THE ELASTO-VISCOPLASTIC-TIME-DEPENDENT NATURE OF WAXY CRUDE OILS

Measurement and Prediction of Time-independent and Time-dependent Rheological Behavior of Waxy Crude Oil

Wax deposition phenomenon changes the rheological behavior of waxy crude oil completely. In the current work, the rheological time-dependent and time-independent behaviors of waxy crude oil samples are studied and flow curve and compliance function are measured for the oil samples with various wax contents at different temperatures. A decrease in temperature and an increase in wax content lead ...

Nonlinear Rheology, Yielding, and Constitutive Modeling of Waxy Crude Oils

In this work, the rheological behavior of a group of model crude oils is experimentally studied at temperatures below their wax appearance temperature (WAT). We consider both a two-component wax-oil system and a three-component oil-water emulsion that is partially stabilized by precipitated wax. We characterize the shear-localization and yielding using a combined approach of bulk rheometry and ...

Modeling the rheological behavior of waxy crude oils as a function of flow and temperature history

Rheo-PIV Analysis of the Yielding and Flow of Model Waxy Crude Oils

Waxes are a commonly encountered precipitate that can result in gelation of crude oils and cessation of flow in pipelines. In this work we develop a model wax-oil system that exhibits rheological behavior similar to waxy crude oils encountered in production scenarios. To study the consequences of gelation on the rheology of the model system we perform simultaneous measurements of the bulk flow ...

Thermo-elasto-viscoplastic Analysis of Problems in Extension and Shear

The problems of extension and shear behavior of structural elements made of carbon steel and subjected to large thermomechanical loads are investigated. The analysis is based on nonlinear geometric and constitutive relations, and is expressed in a rate form. The materiai constitutive eqtiations arc capab!e of reproducing all nonisothermal, elasto-viscoplastic characteristics. The results of the...