Bag type suspending agent and preparation method thereof

Abstract

The invention provides a one-bag type suspending agent. Compared with the prior art, the one-bag type suspending agent provided by the invention adopts the components with specific contents, and the components have good interaction, so that the obtained well cementation flushing spacer fluid or drilling fluid thick plug has the characteristics of low viscosity and high shear, thereby having good suspending capacity, being capable of remarkably improving the suspending stability, being capable of preparing a high-density suspension, and being suitable for being used as a well cementation flushing spacer fluid or drilling fluid thick plug. Meanwhile, the selected raw materials are all natural materials, have the non-toxic characteristic, are safe to the environment and are beneficial to environmental protection; the one-bag type suspending agent is simple in preparation method, convenient to construct and suitable for large-scale industrial production and application.

Description

Technical Field

[0001] This invention belongs to the field of oilfield chemical technology, and particularly relates to a one-bag suspension agent and its preparation method. Background Technology

[0002] Drilling and completion fluid is a circulating fluid used to ensure safe and efficient drilling operations during the drilling and completion process. Drilling fluids are classified into water-based drilling fluids, oil-based drilling fluids, gas-based drilling fluids, and gas-liquid mixed drilling fluids, among which water-based drilling fluids are the most widely used type; completion fluid generally refers to cementing slurry.

[0003] During drilling and completion, special operations are sometimes required. For example, if wellbore collapse or instability occurs, drilling fluid thickening is typically used to promptly remove drill cuttings and debris. This involves increasing the viscosity and shear strength of the drilling fluid to effectively clean the wellbore. Another example is the use of flushing and isolating fluids before cementing to clean the wellbore and prevent mixing between the drilling fluid and cement slurry. To balance formation pressure, weighting materials such as barite powder are added to the flushing and isolating fluid. To suspend these weighting materials, the flushing and isolating fluid should have a good suspension capacity. All of the above drilling fluid formulations require the use of suspending agents to improve the viscosity and shear strength of the drilling fluid thickening and flushing and isolating fluids.

[0004] Currently, single-component bentonite or polymer suspensions are commonly used in field operations. However, these methods suffer from low shear strength, failing to effectively carry drill cuttings or causing spalling, and the flushing fluid is prone to stratification. Therefore, researching a single-bag suspension agent with good suspension performance, simple construction, and wide applicability is of significant strategic importance in providing technical support for oil drilling. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a one-bag suspending agent with good suspending ability and its preparation method.

[0006] This invention provides a single-bag suspension, comprising:

[0007] 30-70 parts by weight of bentonite;

[0008] Hydration accelerator 1.5–3.5 parts by weight;

[0009] 5-40 parts by weight of thickener;

[0010] 3-15 parts by weight of cutting agent;

[0011] Dispersant 5-30 parts by weight;

[0012] 3 to 20 parts by weight of fiber material;

[0013] The hydration accelerator is selected from inorganic alkalis;

[0014] The thickener is selected from one or more of biopolymers, cellulose, and starch;

[0015] The slicing agent is selected from sclerosomannan and / or modified sclerosomannan;

[0016] The dispersant is selected from diatomaceous earth;

[0017] The fiber material is selected from fabric fibers and / or mineral fibers.

[0018] Preferably, the hydration accelerator is selected from one or more of sodium carbonate, sodium hydroxide, and potassium hydroxide.

[0019] Preferably, the thickener is selected from one or more of xanthan gum, high-viscosity sodium carboxymethyl cellulose, high-viscosity polyanionic cellulose, pregelatinized starch, and carboxypropyl methyl cellulose.

[0020] Preferably, the modified sclerodeon has the structure shown in Formula I:

[0021]

[0022] In Formula I, n is 7400–7600, o is 1–20, p is 1–20, q is 1–20, w is 1–20, and M is K or Na.

[0023] Preferably, the fiber material is selected from bamboo fiber and / or silicate fiber.

[0024] Preferably, the length of the fiber material is 75–380 μm; the aspect ratio of the fiber material is 7–13.

