CN117987111A - Chemical descaling blocking remover for oilfield water injection well - Google Patents

Abstract

The invention belongs to the field of oilfield blocking remover, and provides a oilfield water injection well chemical descaling blocking remover, which comprises the following components in percentage by weight: 10-30% of anti-blocking agent, 10-30% of chelating agent, 2-5% of dispersing agent, 1-5% of disodium dihydrogen phosphate, 1-3% of sodium chloride and 0.5% of surfactant; the descaling blocking remover can solve the blocking problem formed by various factors, greatly saves cost in the blocking removing process, can effectively prevent the formation of emulsification and organic scale in an oil reservoir, can solve the existing problems of emulsification and organic scale blocking, is beneficial to improving the extraction efficiency of crude oil, can effectively promote the injection increasing work of a water injection well, has good reservoir reconstruction characteristic, is matched with a reservoir fluid, can effectively remove blocking matters and recover the permeability of the reservoir, has higher blocking removing success rate and lasting blocking removing effect.

Description

Chemical descaling blocking remover for oilfield water injection well

Technical Field

The invention belongs to the field of oilfield blocking remover, and in particular relates to a chemical descaling blocking remover for oilfield water injection wells.

Background

An oilfield is a region of geologic structure that is rich in recoverable petroleum resources, and typically includes one or more wells for recovering petroleum from a subterranean reservoir, where oil recovery is a complex process in which water injection wells play an important role.

The water injection well is a well head that improves the oil recovery rate by injecting water or other liquids into the field. It is near the oil well, and through injection pressure and changing the flow condition of underground reservoir, it promotes the oil to move to the oil well, increases the oil extraction efficiency.

Normal operation and effective water injection of a water injection well are key problems in oilfield exploitation. However, during operation, the water injection well tends to suffer from plugging problems; the plugs mainly comprise sediments, emulsions and organic scales which can be deposited on the walls and bottoms of water injection wells to block the flow of water and chemical agents and reduce the water injection effect.

In order to solve the above problems, various descaling and blocking remover have been developed in the prior art, however, the descaling and blocking remover may have an adverse effect on the reservoir after use, and the components and characteristics of the chemical agent may have a side effect on the rock structure of the reservoir during the removal of the blocking object, resulting in the decrease of the permeability of the reservoir or the damage of the reservoir, thereby affecting the subsequent petroleum extraction effect.

Therefore, a chemical descaling blocking remover for oilfield water injection wells is provided by a person skilled in the art to solve the problems provided by the background art.

Disclosure of Invention

In order to solve the technical problems, the invention provides a chemical descaling and blocking remover for an oilfield water injection well, which is used for solving the problems that the descaling and blocking remover in the prior art can have adverse effects on a reservoir after being used, and the components and the characteristics of the chemical agent can have side effects on the rock structure of the reservoir in the process of removing a blocking object, so that the permeability of the reservoir is reduced or the reservoir is damaged, thereby influencing the subsequent petroleum extraction effect and the like.

The chemical descaling and blocking remover for the oilfield water injection well comprises the following components in percentage by weight: 10-30% of anti-blocking agent, 10-30% of chelating agent, 2-5% of dispersing agent, 1-5% of disodium dihydrogen phosphate, 1-3% of sodium chloride and 0.5% of surfactant.

Preferably, the anti-blocking agent consists of an inorganic scale remover and an organic scale remover, wherein the weight percentage of the inorganic scale remover is 10-50%, and the weight percentage of the organic scale remover is 5-30%.

Preferably, the inorganic scale remover comprises the following components in percentage by weight: lactic acid 20%, alkaline polyvinyl alcohol 30%, sodium octyl sulfonate 10% and polyoxymethylene 5%;

the organic scale remover comprises the following components in percentage by weight: 15% of nitric acid, 10% of ammonium chloride and 5% of sulfonated polyether.

Preferably, the chelating agent is disodium edetate or tetrasodium edetate.

Preferably, the surfactant is polyethylene glycol alcohol ether.

Preferably, the composition comprises the following components in percentage by weight: 30% of anti-blocking agent, 20% of chelating agent, 5% of dispersing agent, 3% of disodium dihydrogen phosphate, 1% of sodium chloride and 0.5% of surfactant.

A preparation method of a chemical descaling blocking remover for an oilfield water injection well comprises the following steps:

S1, adding water in a formula amount into a reaction kettle, adding an inorganic scale remover in the formula amount, controlling the temperature at 60-65 ℃, stirring for 20-30min, then adding an organic scale remover in the formula amount, and continuously stirring for 20-30min to obtain an anti-blocking agent;

s2, sequentially adding a dispersing agent and a chelating agent, stirring for 5-10min, and controlling the reaction temperature to 30-40 ℃;

s3, adding the disodium dihydrogen phosphate, the sodium chloride and the surfactant according to the formula proportion in a volumetric flask, and fully stirring and mixing;

s4, finally adding the anti-blocking agent prepared in the step S1, stirring and mixing, and controlling the temperature to gradually rise to 60 ℃;

S5, naturally cooling to room temperature after stirring is finished, and obtaining the colloid asphalt dispersing agent.

