Rate-Time Spreadsheet (RTS) To Estimate Range of Your Reserves

This Excel spreadsheet helps you to calculate range of  production forecast using seven different methods by analyzing gas or oil production (i.e. rate-time) data.

This tool is available for Excel 2003 and 2007 versions. For those who use newer versions of Excel (2010 and later versions) can use the 2007 version. The authors of this tool provide user guide on how use this tool (see download links at the bottom of this page). They also provide examples using tight gas well. For more details, please read SPE papers 116731, 119897, 132352 from OnePetro website. (more…)

Web-based & Excel Tools To Calculate Dry Gas Properties

It is essential for Petroleum Engineers to make various calculations in order to arrive at certain important figures on dry gas properties when they are engaged in working on their projects. Since these are quite time consuming calculations the presence of a web-based tool that does the calculations when their input figures are entered is of immense benefit for them. What you get in Excel format in this webpage is exactly that. It is a tool that could help them calculate various figures they need. When it comes to dry gas properties you may need inputs such as gas gravity, mole percent of CO₂ and H₂S, bottom hole pressure and temperature. (more…)

Web-based Tool To Calculate Gas Compressibility Factor

The purpose of writing the VBA excel function is to calculate the gas compressibility factor (Z) through JavaScript. This Excel function also aims to be a useful online website tool that can be used by anybody to calculate gas compressibility factor through our website.

About Gas Compressibility Factor

This is a helpful thermodynamic property in modifying the ideal gas law, taking to account the real gas behavior. The gas compressibility factor is a measure of the amount of thermodynamic properties in real gases that deviate from the amount that is expected from ideal gases. The compressibility factor can be considered as the ratio of the volume of real gas to the volume predicted from ideal gas given that the pressure and temperature are similar to that of the volume. (more…)

Cumulative Probability Plot (up to 5 series)

This online tool helps you to create cumulative probability chart from your data. To do this, sort your data in ascending order. Next,  calculate percentile rank from your data. The smallest number in your data has the smallest percentile. Then  plot your sorted data versus percentile rank. (more…)

Imagine you have producing gas wells with small amount of liquid production oil or water. Your liquid productions are not producing continuously (intermittent). Your liquid productions are not tied in directly to sales line. Or your wells are located far away from central facilities. Consequently, liquid productions need to be hauled by truck every certain day or every week. As a result, your production data is not in daily rate but in volume collected from certain day. (more…)

Modified Hyperbolic Decline Curve Formula

Extrapolation of hyperbolic declines over long periods of time frequently results in unrealistically high reserves. To avoid this problem, it has been suggested (Robertson) that at some point in time, the hyperbolic decline be converted into an exponential decline.⁽¹⁾ (more…)

Visualize Horizontal Well Landing Position Easily

This is an extended work from the previous tool called Horizontal Toe Direction posted in this website earlier. The objective of this tool is to visualize horizontal well landing position within target zone using horizontal well deviation survey and top and bottom formation data points. Once we plot these survey and tops formation data, we can determine the following information: (more…)

Visualize Horizontal Well Toe Direction Quickly

The objective of this tool is to visualize horizontal well toe direction using horizontal well deviation survey. Yes you can do easily if you have less well. What if you have more than 1000 wells? This tool can save your time! Once we plot directional survey data, we can determine the following information: (more…)