A water-based mud cuttings composite debonding agent and use method thereof

Abstract

The invention discloses a water-based mud cuttings composite breaker and a method for using the same, belonging to the technical field of oil and gas drilling waste breaker, including the following raw materials in parts by mass: 30-60 parts of copolymer, 1-5 parts of aluminum sulfate, 10-30 parts of polyaluminum ferrosilicate, 1-10 parts of polyaluminum chloride, 1-5 parts of calcium chloride, 0.1-5 parts of sodium hydroxide, 5-25 parts of calcium oxide; the copolymer is prepared from the following raw materials in parts by mass: 200-300 parts of water, 12.5-20.8 parts of methacrylamide, 8.2-10.7 parts of 3-cyclohexylpropionic acid, 3.5-6.5 parts of hydroxymethyl cellulose, 0.2-6.5 parts of EDTA, 0.1-0.15 parts of potassium persulfate, and 0.15-0.2 parts of sodium bisulfite. The breaker of the present invention has strong broad spectrum, strong mud adaptability, high water yield, outstanding breaker effect, and the material is close to neutral, which greatly reduces the corrosion to the filter press.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas drilling waste degumming, and relates to a water-based mud cuttings composite degumming agent and a use method thereof. Background Art

[0002] Water-based drilling waste is the waste generated during the oil and gas drilling process. The most common, largest and most urgent waste to be treated are drilling waste mud and drill cuttings. According to statistics, the total amount generated in my country is 25 to 32 million m3 per year. 3 About. The characteristics of these two types of wastes are complex composition, viscous or semi-fluid appearance, large color, poor gradation, high viscosity, high liquid content and extremely slow natural drying process. The dried matter is easy to form drilling waste mud-like matter again after being soaked in water, which will have long-term adverse effects on the environment of the discharge point and nearby areas. These wastes contain a large amount of harmful substances such as chemical additives (salts, various polymers, surfactants, organic treatment agents and alkaline substances, etc.), sewage, heavy metals (such as mercury, copper, arsenic, chromium, zinc, lead and impurities in barite). If they are not safely and harmlessly treated or treated improperly, they will cause serious pollution to the surrounding soil, vegetation, surface water and groundwater. In particular, the heavy metals and their compounds can accumulate in the water environment or organisms for a long time, causing great harm to human life, and are bound to cause continuous and even irreversible serious damage to the ecological environment.

[0003] In the process of oil drilling, the subsequent treatment of drilling waste mud is a common problem we are currently facing. Drilling mud is the blood of drilling production, but the waste mud during and after the completion of the drilling process needs to be properly treated and cleaned. Chemical agents need to be added during the treatment to carry out effective reactions, generally mainly degelling, forming solid-liquid separation, and then the free water in the mud is separated from the cuttings through a filter press.

[0004] There are several mainstream products of debonding agents on the market: 1. Flocculant - aluminum sulfate; 2. PAC - polyaluminum chloride; 3. High molecular - liquid high coagulant debonding agent. The first two debonding agents can basically meet the production requirements during use, but they are expensive, the filter water is acidic, and they do not meet the standards for later reuse. High molecular high coagulant debonding agents have the advantages of strong universality, low cost, no harm to hands, and filter water can be reused, but the high molecular high coagulant debonding agents on the market currently have low water output and poor debonding effect.

[0005] Therefore, how to develop a water-based mud cuttings composite degumming agent with high water yield and outstanding degumming effect and a method for using the same is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In view of this, the present invention provides a water-based mud cuttings composite breaker and a use method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A water-based mud drill cuttings composite debonder, comprising the following raw materials in parts by weight: 30-60 parts of copolymer, 1-5 parts of aluminum sulfate, 10-30 parts of polyaluminum ferrosilicate, 1-10 parts of polyaluminum chloride, 1-5 parts of calcium chloride, 0.1-5 parts of sodium hydroxide, and 5-25 parts of calcium oxide;

[0009] The copolymer is prepared from the following raw materials in parts by weight: 200-300 parts of water, 12.5-20.8 parts of methacrylamide, 8.2-10.7 parts of 3-cyclohexylpropionic acid, 3.5-6.5 parts of hydroxymethyl cellulose, 0.2-6.5 parts of EDTA, 0.1-0.15 parts of potassium persulfate and 0.15-0.2 parts of sodium bisulfite.

