iPhone / iPad App Offers Gas Well Calculators

By Chad Cluver | Fri, 18 Nov 2011

DRC's online calculators now come to smartphones.

Data Retrieval Corp. has long offered useful Calculators on our website, www.spidr.com. These Calculators allow petroleum engineers to quickly determine the minimum unloading rate for their gas well, or do a quick single point conversion from WHP to BHP for a gas or gas condensate well.  Unfortunately, these sites are not optimized for use on a smart-phone or tablet.  For an engineer traveling, stuck in a meeting, or out in the field this made their use impractical when they were most often needed. 

Download SPIDR Tools for iOS

Now, the power and popularity of devices such as smart-phones and tablets allows us to make these Calculators available to the engineer whenever and wherever they are needed.  We are pleased to announce the release of the SPIDR Tools app, available first on iOS devices directly from the Apple App Store.

The SPIDR Tools Calculators

The SPIDR Tools app brings three useful Calculators to the iOS platform, two of which were mentioned above.  The minimum unloading rate Calculator, the single point conversion Calculator, and the gas flow rate through an orifice plate Calculator are now available in one handy application right on your iPhone or iPad.  This article is a brief overview the app.

Minimum unloading rate Calculator

The minimum unloading rate Calculator is a very helpful tool in determining if a particular gas well can be tested from the surface, particularly if the well makes liquids such as condensate and/or water.  The calculated flow rate is the minimum flow rate that would be required to continuously unload fluids without slugging.  Thus, if your actual flow rate is below this critical rate, then the well may not be suitable for surface testing.  The calculator takes into account the dry gas density and composition, water density, wellhead pressure and temperature, and tubing size to determine the minimum unloading rate for condensate or condensate plus, water. 

Figures 1 and 2 are screenshots of the Calculator screen and the tubing table used for determining the correct tubing ID for your well’s particular grade and weight of tubing.  This same tubing table is available for use in the single point WHP to BHP Calculator as well.

Gas flow rate through an orifice plate Calculator

The gas flow rate through an orifice plate Calculator can be used to select the optimum orifice plate size for accurate rate measurement if you know your expected rate beforehand.  It can also be used to calculate the rate through a d/p cell when doing flow testing.  The Calculator uses the inputs as seen in Figure 3 below, and has options for either a flange tap or pipe tap.

Figure 3: Gas Rate through an Orifice

Single Point WHP to BHP conversion calculator

The third Calculator in the app is the Single Point WHP to BHP conversion calculator, which can be used for both flowing and static pressures and for gas and gas condensate wells.  DRC is the industry leader in converting surface pressures to bottom-hole pressures for pressure transient testing.  Our proprietary modifications of the Cullender-Smith routine for dry gas wells are utilized in this single point calculator.  This Calculator accounts for the produced fluids, divides the tubing into discrete elements, each with a unique "Z" factor, computes a temperature profile based on well depth and temperatures and uses friction loss models for increasing flow rates. The sophistication of this Calculator requires quite a few more inputs than for the Unloading Calculator or the Flow Rate Calculator.  Figures 4 and 5 show the inputs required for the Single Point Calculator.  The gas analysis, detailed production information, and detailed tubing information are all taken into account.

Download the SPIDR Tools app

For iPhone, iPad and iOS devices

The SPIDR Tools app is a very handy reference application for the petroleum engineer. The application may be found in the App Store via this link.

Or by scanning the QR code below with the code scanning app on your device.

For Other Platforms

While currently only available on iOS devices such as the iPhone, iPad, and iPod (requires iOS 4.3 or later), a version for Android smart-phones and tablets is in the works and will be available soon on those respective devices from the Android Marketplace. 

About Data Retrieval Corp and SPIDR

Data Retrieval Corp offers free well test planning and consultation for all your well testing needs, and we are available 24/7 to assist you in any aspect of your test.  We will work with you to help determine if surface testing is a viable option for the wells in your field, and can help review previous test data to determine if there is a better way forward for your well testing programs.