Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
MATHEMATICAL MODEL OF TIGHTNESS TESTS WITH THERMAL EFFECTS
Submission Author:
Ricardo Knesebeck , PR
Co-Authors:
Ricardo Knesebeck, Cezar Otaviano Ribeiro Negrao
Presenter: Ricardo Knesebeck
doi://10.26678/ABCM.ENCIT2022.CIT22-0395
Abstract
During oil exploration, tightness tests are performed to ensure the integrity of pipelines. They are carried out by pressurizing the line to the required pressure, sealing it and measuring the pressure over time. Some field engineers have reported excessive pressure drops during the tests that are not due to fluid leakages. Previous studies show that these pressure drops may be due to rheological and thermal effects. The current study proposes a mathematical approach based on the thermodynamic property changes during the fluid compression to predict temperature rise and pressure drops due to heat transfer to the surroundings. Common fluids properties are used to compute the maximum expected pressure drop after confinement. Results show that the temperature change due to the compression may cause significant pressure changes, depending on the fluid composition. The effect is negligible for water, but is noticeable for mixtures of water with oils and salts. For brines and drilling muds, the maximum expected pressure drop was in the range of 5% to 10% of the final compressed pressure.
Keywords
Tightness test, pressure drop, Heat transfer
