A method of high-pressure air oxidative cracking flooding into low-permeability reservoirs

A high-pressure air, oxidative cracking technology, which is applied in earth-moving drilling, wellbore/well components, and production fluids, etc., can solve the problems of unclear viscosity reduction effect of formation crude oil, inability to identify whether ignition is successful, corrosion of wellbore and increased cost, etc. To achieve the effect of improving oil recovery rate and recovery rate, improving ignition rate and success rate, and improving oil displacement effect

A high-pressure air, oxidative cracking technology, which is applied in earth-moving drilling, wellbore/well components, and production fluids, etc., can solve the problems of unclear viscosity reduction effect of formation crude oil, inability to identify whether ignition is successful, corrosion of wellbore and increased cost, etc. To achieve the effect of improving oil recovery rate and recovery rate, improving ignition rate and success rate, and improving oil displacement effect

CN106050200BActive Publication Date: 2018-10-19中嵘能源科技集团有限公司

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  • A method of high-pressure air oxidative cracking flooding into low-permeability reservoirs
  • A method of high-pressure air oxidative cracking flooding into low-permeability reservoirs

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Effect test

Embodiment 1

[0031] A method of injecting high-pressure air into a low-permeability reservoir for oxidation and cracking oil displacement, comprising:

[0032] Step 1. Carry out special well completion to the gas injection well (2); the order of the components that are lowered into the well in turn is bell mouth (12), single safety valve (13), packer (9), centralizer (8), safety valve ( 7), the sliding sleeve (6), and the compensator (15) are lowered into the well together with the gas injection string (5), and the bell mouth (12) is lowered to 2 meters above the bottom of the artificial well and above the overburden (11) 8 meters, the middle and lower part of the perforation section (14), the single safety valve (13) is adjusted to 1 meter above the overburden (10), and the position of the packer (9) is adjusted to 3 meters above the overburden (10). The centralizer (8) is adjusted to 2 meters above the packer (9), the safety valve (7) is adjusted to 10 meters above the centralizer (8), a...

Embodiment 2

[0038] A method of injecting high-pressure air into a low-permeability reservoir for oxidation and cracking oil displacement, comprising:

[0039] Step 1. Carry out special well completion to the gas injection well (2); the order of the components that are lowered into the well in turn is bell mouth (12), single safety valve (13), packer (9), centralizer (8), safety valve ( 7), the sliding sleeve (6), and the compensator (15) are lowered into the well together with the gas injection string (5), and the bell mouth (12) is lowered to 3 meters above the bottom of the artificial well and above the overburden (11) At 10 meters, in the middle and lower part of the perforation section (14), the single safety valve (13) is adjusted to 2 meters above the overburden (10), and the position of the packer (9) is adjusted to 4 meters above the overburden (10). The centralizer (8) is adjusted to 3 meters above the packer (9), the safety valve (7) is adjusted to 15 meters above the centralize...

Embodiment 3

[0045] A method of injecting high-pressure air into a low-permeability reservoir for oxidation and cracking oil displacement, comprising:

[0046] Step 1. Carry out special well completion to the gas injection well (2); the order of the components that are lowered into the well in turn is bell mouth (12), single safety valve (13), packer (9), centralizer (8), safety valve ( 7), the sliding sleeve (6), and the compensator (15) are lowered into the well together with the gas injection string (5), and the bell mouth (12) is lowered to 5 meters above the bottom of the artificial well and above the overburden (11) At 10 meters, in the middle and lower part of the perforation section (14), the single safety valve (13) is adjusted to 3 meters above the overburden (10), and the position of the packer (9) is adjusted to 5 meters above the overburden (10). The centralizer (8) is adjusted to 2 meters above the packer (9), the safety valve (7) is adjusted to 12 meters above the centralize...

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Abstract

The invention provides a method for injecting high-pressure air into a low-permeability reservoir to perform oxidative pyrolysis and displacement of oil. Before air displacement for oil extraction is performed, high-temperature hot water is firstly injected to form a first slug, then three-phase nitrogen foam is injected to form a second slug, an injected air and the three-phase nitrogen foam mixed-phase substance serves as a third slug, then high-pressure air is injected to perform air displacement for oil extraction, and high-pressure air injection is conducted on stratum under the pressure of 25-50 MPa. The method can effectively conduct viscosity reduction and cooling on formation oil at the initial stage of the air displacement, a round oxidative pyrolysis zone is rapidly formed in the oil layer, the liquidity of the crude oil in an oil reservoir is improved, the low-permeability reservoir originally difficult to develop is improved, and the recovery rate is improved in a long-acting mode. The method is suitable for the low-permeability reservoir, the optimum condition is the reservoir depth of 1300-4900 meters, the reservoir thickness is more than 2.5 meters, the reservoir temperature is greater than 55 degrees, the oil saturation is above 30%, the permeability is greater than 1 millidarcy, and the connectivity is above 80%.

Description

technical field [0001] The invention relates to a method for injecting high-pressure air into low-permeability oil reservoirs for oxidative cracking and oil displacement, and belongs to the field of oil reservoir air flooding and exploitation. Background technique [0002] Low-permeability oil and gas reservoirs in my country are widely distributed and have great development potential. At present, the low-permeability reservoirs that have been put into development in China are basically developed by water injection and fracturing. Due to the special low-permeability characteristics of ultra-low-permeability reservoirs, the development effect of conventional water injection is not ideal. Due to the serious phenomenon of high water sensitivity, it is impossible to inject water. Coupled with multiple fracturing, the reserves of this kind of shut-down and semi-shutdown oil reservoirs are extremely huge, accounting for about 2 billion tons, the recovery rate is only less than 10%...

Claims

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Application Information

Patent Timeline
19 Oct 2018
Publication
CN106050200B
IPC
E21B43/16; E21B43/24
CPC
E21B43/166; E21B43/168; E21B43/24
Inventors
邓晓亮; 洪嵘