Compared with the prior art, the invention has the following beneficial effects:

1. The descaling blocking remover can solve the blocking problem formed by various factors, greatly saves cost in the blocking removing process, can effectively prevent the formation of emulsification and organic scale in an oil reservoir, can solve the existing problems of emulsification and organic scale blocking, is beneficial to improving the extraction efficiency of crude oil, can effectively promote the injection increasing work of a water injection well, has good reservoir reconstruction characteristic, is matched with a reservoir fluid, can effectively remove blocking matters and recover the permeability of the reservoir, has higher blocking removing success rate and lasting blocking removing effect.

Drawings

FIG. 1 is a schematic flow chart of a preparation method of the blocking remover.

Detailed Description

Embodiments of the present invention are described in further detail below with reference to the accompanying drawings and examples. The following examples are illustrative of the invention but are not intended to limit the scope of the invention.

Embodiment one: the invention provides a chemical descaling and blocking remover for an oilfield water injection well, which comprises the following components in percentage by weight: 10-30% of anti-blocking agent, 10-30% of chelating agent, 2-5% of dispersing agent, 1-5% of disodium dihydrogen phosphate, 1-3% of sodium chloride and 0.5% of surfactant, wherein the surfactant is preferably polyethylene glycol alcohol ether. Disodium dihydrogen phosphate is a corrosion inhibitor, can inhibit the corrosion process of metal, and forms a protective phosphate coating with the metal, thereby reducing the generation of corrosion and scale blockage; sodium chloride is used as a stabilizer, so that the ion concentration of the formula can be regulated, and the stability of chemical reaction is ensured; the surfactant can reduce the surface tension of the liquid, so that an oil-water interface is more stable, the surfactant can improve the wettability of the liquid, the contact performance of the liquid and the solid surface is improved, and the surfactant is beneficial to dispersing and dissolving dirt; the dispersing agent can disperse the sediment into smaller particles, prevent the sediment from gathering and adhering to the pipe wall, and reduce the occurrence of blocking phenomenon.

The anti-blocking agent consists of an inorganic scale remover and an organic scale remover, wherein the weight percentage of the inorganic scale remover is 10-50%, and the weight percentage of the organic scale remover is 5-30%.

The inorganic scale remover comprises the following components in percentage by weight: lactic acid 20%, alkaline polyvinyl alcohol 30%, sodium octyl sulfonate 10% and polyoxymethylene 5%; lactic acid is acidic and can dissolve carbonate and rust deposits. The lactic acid can also play a role in sterilization and biological corrosion, and has a certain effect on inhibiting the growth of microorganisms;

The organic scale remover comprises the following components in percentage by weight: 15% of nitric acid, 10% of ammonium chloride and 5% of sulfonated polyether. Nitric acid can carry out complexation reaction with metal ions to promote dissolution and removal of dirt; ammonium chloride has antibacterial and microorganism growth inhibiting effects, and helps to prevent formation of biological sediment; the sulfonated polyether can effectively remove grease and fatty dirt in the cleaning process

The chelating agent is disodium edetate or tetrasodium edetate; disodium edetate is a chelating agent, and can form stable complex with metal ions, so that disodium edetate can effectively chelate metal ions such as calcium, magnesium and the like to prevent the disodium edetate from forming scale products with other components; the tetra sodium ethylenediamine tetraacetate solution is a chelating agent, can jump to form a complex with metal ions, and can effectively dissolve rust and other metal salts.

Lactic acid and disodium ethylenediamine tetraacetate can form lactic acid-EDTA complex by co-compounding, thereby enhancing the capacity of dissolving scale deposit, and especially having a certain effect on calcium and magnesium salt scale blockage.

The mutual coordination of lactic acid and tetra sodium ethylenediamine tetraacetate can enhance the dissolution of rust and other metal salts, and effectively reduce the risk of scale blockage.

Embodiment two: the chemical descaling and blocking remover for the oilfield water injection well comprises the following components in percentage by weight: 30% of anti-blocking agent, 20% of chelating agent, 5% of dispersing agent, 3% of disodium dihydrogen phosphate, 1% of sodium chloride and 0.5% of surfactant.

The scale removal blocking remover can solve the blocking problem formed by various factors, greatly saves the cost in the blocking removal process, can effectively prevent the formation of emulsification and organic scale in an oil reservoir, can solve the existing problems of emulsification and organic scale blocking, is beneficial to improving the extraction efficiency of crude oil, can effectively promote the injection increasing work of a water injection well, has good reservoir transformation characteristics, is matched with a reservoir fluid, can effectively remove blocking matters and restore the permeability of the reservoir, has higher blocking removal success rate, and has lasting blocking removal effect.

