Cationic emulsified asphalt powder plugging filtrate reducer for drilling fluid and preparation method of cationic emulsified asphalt powder plugging filtrate reducer

Abstract

The invention belongs to the technical field of oilfield drilling fluid treatment agents, and particularly relates to a cationic emulsified asphalt powder plugging filtrate reducer for drilling fluid and a preparation method thereof. The cationic emulsified asphalt powder plugging filtrate reducer for the drilling fluid is prepared from the following raw materials in percentage by mass: 50 to 60 percent of petroleum asphalt powder, 20 to 30 percent of humate, 10 to 15 percent of cationic emulsifier and 6 to 8 percent of macromolecular polymer. The cationic emulsified asphalt powder plugging filtrate reducer for the drilling fluid can effectively plug well wall cracks, reduce high-temperature and high-pressure filter loss and improve well wall stability, is suitable for petroleum and natural gas well drilling, reduces underground accidents, improves drilling efficiency and reduces construction cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield drilling fluid treatment agents, and particularly relates to a cationic emulsified asphalt powder plugging and filtration-reducing agent for drilling fluid and a preparation method thereof. BACKGROUND

[0002] With the continuous deepening of domestic oil and gas reservoir development, higher requirements are put forward for the types and qualities of drilling fluid treatment agents. The plugging and anti-sloughing filtration-reducing agent for drilling fluid is one of the more important treatment agents in the use process of drilling fluid, which has the functions of plugging well wall gaps, cementing broken formations, inhibiting shale and clay swelling, forming a dense and smooth mud cake, reducing the high temperature and high pressure filtration loss of drilling fluid, and improving the stability of the well wall.

[0003] At present, the widely used plugging and anti-sloughing filtration-reducing agent for drilling fluid in the drilling process is various modified asphalt treatment agents. The first type is sulfonated asphalt; the second type is emulsified asphalt, including anionic emulsified asphalt and cationic emulsified asphalt. Among them, the cationic emulsified asphalt is mostly in paste form, and the powder is less.

[0004] Patent CN105505345A discloses a plugging and anti-sloughing agent for drilling fluid and a preparation method and application thereof. The specific steps are as follows: high-boiling-point solvent oil and petroleum asphalt powder are added to a reaction kettle, then heated and stirred to dissolve the petroleum asphalt powder, and an asphalt glue solution is obtained; a surfactant (one or both of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide) and a modifier (one or both of oil-soluble phenolic resin and petroleum resin) are added to the asphalt glue solution and reacted at a certain temperature, and a colloid is obtained after the reaction; a blocking agent (one or a combination of several of poly anionic cellulose, carboxymethyl cellulose sodium salt, and pregelatinized starch) is added to obtain a gelatinous product; after cooling to solidification, the product is crushed to obtain the product. The method is complex, the production efficiency is extremely low, and the effect of reducing the high temperature and high pressure filtration loss still needs to be improved.

[0005] Therefore, there is an urgent need for a plugging and filtration-reducing agent with simple preparation, high production efficiency, and excellent filtration loss reduction at high temperature and high pressure. SUMMARY

[0006] The first purpose of the present application is to provide a cationic emulsified asphalt powder plugging and filtration-reducing agent for drilling fluid, which still has excellent filtration loss reduction at high temperature and high pressure.

[0007] The second purpose of the present application is to provide a preparation method of the cationic emulsified asphalt powder plugging and filtration-reducing agent for drilling fluid.

[0008] In order to achieve the above purposes, the technical solution adopted by the present application is as follows:

[0009] The application discloses a cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid.

[0010] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the cationion emulsifier is hexadecyl trimethyl ammonium chloride or hexadecyl trimethyl ammonium bromide; and the purity of the cationion emulsifier is 80-90%.

[0011] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the macromolecular polymer is polyacrylamide.

[0012] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the softening point of the petroleum asphalt powder is 100-150 DEG C; and the oil solubility of the petroleum asphalt powder is 80-90%.

