阅读说明：本技术 全环保高性能合成基钻井液 (Full-environment-friendly high-performance synthetic base drilling fluid ) 是由 孟虎 刘亚东 朱国伟 吴骏峰 于 2019-11-27 设计创作，主要内容包括：本发明公开了一种全环保高性能合成基钻井液,包括：按重量份计,包括基础油78～88份、主乳化剂2～3份、辅乳化剂0.5～1.5份、钠基膨润土1～2份、30％乙酸钾盐水26-30份、油溶纤维5～10份、增粘剂0.3～0.5份、降滤失剂3～5份、重晶石20～30份；本发明生产原料价格低廉,生产成本低,通过采用添加聚异丁烯、乙烯-丙烯共聚物、氢化苯乙烯-异戊二烯共聚物中的一种或几种组合对原本的合成基钻井液进行改进,使得到的合成基钻井液在高温高压的环境下也具有较好的粘度,和较高的动切力。(The invention discloses a full-environment-friendly high-performance synthetic base drilling fluid, which comprises the following components in percentage by weight: the oil-soluble fiber-based heavy oil emulsion comprises, by weight, 78-88 parts of base oil, 2-3 parts of a main emulsifier, 0.5-1.5 parts of an auxiliary emulsifier, 1-2 parts of sodium bentonite, 26-30 parts of 30% potassium acetate brine, 5-10 parts of oil-soluble fiber, 0.3-0.5 part of a tackifier, 3-5 parts of a filtrate reducer and 20-30 parts of barite; the invention has low price of production raw materials and low production cost, and improves the original synthetic base drilling fluid by adding one or a combination of a plurality of polyisobutylene, ethylene-propylene copolymer and hydrogenated styrene-isoprene copolymer, so that the obtained synthetic base drilling fluid has better viscosity and higher dynamic shear force under the environment of high temperature and high pressure.)

1. The fully-environment-friendly high-performance synthetic base drilling fluid is characterized by comprising, by weight, 78-88 parts of base oil, 2-3 parts of a primary emulsifier, 0.5-1.5 parts of an auxiliary emulsifier, 1-2 parts of sodium bentonite, 26-30 parts of 30% potassium acetate brine, 5-10 parts of oil-soluble fiber, 0.3-0.5 part of a tackifier, 3-5 parts of a filtrate reducer and 20-30 parts of barite;

the base oil is one or a combination of more of linear α -olefin, internal olefin and vegetable oil, the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride, the tackifier is one or a combination of more of polyisobutylene, an ethylene-propylene copolymer and a hydrogenated styrene-isoprene copolymer, and the filtrate reducer is organic lignite or modified humic acid.

2. The full-environment-friendly high-performance synthetic-based drilling fluid as claimed in claim 1, which comprises 78 parts of base oil, 3 parts of primary emulsifier, 1 part of secondary emulsifier, 1.5 parts of sodium bentonite, 28 parts of 30% potassium acetate brine, 10 parts of oil-soluble fiber, 0.3 part of tackifier, 3 parts of filtrate reducer and 24 parts of barite in parts by weight.

3. The fully environmentally friendly, high performance synthetic based drilling fluid of claim 1, wherein the tall oil fatty acid has an acid value of from 180mgKOH/g to 205 mgKOH/g.

4. The fully-environment-friendly high-performance synthetic-based drilling fluid according to claim 1, wherein the co-emulsifier is one or more of oleic acid, naphthenic acid amide, coconut oil fatty acid diethanol amide, octyl phenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether.

5. The full-environment-friendly high-performance synthetic-based drilling fluid according to claim 1, wherein the oil-soluble fiber is one or more of straw powder, walnut shell powder and carbon fiber powder.

6. The all-environment-friendly high-performance synthetic-based drilling fluid according to claim 1, wherein the ethylene-propylene copolymer has a relative molecular weight of 7 x 10⁴～15×10⁴The relative molecular weight of the hydrogenated styrene-isoprene copolymer was 5X 10⁴～10×10⁴。

7. The fully-environment-friendly high-performance synthetic base drilling fluid as claimed in claim 1, wherein the sodium bentonite is subjected to modification treatment before use, and the method specifically comprises the steps of adding the sodium bentonite into cationic starch, heating and stirring for 2 hours in a water bath at 80 ℃, filtering, drying, and grinding to obtain powder with the particle size of 68-75 microns.

