Superposition is where spreadsheet material balance becomes genuinely instructive. The unsteady state aquifer models require summing the influx contributions from every pressure change that has occurred, which in a spreadsheet becomes a visible triangular calculation where each row's contribution to influx at every subsequent time can be seen. Engineers who have built this understand what the aquifer model is actually doing in a way that using a software aquifer option does not produce.

Term by term visibility changes how errors are found. When a material balance gives an implausible answer, the question is which term is responsible, and in a spreadsheet the contribution of each term at each time step can be read directly. A gas cap expansion term that dominates when there should be no gas cap, a compaction term larger than the oil expansion term, or a water influx term with the wrong sign are all immediately visible, and all are difficult to diagnose from a single output number.

Solver-based regression makes multi-unknown fitting practical without hiding it. Fitting original oil in place and gas cap ratio simultaneously, or fitting in-place volume together with aquifer parameters, requires minimising an error function across several variables. Excel's solver does this, and building the error function explicitly forces the engineer to decide what is being minimised, how the residuals are weighted and what constraints apply, all of which are decisions embedded and invisible in packaged software.

Finally, a workbook that the engineer built can be adapted. Reservoirs present variations that standard software handles awkwardly: unusual drive combinations, partial pressure support, compartments with different behaviour, non-standard injection schemes. A spreadsheet implementation can be extended to handle these, and an engineer who understands the structure can do so with confidence.

By the end of this training, participants will be able to:

• Build PVT property sheets using black oil correlations and laboratory data tables
• Implement the general material balance equation term by term in a spreadsheet
• Verify each term independently and diagnose implausible results by term
• Construct straight-line material balance plots and determine in-place volumes from them
• Implement regression-based solution using solver for multiple unknowns
• Code van Everdingen-Hurst, Carter-Tracy and Fetkovich aquifer models including superposition
• Fit aquifer parameters and assess non-uniqueness in the fit
• Implement gas and gas condensate material balance formulations
• Build diagnostic plots including drive index and P over Z analysis
• Implement uncertainty and sensitivity analysis and structure workbooks for audit

The training is entirely construction-based. Each element is built from an empty workbook, tested against known cases and verified by hand calculation before the next is added. Participants apply their completed workbooks to real field production and pressure histories, obtain results and diagnose discrepancies. Deliberately flawed implementations are examined so that participants learn to find errors in spreadsheet models. Participants leave with a complete tested material balance workbook they built and understand.

Organisations sending participants to this training will:

• Build material balance capability without software licence dependence
• Improve understanding of material balance among staff who use its results
• Produce transparent analyses that can be reviewed and audited
• Adapt material balance to reservoirs that standard software handles awkwardly
• Improve independent checking of simulation model volumes
• Build tools that can be maintained and extended within the organisation

Participants will:

• Understand every term in the material balance equation
• Build and maintain their own material balance workbooks
• Diagnose material balance results by examining individual terms
• Implement and fit aquifer models with full visibility
• Adapt the method to non-standard reservoir situations
• Acquire a portable capability independent of software availability

• Reservoir engineers at all levels
• Production and petroleum engineers analysing field performance
• Simulation engineers requiring independent volume checks
• Reserves and evaluation engineers
• Technical staff conducting field reviews and due diligence
• Graduate engineers building reservoir engineering fundamentals
• Engineers without access to specialist material balance software

Upon successful completion of this training course, delegates will be awarded an official Certificate of Completion issued by the Petroleum Engineers Association (PEA), an ISO 9001:2015 certified training organization. The certificate carries 10 Credits and formally records the total learning hours completed.

Each certificate is signed by the Course Facilitator and the CEO of the Petroleum Engineers Association, and serves as verifiable proof of professional training that delegates can present to employers and professional bodies worldwide.