[0025] The present invention also provides a method for preparing the above-mentioned one-bag suspension, comprising the following steps:

[0026] Bentonite is mixed with a hydration accelerator, then a thickener and a cutting agent are added and mixed together, and finally a dispersant is added and mixed evenly with the fiber material to obtain a one-bag suspension.

[0027] The present invention also provides a drilling fluid comprising the above-described bagged suspending agent.

[0028] Preferably, the mass of the bagged suspension is 1% to 4% of the drilling fluid mass.

[0029] The present invention also provides a rinsing and isolation fluid, comprising the above-described bagged suspension.

[0030] This invention provides a one-bag suspension agent, comprising: 30-70 parts by weight of bentonite; 1.5-3.5 parts by weight of hydration accelerator; 5-40 parts by weight of thickener; 3-15 parts by weight of cutting agent; 5-30 parts by weight of dispersant; and 3-20 parts by weight of fibrous material. The hydration accelerator is selected from inorganic alkalis; the thickener is selected from one or more of biopolymers, cellulose, and starch; the cutting agent is selected from stearin and / or modified stearin; the dispersant is selected from diatomaceous earth; and the fibrous material is selected from textile fibers and / or mineral fibers. Compared with existing technologies, the one-bag suspension provided by this invention uses components with specific content, and the components have good interaction with each other, so that the resulting cementing flushing and isolation fluid or drilling fluid thickening agent has low viscosity and high shear rate, thus having good suspension ability, significantly improving suspension stability, and can be used to prepare high-density suspensions. At the same time, since the selected raw materials are all natural materials, they have non-toxic properties, are environmentally safe, and are beneficial to environmental protection. Moreover, the preparation method of this one-bag suspension is simple, easy to construct, and suitable for large-scale industrial production and application.

[0031] Experiments show that the one-bag suspending agent provided by this invention has good suspension effect and is suitable for densities of 1.01–2.2 g / cm³. 3 It is suitable for drilling fluids and flushing fluids, formations with temperatures ranging from 15 to 180°C, and has good environmental performance. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides a single-bag suspension, comprising:

[0034] 30-70 parts by weight of bentonite;

[0035] Hydration accelerator 1.5–3.5 parts by weight;

[0036] 5-40 parts by weight of thickener;

[0037] 3-15 parts by weight of cutting agent;

[0038] Dispersant 5-30 parts by weight;

[0039] 3 to 20 parts by weight of fiber material;

[0040] The hydration accelerator is selected from inorganic alkalis;

[0041] The thickener is selected from one or more of biopolymers, cellulose, and starch;

[0042] The slicing agent is selected from sclerosomannan and / or modified sclerosomannan;

[0043] The dispersant is selected from diatomaceous earth;

[0044] The fiber material is selected from fabric fibers and / or mineral fibers.

[0045] According to the present invention, the bentonite is preferably drilling bentonite, which meets the requirements of OCMA grade bentonite in GB / T / 5005 "Drilling Fluid Material Specification"; the content of the bentonite in a bag suspension is preferably 35-65 parts by weight, more preferably 40-60 parts by weight; in some embodiments provided by the present invention, the content of the bentonite in a bag suspension is specifically 40 parts by weight, 60 parts by weight, 50 parts by weight or 45 parts by weight; adding bentonite to the suspension has a slurry-forming effect.

[0046] According to the present invention, the hydration accelerator is an inorganic alkali, preferably one or more of sodium carbonate, sodium hydroxide and potassium hydroxide; the content of the hydration accelerator in a bag-type suspension is preferably 2 to 3 parts by weight; the hydration accelerator has the functions of eliminating calcium and magnesium ions in water, improving the hydration dispersion and pulping effect of bentonite.