8. The fully environmentally friendly, high performance synthetic based drilling fluid of claim 1, wherein one half of the total amount of the viscosifier is loaded into the fully environmentally friendly, high performance synthetic based drilling fluid via a pressure-sensitive slow release device, the pressure-sensitive slow release device comprising:

the shell is a hollow sphere, and the tackifier is filled in the shell;

the backup pad, it sets up in the shell, the backup pad be circular and with shell inner wall connection, on the shell with the backup pad is perpendicular and pass through liquid hole has been seted up in the direction at backup pad center, go out the liquid hole through one with go out liquid hole size assorted shutoff board and connect, the shutoff board with be equipped with a pair of just right fixing base on the relative face of backup pad, a stereoplasm compression spring's both ends are connected respectively fixing base on the shutoff board and corresponding fixing base in the backup pad, the circumference in liquid hole becomes the echelonment structure, compression spring is compression state for liquid hole is blocked up to the shutoff board.

9. The fully-environment-friendly high-performance synthetic base drilling fluid as claimed in claim 8, wherein the outer wall of the outer shell is provided with weighting ring grooves, and weighting rings with different weights are clamped on the weighting ring grooves.

10. The all-environment-friendly high-performance synthetic base drilling fluid as claimed in claim 8, wherein a liquid filling hole is formed in the casing at a position close to the support plate, a circle of seal ring groove is formed in the casing at the position of the liquid filling hole, the liquid filling hole is located in the seal ring groove, and a seal ring is arranged in the seal ring groove.

Technical Field

The invention relates to the field of preparation of petroleum drilling fluid. More particularly, the invention relates to a full-environment-friendly high-performance synthetic base drilling fluid.

Background

The synthetic base drilling fluid is a new type of drilling fluid which is developed according to the requirements of the times and used for replacing oil-base drilling fluid, has the advantages of physical properties of the existing oil-base drilling fluid and high biodegradability, can completely reach the international discharge standard, has strong anti-fouling capability, can be repeatedly used, and has lower use cost than the oil-base drilling fluid and the water-base drilling fluid after comprehensive calculation.

Synthetic based drilling fluids have many stages of development, including the earliest ester based drilling fluids, but the ester groups are easily hydrolyzed under acidic or basic conditions during drilling to obtain the corresponding alcohols and carboxylic acids, and thus the stability is not high, acetal based drilling fluids are prepared by aldehyde condensation, have the advantages of lower kinematic viscosity and flash point than ester and ether based fluids, but have relatively higher cost, and are less in practical use, and later drilling fluids are ether based, poly α -olefin drilling fluids, and later linear α -olefin drilling fluids, internal olefin based drilling fluids, linear paraffin based drilling fluids, and the like;

the main reason of the existing synthetic base drilling fluid is that the temperature has obvious influence on the rheological property, the viscosity of the drilling fluid is very high at low temperature, and the viscosity of the drilling fluid is low at high temperature, and the key point is that the dynamic shear force is too low to effectively carry the solid phase in the drilling fluid, so the existing synthetic base drilling fluid needs to be improved to improve the dynamic shear force at high temperature.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.

The invention also aims to provide the full-environment-friendly high-performance synthetic base drilling fluid which is low in production raw material price and production cost, and the original synthetic base drilling fluid is improved by adding one or a combination of a plurality of polyisobutylene, an ethylene-propylene copolymer and a hydrogenated styrene-isoprene copolymer, so that the obtained synthetic base drilling fluid has better viscosity and higher dynamic shear force under the high-temperature and high-pressure environment.

