Heavy oil recovery method and system capable of being recycled and heating injection solvent underground

Abstract

The invention discloses a heavy oil recovery method and system capable of being recycled and heating an injection solvent underground. The method comprises the following steps that S1, single-well production operation is carried out; S2, production separation operation is carried out, specifically, the produced fluid is injected into a gas-liquid separator, oil-gas separation is carried out, the solvent extracted along with crude oil is separated from heavy oil, the heavy oil is conveyed into a sales link through pipelines, and the separated solvent is treated, recycled and input into a solvent storage tank for cyclic utilization; and S3, adjacent well cooperative operation is carried out, specifically, a plurality of wells are arranged to form a well group. The method has the advantages that solvent is injected into the stratum at normal temperature, and due to the fact that the saturation pressure of the solvent rises along with the increase of the temperature, when the liquid solvent is injected into the stratum under the high-temperature condition, energy consumption is large; and under the normal temperature condition, the solvent can be compressed into a liquid state under the low pressure, and the solvent is injected into the stratum to the maximum extent in a liquid state mode.

Description

Technical field [0001] The invention belongs to the technical field of petroleum exploitation, and in particular relates to a method and system for exploitation of heavy oil that can be recycled and used to heat an injected solvent in a well. Background technique [0002] In order to meet the increasing energy demand, heavy oil resources have been paid more and more attention. In the process of heavy oil development, the biggest problem affecting the efficient development of heavy oil resources is the high viscosity of heavy oil, which makes it difficult for heavy oil to flow in the reservoir. In order to reduce the viscosity of heavy oil, make it easy to flow in the formation, so as to realize the efficient development of heavy oil. At present, the commonly used methods to reduce the viscosity of heavy oil mainly include: heat injection (hot water, steam, superheated steam, etc.) and solvent injection (methane, nitrogen, natural gas, carbon dioxide, etc.), using heat and dissol...

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Problems solved by technology

In order to solve the problems of low solvent injection efficiency and low energy utilization rate in today's oil reservoirs, this patent designs a way of downhole heating and recycling for solvent-assisted thermal development

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