[0010] Furthermore, the preparation method of the above copolymer comprises the following steps:

[0011] (1) Weigh each raw material according to the above mass parts;

[0012] (2) adding methacrylamide to water while stirring, and stirring until the methacrylamide is completely dissolved;

[0013] (3) Add 3-cyclohexylpropionic acid while stirring until the 3-cyclohexylpropionic acid is completely dissolved;

[0014] (4) adding hydroxymethyl cellulose while stirring until the hydroxymethyl cellulose is completely dissolved;

[0015] (5) adding EDTA while stirring, and adding potassium persulfate and sodium bisulfite at intervals of 1 minute after the addition of EDTA is completed to obtain a mixture;

[0016] (6) The mixture is heated to react to obtain the above copolymer.

[0017] Furthermore, in step (6), the temperature is raised to 60-80° C. and the reaction time is 2-6 hours.

[0018] The present invention also provides a method for using a water-based mud cuttings composite breaker, comprising the following steps:

[0019] 1) Weigh each raw material according to the above mass parts;

[0020] 2) mixing the copolymer, aluminum sulfate, polyaluminum ferrosilicate, polyaluminum chloride, calcium chloride and sodium hydroxide, and adding the mixture into the water-based mud cuttings and stirring;

[0021] 3) After adding calcium oxide, continue stirring until the gel is broken.

[0022] Furthermore, in step 2), the stirring speed is 600-1400 rpm, and the stirring time is 10-40 min.

[0023] Furthermore, in step 3), the stirring speed is 600-1400 rpm.

[0024] The beneficial effects of the present invention are as follows: the composite degumming agent of the present invention is suitable for drilling sludge. Since the colloidal particles of the sludge are very small and have a large surface area compared to their volume, a lot of water is adsorbed due to the effect of surface tension. The colloidal particles carry charges of the same nature and repel each other, hindering the aggregation and growth of the particles while maintaining a stable state, thereby adsorbing water on the surface. It is difficult to remove using ordinary concentration or dehydration methods. Only after the addition of electrolytes and copolymers that can play a role in coagulation, flocculation, and degumming, and the charge of the colloidal particles is neutralized, the particles are in an unstable state, adhere together, and finally settle down. After the particles increase in size, their specific surface area decreases, and the surface tension decreases accordingly, and the surface adsorbed water also detaches from the colloidal particles.

[0025] The composite degumming agent of the present invention takes chemical complexation and coagulation as the synthesis theoretical basis, adopts the copolymerization and cationization method, and develops a high-efficiency degumming agent with degumming, decolorization and COD removal. It breaks the charge balance of the wastewater-based drilling fluid, compresses the double electron layer, destroys the colloidal stability of the drilling fluid, and forms a "spider web" structure through chemical complexation and flocculation and wrapping, condenses the small particles in the waste drilling fluid into larger flocculation, and quickly settles and separates from the free water. It has strong broad spectrum and strong mud adaptability, and can be used for conventional waste water-based drilling fluid, waste polysulfone drilling fluid, waste high temperature salt water anti-collapse drilling fluid and other waste drilling fluid degumming and solid-liquid separation treatment. After mixing with the mud, a series of chemical and physical reactions are generated to destroy the colloidal suspension system of the mud, the water output rate is high, the water output can reach more than 60%, and the degumming effect is outstanding. The material is nearly neutral and non-corrosive, and the environmental protection is outstanding, which greatly reduces the corrosion to the filter press and complies with the current environmental protection policy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The comparison chart of chromaticity reduction when the composite breaker of Example 3 is added to high COD and high chromaticity wastewater, wherein (a) is a composite breaker dosage of 500ppm; (b) is a composite breaker dosage of 750ppm; (c) is a composite breaker dosage of 1000ppm. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] The preparation method of the copolymer comprises the following steps:

[0030] (1) Weigh 200 kg of water, 12.5 kg of methacrylamide, 8.2 kg of 3-cyclohexylpropionic acid, 3.5 kg of hydroxymethyl cellulose, 0.2 kg of EDTA, 0.1 kg of potassium persulfate, and 0.15 kg of sodium bisulfite;

