Chemical cold-production method applicable to medium-deep low-permeability heavy oil reservoir

A heavy oil reservoir, chemical cold recovery technology, applied in the direction of production fluid, earth drilling, wellbore/well components, etc., can solve the problem of high development cost

Inactive Publication Date: 2014-01-15
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The patent number is CN101255788A, which is a thermochemically assisted enhanced steam flooding method. This type of method uses oil-soluble viscosity reducer and carbon dioxide to assist the thermal recovery development of horizontal wells, and the development cost is relatively high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The burial depth of an oil layer in an oilfield is selected as 2800m, and the permeability is 0.12×10 -3 um 2 , the total thickness of oil layers is 3.9m, the net total thickness ratio is 0.3, and the single reservoir coefficient is 14.1×10 4 t / km 2 .m, oil layer porosity 0.10, permeability variation coefficient ≤ 0.8 medium-deep low-permeability heavy oil reservoir, 50 ℃ surface crude oil viscosity 11525mPa·s is extra heavy oil reservoir;

[0026] Into the selected oil layer according to the injection rate of 0.05t / m and the injection speed of 30m 3 / h Squeeze injection of microemulsion viscosity reduction system and according to the injection volume of 0.75t / m, the injection speed of 20m 3 Squeeze liquid carbon dioxide per hour, the microemulsion viscosity reducing system and liquid carbon dioxide are squeezed in 6 segments, the microemulsion viscosity reducing system is first squeezed into the oil layer, and then the liquid carbon dioxide is squeezed in alternatel...

Embodiment 2

[0039] The burial depth of an oil layer in an oilfield is selected to be 1500m, and the permeability is 50×10 -3 um 2 , the total thickness of the oil layer is 3.0m, the net total thickness ratio is 0.5, and the single reservoir coefficient is 14.1×10 4 t / km 2 .m, oil layer porosity 0.20, permeability variation coefficient ≤ 0.2 medium-deep low-permeability heavy oil reservoirs, the crude oil viscosity range in this block is large, up to 20×10 4 mPa·s, there are 7987×10 4 t It is difficult to produce deep heavy oil reserves using existing technologies. For this type of reservoir, there is no theory and field experiment experience at home and abroad to use for reference, and its development is quite difficult. The above characteristics lead to the lack of industrial oil flow in medium-deep low-permeability heavy oil reservoirs, which affects the upgrade and production of reserves.

[0040] Into the selected oil layer according to the injection rate of 0.1t / m and the inject...

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Abstract

The invention provides a chemical cold-production method applicable to a medium and deep stratum low-permeability heavy oil reservoir. The method includes the first step of selecting a medium-deep low-permeability heavy oil reservoir, wherein the depth of the selected oil layer is 1500-2800m, the permeability of the selected oil layer is smaller than or equal to 50*10-3 square microns, the total thickness of the selected oil layer is larger than or equal to 3.0m, the total net thickness ratio of the selected oil layer is larger than or equal to 0.3, the porosity of the selected oil layer is larger than or equal to 0.10, and the permeability variation coefficient of the selected oil layer is small than or equal to 0.8, the second step of squeezing microemulsion viscosity reduction systems and liquid carbon dioxide into the selected oil layer alternately in a staged plugging mode, the third step of carrying out well shut-in, well soaking, well opening and blowout prevention, and the fourth step of continuing extracting oil through a downhole pump. The chemical cold-production method has the advantages that microemulsion can enable crude oil to be stripped to be oil droplets with hydrophilic surfaces, heavy oil spontaneously diffuses on the surface of system water solution, carbon dioxide has functions of reducing viscosity and increasing energy can enlarge the viscosity reduction radius of the microemulsion, the water recovery rate is improved, and the output and the recovery efficiency of the medium-deep low-permeability heavy oil through a synergistic effect are improved.

Description

technical field [0001] The invention relates to the technical field of oilfield exploitation, and is a chemical mining method for medium-deep low-permeability heavy oil reservoirs suitable for improving oil production speed and recovery rate. Background technique [0002] Medium-deep low-permeability heavy oil reservoirs, that is, reservoirs with a buried depth of 1500-2800m and a permeability of <50×10 -3 um 2 of heavy oil reservoirs. For this type of reservoir, due to the high viscosity of crude oil, water injection development cannot achieve the effect. However, if the method of steam injection is adopted, due to the deep reservoir, serious heat loss and low reservoir permeability, the steam injection pressure will be high, or the steam injection will fail. [0003] For low-permeability deep heavy oil, the matching technology of early fracturing wellbore viscosity reduction cold recovery and later steam injection thermal recovery has good development effect. "Resea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/22
Inventor 曹嫣镔王善堂孙克己杜永欣谢志勤张仲平于田田王秋霞何绍群刘冬青赵晓红
Owner CHINA PETROLEUM & CHEM CORP
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