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automate your choke/valve manifold systems.
Objective Solutions (OS) is a software development company with over 40 years of experience, the past 14 years of which were in the Oil & Gas industry, designing and building PLC/HMI systems for automation of valve and choke manifolds on drilling rigs. From this experience OS has developed a choke setpoint control system that works with hydraulic chokes.
One of the things we have noticed is that the Oil & Gas industry is pushing choke control to the electric choke. But we also know there are many small companies that have invested in hydraulic systems and cannot afford to go electric. That is why OS has focused on the hydraulic choke. The OS system provides an affordable solution to these people. It is fast so it can be used for may purposes, i.e. holding pressure during connections, allowing for a much faster pump shutdown, MPD, etc. But we also know that to get it to these people we must get over the hurdle of proving to them that it works. We have had some success in doing this, but COVID shut it all down. So now OS is looking for someone to help us finish the testing to prove the system works.
If you are in need of automation for choke control or valve manifold control, give us a call. Maybe we can help. And if you are interested in the choke setpoint control system, help us get it over the finish line with final testing (see the HISTORY section below for more details) and we can talk about how you can get one for yourself.
CHOKE SETPOINT CONTROL SYSTEM
The choke setpoint control system is simple. It consists of a PLC rack and any HMI device, i.e. laptop, connected via internet CAT 5 or better. The PLC is connected to the choke HPU with 4 wires:
4-20ma signal from choke position indicator,
4-20ma signal from pressure transducer,
0-24volt signal to HPU OPEN solenoid,
0-24volt signal to HPU CLOSE solenoid
If your hydraulic choke system has these 4 components then we can automate your choke system. If it does not, maybe it can be modified to meet these requirements.
Choke Setpoint Control PLC Rack
Example HMI program for laptop
MANIFOLD CONTROL SYSTEMS
Objective Solutions can help spec out everything needed for the electrical control box, glands, 24v transformer, etc., that meet all the safety requirements for rig operations. OS uses Siemens PLC equipment and are able to design that portion of the control box. But what we do best is development of all the software for the system, both PLC and HMI.
Example of manifold control screen:
CHOKE SETPOINT CONTROL SYSTEM HISTORY
In order to build this system a choke/hpu system was required. But at the time OS did not have this equipment. So the next best thing to get started was to build a choke simulator. The choke simulator is also a PLC rack and a program that runs on a PC. The simulator uses the Cv curves for a choke to determine a ballpark pressure value for any choke position. This value is then fed to the choke setpoint control system. The simulator also has two 24 volt inputs to simulate the movement of the choke when the OPEN or CLOSE signal is sent by the control system.
1) Utilizing the simulator the control system could be written and debugged. We will call this first stage of development the FULL SIM since a full choke is simulated. In this stage of development the response of the system is IDEAL, where the pressure follows the setpoint exactly.
2) The next stage is called PARTIAL SIM. Here the simulator is used to only produce the simulated pressure. The simulator is used in conjunction with a choke actuator connected and controlled by an HPU. The control system 24 volt signals now go to the HPU. This stage then includes the choke mechanism so that the hardware is providing feedback to the control system. This makes this stage more realistic than the FULL SIM stage. The following plot shows the response of the control system using a very old choke with a linear actuator and a modified HPU where two solenoids were added.
You can see the noise present in the previous system. This was cleaned up by adding a 5-gallon accumulator tank just after the pump.
3) The third stage is called NO SIM. At this point the choke is installed in a system with a mud pump and a pressure transducer. The simulator is no longer used since the choke is installed in a working environment. What we found in this stage was that the system was very noisy. This noise can wreak havoc on a control system. We had plans to fix this noise when COVID hit and the project was shutdown. But from the following plots you can see that it was still working.
With choke holding pressure, changed the flow from the pumps, i.e. 6 BBL/min to 10 BBL/min, to simulate an event. Choke held the setpoint pressure with some pressure spiking, but acceptable.
4) The fourth stage of testing is to install the control system and choke on a rig and try it in the actual working environment. This is where you come in. We need help in performing this last step. We need a rig that we can test it on. Any takers? Call us.