Temperature controlled plugging agent for heavy oil steam stimulation

A technology for steam and heavy oil, applied in the direction of production of fluids, wellbore/well components, drilling composition, etc., can solve the problems of easy dehydration and aging, poor temperature resistance, easy to contaminate reservoirs, etc.

CN109181665AInactive Publication Date: 2019-01-11PETROCHINA CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2019-01-11
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to the technical field of oil production engineering and in particular relates to a temperature controlled plugging agent for heavy oil steam stimulation. The problem that the conventional plugging agent is poor in temperature resistance and easily contaminates the reservoir is solved. The plugging agent disclosed by the invention is composed of the following components in percentage by weight: 3-6.9% of cellulose ether, 3-5% of a temperature control agent, 0.9-3.2% of a stabilizer, 1-2.8% of a cosolvent and the balance of water. The plugging agent disclosed by the invention has the characteristic of phase reversibility, is liquid under the normal temperature condition, is changed from liquid to gel while meeting high-temperature steam, then changed from the gel to liquid when the temperature is lower than a gelling temperature of the gel, and can be produced along with crude oil. The plugging agent has excellent temperature resistance and low pollution to the reservoir, and the development effect of steam stimulation is greatly improved.
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Description

technical field

[0001] The invention relates to the field of oil production engineering, in particular to a temperature-controlled plugging agent for heavy oil steam stimulation. Background technique

[0002] Steam huff and puff is the main production method for heavy oil reservoirs. After multiple rounds of steam huff and puff, channeling channels are formed in the oil layer due to long-term scour of high-temperature steam, resulting in low efficiency of steam injection and serious ineffective circulation, which affects the effect of thermal recovery development.

[0003] Conventional plugging agents for steam stimulation are mainly gels and resins. Among them, gel plugging agents have poor temperature resistance and are prone to dehydration and aging when the temperature is higher than 120°C. Although the resin plugging agent has high curing strength, the resulting substance is insoluble in acid and alkali after curing, and is easy to pollute the reservoir. Therefore, it ...

Examples

specific Embodiment approach

[0015] Specific embodiments: the present invention will be further described in conjunction with specific examples below: it consists of the following components by weight percentage: 3%-6.9% cellulose ether, 3%-5% temperature control agent, 0.9%-3.2% stabilizer , 1%-2.8% co-solvent, the balance is water.

[0016] Cellulose ether is one of methyl cellulose ether or hydroxypropyl methyl cellulose ether.

[0017] The temperature control agent is one or any combination of sodium chloride, magnesium chloride, ammonium thiocyanate, and thiourea.

[0018] Stabilizer is a kind of in polyethylene glycol or glycerol.

[0019] The co-solvent is ethanol.

Embodiment 1

[0020] Embodiment 1, in the present embodiment the present invention is made up of following composition by weight percentage:

[0021] Methyl cellulose ether: 3.5%, viscosity (2% aqueous solution) 20mPa s;

[0022] Sodium chloride: 1.5%;

[0023] Magnesium chloride: 1.5%;

[0024] Polyethylene glycol: 1%;

[0025] Ethanol: 1%;

[0026] The remainder is water;

[0027] The specific preparation process is:

[0028] 1. Add 10g of ethanol solution to a 1L beaker, add 60g of water, and stir to fully dissolve it.

[0029] 2. Add 35g of methyl cellulose ether to the above solution, and stir evenly to obtain the main agent solution of the present invention.

[0030] 3. Add 855g of water to the main agent solution obtained in the second step, stir evenly, add 15g of sodium chloride, 15g of magnesium chloride, and 10g of polyethylene glycol, and stir to fully dissolve it. The blocking agent of the present invention can be obtained.

Embodiment 2

[0031] Embodiment 2, in the present embodiment the present invention is made up of following composition by weight percentage:

[0032] Methyl cellulose ether: 6.5%, viscosity (2% aqueous solution) 20mPa s;

[0033] Ammonium thiocyanate: 1.5%;

[0034] Thiourea: 1.5%;

[0035] Polyethylene glycol: 2%;

[0036] Ethanol: 1.5%;

[0037] The remainder is water;

[0038] The preparation method is the same as in Example 1.