To achieve these objects and other advantages in accordance with the present invention, there is provided a live, all-environmentally friendly, high performance synthetic based drilling fluid comprising:

78-88 parts of base oil, 2-3 parts of a main emulsifier, 0.5-1.5 parts of an auxiliary emulsifier, 1-2 parts of sodium bentonite, 26-30 parts of 30% potassium acetate brine, 5-10 parts of oil-soluble fiber, 0.3-0.5 part of a tackifier, 3-5 parts of a filtrate reducer and 20-30 parts of barite;

the base oil is one or a combination of more of linear α -olefin, internal olefin and vegetable oil, the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride, the tackifier is one or a combination of more of polyisobutylene, an ethylene-propylene copolymer and a hydrogenated styrene-isoprene copolymer, and the filtrate reducer is organic lignite or modified humic acid.

Preferably, the oil-soluble fiber comprises 78 parts of base oil, 3 parts of a main emulsifier, 1 part of an auxiliary emulsifier, 1.5 parts of sodium bentonite, 28 parts of 30% potassium acetate brine, 10 parts of oil-soluble fiber, 0.3 part of a tackifier, 3 parts of a fluid loss additive and 24 parts of barite in parts by weight.

Preferably, the tall oil fatty acid has an acid value of from 180mgKOH/g to 205 mgKOH/g.

Preferably, the auxiliary emulsifier is one or more of oleic acid, naphthenic acid amide, coconut oil fatty acid diethanolamide, octyl phenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether.

Preferably, the oil-soluble fiber is one or a combination of more of straw powder, walnut shell powder and carbon fiber powder.

Preferably, the ethylene-propylene copolymer has a relative molecular weight of 7X 10⁴～15×10⁴The relative molecular weight of the hydrogenated styrene-isoprene copolymer was 5X 10⁴～10×10⁴。

Preferably, the sodium bentonite is subjected to modification treatment before use, and the specific method comprises the steps of adding the sodium bentonite into cationic starch, heating and stirring for 2 hours in a water bath at 80 ℃, filtering, drying, and grinding to obtain powder with the particle size of 68-75 microns.

Preferably, one half of the total amount of the tackifier is filled through a pressure-sensitive slow-release device and then added into the fully environment-friendly high-performance synthetic base drilling fluid, and the pressure-sensitive slow-release device comprises:

the shell is a hollow sphere, and the tackifier is filled in the shell;

the backup pad, it sets up in the shell, the backup pad be circular and with shell inner wall connection, on the shell with the backup pad is perpendicular and pass through liquid hole has been seted up in the direction at backup pad center, go out the liquid hole through one with go out liquid hole size assorted shutoff board and connect, the shutoff board with be equipped with a pair of just right fixing base on the relative face of backup pad, a stereoplasm compression spring's both ends are connected respectively fixing base on the shutoff board and corresponding fixing base in the backup pad, the circumference in liquid hole becomes the echelonment structure, compression spring is compression state for liquid hole is blocked up to the shutoff board.

Preferably, the outer wall of the shell is provided with a weight increasing ring groove, and the weight increasing ring groove is clamped with weight increasing rings with different weights.

Preferably, a liquid filling hole is formed in the position, close to the supporting plate, on the shell, a circle of sealing ring groove is formed in the position, where the liquid filling hole is located, in the shell, the liquid filling hole is located in the sealing ring groove, and a sealing ring is arranged in the sealing ring groove.

The invention at least comprises the following beneficial effects:

firstly, the EC of each treating agent adopted by the full-environment-friendly high-performance drilling fluid provided by the invention₅₀Are all greater than 4 × 10⁴mg/L, the adopted base oil is LAO, IO and vegetable oil which can be effectively biodegraded, thereby ensuring the non-toxicity and environmental protection of the drilling fluid;

secondly, by adding the tackifiers polyisobutylene, the ethylene-propylene copolymer and the hydrogenated styrene-isoprene copolymer, the dynamic shear force of the synthetic base drilling fluid in use is increased, so that underground silt is brought out more cleanly;

thirdly, performing cation modification on the sodium bentonite to ensure that the sodium bentonite can be dispersed in the synthetic base drilling fluid more uniformly, and reducing the temperature change of the synthetic base drilling fluid as much as possible;

and fourthly, the pressure-sensitive slow release device is adopted, the tackifier is partially filled into the device, when the device enters the bottom of the well along with the increase of the pressure in the well while drilling well fluid, and simultaneously, the drill bit drives the silt to impact the pressure-sensitive slow release device when rotating, so that the tackifier in the device is slowly released, the dynamic shear force of the drilling fluid is further improved, the mobility of the drilling fluid initially entering the well is not influenced, and the defect that the dynamic shear force of the synthetic-base drilling fluid is insufficient when the environmental temperature changes is relieved.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

