedures as a step-by-step validation methodology, extending the general model validation discipline with the sector-specific checks this domain requires.

What Is Model Risk?

Model risk is the risk that a decision is wrong not because the underlying business or investment case was flawed, but because the model used to evaluate it was. It is a distinct category of risk from market risk, credit risk, or operational risk, and it applies to any organisation that relies on a financial model, spreadsheet or otherwise, to support a material decision. Most published model risk content addresses statistical and regulatory capital models used inside banks. This page defines model risk specifically as it applies to Excel based financial models, the kind used every day for investment decisions, lending, and transaction evaluation, which is a related but distinct problem from the quantitative model risk literature most search results return.