Study of mechanism of oil magnetic activation in order to protect production wells from wax deposition

• Main Author: Aleksandr A. Zlobin
• Format: Article
• Language: English
• Published: Perm National Research Polytechnic University 2017-03-01
• Series: Perm Journal of Petroleum and Mining Engineering
• Subjects: magnetic and hydrodynamic activation; wax deposition; nuclear magnetic resonance method; supramolecular asphaltene structures; aggregation and peptization of asphaltenes; paramagnetism; spin dynamics of radical pairs
• Online Access: http://vestnik.pstu.ru/get/_res/fs/file2.pdf/6439/Study+of+mechanism+of+oil+magnetic+activation+in+order+to+protect+production+wells+from+wax+depositionfile2.pdf

The purpose of the paper is experimental study and description of mechanism of magnetic and hydrodynamic (MHD) activation of oil for protection from wax deposition and to increase efficiency of heavy oil production. A brief review of history of magnetic activation (MA) application is performed. Laboratory methods used to record efficiency of MA are described. As a result of experiments several points were established. Firstly, a positive effect of protection from wax deposition is implemented for all types of oil, regardless composition and viscosity, but it is necessary to select individual activation regimes. Secondly, it is shown that magnitude of the "magnetic memory" of oil increases nonlinearly with increase of magnetic field strength and can reach 20-40 hours. Thirdly, a common resonance mechanism for MA of oil is established. Fourthly, a magnitude of MHD activation effectiveness is determined by content of asphaltene and resin matter, that is dispersed oil phase. A brief theory of spin dynamics of paramagnetic radical pairs which takes place when oil is activated is described. The mechanism of MHD activation is as follows: a magnetic field with a small amount of excitation energy in capacity selects chemical and physical reactions by controlling spin state of electrons and stimulates recombination and birth of paramagnetic radical pairs. That ensures appearance of long-term high-energy activity (phase transitions) of asphaltene molecules with emission or input of energy, leading to structural rearrangement of nuclei of asphaltene structures and physical macroparameters of oil as a whole. Wherein, the positive protective effect against wax deposition after MA is caused by aggregation and enlargement of asphaltene complexes, a decrease in specific adsorption surface of paraffin crystals and creation of harmonic vibration modes in oil matter, which reduce a probability of nucleation and subsequent growth of paraffin crystals. Obtained results can be used in development of modern methods for controlling the properties of oil dispersed systems and development of downhole and ground surface MHD activators.