Physical Simulation Study Of Ultra Heavy Oil In-situ Combustion

Ultra heavy oil is the oil that has a viscosity more than 50000mPa·s.Xinjiang Fengcheng ultra heavy oil field has reserves of 0.37 billion tons.Ultra heavy oil has large reserves and can be a replacement technology of the heavy oil recovery,so the development of the Ultra heavy oil is very important and strategic.In-situ combustion is one of the improved recovery methods.The laboratory experiment shows that the recovery of ISC technology can be 70%-90%,while 50%-80% in the ISC field project.The ISC technology has a wide range of application and it has the potential to be a replacement technology in the ultra heavy oil recovery.This paper takes the Xinjiang Zhong18 area ultra heavy oil as research object which experienced steam huff and puff period.Firstly,doing the oxidation kinetics analysis experiments to get the oxidation kinetics parameters.Then doing the one-dimensional combustion tube physical simulation experiments to analyse the combustion characteristic and the stability of the combustion front.Finally using the numerical simulation and field experience to make an optimized reservoir engineering design of the ultra heavy oil field.The following results were obtained through this research:1.The activation energy of Xinjiang Zhong18 area is 126KJ/mol at the low temperature oxidation stage,while 155KJ/mol at the high temperature stage,having a good high temperature combustion characteristics and exothermic reaction.The high temperature combustion can be formed at the temperature higher than 450? and lots of heat is released.2.The one-dimensional physical simulation experiment shows that the apparent H/C atomic ratio is 1.27,which means that the high temperature oxidation plays a leading role in the combustion period.The fuel consumption is 26.64kg/m3 and the front of the in-situ combustion is stable.The oil displacement efficiency is 91% and the air-oil ratio is 1022m3/t in the experiment,having a high oil displacement efficiency and low air-oil ratio.3.The optimized reservoir engineering project of the Xinjiang Zhong18 ultra heavy oil area was designed according to the numerical simulation and field experience.