[0013] The petroleum asphalt powder can be more stable under high temperature and high pressure conditions, the oil soluble matter in the petroleum asphalt can be dissolved and penetrated into the formation pores and cracks during the drilling process, and further dissolved and diffused at the formation temperature after the drilling fluid loss enters the formation, so that a film or a belt with plugging effect is formed, the petroleum asphalt with the oil solubility of 80-90% can be better combined with the oil-based components in the drilling fluid, a stable suspension system is formed, the uniformity of the drilling fluid is maintained, the carrying capacity and lubricating performance of the drilling fluid are improved, and the stability of the well wall during the drilling process is improved.

[0014] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the particle diameter of the petroleum asphalt powder is less than 0.074 mm; and further, the petroleum asphalt powder does not contain aromatic hydrocarbons.

[0015] The petroleum asphalt powder can be more stable under high temperature and high pressure conditions, the oil soluble matter in the petroleum asphalt can be dissolved and penetrated into the formation pores and cracks during the drilling process, and further dissolved and diffused at the formation temperature after the drilling fluid loss enters the formation, so that a film or a belt with plugging effect is formed, the petroleum asphalt with the oil solubility of 80-90% can be better combined with the oil-based components in the drilling fluid, a stable suspension system is formed, the uniformity of the drilling fluid is maintained, the carrying capacity and lubricating performance of the drilling fluid are improved, and the stability of the well wall during the drilling process is improved.

[0016] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the water solubility of the humic acid salt is 80-90%.

[0017] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the particle diameter of the humic acid salt is less than 0.2mm.

[0018] By adopting the above scheme, the filtration loss can be effectively reduced, and the oil and gas layer is protected, in addition, the humic acid salt has the function of reducing filtration loss, and the use amount of other chemical agents can be reduced; the humic acid salt can form a thin and tough filter cake in the drilling fluid, and can block the formation pores and cracks, reduce the filtration loss of the drilling fluid, and by selecting the humic acid salt with a water solubility of 80-90% and a diameter of less than 0.2mm, the drilling fluid has appropriate viscosity and shear force, and the suspension and rock carrying capacity of the drilling fluid is improved, and then the filtration loss is reduced; and when the water solubility is too high, the rheological property will be out of control, the viscosity and shear force of the drilling fluid will sharply rise, high-viscosity mud is formed, the drill tool wear will be aggravated, the drilling efficiency will be reduced, and the operation cost will be increased.

[0019] According to the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, further, the molecular weight of the macromolecular polymer is 8-10 million.

[0020] By adopting the above scheme, the drill bit and drill pipe can be effectively lubricated, the frictional resistance in the drilling process is reduced, and the filtration loss is reduced; by selecting the polyacrylamide with a molecular weight of 8-10 million, the polyacrylamide can be quickly dissolved, the drill bit can be lubricated, the multi-point adsorption and bridging effect can be played, the solid-phase particles such as mud and cuttings in the drilling fluid are flocculated into large flocs, and the large flocs are convenient for being removed through the solid control equipment; if the molecular weight is too small, the large flocs are not conducive to be formed; and if the molecular weight is too large, the solution system is not stable, and the drilling difficulty is increased.

[0021] The preparation method of the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid comprises the following steps:

[0022] The petroleum asphalt powder, the humic acid salt, the cationic emulsifier and the macromolecular polymer are mixed and stirred according to the mass percentage, and then the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid is obtained after stirring for 2-5 minutes.

[0023] The beneficial technical effects of the present application are as follows:

[0024] 1. The emulsified asphalt powder prepared by compounding the petroleum asphalt powder, the humic acid salt, the cationic emulsifier and the macromolecular polymer is used as a plugging fluid loss agent, the prepared plugging fluid loss agent is easy to disperse in the drilling fluid, has good inhibition on the dispersion of drilling cuttings and mud making, can effectively plug the cracks of the well wall, reduce the filtration loss under high temperature and high pressure, improve the stability of the well wall, is suitable for oil and gas well drilling, reduces downhole accidents, improves the drilling efficiency and reduces the construction cost.

