When extracting oil in the multiple shale plays across the US, there is a water produced as a by-product along with the oil and gas. This water is referred to as produced water or saltwater. In North Dakota’s Bakken shale play, there is approximately two to three barrels of produced water for every barrel of oil. Of particular note is that Bakken produced water is about 10 times saltier than ocean water. Ocean water contains approximately 35,000 parts per million (PPM) sodium chloride, compared to 250,000 to 300,000-PPM of sodium chloride in Bakken produced water.
Due to the high concentrations of sodium chloride in the produced water, the environmental and financial impacts of a saltwater spill can be significant. One particular produced water gathering system is leading the way with advanced technology that focuses on leak prevention and detection, as well as streamlining operation costs and efficiencies. The Hidden Bench Produced Water Gathering Systems use pipelines to gather production water from oil well pads and deliver to off-site saltwater disposal facilities. “One of the major benefits of this pipeline system is the reduction of heavy truck traffic in the Bakken. Minimizing the traffic dangers related to transporting water is one of the fundamental goals of the Hidden Bench project,” says Grant Slick, AE2S Water Solutions General Manager.
The Hidden Bench infrastructure has multiple high-tech risk management measures in place to prevent leaks and spills from occurring. The Supervisory Control and Data Acquisition (SCADA) System allows for real-time monitoring of pipeline conditions. OpWorks™, a unique web-based reporting and operator logging application, consolidates instrumentation data from SCADA, operator field readings and other sources to monitor and report performance and operational parameters. Dual metering simultaneously monitors input and delivery, plus verifies the safe transfer of all source water captured by the Hidden Bench Systems.
Together, OpWorks™ and SCADA can calculate the expected flows and pressures at critical locations within the pipelines. By continuously measuring and recording the actual flows and pressures, SCADA is able to detect a possible leak and activate an alarm to shut down the well pad pumps, nearly immediately with no required direct operator action.
Both “CloudSCADA” and OpWorks™ can be accessed by mobile as well as desktop devices, to ensure those working in the field have real-time access to Hidden Bench Systems data. “We are able to remotely monitor and automate so many safety features with our SCADA system. For instance, the back pressure of the pipeline is continuously monitored at the inlet piping at the salt water disposal facility. If an acceptable system pressure cannot be maintained, the pumping systems and isolation valves are automatically shut down and an alert is sent to the system operators,” says Slick.
The tank levels at the disposal site are also monitored by the site’s SCADA system to prevent the pumps from operating when the tanks are full. When a tank reaches a certain level, an alert is automatically sent to an operator or manager to determine the cause. When a tank reaches the lockout level, a signal is sent to the pump control system to automatically shut down the pumps. The system can even recognize a full oil tank at the disposal site and send an alert to dispatch a truck to empty the tank.
A project team from the Energy and Environmental Research Center (EERC) in Grand Forks, North Dakota toured the Hidden Bench Systems site to learn about its operations systems. The EERC is performing a study, funded by the state of North Dakota, to gather and report on leak detection methods and processes which will drive future regulations in the State. “The Hidden Bench project utilizes industry leading monitoring equipment and safety practices that will hopefully pave the way for a more reliable and trustworthy gathering pipeline future for the entire industry,” says Slick. /p>