Studies On Aquathermolysis Catalyst And Its Carrier For Super Heavy Oil

The world's conventional crude oil production is expected to reach its peak in the second decade ofthe coming century and enter a permanent decline phase. Unconventional oil from heavy oil resources willstart making significant contributions to the world's growing population. The peaking of conventional oilcombined with physical shortages and crude price escalation, will mark the beginning of commercialproduction from the world's huge deposits of tar sands and super heavy oil. Super heavy oil is an importantportion of the global petroleum resource. Thermal methods particularly stem injection are the mostsuccessful enhanced oil recovery processes. It has the advantages of higher oil recovery speed, fewerinvestment and simple technology method, yet its crude oil recovery ratio is not high. Therefore, it isnecessary to study and development a new kind of technology which has low cost and higher oil recoveryto instruct the field experiments.According to heavy oil and super heavy oil' properties of Liaohe oil field reality, especially aim atoccurring aquthermolysis reaction between super heavy oil and stem when stem inject in the oil well, anew chemical agent and its technology which has been developed for the purpose irreversible reducingviscosity in situ. The important content of the article is to develop and select a kind of suitable catalyst andits carrier to enhance aquthermolysis reaction so as to achieve irreversible reducing viscosity.In order to investigate the reaction mechanism of heavy oils, the model compounds were determinedbased on the heavy oil's properties. Thiophene and tetrahydrothiophene are the suitable candidates formodel compounds for investigate the mechanisms of aquathermolysis. The studing on mechanisms ofaquathermolysis for super heavy oils shows that:The aquathermolysis reaction of heavy oil can bepromoted after adding suitable catalyst in the system with water at high temperature, the reaction timedecreased and the viscosity of super heavy oil droped obviously. At the same time, the super heavy oilgroup composing, the mean molecular weight and the structure changed greatly.The catalyst system has been developed for Liaohe oil field. The main catalysts for aquathermolysisare made from nickel, iron and so on. After joined the transition metal active components, the effects ofdecreasing viscosity of super heavy oil were obvious. The degree of decreasing viscosity of Fe2+ and Ni2+reached to 50.3% and 54.7% respectively. Self-made a kind of emulsification viscosity reducer preparedfrom a fatty alcohol polyoxyethylene ether,aim at being catalyst external carrier insure the repetition ofreducing viscosity is better. Tetrahydric naphthalin, being the auxiliary catalyst, is added in catalyst system,the reducing viscosity rate increase to 72.6% from 57.1%, which indicate tetrahydric naphthalin has thefunction of restraining super heavy oil increasing viscosity. When pH achieves to 6 (acid concentration =3×10-4wt%)around , the reducing viscosity rate of super heavy oil increase to 92%, indicated the acidplayed as the cracking role.Under the optimum processing conditions of reaction temperature:180℃,reaction time:24hrs;catalyst concentration :0.20wt%,water adding:20～30wt%,hydrogen donor:0.06 wt %,pH:6,the viscosity of heavy oil from 183.8 Pa.s decrease 14.4 Pa.s,reducing viscosity ratio reach to 92.4%,andwithin 60d observed these viscosities were re-increased no more than 5%,shows that :Being a new superoil recovery method, aquthermolysis is able to achieve irreversible reducing viscosity goal.This research work has an important guiding sense to heavy oil and super heavy oil of Liaohe oil fieldfor effective developing.