[0047] According to the present invention, the thickener is one or more of biopolymers, cellulose, and starch, preferably one or more of xanthan gum, high-viscosity sodium carboxymethyl cellulose, high-viscosity polyanionic cellulose, pregelatinized starch, and carboxypropyl methyl cellulose; the molecular weight of the hydroxypropyl methyl cellulose is preferably 100,000 to 300,000, more preferably 150,000 to 250,000, even more preferably 180,000 to 220,000, and most preferably 200,000; the viscosity of the thickener is preferably 10,000 to 30,000 mPa·s, more preferably 15,000 to 25,000 mPa·s; the content of the thickener in a bag-type suspension is preferably 10 to 35 parts by weight, more preferably 15 to 30 parts by weight, and even more preferably 17 to 25 parts by weight; in some embodiments provided by the present invention, the content of the thickener in a bag-type suspension is specifically 23 parts by weight, 15 parts by weight, 17 parts by weight, 25 parts by weight, or 20 parts by weight. The thickener has the function of increasing viscosity.

[0048] According to the present invention, the slicing agent is stearin and / or modified stearin, more preferably modified stearin; the modified stearin preferably has the structure shown in Formula I:

[0049]

[0050] In Formula I: n is 7400-7600, preferably 7450-7550, and most preferably 7500; o is 1-20, preferably 5-15, more preferably 8-12, and most preferably 10; p is 1-20, preferably 5-15, more preferably 8-12, and most preferably 10; q is 1-20, preferably 5-15, more preferably 8-12, and most preferably 10; w is 1-20, preferably 5-15, more preferably 8-12, and most preferably 10; M is K or Na. The content of the cutting agent in the bagged suspension is preferably 3-12 parts by weight, more preferably 5-10 parts by weight; in some embodiments provided by the present invention, the content of the cutting agent in the bagged suspension is specifically 10 parts by weight, 5 parts by weight, 8 parts by weight, or 10 parts by weight. Adding sclerodecane and / or modified sclerodecane as a cutting agent to the suspension can improve the cutting force of the bagged suspension.

[0051] According to the present invention, the dispersant is diatomaceous earth, which has the function of uniformly dispersing the thickener and the shearing agent and avoiding agglomeration during the dissolution process; the content of the dispersant in a bag suspension is preferably 10 to 30 parts by weight, more preferably 10 to 25 parts by weight, and even more preferably 10 to 20 parts by weight; in some embodiments provided by the present invention, the content of the dispersant in a bag suspension is specifically 20 parts by weight, 10 parts by weight, 15 parts by weight, or 12 parts by weight.

[0052] According to the present invention, the fiber material has the function of bridging and improving suspension capacity. The length of the fiber material is preferably 75-380 μm; the aspect ratio of the fiber material is preferably 7-13; the content of the fiber material in a bag-type suspending agent is preferably 5-20 parts by weight, more preferably 5-18 parts by weight, and even more preferably 5-15 parts by weight. In some embodiments provided by the present invention, the content of the fiber material in a bag-type suspending agent is specifically 5 parts by weight, 7 parts by weight, 6 parts by weight, or 15 parts by weight.

[0053] The one-bag suspension agent provided by this invention uses components with specific content, and the components have good interaction with each other, so that the resulting cementing flushing and isolation fluid or drilling fluid thickening agent has low viscosity and high shear rate, thus having good suspension ability and significantly improving suspension stability. It can be used to prepare high-density suspensions. At the same time, since the selected raw materials are all natural materials, they have non-toxic properties, are environmentally safe, and are beneficial to environmental protection. Moreover, the preparation method of this one-bag suspension agent is simple, easy to construct, and suitable for large-scale industrial production and application.

[0054] The present invention also provides a method for preparing the above-mentioned one-bag suspension, comprising the following steps: mixing bentonite with a hydration accelerator, then adding a thickener and a cutting agent and mixing them together, then adding a dispersant and mixing them evenly with fiber materials to obtain a one-bag suspension.

[0055] This invention does not impose any special restrictions on the source of any raw materials; commercially available materials are acceptable. The bentonite, hydration accelerator, thickener, cutting agent, dispersant, and fiber material are all as described above and will not be repeated here.

