Carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation

A carbonate rock reservoir, carbon dioxide technology, applied in chemical instruments and methods, earthwork drilling, wellbore/well components, etc., can solve the problems of reservoir damage to water resources, excessive consumption, etc.

Active Publication Date: 2021-07-30
新疆恒洲景业石油技术服务有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In addition, conventional hydraulic fracturing technology also faces problems such as reservoir damage and excessive consumption of water resources, making it face great challenges and controversies in its promotion and application

Method used

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  • Carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation
  • Carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation
  • Carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation

Examples

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Effect test

Embodiment 1

[0073] The above method was applied to the acid fracturing operation of a carbonate reservoir in a well in an oilfield in western China. The target reservoir depth was 6009.5m, the original formation pressure was 64.99MPa, and the latest static pressure test was 58.73MPa; the reservoir temperature was 143°C, and the average porosity The density is 16.6%; the average permeability is 0.33md; among them, the actual construction parameters of carbon dioxide acid fracturing in ultra-deep wells are as follows:

[0074] High viscosity fracturing fluid: liquid CO 2 +20% hydrochloric acid +2.5% CO 2 Thickening drag reducer + 1% atomization stabilizer;

[0075] Medium viscosity fracturing fluid: liquid CO 2 +20% hydrochloric acid +1.5% CO 2 Thickening drag reducer + 1% atomization stabilizer;

[0076] Low viscosity fracturing fluid: liquid CO 2 +20% hydrochloric acid +1% CO 2 Thickened drag reducer + 1% fogging stabilizer.

[0077] Actual construction parameters of carbon dioxide...

Embodiment 2

[0084] The above method was used to carry out acid fracturing operation on a sandstone condensate gas reservoir reservoir in a well in an oilfield in western China. The target reservoir depth was 4320.8m. Due to the pollution of some reservoirs caused by previous operations, and considering the characteristics of the condensate gas reservoir, the The technology of the present invention performs acid fracturing and plugging removal operations on target reservoirs to dredge seepage channels, remove near-well pollution caused by well workover operations, and simultaneously remove near-well reverse condensate oil plugging, thereby restoring production. Among them, the actual construction parameters of carbon dioxide acid fracturing in ultra-deep wells are as follows:

[0085] Medium viscosity fracturing fluid: liquid CO 2 +20% hydrochloric acid +1% CO 2 Thickening drag reducer + 1% atomization stabilizer;

[0086] Low viscosity fracturing fluid: liquid CO 2 +20% hydrochloric ac...

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Abstract

The invention belongs to the technical field of carbon dioxide sequestration and oil and gas reservoir yield increase transformation, and particularly relates to a carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation. The carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation is characterized in that the fluidity of a system is controlled by adjusting the viscosity of a CO2 composite acid liquor system, acid liquor is composed of hydrochloric acid with the concentration of 20%, a CO2 thickening drag reducer and an atomization stabilizer, the acid liquor with different viscosities is obtained by adjusting the using amount of the CO2 thickening drag reducer, and the CO2 composite acid liquor system with the high viscosity is suitable for making complex fractures at the ends of main fractures; the CO2 composite acid liquid system with the medium viscosity is suitable for making the complex fractures in the middle of the ends of the main fractures; the CO2 composite acid liquid system with the low viscosity is suitable for making the complex fractures around the main fractures of a near-well section. According to the carbon dioxide acid fracturing method for ultra-deep well carbonate reservoir transformation, the complexity of the reservoir fractures can be effectively improved, the volume of the fractures can be increased to meet the exploitation requirement, meanwhile, the effective action range of the artificial fractures can be further increased, and the exploitation efficiency of carbonate reservoir oil and gas resources can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of carbon dioxide sequestration and oil-gas reservoir stimulation and transformation, and in particular relates to a carbon dioxide acid fracturing method for transformation of ultra-deep carbonate reservoirs. Background technique [0002] Acid fracturing reservoir stimulation technology has become one of the main technical means of exploration and development at home and abroad. With the deepening of exploration and development, acid fracturing objects become more and more complex, such as ultra-low permeability / ultra-low permeability, special lithology, complex lithology, ultra-deep wells, etc., making acid fracturing more difficult and more adaptable. is getting worse. At present, when acid fracturing is carried out at home and abroad, the acid liquid system with hydrochloric acid as the main body is mostly used. Generally, the viscosity of the system is increased to delay the H + Therefore, the acid-ro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/27E21B43/16C09K8/74
CPCE21B43/26E21B43/164C09K8/74C09K8/725Y02P90/70
Inventor 罗攀登杨飞孟磊峰张杰贾巍然郭小合付美龙宋博余勇刚
Owner 新疆恒洲景业石油技术服务有限公司
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