[0031] (2) adding methacrylamide to water while stirring, and stirring until the methacrylamide is completely dissolved;

[0032] (3) Add 3-cyclohexylpropionic acid while stirring until the 3-cyclohexylpropionic acid is completely dissolved;

[0033] (4) adding hydroxymethyl cellulose while stirring until the hydroxymethyl cellulose is completely dissolved;

[0034] (5) adding EDTA while stirring, and adding potassium persulfate and sodium bisulfite at intervals of 1 minute after the addition of EDTA is completed to obtain a mixture;

[0035] (6) The mixture was heated to 60°C and reacted for 2 hours to obtain a copolymer.

[0036] The method for using the water-based mud cuttings composite debonder comprises the following steps:

[0037] 1) Weigh 30 kg of copolymer, 1 kg of aluminum sulfate, 10 kg of polyaluminum ferrosilicate, 1 kg of polyaluminum chloride, 1 kg of calcium chloride, 0.1 kg of sodium hydroxide, and 5 kg of calcium oxide;

[0038] 2) Mix the copolymer, aluminum sulfate, polyaluminum ferrosilicate, polyaluminum chloride, calcium chloride and sodium hydroxide, add them into the water-based mud cuttings and stir at a stirring speed of 600 rpm for 10 min;

[0039] 3) After adding calcium oxide, continue stirring until the gel is broken, and the stirring speed is 600 rpm.

[0040] Example 2

[0041] The preparation method of the copolymer comprises the following steps:

[0042] (1) Weigh 300 kg of water, 20.8 kg of methacrylamide, 10.7 kg of 3-cyclohexylpropionic acid, 6.5 kg of hydroxymethyl cellulose, 6.5 kg of EDTA, 0.15 kg of potassium persulfate, and 0.2 kg of sodium bisulfite;

[0043] (2) adding methacrylamide to water while stirring, and stirring until the methacrylamide is completely dissolved;

[0044] (3) Add 3-cyclohexylpropionic acid while stirring until the 3-cyclohexylpropionic acid is completely dissolved;

[0045] (4) adding hydroxymethyl cellulose while stirring until the hydroxymethyl cellulose is completely dissolved;

[0046] (5) adding EDTA while stirring, and adding potassium persulfate and sodium bisulfite at intervals of 1 minute after the addition of EDTA is completed to obtain a mixture;

[0047] (6) The mixture was heated to 80°C and reacted for 6 hours to obtain a copolymer.

[0048] The method for using the water-based mud cuttings composite debonder comprises the following steps:

[0049] 1) Weigh 60kg of copolymer, 5kg of aluminum sulfate, 30kg of polyaluminum ferrosilicate, 10kg of polyaluminum chloride, 5kg of calcium chloride, 5kg of sodium hydroxide, and 25kg of calcium oxide;

[0050] 2) Mix the copolymer, aluminum sulfate, polyaluminum ferrosilicate, polyaluminum chloride, calcium chloride and sodium hydroxide, add them into the water-based mud cuttings and stir at a stirring speed of 1400 rpm for 40 min;

[0051] 3) After adding calcium oxide, continue stirring until the gel is broken, and the stirring speed is 1400 rpm.

[0052] Example 3

[0053] The preparation method of the copolymer comprises the following steps:

[0054] (1) Weigh 250 kg of water, 17 kg of methacrylamide, 9 kg of 3-cyclohexylpropionic acid, 5 kg of hydroxymethyl cellulose, 3 kg of EDTA, 0.12 kg of potassium persulfate, and 0.17 kg of sodium bisulfite;

[0055] (2) adding methacrylamide to water while stirring, and stirring until the methacrylamide is completely dissolved;

[0056] (3) Add 3-cyclohexylpropionic acid while stirring until the 3-cyclohexylpropionic acid is completely dissolved;

[0057] (4) adding hydroxymethyl cellulose while stirring until the hydroxymethyl cellulose is completely dissolved;

[0058] (5) adding EDTA while stirring, and adding potassium persulfate and sodium bisulfite at intervals of 1 minute after the addition of EDTA is completed to obtain a mixture;

[0059] (6) The mixture was heated to 70°C and reacted for 4 hours to obtain a copolymer.

