Preparation Of Ferric Oleate And Its Application In Catalytic Aquathermolysis Of Heavy Crude Oil

With the excessive exploitation and rapid consumption of the conventional oil and gas resources,the exploitation of heavy crude oil and other low-grade oil and gas resources is attracting more and more attention.As a kind of important supplement energy,heavy crude oil has high value of exploitation and good potentiality to develop due to the abundance in resource.However,the key issue of heavy crude oil mining is to reduce the viscosity and increase the fluidity of it.Many recovery technologies have been developed to solve these problems,and catalytic aquathermolysis could be potential for viscosity reduction of heavy crude oil.And the catalytic aquathermolysis can promote the transformation of heavy components into light components,thereby reducing the viscosity of heavy oil and improving the liquidity as well as improving the quality of the heavy crude oil.Oil-soluble catalysts as potential catalysts for reducing the viscosity of heavy crude oil could be of special significance,because of their good dispersion in crude oil and high catalytic efficiency towards aquathermolysis.In this study,the ferric oleate was prepared by direct hydrothermal method using oleic acid and iron nitrate nonahydrate as the raw materials,and applied for the aquathermolysis of the Shengli heavy crude oil?the viscosity of the crude oil was measured to be larger than 170000 mPa·s at 50°C?at a lower temperature.The changes of the heavy crude oil samples before and after aquathermolysis reaction were studied in detail by the SARA,EL,¹H-NMR,FT-IR.And we also investigate the reaction mechanism of the ferric oleate.The main research contents of this paper are as follows:1.Preparation of oleate catalyst and its application in catalytic viscosity reduction of heavy oilThe ferric oleate,nickel oleate and cobalt oleate were prepared by direct hydrothermal method using oleic acid as raw material.The structure and stability of as-catalyst were analyzed and characterized by infrared analysis,thermogravimetric analysis and so on.The three kinds of oil-soluble oleates were applied to the catalytic viscosity reduction experiments for the Shengli heavy oil.And the reaction system was heated to 200°C and held for 24 h?the catalyst does not contain water,and the heavy crude oil contains only 12.0 wt%water?.Results indicate that ferric oleate is more active for the viscosity reduction than nickle and cobalt oleates.The viscosity reduction ratio increases gradually with increasing the dosage of ferric oleate.Particularly,the highest viscosity reduction ratio?up to 86.11%?is achieved in the presence of 10.0 wt%ferric oleate catalyst.And we also investigate the reaction mechanism of the ferric oleate by using the SARA,EL,¹H-NMR,FT-IR.The good ability for ferric oleate to reduce the viscosity of the heavy crude oil is attributed to the catalytic role of Fe³⁺and the emulsification function of oleic long-alkyl chain.Such a dual function of the ferric oleate during the catalytic aquathermolysis contributes to increase the contact area of transition metal with oil and promoting the hydrogenation,desulfurization and denitrification of the heavy crude oil,thereby reducing the viscosity and improving the quality of the heavy crude oil.2.Effect of surfactant during the catalytic viscosity reduction of ferric oleateThe surfactant was added to the catalytic system of ferric oleate to promote the catalysis of ferric oleate,reducing the viscosity of heavy oil and the content of asphaltene,and decreasing the aggregation and precipitation of asphaltene.The three types of surfactants were applied to the catalytic viscosity reduction experiments in combination with ferric oleate.The study found that the viscosity-reduction ratio is CTAB>petroleum sulfonate>Triton X-100>SDS>SDBS>pvp-k30,and the content of asphaltenes after reaction is SDBS>Triton X-100>pvp-k30>petroleum sulfonate>SDS>CTAB.The results show that the cationic surfactant CTAB has a good effect on the viscosity reduction of ferric oleate.After the reaction,the content of resin and asphaltene decreased,and the content asphaltene were reduced 0.69%.The changes and the reaction mechanism of the heavy crude oil samples were studied in detail by the SARA,EL,¹H-NMR,FT-IR.The results showed that the addition of CTAB was more promoting the hydrogenation of resin and the pyrolysis of asphaltene.3.The influence of oil-soluble iron based catalysts with different lipophilic ligands on viscosity of heavy oilThe ferric stearate,ferric myristate and ferric laurate were synthesized successfully and applied to viscosity-reducing experiments of the Shengli heavy crude oil.The viscosity reduction rate is ferric oleate>ferric stearate>ferric myristate>ferric laurate.And the effect of four oil-soluble iron-based catalysts with different lipophilic long-chain ligands was studied by four components analysis,elemental analysis,nuclear magnetic proton analysis and infrared analysis and other analytical method.The results idicate that with the increase of the ligands,the contact area of transition metal with oil was increased,and promote the transformation of heavy components into light components,thereby reducing the viscosity and improving the quality of the heavy crude oil.Besides,the viscosity reduction is also related to the structure of the ligand itself.