Method for exploiting high-viscosity oil

Abstract

The invention provides a method for exploiting high-viscosity oil. According to the method, high-temperature low-viscosity oil or a combination of the high-temperature low-viscosity oil and gas is injected into a high-viscosity oil reservoir for huff-puff exploitation; the high-temperature low-viscosity oil or the combination of the high-temperature low-viscosity oil and the gas is used for reducing the viscosity of the high-viscosity oil in the stratum by dissolving and heating, and increasing the stratum pressure; the high-temperature low-viscosity oil comprises one or a combination of morethan two of a light fraction and a middle fraction obtained by on-site distillation of the high-viscosity oil; the light fraction is obtained by carrying out atmospheric distillation on high-viscosityoil subjected to dehydration and desalination treatment; and the middle fraction is obtained by performing reduced pressure distillation on a heavy fraction obtained by performing normal pressure distillation on high-viscosity oil subjected to dehydration and desalination treatment.

Description

technical field [0001] The invention relates to a method for extracting high-viscosity oil, which belongs to the technical field of oil extraction. Background technique [0002] Viscous heavy oil and high pour point oil are generally exploited by thermal methods such as steam injection, among which steam injection exploitation methods include steam huff and puff, steam flooding and steam assisted gravity drainage. In addition to purifying the injected water and dehydrating the produced liquid during steam injection, a boiler is also required to heat the purified water to generate high-temperature steam. Although the exploitation of heavy oil by steam injection can achieve significant recovery effects, there are still many problems: (1) Steam injection exploitation mainly uses high-temperature steam to heat the oil layer, which consumes a lot of energy, costs high and is harmful to the environment due to the production of a large amount of carbon dioxide and sewage. Adverse ...

AI Technical Summary

Problems solved by technology

Although the exploitation of heavy oil by steam injection can achieve significant recovery effects, there are still many problems: (1) Steam injection exploitation mainly uses high-temperature steam to heat the oil layer, which consumes a lot of energy, costs high and is harmful to the environment due to the production of a large amount of carbon dioxide and sewage. Adverse effects; (2) The water treatment cost of boiler water is high, and the dehydration treatment of produced fluid is difficult (the problem is particularly prominent when the water content is high and the liquid production rate is high); (3) Scaling is easy to occur due to the complex water quality of injected water and groundwater , mineral dissolution, and oil-water emulsification are also prone to occur; (4) complex production problems such as steam overburden and steam channeling are prone to occur; (5) high-viscosity heavy oil and high-condensation oil flow due to temperature drop during wellbore lifting In order to ensure the fluidity of heavy oil and high pour point oil in the wellbore, it is necessary to use methods such as downhole mixing of thin oil and wellbore electric heating

Therefore, for heavy oil reservoirs and high pour point oil reservoirs, the existing methods and processes are only auxiliary measures for high-temperature "water" steam injection, but cannot fundamentally solve the problems of high energy consumption and high cost of high-temperature "water" steam injection. core problem, and cannot replace steam injection to exploit heavy oil reservoirs and high pour point oil reservoirs

Images