[0060] The method for using the water-based mud cuttings composite debonder comprises the following steps:

[0061] 1) Weigh 40 kg of copolymer, 3 kg of aluminum sulfate, 20 kg of polyaluminum ferrosilicate, 5 kg of polyaluminum chloride, 3 kg of calcium chloride, 3 kg of sodium hydroxide, and 15 kg of calcium oxide;

[0062] 2) Mix the copolymer, aluminum sulfate, polyaluminum ferrosilicate, polyaluminum chloride, calcium chloride and sodium hydroxide, add them into the water-based mud cuttings and stir at a stirring speed of 1000 rpm for 30 min;

[0063] 3) After adding calcium oxide, continue stirring until the gel is broken, and the stirring speed is 1000 rpm.

[0064] Effect Experiment

[0065] Table 1 Performance of water-based mud cuttings composite debonder

[0066]

[0067] Table 2 COD value and chromaticity reduction value after adding the composite degumming agent of Example 3 to high COD and high chromaticity wastewater

[0068]

[0069] The composite gel breaker of the present invention is suitable for a pH value of 5-12 and has a wide application range.

[0070] Traditional flocculants such as polyferric sulfate, aluminum sulfate, ferrous sulfate, and polyaluminum chloride generally have a pH value of about 3-5, which is acidic. The mechanism of action is that the hydrolysis products have a bridging adsorption effect on the suspended matter in the mud to break the gel, and have a strong electrical neutralization effect on the colloidal substances in the mud.

[0071] Table 3 Comparison of water yield after adding different degumming agents

[0072]

[0073] The disclosed embodiments are described to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water-based mud cuttings composite breaker, characterized in that: The invention comprises the following raw materials in parts by weight: 30-60 parts of copolymer, 1-5 parts of aluminum sulfate, 10-30 parts of polyaluminum ferrosilicate, 1-10 parts of polyaluminum chloride, 1-5 parts of calcium chloride, 0.1-5 parts of sodium hydroxide and 5-25 parts of calcium oxide; The copolymer is prepared from the following raw materials in parts by weight: 200-300 parts of water, 12.5-20.8 parts of methacrylamide, 8.2-10.7 parts of 3-cyclohexylpropionic acid, 3.5-6.5 parts of hydroxymethyl cellulose, 0.2-6.5 parts of EDTA, 0.1-0.15 parts of potassium persulfate, and 0.15-0.2 parts of sodium bisulfite; The preparation method of the copolymer comprises the following steps: (1) Weighing each raw material according to the mass parts; (2) adding methacrylamide to water while stirring, and stirring until the methacrylamide is completely dissolved; (3) Add 3-cyclohexylpropionic acid while stirring until the 3-cyclohexylpropionic acid is completely dissolved; (4) adding hydroxymethyl cellulose while stirring until the hydroxymethyl cellulose is completely dissolved; (5) adding EDTA while stirring, and adding potassium persulfate and sodium bisulfite at intervals of 1 minute after the addition of EDTA is completed to obtain a mixture; (6) heating the mixture to react and obtain the copolymer.

2. A water-based mud cuttings composite breaker according to claim 1, characterized in that: In step (6), the temperature is raised to 60-80° C. and the reaction time is 2-6 hours.

3. A method for using a water-based mud cuttings composite breaker, characterized in that: The following steps are involved: 1) Weighing each raw material according to the mass parts of any one of claims 1-2; 2) mixing the copolymer, aluminum sulfate, polyaluminum ferrosilicate, polyaluminum chloride, calcium chloride and sodium hydroxide, and adding the mixture into the water-based mud cuttings and stirring; 3) After adding calcium oxide, continue stirring until the gel is broken.

4. The method for using a water-based mud cuttings composite breaker according to claim 3, characterized in that: In step 2), the stirring speed is 600-1400 rpm, and the stirring time is 10-40 min.

5. The method for using a water-based mud cuttings composite breaker according to claim 3, characterized in that: In step 3), the stirring speed is 600-1400 rpm.

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