Petroleum Office

Your Engineering Calculations, Simplified and Standardized, Right in Excel.

213 Excel Functions for Petroleum Engineering

Petroleum Office provides a large collection of specialized functions for oil and gas professionals.
With these functions you can build powerful, yet easy to read spreadsheets.

Decline Curves

Arps decline functions for both rate and cumulative production. Modified hyperbolic and power law exponential production decline curves.

Well Productivity

Productivity indexes and flow equations for oil and gas, vertical and horizontal wells, steady state, pseudosteady state and transient flow conditions.

Pipe Flow Performance

Pressure drop calculation for single phase, oil and gas flows. Popular correlations for multiphase pipe flow: Hagedorn and Brown, Beggs and Brill, Gray.

PVT Modeling

Common correlations for oil, gas and water properties: bubble point pressure, formation volume factor, viscosity, compressibility and more.

Reservoir Rock Properties

Corey and LET type curves. Honarpour and Ibrahim-Koederitz correlations for predicting relative permeability in different fluid systems and reservoir types.

Utility Functions

Linear and cubic splines allows you easily interpolate, differentiate and integrate tabulated data. Unit converter function has more than 1500 units.

Browse the full list

Who Uses Petroleum Office?

Trusted by petroleum engineers at every level - from the field to the boardroom

Engineering Managers & VPs

Former petroleum engineers now making strategic decisions in Excel

Speed: Validate assumptions in minutes, not hours
Transparency: Quick sanity checks for stakeholder discussions
Risk Mitigation: Eliminate calculation drift across teams
Standardization: Consistent methodology across all projects

Reservoir & Production Engineers

Hands-on professionals building models and running daily analyses

Productivity: 200+ functions eliminate custom VBA maintenance
Accuracy: 1500+ unit conversions prevent costly errors
Consistency: Industry-verified correlations and formulas
Time Savings: Snippets and samples accelerate workflows

Consultants & Independents

Professionals delivering client-ready screening calculations and technical analyses

Affordable: Pennies compared to traditional oil & gas software
Professional: Commercially validated functions for client trust
Efficiency: Standardized calculations across multiple projects
ROI: Save 10-15 hours per client engagement

Why Petroleum Office?

Instead of creating a stand-alone petroleum engineering application, we decided to build upon the strengths of Excel and make it better tool for petroleum engineering calculation.
Here’s how and why.

Ease of Use

Many say that Excel is a #1 tool for engineers. Everybody knows how to use it, hence the learning curve for addin is very shallow.

Simplicity

We are fans of simple calculations that allow the engineer to get a 90% answer quickly rather than a laborious effort to get a supposed 100% outcome.

Readability

You only create spreadsheet once. You read and edit it many times. Meaningful function names instead of complex formulas will keep your spreadsheets concise.

Consistency

Consistent result across all spreadsheet models. Reduce errors and eliminate typos.

Productivity

Keep all related inputs and calculations in one place. Less copying and pasting between applications.

Save time

Unit converter, file generator, snippets will save you a lot of time. Not to mention that coding VBA functions could be hard and time consuming.

How Does Petroleum Office Work?

Petroleum Office integrates seamlessly into Excel, adding a ribbon tab with 200+ petroleum engineering functions and powerful tools.

1. Download & Install

Download the free version—no credit card required. Install in minutes.

2. Open Excel

Find the Petroleum Office ribbon tab with all functions organized by category.

3. Start Calculating

Insert functions directly into your spreadsheets or use built-in tools and samples.

Function Library

Each function from addin can be selected from Insert function dialog as well as from ribbon group. All functions are organized by categories for easy navigation and have informative descriptions.

Snippets

Snippet is a block of cells with function name, its arguments, cells for input values, formula with referenced inputs and descriptions. It's quick and easy way to start using any function!

Right click on any cell in your spreadsheet and in context menu find "Insert Snippet", choose required function, click on the name and you've inserted a snippet.

Unit Conversion

Unit conversion in Petroleum Office is based on UnitConverter() Excel function which is part of add-in function library. Popular categories of units can be found on ribbon, select cell, choose units and you have your answer. All units button will show the full list of 1500+ registered units. Search and copy required abbreviation.

Sample Spreadsheets

Another easy way to start is to explore sample spreadsheets.

Click on Samples button and select an example spreadsheet from dropdown menu.

File Generator

If you work with text input files for popular simulators, you can save a lot of time, when creating different scenarios for sensitivity or history matching projects.

Create a template input file with tokens, fill the table with case names and its parameters. Then use File Generator tool within Toolbox button on the ribbon and it will create case files where each token is substituted by appropriate value from the table. Chances are that you keep the summary of your simulation runs in Excel anyway.

Petroleum Office - Import Eclipse Output

Import ECLIPSE Outputs

This tool allows you to read and load output files from ECLIPSE reservoir simulator directly to Excel.

Click on Toolbox button and choose Import Eclipse Results…. Select the cases (.SMSPEC, .FSMSPEC files) you want to import and click Open. Each case will be imported in the current workbook as separate sheet with the name as case file and contain all data vector results in columns.