Study On Preparing, Evaluating Capability And Exploring Mechanism Of The Pour Point Depressants And Viscosity Reducers In Crude Olis

The first chapter was the overview. it was mainly introduce the concept, category and constitutive component of the Pour Point Depressants and Viscosity Reducers. It was detailed elaborated that its development history , main sorts in the present, its action mechanism , and the civil applied instances. The second chapter aimed at the Tahe Crude Oils'character. The TH-2 decreased viscosity agent was compound by selected from many surfactants, it was composed of nonionic-surfactant, anionic-surfactant and improved-property agent. Its capability of decreased viscosity to Tahe crude oils was estimated, the result showed the ratio of reducing viscosity was more than 95% , the decrease ratio of reducing viscosity was lower than 0.1% at 250℃, at the same time, demulsifying and dewatering were much easier, it was a good kind of viscosity reducer for Tahe crude oils. The third chapter studied mainly that the pour point depressants (PPDS) was used to improve of the waxy crude oil. The effects of various factors on rheology and thermal characteristic of treated waxy crude oil have been investigated. The experimental results show: the optimal PPDS is EVA+AA, treated at 70℃, added the concentration 100ppm. PPDS can reduce the pour point and the abnormal point of crude oil. It can broaden the temperature scope of Newtonian liquid of crude oil and lower greatly viscosity of non-Newtonian liquid crude oil. The influence of reheat and high-speed shear on PPDS mainly depends on their temperature. When the temperature is below 70℃, the reheating process will reduce the modifying efficiency of PPDS. The lower the reheating temperature, the worsen its effect. When the high-speed shear carried out in the period of a great large of waxy crystals, it will greatly reduce the modification of PPDS. The static experiment indicates the PPDS was good at keeping capability.