Plug removal agent for oil-water well of tight oil reservoir

A technology for tight oil reservoirs and oil-water wells, which is applied to drilling compositions, chemical instruments and methods, etc., and can solve the problems of high shale content in tight oil reservoirs, clogging of primary particles and secondary particles, and small pore throat radius.

Inactive Publication Date: 2017-05-10
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to solve the problem that tight oil reservoirs are easily blocked by primary particles and secondary particles due to high shale content, poor reservoir physical properties and small pore throat radius. , A

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] A plugging remover for oil and water wells in tight oil reservoirs, consisting of the following components in mass percentage:

[0033] Organic sulfonic acid 8.0-15.0%;

[0034] Organic carboxylic acid 5.0-8.0%;

[0035] Hydrofluoric acid 0.5-1.5%;

[0036] Fluoboric acid 3.0-12.0%;

[0037] Mutual solvent 0.5-1.5%;

[0038] Wetting reversal agent 0.5-1.0%;

[0039] Chelating agent 5-10.0%;

[0040] Clay stabilizer 0.5-1.5%;

[0041] The balance is water.

[0042] The preparation method of the plugging removal agent for oil and water wells in tight oil reservoirs, the specific operation steps are as follows: first, add the formula amount of organic sulfonic acid, organic carboxylic acid, hydrofluoric acid, fluoroboric acid, mutual solvent, and wetting reversal agent to the acid-resistant reaction Kettle, stir evenly and heat up to 60-80°C; then, while stirring, add the chelating agent and clay stabilizer of the formulated amount in sequence, and finally add the w...

Embodiment 2

[0044] On the basis of Example 1, the organic sulfonic acid is a kind of organic strong acid prepared by methanesulfonic acid, benzenesulfonic acid and toluenesulfonic acid in a weight ratio of 6:3:1, and the general formula R- SO 3 H and R represent hydrocarbon groups, which have relatively large water solubility, and are used to make dyes, medicines, and detergents, and have acidic properties; the sulfonic acid group is a strongly water-soluble and strongly acidic group, so sulfonic acids are all water-soluble Sexual strong acidic compounds, such as naphthalene is soluble in ether but not in water, while β-naphthalenesulfonic acid is soluble in water but not in ether. The sulfonic acid groups in aromatic sulfonic acid molecules can be replaced by hydroxyl and cyano groups, and are intermediates for the preparation of phenol and nitrile.

[0045] Organic sulfonic acids can be used as analytical reagents, preservatives, bleaching agents and reducing agents. For example, metha...

Embodiment 3

[0048] On the basis of Example 1, the organic carboxylic acid is a kind of organic weak acid prepared by formic acid, acetic acid and citric acid in a weight ratio of 2:3:1, wherein formic acid and acetic acid have strong sour taste and irritation, Soluble in water, ether, ethanol and other solvents, citric acid is transparent crystal or white granular solid, fragrant and odorless, slightly weathered in the air, deliquescent in humid air, easily soluble in water and ethanol, soluble in Diethyl ether is insoluble in organic solvents such as chloroform, benzene, and carbon tetrachloride, and can form stable complexes with ferric ions. It has good temperature resistance.

[0049]Formic acid and acetic acid can be used as pH regulators for drilling and fracturing fluids; citric acid can be used as ferric ion stabilizers in oil field measures; Inject additives, the manufacturers are Tianjin Organic Synthesis Plant, Shanghai Jinshan Petrochemical General Plant, Shijiazhuang Yongxian...

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PUM

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Abstract

The invention discloses a plug removal agent for an oil-water well of a tight oil reservoir. The plug removal agent is prepared from the following components in percentage by mass: 8.0 to 15.0 percent of organic sulfonic acid, 5.0 to 8.0 percent of organic carboxylic acid, 0.5 to 1.5 percent of hydrofluoric acid, 3.0 to 12.0 percent of fluoroboric acid, 0.5 to 1.5 percent of mutual solvent, 0.5 to 1.0 percent of wetting reversion agent, 5.0 to 10.0 percent of chelating agent, 0.5 to 1.5 percent of clay stabilizer, and the balance of water. According to the plug removal agent disclosed by the invention, the problem that the tight oil reservoir is easily plugged by primary particles and secondary particles due to high mud content, poor reservoir physical property and small pore throat radius is solved, the reservoir permeability is recovered and improved to the maximum extent, the percolation capacity of a stratum with actual control radius of the oil-water well is improved, and the aims of improving the production capacity of the oil-water well, and realizing enhanced production of an oil well and intensified injection of a water well are achieved.

Description

technical field [0001] The invention relates to the technical field of chemicals used in the petroleum industry, in particular to a plug-removing agent for oil-water wells in tight oil reservoirs. Background technique [0002] In recent years, more than 80% of my country's proven reserves are tight oil reservoirs with ultra-low permeability and ultra-low permeability, which are difficult to develop, and there are problems such as low single well production, high water injection pressure, and large underinjection. However, water injection is the main way to develop tight oil reservoirs, and solving the problem of water injection is the key to the efficient development of tight oil reservoirs. [0003] Technicians believe that water injection wells in tight oil reservoirs have high water injection pressure and no water can be injected, and it is difficult to effectively establish an injection-production system. The permeability of the formation decreases and the water absorpt...

Claims

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Application Information

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IPC IPC(8): C09K8/528
CPCC09K8/528C09K2208/12C09K2208/32
Inventor 唐泽玮何治武刘宁董俊周志平刘爱华杨会丽王小勇张振云付彩利
Owner PETROCHINA CO LTD
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