[0025] 2. The application provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid. DETAILED DESCRIPTION

[0026] The following further describes the application in connection with specific preferred embodiments, which should not be construed as limiting the application to these descriptions. Those skilled in the art to which the application pertains can make some simple deductions or substitutions without departing from the concept of the application, which should be considered as falling within the protection scope of the application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturers. The reagents or instruments used are conventional products obtained from the market channels, unless otherwise specified.

[0027] Polyacrylamide (CAS: 9003-05-8) was purchased from Shandong Ruishai New Material Technology Co., Ltd.

[0028] (I) Examples

[0029] Example 1

[0030] Example 1 provides a cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, which is composed of the following raw materials in mass percentage: petroleum asphalt powder 52%, sodium humate 30%, cetyltrimethylammonium chloride 12%, and polyacrylamide 6%.

[0031] The oil solubility of the petroleum asphalt powder is 85%, the particle diameter is less than 0.074 mm, and it is a mixture of petroleum asphalt powder with a softening point of 140℃ and petroleum asphalt powder with a softening point of 150℃; the water solubility of the sodium humate is 80%, the particle diameter is less than 0.02 mm; the purity of the cetyltrimethylammonium chloride is 90%; and the molecular weight of the polyacrylamide is 8 million.

[0032] The example also provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, and the specific operation steps are as follows: in a pulverizer, 12.0 g of petroleum asphalt powder with a softening point of 140℃, 14.0 g of petroleum asphalt powder with a softening point of 150℃, 15.0 g of sodium humate, 6.0 g of cetyltrimethylammonium chloride, and 3.0 g of polyacrylamide (PAM) are added respectively, intermittent pulverization and mixing are carried out for 2 min, and then 50.0 g of the cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid is obtained.

[0033] Example 2

[0034] The embodiment 2 provides a cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, which is composed of the following raw materials in mass percentage: petroleum asphalt powder 60%, sodium humate 20%, cetyl trimethyl ammonium chloride 12%, and polyacrylamide 8%.

[0035] The petroleum asphalt powder has an oil solubility of 90%, a particle diameter less than 0.074 mm, and is mixed by petroleum asphalt powder with a softening point of 120 DEG C and petroleum asphalt powder with a softening point of 150 DEG C; the sodium humate has a water solubility of 90%, a particle diameter less than 0.02 mm; the cetyl trimethyl ammonium chloride has a purity of 90%; and the polyacrylamide has a molecular weight of 10 million.

[0036] The embodiment also provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, and the specific operation steps are as follows: in a pulverizer, 15.0 g of petroleum asphalt powder with a softening point of 120 DEG C, 15.0 g of petroleum asphalt powder with a softening point of 150 DEG C, 10.0 g of sodium humate, 6.0 g of cetyl trimethyl ammonium chloride and 4.0 g of polyacrylamide (PAM) are added respectively, intermittent pulverization and mixing are carried out for 2 min, and then 50.0 g of the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid is obtained.

[0037] Embodiment 3

[0038] The embodiment 3 provides a cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, which is composed of the following raw materials in mass percentage: petroleum asphalt powder 56%, potassium humate 24%, cetyl trimethyl ammonium bromide 14%, and polyacrylamide 6%.

[0039] The petroleum asphalt powder has an oil solubility of 80%, a particle diameter less than 0.074 mm, and is mixed by petroleum asphalt powder with a softening point of 130 DEG C and petroleum asphalt powder with a softening point of 140 DEG C; the potassium humate has a water solubility of 90%, a particle diameter less than 0.02 mm; the cetyl trimethyl ammonium bromide has a purity of 90%; and the polyacrylamide has a molecular weight of 10 million.

