One of the byproducts of the shale oil & gas revolution in the United States has been the need for trucking of crude oil where pipelines do not yet exist.In an August E&P magazine article, Automation optimizes trucking operations, Emerson’s Joey Raskie and Al Majek teamed with local business partner Ricky Strong of Vinson Process Controls and Apache Corp.’s Brad Long and Gerald Price to tell a great story of improving safety and increasing efficiency.
…performed a manual gauging operation that required climbing to the top of a crude oil tank. A sample was taken to determine the water content and the beginning tank level measured. Fluid loading would be executed using a pump mounted on the truck along with a sight glass or flowmeter.
After loading the truck:
…the driver would make a second trip to the top of the tank top to gauge the haul closing level. A load ticket would be manually created, with a copy left for the operating company. Field pumper personnel would pick up the tickets within a 24-hour to 48-hour period during their normal rounds.
To improve this inefficient and potentially dangerous operation given the sometimes-harsh weather in this part of Texas, a central tank battery (CTB) was created. This facility included:
…a lease automatic custody transfer (LACT) unit implemented with an automation package. Electronics managing the process have to be suitable for harsh outdoor environments. In particular, the human-machine interface (HMI) at each loading spot needs to be easy to read, viewable under strong sunlight and able to hold up to occasional wind-driven rain and hail.
The technologies involved in this solution included [hyperlinks added]:
Instead of manually having to climb the tank to read levels, the [hyperlink added]:
…process begins with level measurement of the storage tanks. Each tank level is monitored by an individual guided wave radar gauge. The tanks are treated as an equalized group all connected to a central header. Based upon the level readings, operations personnel manually select which tanks are to be opened or closed, assuring enough crude is always available for the truck drivers. Level totals are forwarded to a central logistics call center over the company’s SCADA computer network.
Loading the trucks became a touchscreen panel operation even down to the system verifying that the driver had grounded the truck to prevent sparks before dispensing the liquids from the tank.
Other technologies in this automated solution included Coriolis mass flow meters, temperature, pressure and basic sediment and water (BS&W) meters for the Tank Manager to determine gross barrels, gross standard barrels and net standard barrels.
Read the article for more on some of the benefits achieved including improved accuracy of the custody transfer process, improved safety for the drivers and faster accounting reconciliation through the use of these technologies.
The authors concluded:
Overall, the CTB approach coupled with its associated automation package has crafted a formidable solution for improving onsite safety as well as the financial bottom line for operations.