Combined effect of asphaltenes and flow improvers on the rheological behaviour of Indian waxy crude oil
1998; Elsevier BV; Volume: 77; Issue: 11 Linguagem: Inglês
10.1016/s0016-2361(98)00029-5
ISSN1873-7153
AutoresDipankar Chanda, Anubhav Sarmah, A. Borthakur, Kosuru Venkateswara Rao, B. Subrahmanyam, Himangshu Das,
Tópico(s)Rheology and Fluid Dynamics Studies
ResumoThe effect of asphaltenes in the rheological behaviour of waxy Indian crude oils, having a middle-range API gravity (28–30), were studied. Dikom (DK) and Kathaluni (KH) crude oils were selected on the basis of their similar wax (> 10%) and asphaltene (> 2.5%) contents. Polybehenyl acrylate (PBA) with a range of molecular weights were prepared and their efficacy as flow improver (FI)/pour point depressant (PPD) were evaluated. Lower molecular weight PBA shows better efficacy as FI/PPD. Addition of asphaltene soluble solvents such as benzene, xylene, pyridine, nitrobenzene etc. alone or in combination with FI lowers the pour point, viscosity, yield stress considerably. Owing to the dissolution of asphaltene micelles, clear solution will form resulting in lower viscosity, DK crude oil behaves as a time dependent rheopexy fluid when allowed to stand under shear for a period. The high molecular weight asphaltenes are found to be responsible for rheopexy behaviour of DK crude oil.
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