Modified oxidized asphalt viscosity and filtrate reducer for drilling fluid

Abstract

The invention belongs to the technical field of petroleum geology exploration and development, and particularly relates to a modified oxidized asphalt viscosity and filtrate reducer for drilling fluid. The modified oxidized asphalt viscosity and filtrate reducer for the drilling fluid comprises the following components: modified asphalt powder, potassium humate, modified ammonium salt, modified resin and a plugging material. The product provided by the invention contains various graded rigid particles and particles capable of being softened to form a film, the particles directly participate in the formation of a mud cake, a high-strength adsorption film is formed on the surface of the mud cake, the permeability of the mud cake is reduced by applying a plugging principle, the quality of the mud cake is improved, and the effect of reducing the filter loss is achieved. And the anti-sloughing capability of the drilling fluid system is improved through the action mechanisms of embedding, semi-embedding plugging, membrane covering and the like on micro-pores and micro-cracks of stratums.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum geological exploration and development, and in particular relates to a modified oxidized asphalt viscosity reducing and filtration reducing agent for drilling fluid. Background Art

[0002] In the process of oil and gas drilling, drilling fluid (also known as drilling mud) is an important process material to ensure the smooth progress of drilling operations. Drilling fluid has multiple functions, including cooling and lubricating the drill bit, removing debris in the wellbore, balancing the formation pressure, plugging formation cracks and pores to prevent well leakage, etc. Among them, plugging and inhibition performance is the key to maintaining wellbore stability and reducing mud loss.

[0003] However, traditional drilling fluids often face some problems in practical applications, such as insufficient plugging effect, poor inhibition performance, high filtration rate, etc. These problems may lead to lost circulation, wellbore collapse, wellbore instability and reduced drilling efficiency, thereby increasing drilling costs and risks.

[0004] At present, the commonly used plugging inhibitors on the market mainly include some inorganic materials (such as bentonite) and organic polymers (such as polyacrylamide). Although these materials can improve the performance of drilling fluids to a certain extent, they have the following limitations:

[0005] Inorganic materials: Inorganic materials such as bentonite are prone to failure under high temperature and high pressure conditions, and their particles are large and difficult to penetrate into small stratum cracks, so their sealing effect is limited.

[0006] Organic polymers: Although organic polymers such as polyacrylamide have certain plugging and inhibition capabilities, they are easily degraded in complex formation environments, have poor stability, and may cause environmental pollution.

[0007] In view of the above problems, it is particularly important to research and develop a new type of plugging inhibitor that is efficient, environmentally friendly and has excellent plugging and inhibition performance. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a modified oxidized asphalt viscosity reducer and filtrate reducer for drilling fluid, the components of which include modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material.

[0009] Furthermore, the mass ratio of the modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material is 50:15:15:5:15.

[0010] Furthermore, the plugging material includes 400 mesh calcium carbonate and 1200 mesh calcium carbonate.

[0011] Furthermore, the weight ratio of the 400-mesh calcium carbonate to the 1200-mesh calcium carbonate is 10:5.

[0012] Furthermore, the modified resin meets the following parameters: appearance is black-brown powder, moisture: 16.9%, water-insoluble matter: 10.9%, pH value: 9.5-10.0, API filtration loss of fresh water slurry: 7.0ml, API filtration loss of sodium chloride contaminated slurry: 9.2ml, high-temperature and high-pressure filtration loss of fresh water slurry: 25.4ml, high-temperature and high-pressure filtration loss of sodium chloride contaminated slurry: 32.0ml, apparent viscosity of fresh water slurry: 14.25mPa·s, apparent viscosity of sodium chloride contaminated slurry: 29.0mPa·s.

[0013] Further, the modified ammonium salt meets the following parameters: appearance: free-flowing powder, sieve residue: 0.25%, room temperature: fresh water: AV: 4.75 mpa.s API reduction rate: 66.2%, salt water: AV: 6.0 mpa.s API reduction rate: 76.9%, 120°C / 16h: fresh water: AV: 4.25 mpa.s API reduction rate: 52.0%, salt water: AV: 6.25 mpa.s API reduction rate: 74.0%.

[0014] Furthermore, the modified asphalt meets the following parameters: appearance: black powder, sieve residue (200 mesh): 7.9%, oil solubility: 72%, softening point: >150°C.

[0015] The present invention also provides the use of the modified oxidized asphalt viscosity reducer and fluid loss reducer for drilling fluid in petroleum geological exploration and development.

[0016] The present invention has the following beneficial effects:

[0017] The product provided by the present invention contains rigid particles of various gradations and softenable film-forming particles, which directly participate in the formation of mud cakes and form a high-strength adsorption film on the surface of mud cakes, and use the plugging principle to reduce the permeability of mud cakes, improve the quality of mud cakes, and achieve the effect of reducing the amount of filtration loss. And through the mechanism of embedding, semi-embedding and plugging of micropores and microcracks in the formation, and membrane covering, the anti-collapse ability of the drilling fluid system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 Main technical indicators;

[0020] Figure 2 Quality inspection results;

[0021] Figure 3 Biological toxicity test results;

[0022] Figure 4 Infrared analysis results. DETAILED DESCRIPTION

[0023] Now, various exemplary embodiments of the present invention are described in detail. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared by conventional methods unless otherwise specified. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0024] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0025] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0026] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0027] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0028] Example 1

[0029] The invention provides a modified oxidized asphalt viscosity and fluid loss reducing agent for drilling fluid, the components of which include modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material.

