Dynamics of the destruction of paraffin deposits in oil‒gas systems under cyclic pressure
摘要
Paraffin deposits in oil and gas pipelines and drilling systems restrict flow, increase operational expenditures, and increase the risks of equipment; − 5.0 Hz, microstructural analysis (i.e., SEM and FTIR), viscoelastic modeling using the generalized Maxwell model, and finite-element simulations (i.e., ANSYS). Synthetic paraffin samples that contained 10–30 wt% wax were tested in the oil matrix model. The key results included the following: Increasing the pressure amplitude and frequency reduced the critical failure stress by up to 43% (from 2.8 MPa to 1.6 MPa) and the number of cycles to failure by up to 76% (from 850 to 200) for 20 wt% wax content. The crack density increased from 5 to 20 cracks/mm², and the crystalline phase fraction increased from 45% to 60%, thus increasing the brittleness. The model predicted crack propagation with an error of 10% for ≤ 2.0 MPa. Beyond those of static-pressure studies, these findings demonstrate that cyclic pressure induces fatigue-like destruction and pressure-promoted recrystallization. This work advances the literature (which is focused mainly on static conditions or deposit formation) by quantifying dynamic mechanical degradation and proposing optimized cyclic pressure protocols for hybrid removal, which potentially reduce downtime by 10–15% and maintenance expenses by 5–10%.