[0040] The embodiment also provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid, and the specific operation steps are as follows: in a pulverizer, 13.0 g of petroleum asphalt powder with a softening point of 130 DEG C, 15.0 g of petroleum asphalt powder with a softening point of 140 DEG C, 12.0 g of potassium humate, 7.0 g of cetyl trimethyl ammonium bromide and 3.0 g of polyacrylamide (PAM) are added respectively, intermittent pulverization and mixing are carried out for 2 min, and then 50.0 g of the cationic emulsified asphalt powder plugging fluid loss agent for drilling fluid is obtained.

[0041] Embodiment 4

[0042] Example 4 provides a cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, which is composed of the following raw materials in mass percentage: petroleum asphalt powder 54%, humic acid sodium 26%, cetyl trimethyl ammonium bromide 12%, polyacrylamide 8%.

[0043] The oil solubility of the petroleum asphalt powder is 85%, the particle diameter is less than 0.074 mm, and the softening point is 140°C; the water solubility of the humic acid potassium is 90%, the particle diameter is less than 0.02 mm; the purity of the cetyl trimethyl ammonium bromide is 90%; and the molecular weight of the polyacrylamide is 10 million.

[0044] The present embodiment also provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, and the specific operation steps are as follows: in a pulverizer, add 27.0 g of petroleum asphalt powder, 13.0 g of humic acid sodium, 6.0 g of cetyl trimethyl ammonium bromide, and 4.0 g of polyacrylamide (PAM), intermittently pulverize and mix for 2 min, and then pour out, to obtain 50.0 g of the cationic emulsified asphalt powder fluid loss additive for drilling fluid.

[0045] Example 5

[0046] Example 5 provides a cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, which is composed of the following raw materials in mass percentage: petroleum asphalt powder 58%, humic acid potassium 24%, cetyl trimethyl ammonium chloride 12%, and polyacrylamide 6%.

[0047] The oil solubility of the petroleum asphalt powder is 85%, the particle diameter is less than 0.074 mm, and the softening point is 140°C; the water solubility of the humic acid potassium is 90%, the particle diameter is less than 0.02 mm; the purity of the cetyl trimethyl ammonium chloride is 90%; and the molecular weight of the polyacrylamide is 10 million.

[0048] The present embodiment also provides a preparation method of the cationic emulsified asphalt powder plugging fluid loss additive for drilling fluid, and the specific operation steps are as follows: in a pulverizer, add 29.0 g of petroleum asphalt powder, 12.0 g of humic acid potassium, 6.0 g of cetyl trimethyl ammonium chloride, and 3.0 g of polyacrylamide (PAM), intermittently pulverize and mix for 2 min, and then pour out, to obtain 50.0 g of the cationic emulsified asphalt powder fluid loss additive for drilling fluid.

[0049] (II) Comparative Example

[0050] Comparative Example 1

[0051] The content of Comparative Example 1 is basically the same as that of Example 1, except that the sodium humate in Example 1 is omitted; the use amount ratio of petroleum pitch powder, polyacrylamide and cetyltrimethylammonium chloride is the same as that of Example 1.

[0052] Comparative Example 2

[0053] The content of Comparative Example 2 is basically the same as that of Example 1, except that the polyacrylamide in Example 1 is omitted; the use amount of petroleum pitch powder, sodium humate and cetyltrimethylammonium chloride is the same as that of Example 1.

[0054] Comparative Example 3

[0055] The content of Comparative Example 3 is basically the same as that of Example 1, except that the sodium humate and polyacrylamide in Example 1 are omitted; the use amount ratio of petroleum pitch powder and cetyltrimethylammonium chloride is the same as that of Example 1.

[0056] Comparative Example 4

[0057] The content of Comparative Example 4 is basically the same as that of Example 1, except that the use amount of cetyltrimethylammonium chloride in Example 1 is omitted; the use amount ratio of petroleum pitch powder, sodium humate and polyacrylamide is the same as that of Example 1.

[0058] (Three) Test Example

[0059] The performance of Examples 1-5 and Comparative Examples 1-4 was detected according to the standard “Q / SH CG0003.4-2023” of Sinopec, and the results are shown in Table 1.

