Introduction
The purpose of a Blow Out Preventer (BOP) is to aid in controlling underground pressure in the event that the pressure starts to overwhelm the mechanical systems used to extract crude and/or natural gas from the ground. BOPs are critical to the safety of the environment and the work crew operating the equipment. They are also important to help preserve the well for financial reasons. Such critical systems need to be verified and validated against established standards dictated by the American Petroleum Institute (API) for quality purposes to ensure that they work as intended.
A BOP stripping test evaluates the constriction applied to a simulated drill string. While the drill string moves vertically in either the up or down direction, the closing pressure can be applied to "strip" the tool joints.
Case Presentation
Houston Hydraulic teamed up with Blaze Technology, LLC to design a means to perform BOP stripping test for a mutual client located in Houston, Texas. The team developed and deployed an Automated BOP Stripping Test System that automatically controls the direction of the simulated drill string, power of the pump motors, and the pressure of the hydraulic fluid. The software application captures the inlet and outlet pressures; amount of flow during any given portion of the test; direction of the tool being stripped; Well Bore Pressure and Hydraulic Closing Pressure; user defined Temperatures (up to four); linear position during any part of a test as well as calculated values such as vertical force, number of tool joints stripped, and linear velocity.
The client's management team provided the requirements for the system and governed the development process. Houston Hydraulic, led by Webb Spencer designed and deployed the mechanical systems in accordance with the client's requirements. Blaze Technology, LLC, led by Justin Loop, developed the application for the monitoring, control, and automation of the BOP system.
Automation
The Automated BOP Stripping Test system utilizes National Instruments hardware and software platforms. The system requirements included digital inputs used for safety and emergency inputs; digital outputs to controlling AC solenoid driven valves; analog inputs for reading current signals from a linear displacement sensor, provided by Balluff, flow sensor to measure the leak rate, 14 pressure transducers, and four temperature sensors (type J thermocouples); and analog outputs for driving the pump controls.
Blaze Technology, LLC utilized the power of the LabVIEW Professional Development system software suite. The software was able to provide both fully manual control of the system to operate as needed and a fully automated control for testing purposes. Having the ability to automate such a system provides the ability to be repeatable.
The application provides the client the ability to create a stripping test profile. The profile would allow a test engineer to change the velocity of the tool at any given point of the linear position. For example, when changing direction of the tool, the velocity in which it is traveling can be reduced to lessen the shock caused by the change in direction. Furthermore, the profile can be modified per test.
The application also captures the calibration details of the pressure transducers and displacement sensor as well as provides an avenue for the user to dynamically rescale all of the sensors. This gets saved in the data file along with the Client's customer details.
The goal of this project was not only to provide all of the functionality required by the client, but also provide an intuitive user interface that eases the complexity of this system.