Advisory · forming
Reserves are a number someone has to stand behind.
Stonebridge Advisory is built on three decades of petroleum reserves and reservoir engineering work at operators, in oilfield services and in consulting, and on the same discipline as our software: reconcile to the source, state the assumption next to the figure, and leave the decision with the person who carries the consequence.
The first engagement · 01
Technical data QA sprint.
Fifteen business days, fixed fee, one asset package, one named decision. We find and explain the material inconsistencies between the technical and economic data a decision rests on, before the date that makes them expensive.
- Input and permission register
- Reproducible checks, versioned with the inputs
- Source-linked exception log
- Quantified bridge with agreed sensitivities
- Reviewed findings meeting and a signed disposition log
Acceptance: every supplied record matched, excluded with a reason or marked unresolved; every material finding linked to evidence; totals tie within agreed tolerances; your reviewer signs the disposition log.
Four situations it is built for
Acquisition or financing
Reconcile the supplied reserves, production and economic data to the cases, and surface the material differences and sensitivities before the signing date.
Buyer: CFO or transaction sponsor, with the reservoir team reviewing
Reserves close or system conversion
A supported source-to-report bridge across the year-end movement or across a database migration, with the unresolved exceptions prioritised.
Buyer: Reserves and finance leads ahead of the auditor
Post-acquisition integration
Tie out identifiers, interests, production and economics across the acquired and existing systems before the first combined report.
Buyer: Integration lead, reserves lead
Recurring controls
Monthly exceptions and quarterly change explanations for a stable asset population. Offered only where the problem genuinely recurs.
Buyer: Controller or reserves manager
What the sprint is not
Not a reserves audit or certification under SEC or SPE definitions, and not a substitute for one where a lender or regulator requires it. Not a promise of valuation uplift, regulatory acceptance or lender approval. Not a replacement for your engineering platform or your advisers. Engineering opinions are issued only where the applicable professional registration is held; otherwise the deliverable is technical data assurance prepared for your qualified reviewer, who retains responsible charge.
Oil and gas · the wider practice
Where a reserves executive earns their fee.
Each area is work the principal has done inside an operator, not a service line borrowed from a brochure. The common thread is a figure that reaches a filing, a deal or a sanction decision and has to survive an audit.
Reserves and resources assurance
Independent review of estimates and their classification under PRMS and SEC rules: categories, PUD conversion and the five-year rule, economic limit and entitlement, and reconciliation of the movement. Readiness for the reserves committee and the external auditor.
Transaction due diligence
Reserves, production and economics review for acquisitions, divestitures and financings. We test the reserves basis a price depends on and re-run the economics on our own assumptions.
Reserves systems and process
Design and migration of corporate reserves databases and the workflows around them, the process documents that make the output auditable, and the controls that follow.
Reservoir engineering peer review
Independent evaluation of geologic and reservoir models, development plans, waterflood and EOR designs and the forecasts behind a sanction decision. Conventional and unconventional.
Standards, policy and training
Contributions to the PRMS revision process and resource-management frameworks, reserves policy for a company, and training for engineers, finance teams and boards on how reserves are estimated, classified and disclosed.
What we do not sell
Another forecasting engine, an automated reserves waterfall, or a prompt library. Installed platforms and established evaluators already occupy those categories. We sell accountable interpretation of the exceptions they leave behind, around a real deadline.
Where it comes from
Thirty years, three vantage points.
- Led a corporate reserves function at a US independent: quarterly and year-end SEC reporting, PUD analysis, external reserves audits, SOX controls and a full reserves-system migration.
- Regional reserves and economics lead for North Sea, Suriname and Egypt assets; earlier, reservoir engineering across the Permian, Anadarko, Western Canada and the Gulf of Mexico, conventional and unconventional.
- Participation in more than a dozen acquisition and divestiture transactions across the United States, Canada and North Africa.
- Oilfield services and consulting beginnings: fracture and acid stimulation design in the Permian, then field studies and production optimisation for small independents.
- Operator experience under a West African production-sharing contract: annual reserves reports to government, budgets and work programmes with the regulator.
- Standards work: member of the SPE Oil and Gas Reserves Committee, lead of a sub-committee for the PRMS 2028 revision, member of a United Nations Expert Group on Resource Management working group, long-serving SPE Journal technical editor.
PhD and MSc in petroleum engineering, MBA. Employer and client names are not published; references on request.
Accounting firms and small business
One measurable bottleneck, across the systems you already pay for.
Built on the engine work behind our tax tools and on running a multi-host software fleet with one operator. We leave tax conclusions and client responsibility with the qualified practitioner and work on the operations around them:
- Cross-system operations for a tax or accounting practice: client document collection, reviewer queues, work-status reporting and billing exceptions, measured before and after.
- Books that reconcile: a monthly close that ties to the bank and holds up in a tax engagement.
- Entity, compensation and retirement-plan structure for an owner, modelled on the full return rather than a rule of thumb.
- Technology selection and automation with a fail-closed bias: nothing that can silently be wrong, and client data handled under the Safeguards Rule.
Starts with a short paid diagnostic; a recurring service is proposed only where the work genuinely recurs.
How an engagement runs
Discovery call
Thirty minutes. You walk us through the last real close, transaction or migration; we say plainly whether it is ours to take and who else should be in the room.
Written scope
A one-page scope: the question, the sources we will reconcile to, the deliverable, the timeline, the price and the data-handling terms. Read the template.
Deliverable with provenance
Every figure and recommendation traces to a document, a model run or a calculation you can inspect, with the assumption stated beside it, and your reviewer signs the disposition.
Book a discovery call.
Tell us the asset or the situation, the date that matters and what a good outcome looks like. We reply within two working days.