Embodiment III: a preparation method of a chemical descaling blocking remover for an oilfield water injection well comprises the following steps:

S1, adding water in a formula amount into a reaction kettle, adding an inorganic scale remover in the formula amount, controlling the temperature at 60-65 ℃, stirring for 20-30min, then adding an organic scale remover in the formula amount, and continuously stirring for 20-30min to obtain an anti-blocking agent;

s2, sequentially adding a dispersing agent and a chelating agent, stirring for 5-10min, and controlling the reaction temperature to 30-40 ℃;

s3, adding the disodium dihydrogen phosphate, the sodium chloride and the surfactant according to the formula proportion in a volumetric flask, and fully stirring and mixing;

s4, finally adding the anti-blocking agent prepared in the step S1, stirring and mixing, and controlling the temperature to gradually rise to 60 ℃;

S5, naturally cooling to room temperature after stirring is finished, and obtaining the colloid asphalt dispersing agent.

Except in the foregoing examples, or where otherwise explicitly indicated, all numerical values in this description describing the amounts of materials, reaction conditions, molecular weights, number of carbon atoms, etc. should be understood as modified by the word "a". All% values are by weight, and all ppm values are based on weight, unless otherwise indicated. Unless otherwise indicated, each chemical or composition referred to herein should be construed as a commercial grade material that may contain isomers, byproducts, derivatives, and other such materials that are generally understood to be present in the commercial grade. However, unless otherwise indicated, the amounts of the individual chemical components are not to be construed as any solvent or diluent that may normally be present in a commercial material. It is to be understood that the upper and lower limits of the amounts, ranges and ratios described herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used with any other element range or amount. As used herein, the expression "consisting essentially of" is allowed to include substances that do not materially affect the basic and novel characteristics of the compositions under consideration.

It is important to note that the construction and arrangement of the application as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in this application. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present applications. Therefore, the application is not limited to the specific embodiments, but extends to various modifications that nevertheless fall within the scope of the appended claims.

Furthermore, in order to provide a concise description of the exemplary embodiments, all features of an actual implementation may not be described (i.e., those not associated with the best mode presently contemplated for carrying out the invention, or those not associated with practicing the invention).

It should be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions may be made in any engineering or design project. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

While embodiments of the present invention have been shown and described above for purposes of illustration and description, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (7)

1. The chemical descaling blocking remover for the oilfield water injection well is characterized by comprising the following components in percentage by weight: 10-30% of anti-blocking agent, 10-30% of chelating agent, 2-5% of dispersing agent, 1-5% of disodium dihydrogen phosphate, 1-3% of sodium chloride and 0.5% of surfactant.

2. The oilfield water injection well chemical descaling blocking remover as claimed in claim 1, wherein: the anti-blocking agent consists of an inorganic scale remover and an organic scale remover, wherein the weight percentage of the inorganic scale remover is 10-50%, and the weight percentage of the organic scale remover is 5-30%.

3. The chemical descaling blocking remover for oilfield water injection wells as defined in claim 2, wherein: the inorganic scale remover comprises the following components in percentage by weight: lactic acid 20%, alkaline polyvinyl alcohol 30%, sodium octyl sulfonate 10% and polyoxymethylene 5%;

the organic scale remover comprises the following components in percentage by weight: 15% of nitric acid, 10% of ammonium chloride and 5% of sulfonated polyether.

4. The oilfield water injection well chemical descaling blocking remover as claimed in claim 1, wherein: the chelating agent is disodium edetate or tetrasodium edetate.

5. The oilfield water injection well chemical descaling blocking remover as claimed in claim 1, wherein: the surfactant is polyethylene glycol alcohol ether.

6. The oilfield water injection well chemical descaling blocking remover as claimed in claim 1, wherein: comprises the following components in percentage by weight: 30% of anti-blocking agent, 20% of chelating agent, 5% of dispersing agent, 3% of disodium dihydrogen phosphate, 1% of sodium chloride and 0.5% of surfactant.

7. A preparation method of a chemical descaling blocking remover for an oilfield water injection well is characterized by comprising the following steps: the method comprises the following steps:

S1, adding water in a formula amount into a reaction kettle, adding an inorganic scale remover in the formula amount, controlling the temperature at 60-65 ℃, stirring for 20-30min, then adding an organic scale remover in the formula amount, and continuously stirring for 20-30min to obtain an anti-blocking agent;

s2, sequentially adding a dispersing agent and a chelating agent, stirring for 5-10min, and controlling the reaction temperature to 30-40 ℃;

s3, adding the disodium dihydrogen phosphate, the sodium chloride and the surfactant according to the formula proportion in a volumetric flask, and fully stirring and mixing;

s4, finally adding the anti-blocking agent prepared in the step S1, stirring and mixing, and controlling the temperature to gradually rise to 60 ℃;

S5, naturally cooling to room temperature after stirring is finished, and obtaining the colloid asphalt dispersing agent.