Fig. 1 is a schematic structural diagram of a pressure-sensitive sustained-release device according to one embodiment of the present invention.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

< example 1>

A full-environment-friendly synthetic base drilling fluid comprises the following components in parts by weight: 78 parts of base oil, 3 parts of a main emulsifier, 1 part of an auxiliary emulsifier, 1.5 parts of sodium bentonite, 28 parts of 30% potassium acetate saline, 10 parts of oil-soluble fiber, 0.3 part of tackifier, 3 parts of filtrate reducer and 24 parts of barite;

wherein the base oil is a combination of linear α -olefin, internal olefin and vegetable oil in a specific weight ratio of 3: 1: 3;

the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride; specifically, at 150 ℃, the tall oil fatty acid and oxygen react with each other and are connected through carbon-carbon bonds, and carbon-carbon double bonds are added under the modification of phthalic anhydride;

the auxiliary emulsifier is oleic acid, naphthenic acid amide and coconut oil fatty acid diethanol amide according to the weight ratio of 1: 1: 1, mixing to obtain;

the tackifier is polyisobutylene and an ethylene-propylene copolymer according to the weight ratio of 1: 1.2 wherein the ethylene-propylene copolymer has a relative molecular weight of 11X 10⁴；

The oil-soluble fiber is straw powder;

the fluid loss additive is organic lignite.

The preparation method of the all-environment-friendly synthetic base drilling fluid comprises the following steps:

s1, adding the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber in parts by weight into the base oil until the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber are fully dissolved, and stirring and mixing the mixture uniformly;

s2, slowly adding the 30% potassium acetate brine in parts by weight into the mixed solution obtained in the step S1, and mixing to form emulsion;

and S3, adding a fluid loss additive and a tackifier into the mixed liquid obtained in the S2, measuring the rheological property of the slurry, adding barite, and uniformly mixing.

< example 2>

A full-environment-friendly synthetic base drilling fluid comprises the following components in parts by weight: 88 parts of base oil, 2 parts of a main emulsifier, 1.5 parts of an auxiliary emulsifier, 2 parts of sodium bentonite, 30 parts of 30% potassium acetate brine, 8 parts of oil-soluble fiber, 0.5 part of tackifier, 5 parts of filtrate reducer and 30 parts of barite;

wherein the base oil is obtained by mixing linear α -olefin and internal olefin according to the weight ratio of 1: 2;

the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride; specifically, at 150 ℃, the tall oil fatty acid and oxygen react with each other and are connected through carbon-carbon bonds, and carbon-carbon double bonds are added under the modification of phthalic anhydride;

the auxiliary emulsifier is oleic acid, naphthenic acid amide and coconut oil fatty acid diethanol amide according to the weight ratio of 1: 1: 1, mixing to obtain;

the tackifier is polyisobutylene and a hydrogenated styrene-isoprene copolymer according to the weight part ratio of 1: 1, the relative molecular weight of the hydrogenated styrene-isoprene copolymer is 8X 10⁴；

The oil-soluble fiber is straw powder and walnut shell powder according to the weight ratio of 1: 1, mixing to obtain;

the filtrate reducer is modified humic acid.

The preparation method of the all-environment-friendly synthetic base drilling fluid comprises the following steps:

s1, adding the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber in parts by weight into the base oil until the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber are fully dissolved, and stirring and mixing the mixture uniformly;

s2, slowly adding the 30% potassium acetate brine in parts by weight into the mixed solution obtained in the step S1, and mixing to form emulsion;

and S3, adding a fluid loss additive and a tackifier into the mixed liquid obtained in the S2, measuring the rheological property of the slurry, adding barite, and uniformly mixing.

