Single-well parallel crack water injection and oil extraction method of offshore low-permeability reservoir

Abstract

The invention relates to a single-well parallel crack water injection and oil extraction method of an offshore low-permeability reservoir. A single well at least consists of a main well hole, and two oil extraction branches, a water injection branch and a set of parallel manual cracks positioned in a reservoir, wherein the oil extraction branches and the water injection branch are horizontal wells, and extend along a maximum main stress direction of a stratum; the water injection branch is positioned between the two oil extraction branches; the water injection branch and the oil extraction branches are subjected to the staged fracturing operation to generate the manual cracks parallel to shafts; the water injection operation is performed by the water injection branch positioned between the two oil extraction branches; and injected water diffuses along crack surfaces and enters the stratum after entering the manual cracks. The method has prominent effects on increment of the controlled reserve, reduction of the cost and improvement of the development effect in the development of the offshore low-permeability reservoir.

Description

technical field [0001] The invention relates to a water injection and oil recovery method for single well parallel fractures in an offshore low-permeability oil reservoir. technical background [0002] Since offshore oil and gas fields are located in a marine environment, production facilities and production wells need to be concentrated on offshore production platforms or wellhead platforms. Due to the constraints of platform construction and huge investment in drilling, offshore oil and gas fields can only be developed with a limited number of wells. The degree of recovery, rate of oil recovery and economy are limited to a certain extent. [0003] When developing offshore low-permeability reservoirs, due to poor reservoir permeability, it is more difficult for oil and gas to flow underground, and there are fewer exploitable oil and gas resources within the control range of a well. Due to investment restrictions in offshore oil production facilities and drilling and complet...

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Problems solved by technology

[0002] Since offshore oil and gas fields are located in a marine environment, production facilities and production wells need to be concentrated on offshore production platforms or wellhead platforms. Due to the constraints of platform construction and huge investment in drilling, offshore oil and gas fields can only be developed with a limited number of wells. The degree of recovery, rate of oil recovery and economy are limited to a certain extent

[0003] When developing offshore low-permeability reservoirs, due to poor reservoir permeability, it is more difficult for oil and gas to flow underground, and there are fewer exploitable oil and gas resources within the control range of a well. Due to investment restrictions in offshore oil production facilities and drilling and completion operations However, it is impossible to effectively develop offshore low-permeability reservoirs by drilling multiple production wells and water injection wells in onshore low-permeability oilfields

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