[0030] Furthermore, the mass ratio of the modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material is 50:15:15:5:15.

[0031] Furthermore, the plugging material includes 400 mesh calcium carbonate and 1200 mesh calcium carbonate.

[0032] Furthermore, the weight ratio of the 400-mesh calcium carbonate to the 1200-mesh calcium carbonate is 10:5.

[0033] Furthermore, the modified resin meets the following parameters: appearance is black-brown powder, moisture: 16.9%, water-insoluble matter: 10.9%, pH value: 9.5-10.0, API filtration loss of fresh water slurry: 7.0ml, API filtration loss of sodium chloride contaminated slurry: 9.2ml, high-temperature and high-pressure filtration loss of fresh water slurry: 25.4ml, high-temperature and high-pressure filtration loss of sodium chloride contaminated slurry: 32.0ml, apparent viscosity of fresh water slurry: 14.25mPa·s, apparent viscosity of sodium chloride contaminated slurry: 29.0mPa·s.

[0034] Further, the modified ammonium salt meets the following parameters: appearance: free-flowing powder, sieve residue: 0.25%, room temperature: fresh water: AV: 4.75 mpa.s API reduction rate: 66.2%, salt water: AV: 6.0 mpa.s API reduction rate: 76.9%, 120°C / 16h: fresh water: AV: 4.25 mpa.s API reduction rate: 52.0%, salt water: AV: 6.25 mpa.s API reduction rate: 74.0%.

[0035] Furthermore, the modified asphalt meets the following parameters: appearance: black powder, sieve residue (200 mesh): 7.9%, oil solubility: 72%, softening point: >150°C.

[0036] Example 2 Property Detection

[0037] 2.1 Main technical indicators testing

[0038] The main technical indicators test results are as follows: Figure 1 shown.

[0039] 2.2 Third-party quality inspection

[0040] The third-party quality inspection results are as follows: Figure 2 shown.

[0041] 2.3 Third-party biological toxicity testing

[0042] Third-party biotoxicity testing such as Figure 3 shown.

[0043] 2.4 Third-party infrared analysis

[0044] Third-party infrared analysis results such as Figure 4 shown.

[0045] From the above results, it can be seen that the product provided by the present invention contains rigid particles of various gradations and softenable film-forming particles, which directly participate in the formation of mud cakes and form a high-strength adsorption film on the surface of mud cakes, and use the plugging principle to reduce the permeability of mud cakes, improve the quality of mud cakes, and achieve the effect of reducing the amount of filtration. And through the mechanism of embedding, semi-embedding and plugging of micropores and microcracks in the formation, and membrane covering, the anti-collapse ability of the drilling fluid system is improved.

Claims

1. A modified oxidized asphalt viscosity reducer and fluid loss reducer for drilling fluid, characterized in that: The components include modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material.

2. The modified oxidized asphalt viscosity reducing and filtrate reducing agent for drilling fluid according to claim 1, characterized in that: The mass ratio of the modified asphalt powder, potassium humate, modified ammonium salt, modified resin and plugging material is 50:15:15:5:

15.

3. The modified oxidized asphalt viscosity reducing and filtrate reducing agent for drilling fluid according to claim 1, characterized in that: The plugging material includes 400 mesh calcium carbonate and 1200 mesh calcium carbonate.

4. The modified oxidized asphalt viscosity reducing and filtrate reducing agent for drilling fluid according to claim 3, characterized in that: The weight ratio of the 400-mesh calcium carbonate to the 1200-mesh calcium carbonate is 10:

5.

5. The modified oxidized asphalt viscosity reducing and filtrate reducing agent for drilling fluid according to claim 1, characterized in that: The modified resin meets the following parameters: appearance is dark brown powder, moisture: 16.9%, water insoluble matter: 10.9%, pH value: 9.5-10.0, fresh water slurry API filtration loss: 7.0ml, API filtration loss of sodium chloride contaminated slurry: 9.2ml, high temperature and high pressure filtration loss of fresh water slurry: 25.4ml, high temperature and high pressure filtration loss of sodium chloride contaminated slurry: 32.0ml, apparent viscosity of fresh water slurry: 14.25mPa·s, apparent viscosity of sodium chloride contaminated slurry: 29.0mPa·s.

6. The modified oxidized asphalt viscosity reducer and fluid loss reducer for drilling fluid according to claim 1, characterized in that the modified ammonium salt meets the following parameters: Appearance: free-flowing powder, sieve residue: 0.25%, normal temperature: fresh water: AV: 4.75mpa.s API reduction rate: 66.2%, salt water: AV: 6.0mpa.s API reduction rate: 76.9%, 120℃ / 16h: fresh water: AV: 4.25mpa.s API reduction rate: 52.0%, salt water: AV: 6.25mpa.s API reduction rate: 74.0%.

7. The modified oxidized asphalt viscosity reducing and filtrate reducing agent for drilling fluid according to claim 1, characterized in that: The modified asphalt meets the following parameters: appearance: black powder, sieve residue (200 mesh): 7.9%, oil solubility: 72%, softening point: >150°C.

8. Use of the modified oxidized asphalt viscosity reducer and fluid loss reducer for drilling fluid as claimed in claim 1 in petroleum geological exploration and development.

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