< example 3>

A full-environment-friendly synthetic base drilling fluid comprises the following components in parts by weight: 82 parts of base oil, 2.6 parts of a main emulsifier, 0.5 part of an auxiliary emulsifier, 1 part of sodium bentonite, 26 parts of 30% potassium acetate saline, 5 parts of oil-soluble fiber, 0.4 part of a tackifier, 4 parts of a filtrate reducer and 20 parts of barite;

wherein the base oil is a combination of one or more of linear α -olefins, internal olefins, and vegetable oils;

the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride;

the auxiliary emulsifier is obtained by uniformly mixing oleic acid, octyl phenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether according to the weight ratio of 1: 2: 1;

the tackifier is polyisobutylene and hydrogenated styrene-isoprene copolymer according to the weight ratio of 1: 1, wherein the hydrogenated styrene-isoprene copolymer has a relative molecular weight of 8X 10⁴；

The oil-soluble fiber is straw powder and carbon fiber powder according to the weight ratio of 1: 1, mixing to obtain;

the fluid loss additive comprises organic lignite;

the preparation method of the all-environment-friendly synthetic base drilling fluid comprises the following steps:

preparing modified sodium bentonite: adding the sodium bentonite in parts by weight into cationic starch, heating and stirring for 2 hours in a water bath at 80 ℃, filtering, drying, and grinding to obtain powder with the particle size of 68-75 micrometers;

s1, adding the modified sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber in parts by weight into the base oil until the modified sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber are fully dissolved, and stirring and mixing the mixture uniformly;

s2, slowly adding the 30% potassium acetate brine in parts by weight into the mixed solution obtained in the step S1, and mixing to form emulsion;

and S3, adding a fluid loss additive and a tackifier into the mixed liquid obtained in the S2, measuring the rheological property of the slurry, adding barite, and uniformly mixing.

< example 4>

A full-environment-friendly synthetic base drilling fluid comprises the following components in parts by weight: 78 parts of base oil, 3 parts of a main emulsifier, 1 part of an auxiliary emulsifier, 1.5 parts of sodium bentonite, 28 parts of 30% potassium acetate saline, 10 parts of oil-soluble fiber, 0.3 part of tackifier, 3 parts of filtrate reducer and 24 parts of barite;

wherein the base oil is a combination of linear α -olefin, internal olefin and vegetable oil in a specific weight ratio of 3: 1: 3;

the main emulsifier is obtained by high-temperature oxidation reaction of tall oil fatty acid and phthalic anhydride; specifically, at 150 ℃, the tall oil fatty acid and oxygen react with each other and are connected through carbon-carbon bonds, and carbon-carbon double bonds are added under the modification of phthalic anhydride;

the auxiliary emulsifier is oleic acid, naphthenic acid amide and coconut oil fatty acid diethanol amide according to the weight ratio of 1: 1: 1, mixing to obtain;

the tackifier is polyisobutylene and an ethylene-propylene copolymer according to the weight ratio of 1: 1.2 wherein the ethylene-propylene copolymer has a relative molecular weight of 11X 10⁴；

The oil-soluble fiber is straw powder;

the fluid loss additive is organic lignite.

The preparation method of the all-environment-friendly synthetic base drilling fluid comprises the following steps:

s1, adding the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber in parts by weight into the base oil until the sodium bentonite, the main emulsifier, the auxiliary emulsifier and the oil-soluble fiber are fully dissolved, and stirring and mixing the mixture uniformly;

s2, slowly adding the 30% potassium acetate brine in parts by weight into the mixed solution obtained in the step S1, and mixing to form emulsion;

and S3, adding half of the weight parts of the filtrate reducer and the tackifier into the mixture obtained in the step S2, uniformly stirring, adding barite, uniformly mixing to obtain a primary drilling fluid product, finally injecting the other half of the tackifier into a pressure-sensitive slow release device, and adding the pressure-sensitive slow release device into the primary drilling fluid product before the drilling fluid is put into a well.

