Global demand continues for the safe and reliable transport of crude oil. Many midstream energy companies are finding creative solutions to optimize capacity and reduce operating costs of their existing infrastructure in the absence of building new pipelines. As enhancements are made to the crude oil pipeline operation, it may lead to increased operating temperatures and thus increased adjacent ground temperatures. Increased operating temperatures may also have adverse effects to pipeline capacity, mechanical integrity, mechanical stress, vaporization of lighter crude products and vapor emission limits. Developing accurate trans-thermal hydraulic pipeline models is a critical enabler in evaluating and implementing engineered solutions as part of a holistic thermal management strategy.
The key contributors to temperature of fluids in a pipeline are as follows: ground temperature, ground thermal properties (ie. thermal conductivity, density, and heat capacity), fluid properties, pipeline flowrate, pipeline injection temperature, use of Drag Reducing Agent (DRA), station temperature rise, and pipeline operating procedures.
The proposed methodology comprises of first using the Statefinder module in Synergi Pipeline Simulator (SPS) software developed by DNV (hereafter referred to as “simulation software” in this paper) to connect to the SCADA (Supervisory Control and Data Acquisition) and utilize historical operating data to simulate the hydraulics of the system and tune its performance. This initial methodology step will reduce various sources of uncertainty and error in the modeling process. Using actual measurements from the field, the most important thermal properties of the pipeline are calibrated so that the temperature error between the similulation model and SCADA is within acceptable ranges. Next, the calibrated thermal properties will be used in the Simulator module of the simulation software to predict the operating temperature for unknown scenarios and perform sensitivity study with respect to six independent variables contributing to the pipeline temperature profile.