[0060] Table 1

[0061]

[0062] As shown in Table 1, the cationic emulsified asphalt powder plugging and filtration loss reducer for drilling fluid prepared by the embodiments 1-5 of the present application has high oil solubility content, high inhibition rate, and small filtration loss under high temperature and high pressure, which is obviously higher than the requirement of SINOPEC standard. The specific analysis is as follows: the petroleum asphalt powder with softening point of 100-150℃ and oil solubility of 80-90% is dispersed in the drilling fluid by good wetting and emulsification, which helps to inhibit the dispersion of drilling cuttings to form mud, to form a stable plugging film or bag under high temperature or high pressure, and to better plug the well wall cracks under high temperature and high pressure. The humic acid salt with water solubility of 80-90% and diameter less than 0.2mm can reduce the viscosity and shear force of the drilling fluid after dissolution, and can form a thin and tough filter cake in the drilling fluid, thereby reducing the filtration loss of the drilling fluid; the polyacrylamide with molecular weight of 8-10 million is dissolved in the drilling fluid, which not only lubricates the drill bit, but also plays a multi-point adsorption and bridging role to flocculate the solid phase particles such as drilling cuttings in the drilling fluid into large flocs, which is convenient for removal by solid control equipment.

[0063] Compared with the embodiment 1, the inhibition rate of the comparative examples 1-4 is greatly reduced, and the high temperature and high pressure filtration loss of the drilling fluid is greatly increased. The performance of the drilling fluid is poor. The specific analysis shows that: the present application prepares an emulsified asphalt powder as a plugging and filtration loss reducer by compounding the petroleum asphalt powder, humic acid salt, cationic emulsifier and macromolecular polymer. The plugging and filtration loss reducer is prepared by the humic acid salt with wetting and dispersion function, the macromolecular polyacrylamide with glue protection and flocculation bridging effect, the cationic emulsifier and the petroleum asphalt, and is prepared by specific properties and proportions. When used in the drilling fluid, it is easy to disperse, has good ability to inhibit the dispersion of drilling cuttings to form mud, can effectively plug the well wall cracks, reduce the high temperature and high pressure filtration loss, improve the well wall stability, and is suitable for oil and gas well drilling.

[0064] Finally, it is pointed out that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it. The basic principles and main features of the present application have been described in the above embodiments, and some modifications or replacements can be made on the basis of the present application, but these modifications or replacements do not make the corresponding technical solutions deviate from the scope of the present application.

Claims

1. A cationic emulsified asphalt powder plugging fluid loss reducer for drilling fluid, characterized in that: The cationic emulsified asphalt powder plugging and filtration reducer for drilling fluid is composed of the following raw materials in percentage by mass: 50-60% of petroleum asphalt powder, 20-30% of humate, 10-15% of cationic emulsifier and 6-8% of macromolecular polymer.

2. The cationic emulsified asphalt powder plugging and filtration reducer for drilling fluid according to claim 1, characterized in that: The cationic emulsifier is cetyltrimethylammonium chloride or cetyltrimethylammonium bromide; the purity of the cationic emulsifier is 80-90%.

3. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The macromolecular polymer is polyacrylamide.

4. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The softening point of the petroleum asphalt powder is 100-150° C.; and the oil solubility of the petroleum asphalt powder is 80-90%.

5. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The particle diameter of the petroleum asphalt powder is less than 0.074 mm.

6. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The water solubility of the humate is 80-90%.

7. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The particle diameter of the humate is less than 0.2 mm.

8. The cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid according to claim 1, characterized in that: The molecular weight of the macromolecular polymer is 8-10 million.

9. The method for preparing the cationic emulsified asphalt powder plugging fluid loss reducer for drilling fluid according to any one of claims 1 to 8, characterized in that: The following steps are involved: Petroleum asphalt powder, humate, cationic emulsifier and macromolecular polymer are mixed and stirred according to the mass percentage, and stirred for 2-5 minutes to obtain a cationic emulsified asphalt powder plugging and fluid loss reducer for drilling fluid.

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