[0056] The present invention also provides a drilling fluid comprising the above-described bagged suspending agent.

[0057] More specifically, the drilling fluid is preferably a water-based drilling fluid.

[0058] More specifically, the density of the drilling fluid is preferably 1.01–2.2 g / cm³. 3 In some embodiments provided by this invention, the density of the drilling fluid is specifically 1.01 g / cm³. 3 1.5g / cm 3 1.8g / cm 3 2.0g / cm 3 Or 2.2g / cm 3 .

[0059] More specifically, the mass of the bagged suspension is preferably 1% to 5% of the drilling fluid mass, more preferably 1% to 4%; in some embodiments provided by the present invention, the mass of the bagged suspension is specifically 1%, 2%, 3% or 4% of the drilling fluid mass.

[0060] More specifically, the drilling fluid is suitable for formations with temperatures ranging from 15°C to 180°C.

[0061] The present invention also provides a rinsing and isolation fluid, comprising the above-described bagged suspension.

[0062] More specifically, the mass of the bag-type suspension is preferably 1% to 4% of the mass of the rinsing and isolation fluid; in some embodiments provided by the present invention, the mass of the bag-type suspension is specifically 1%, 2%, 3% or 4% of the mass of the rinsing and isolation fluid.

[0063] More specifically, the density of the rinsing and isolating fluid is preferably 1.01–2.2 g / cm³. 3 In some embodiments provided by this invention, the density of the rinsing and isolating fluid is specifically 1.01 g / cm³. 3 1.5g / cm 3 1.8g / cm 3 2.0g / cm 3 Or 2.2g / cm 3 .

[0064] More specifically, the flushing and isolation fluid is suitable for formations with temperatures ranging from 15°C to 180°C.

[0065] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a one-bag suspension agent and its preparation method provided by the present invention.

[0066] All reagents used in the following examples are commercially available. The bentonite used in the examples was provided by Puyang Jintai Chemical Co., Ltd.; the hydration accelerators were sodium carbonate (A1), sodium hydroxide (A2), and potassium hydroxide (A3) provided by Tianjin Kemei Chemical Reagent Co., Ltd.; the thickeners were xanthan gum (XC) (B1) provided by Ordos Zhongxuan Biochemical Co., Ltd., sodium carboxymethyl cellulose (HV-CMC) (B2) and polyanionic cellulose (HV-PAC) (B3) provided by Puyang Jintai Chemical Co., Ltd., pregelatinized starch (B4) provided by Jiangsu Puleisi Biotechnology Co., Ltd., or hydroxypropyl methylcellulose (HPMC, fast-dissolving hydroxypropyl methylcellulose HPMC, specification 20000, viscosity range 15000~25000 mPa.s) provided by Shanxi Zhicheng Cellulose Co., Ltd.; the cutting agent was the modified hard dextran high-temperature resistant thickening and cutting agent of Example 5 (CN113087846A); the dispersant was diatomaceous earth provided by Qingdao Shengtai Silicon Industry Co., Ltd., and the fluxing calcined diatomaceous earth filter aid DZ. 200; The fiber material is C1 bamboo fiber or C2 silicate fiber provided by Puyang Huashuo Chemical Co., Ltd., with a fiber length of 75-380μm and an aspect ratio of 7-13.

[0067] Example 1

[0068] (1) Mix 40g of bentonite and 2g of hydration accelerator A1 thoroughly.

[0069] (2) Add 23g of thickener B2 and 10g of modified hard dextran to step (1) and mix well.

[0070] (3) Add 20g of diatomaceous earth and 5g of fiber material C2 to step (2), mix evenly, and obtain a bag suspension.

[0071] Example 2

[0072] (1) Mix 60g of bentonite and 3g of hydration accelerator A2 thoroughly.

[0073] (2) Add 15g of thickener B1 and 5g of modified hard dextran to step (1) and mix well.

[0074] (3) Add 10g of diatomaceous earth and 7g of fiber material C1 to step (2), mix evenly, and obtain a bag suspension.

