WELL TESTING

Oil and Gas Well Testing is a common method to cost effectively measure gas, oil and water production from several wells in close proximity to each other. Manual or automated valves are used to direct the flow from a single well through a test seperator. This seperator employs measurement devices and flow computers to determine flow accumulation for each component (gas, oil and water) over a set period of time.

Well Testing is a complex solution as it requires multiple pieces to work together seamlessly, such as;

1. Measurement. Accurately measure production using standard algorithms.

2. Automation. Control the physical site and measurement equipment.

3. Operator HMI. Allow the operator to start and stop tests, view test results, and otherwise control the process.

4. Reporting. How test results are presented. For the demo we use Microsoft Power BI.

Well testing solutions range from turnkey products to completely custom solutions. Turnkey products are easy to get started with, but lack flexibility for end user and site specific requirements. Completely custom solutions are perfectly fit for purpose, but take time to build, test, document and maintain.

PLC Shift treads the middle ground between turnkey solutions and custom code. PLC Shift gas and liquid flow computers can be used to easily and quickly build reliable and accurate well testing solutions that are flexible enough to meet any need. Features that are built into the flow computers, like purge control, allow for significantly less custom code in the PLC when compared to custom solutions. However, by relying on some PLC code and integration effort, the solution can be perfectly tailored to your exact requirements.

The PLC Shift Well Test solution is a comprehensive guide on how to assemble an end to end solution leveraging the unique value of PLC Shift Gas flow and Liquid flow apps.

The complete documented guide and example projects are detailed in the PLC Shift Reference Manual. This manual includes a comprehensive section for each of the following solution components;

1. Measurement

We use PLC Shift gas and liquid flow computers to accurately measure production volumes and to export data for reporting. We use three apps: a Gas Flow app to measure gas, a Liquid Flow app to measure oil and another Liquid Flow app to measure water. See here for more details on the PLC Shift Gas Flow App and Liquid Flow App

PLC Shift Apps for Well Testing

2. Automation

Automation for this demo takes the form of structured text code that runs on a Codesys soft PLC. The code is straightforward, and only comprises a couple of routines.

While this example is built in Codesys, the code is intended to be portable to other IEC 61131 Structured Text PLCs that are supported by PLC Shift, such as AB CompactLogix, ControlLogix, and SCADAPack RTUs.

Structured Text Code for Well Testing

3. Operator HMI

The operator HMI is built using Codesys and is browser based. It's suitable for operation via mobile phone.

A similar HMI can be easily built in other controllers with web capability, stand alone HMIs, or SCADA.

Operator HMI

4. Reporting

We have built a sample report with interactivity using Microsoft Power BI desktop reporting tools, but any tool can be used. Flow computer data that is generated by PLC Shift flow computers have indexes, like the Batch User ID, Asset ID, and others that make it trivial to link records in different tables together. This greatly reduces the data transformation that is required to build usable and interactive reports, regardless of the actual reporting tool used.

A sample report in desktop format can be found online at this link. A simpler version that is suitable for mobile devices is here.

Well Test Results in PowerBI