One half of the total amount of the tackifier is filled through a pressure-sensitive slow-release device and then added into the full-environment-friendly high-performance synthetic base drilling fluid, the diameter of the pressure-sensitive slow-release device is 2-5 mm, and the pressure-sensitive slow-release device comprises:

the shell 1 is a hollow sphere, and the tackifier is filled in the shell 1;

the supporting plate 2 is arranged in the shell 1, the supporting plate 2 is circular and is connected with the inner wall of the shell 1, a liquid outlet hole is formed in the shell 1 in a direction perpendicular to the supporting plate 2 and passing through the center of the supporting plate 2, the liquid outlet hole is connected with a blocking plate 3 matched with the size of the liquid outlet hole, a pair of opposite fixed seats 4 are arranged on the opposite surface of the blocking plate 3 and the supporting plate 2, two ends of a hard compression spring 5 are respectively connected with the fixed seats 4 on the blocking plate 3 and the corresponding fixed seats 4 on the supporting plate 2, the circumferential direction of the liquid outlet hole is of a stepped structure, and the compression spring 5 is in a compression state, so that the liquid outlet hole is blocked by the blocking plate 3;

the outer wall of the shell 1 is provided with a weighting ring 6 groove, and the weighting ring 6 groove is clamped with weighting rings 6 with different weights; the weight increasing rings with different weights are arranged, so that the position of the pressure-sensitive slow-release device in the drilling fluid can be adjusted, the weight increasing rings are arranged in a detachable connection mode, and a plurality of batches of pressure-sensitive slow-release devices with different weights can be arranged in the drilling fluid to ensure that the tackifier is released uniformly and effectively;

a liquid filling hole 7 is formed in the position, close to the supporting plate 2, on the shell 1, a circle of sealing ring groove is formed in the position, where the liquid filling hole 7 is located, in the shell 1, the liquid filling hole 7 is located in the sealing ring groove, and a sealing ring 8 is arranged in the sealing ring groove;

filling the tackifier into the device through the liquid filling hole, and when the device is filled, extruding the tackifier to the sealing ring to block the liquid filling hole;

adopt the device, along with the increase of well internal pressure when the device enters into the shaft bottom along with well drilling fluid, drive silt drill chip striking pressure when the drill bit rotates simultaneously and feel the sustained-release devices for the tackifier in the device slowly releases, and then improves the dynamic shear of drilling fluid, does not influence the mobility that the drilling fluid just entered in the pit on the one hand, also alleviates simultaneously when ambient temperature changes that synthetic base drilling fluid moves the shear not enough, is difficult to take away the shortcoming of drill chip.

< comparative example 1>

The other formulation and preparation steps were the same as in example 1, except that no tackifier was added.

< comparative example 2>

The other formulation and preparation steps were the same as in example 3, except that the sodium bentonite was not modified.

Examples of the experiments

The environmental evaluation performance of each component and the total system of the drilling fluid in the embodiment 1;

TABLE 1

As can be seen from table 1, the components in example 1 of the present invention are all non-toxic materials with good biodegradability, and do not contain toxic components such as asphalt and heavy metal salts, so as to meet the requirements of the all-environmental protection drilling fluid.

Secondly, detecting the performance of the drilling fluid;

aging the drilling fluid obtained in the example 1 for 16 hours under the aging conditions of 100 ℃, 150 ℃, 180 ℃ and 220 ℃, and detecting the performance of the drilling fluid, wherein the density is 1.2g/cm³The specific results are shown in Table 2; aging the drilling fluid of the comparative example 1 for 16h under the aging conditions of 100 ℃, 150 ℃, 180 ℃ and 220 ℃, and detecting the performance of the drilling fluid, wherein the density is 1.2g/cm³The specific results are shown in Table 3;

TABLE 2

TABLE 3

As can be seen from tables 2 and 3, with the increase of temperature, the rheological property of the drilling fluid of example 1 is in a form of increasing, then decreasing and then smoothing the region, and compared with the drilling fluid of comparative example 1 without tackifier, the decrease of dynamic shear force of the drilling fluid of example 1 is obviously slowed down under high temperature conditions;