[0075] Example 3

[0076] (1) Mix 50g of bentonite and 3g of hydration accelerator A3 thoroughly.

[0077] (2) Add 17g of thickener B3 and 8g of modified hard dextran to step (1) and mix well.

[0078] (3) Add 15g of diatomaceous earth and 7g of fiber material C2 to step (2), mix evenly, and obtain a bag suspension.

[0079] Example 4

[0080] (1) Mix 45g of bentonite and 2g of hydration accelerator A1 thoroughly.

[0081] (2) Add 25g B4 and 10g modified hard glucan to step (1) and mix well.

[0082] (3) Add 12g of diatomaceous earth and 6g of fiber material C1 to step (2), mix evenly, and obtain a bag suspension.

[0083] Example 5

[0084] (1) Mix 45g of bentonite and 2g of hydration accelerator A1 thoroughly.

[0085] (2) Add 20g of thickener B5 and 8g of modified hard dextran to step (1) and mix well.

[0086] (3) Add 10g of diatomaceous earth and 15g of fiber material C1 to step (2), mix evenly, and obtain a bag suspension.

[0087] Example 6

[0088] (1) Mix 50g of bentonite and 3g of hydration accelerator A2 thoroughly.

[0089] (2) Add 20g of thickener B2 and 10g of modified hard dextran to step (1) and mix well.

[0090] (3) Add 10g of diatomaceous earth and 7g of fiber material C2 to step (2), mix evenly, and obtain a bag suspension.

[0091] The performance of the bagged suspensions obtained in Examples 1-6 was evaluated. 400 mL of water was taken, and 8 g of the bagged suspensions obtained in Examples 1-6 were added to each. The mixture was stirred at 8000 r / min for 20 min to obtain the suspension. The suspensions were measured and calculated according to GB / T16783.1 "Field Testing of Drilling Fluids for Petroleum and Natural Gas Industry - Part 1: Water-based Drilling Fluids" at room temperature (20℃). The test results are shown in Table 1. The biotoxicity evaluation experiment of the bagged suspensions provided by this invention was conducted according to the national standard GB / T 15441-1995 "Determination of Acute Toxicity of Water - Luminescent Bacteria Method". The toxicity of Examples 1-6 was measured, and the test results are shown in Table 1.

[0092] Table 1. Performance and toxicity test results of single-bag suspension.

[0093]

[0094]

[0095] As shown in Table 1, the bag-type suspension prepared in Examples 1 to 6 of the present invention has good viscosity and shear force, and the filtration loss is well controlled; the suspension provided by the present invention is non-biotoxic and beneficial to environmental protection.

[0096] The performance of the one-bag suspension prepared in Example 5 was evaluated after different dosages, aging at different temperatures, and different densities. The experimental results are shown in Tables 2 to 4. Suspensions of different densities were obtained by adjusting the amount of barite added.

[0097] Table 2 Performance of different dosages in Example 5

[0098]

[0099] Table 3 Performance of Example 5 after aging at different temperatures

[0100]

[0101] Note: The dosage in Example 5 was 3%.

[0102] Table 4 shows the performance of preparing suspensions of different densities in Example 5.

[0103]

[0104]

[0105] As shown in Tables 2-4, in Example 5 of the present invention, with the increase of the dosage, the viscosity and shear force of the suspension showed an increasing trend, while the filtration loss gradually decreased. After aging at 150℃ for 4 hours, the suspension did not separate into layers and still maintained good viscosity and shear force, indicating that the present invention can withstand temperatures up to 150℃. The prepared density was 2.2 g / cm³. 3 The suspension remained stable after standing for 4 hours without stratification, indicating that the present invention achieves a density of 2.2 g / cm³. 3 It can still effectively suspend barite powder.

[0106] Comparative Example 1

[0107] A one-bag suspension was obtained according to the preparation method provided in Example 5; the difference is that in Comparative Example 1, bentonite was replaced with salt-resistant clay (purchased from Lingshou County Huimao Mineral Products Processing Plant).

[0108] Comparative Example 2

[0109] According to the preparation method provided in Example 5, a bag-type suspension was obtained; the difference is that the thickener used in Comparative Example 2 is low-viscosity sodium carboxymethyl cellulose (3% suspension, six-speed rotational viscometer reading ≤90 at 600 r / min, which meets the requirements of Q / SHCG0165).

[0110] Comparative Example 3

[0111] Following the preparation method provided in Example 5, a one-bag suspension was obtained; the difference being that in Comparative Example 3, diatomaceous earth was replaced with organic bentonite (purchased from Zhejiang Fenghong New Material Co., Ltd.).

[0112] Comparative Example 4

[0113] A one-bag suspension was obtained according to the preparation method provided in Example 5; the difference is that the component ratio of Comparative Example 4 is different from that of Example 5.

[0114] (1) Mix 65g of bentonite and 4g of hydration accelerator A1 thoroughly.

[0115] (2) Add 1g of thickener B5 and 1g of modified hard dextran to step (1) and mix well.

[0116] (3) Add 4g of diatomaceous earth and 25g of fiber material C1 to step (2), mix evenly, and obtain a bag suspension.

[0117] Take 400g of water and add 8g of the one-bag suspension prepared in Comparative Examples 1-4 and Example 5 respectively. Stir for 20min at 8000r / min high speed stirring. The performance of the suspension is measured at room temperature. The results are shown in Table 5.

[0118] Table 5 shows the performance of Comparative Examples 1-4 and Example 5.

[0119]

[0120] As shown in Table 5, the data comparison between Example 5 and Comparative Examples 1-4 demonstrates that the specific hydration accelerator, thickener, shearing agent, dispersant, and fiber material used in this invention have a good synergistic effect, enabling the one-bag suspension provided by this invention to have better performance.

[0121] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A single-bag suspension concentrate, characterized in that, include: The hydration accelerator is selected from inorganic alkalis; The thickener is selected from one or more of biopolymers, cellulose, and starch; The slicing agent is selected from sclerosomannan and / or modified sclerosomannan; The dispersant is selected from diatomaceous earth; The fiber material is selected from fabric fibers and / or mineral fibers.

2. The single-bag suspension according to claim 1, characterized in that, The hydration accelerator is selected from one or more of sodium carbonate, sodium hydroxide, and potassium hydroxide.

3. The single-bag suspension according to claim 1, characterized in that, The thickener is selected from one or more of xanthan gum, high-viscosity sodium carboxymethyl cellulose, high-viscosity polyanionic cellulose, pregelatinized starch, and carboxypropyl methyl cellulose.

4. The single-bag suspension according to claim 1, characterized in that, The modified sclerodecanol has the structure shown in Formula I: In Formula I, n is 7400–7600, o is 1–20, p is 1–20, q is 1–20, w is 1–20, and M is K or Na.

5. The single-bag suspension according to claim 1, characterized in that, The fiber material is selected from bamboo fiber and / or silicate fiber.

6. The single-bag suspension according to claim 1, characterized in that, The length of the fiber material is 75–380 μm; the aspect ratio of the fiber material is 7–13.

7. A method for preparing a bag-type suspension according to claim 1, characterized in that, Includes the following steps: Bentonite is mixed with a hydration accelerator, then a thickener and a cutting agent are added and mixed together, and finally a dispersant is added and mixed evenly with the fiber material to obtain a one-bag suspension.

8. A drilling fluid, characterized in that, Includes the bag-type suspension as described in any one of claims 1 to 6 or the bag-type suspension prepared by the preparation method described in claim 7.

9. The drilling fluid according to claim 8, characterized in that, The mass of the bagged suspension is 1% to 4% of the drilling fluid mass.

10. A flushing and isolating fluid, characterized in that, Includes the bag-type suspension as described in any one of claims 1 to 6 or the bag-type suspension prepared by the preparation method described in claim 7.

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