JPH07776B2 - Additive for drilling stabilization liquid - Google Patents

Description

TECHNICAL FIELD The present invention relates to an additive for a drilling stabilization liquid.

[Prior Art] Conventionally, bentonite-based stabilizers and polymer-based stabilizers have been used in the ground excavation method, but it is known that the performance of the stabilizers deteriorates due to the inclusion of seawater, cement, and other electrolytes. Has been.

Therefore, an additive composed of a monovalent salt of polyacrylic acid having a degree of polymerization of 5,000 or less and sodium fiber glycolate (CMC) has been proposed (for example, Japanese Patent Publication No. 4946763).

[Problems to be Solved by the Invention] However, the conventional techniques have a problem in that deterioration of the stabilizing solution performance due to the mixing of seawater, cement, etc. is not sufficient, and deterioration due to decay due to bacteria occurs.

[Means for Solving Problems] The inventors of the present invention have arrived at the present invention as a result of extensive studies to solve the deterioration of stable liquid performance due to the mixing of seawater, cement, etc. and the deterioration due to bacteria.

That is, according to the present invention, a monovalent salt (a) of an unsaturated carboxylic acid type (co) polymer having a degree of polymerization of 5,000 or less and a group II or group
An additive for a drilling stabilization liquid, which comprises a compound (b) selected from the group consisting of Group III metal oxides, sodium alum, potassium alum, and ammonium alum.

Examples of the monovalent salt (a) of the unsaturated carboxylic acid (co) polymer having a degree of polymerization of 5,000 or less in the present invention include unsaturated carboxylic acids (unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; Unsaturated dicarboxylic acids such as fumaric acid, maleic acid and itaconic acid) and monohydric salts of (co) polymers obtained by copolymerizing monomers such as anhydrides (such as maleic anhydride). The monovalent salts include alkali metal salts (sodium salt, potassium salt, etc.), ammonium salts and amine salts [monoethanolamine, diethanolamine, triethanolamine,
Alkyl (C ₁ -C ₄ ) amine salts and the like]. Preferred are sodium salt and potassium salt. The degree of neutralization is usually 50 to 100%, preferably 80 to 100%.

In the (co) polymer, if necessary, other hydrophilic monomers such as sulfonic acid group-containing monomers [vinylsulfonic acid, arylsulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid and The monovalent salt, etc.],
Hydroxyl group-containing monomer [allyl alcohol, hydroxyethyl (meth) acrylate, etc.], Amido group-containing monomer [(meth) acrylamide, N-methyl (meth)]
Acrylamide, N-hydroxylethyl (meth) acrylamide, N-vinylpyrrolidone and the like], amino group-containing monomer [dimethylaminoethyl (meth) acrylate, morpholinoethyl (meth) acrylate, dimethylaminoethyl fumarate, 2-vinylpyridine , 4-vinylpyridine, N-vinylpyridine, N-vinylimidazoline, etc.], quaternary ammonium salt-containing monomer [N, N, N
-Trimethyl-N-acryloyloxyethylammonium chloride, etc.] and a nitrile group-containing monomer [(meth) acrylonitrile, etc.] may be contained.

The amount of the other hydrophilic monomer is usually 30% or less, preferably 10% or less, based on the weight of all the monomers.

The monovalent salt of the unsaturated carboxylic acid (co) polymer may be polymerized to form a monovalent salt, or a monovalent salt of a monomer may be polymerized.

The degree of polymerization of the unsaturated carboxylic acid (co) polymer is usually 5,00
It is 0 or less, preferably 50 to 2,500. If the degree of polymerization exceeds 5,000, the flocculation action will be strengthened and soil or cement will be easily flocculated, and if heavy metal ions are mixed, it will easily become an insoluble matter and the excavation stabilization liquid will become a gel and the stability performance will deteriorate.

In the compound (b), examples of the group II or group III metal oxide include magnesium oxide, aluminum oxide, and calcium oxide. Of these, preferred is magnesium oxide.

Further, as the compound (b), sodium myoban, potassium myoban and ammonium myoban can be used.

If necessary, a monovalent salt of aluminate may be used in combination with the compound (b). Examples of monovalent salts of aluminic acid include hydrated metaaluminic acid alkali metal salts [M ¹ AlO ₂ · mH ₂ O (M ₁ is an alkali metal) such as NaAlO ₂ 5 / 4H ₂ O, NaAlO ₂ · 3H ₂ O
And KAlO ₂ .3 / 2H ₂ O etc.], anhydrous alkali metal aluminate [M ¹ AlO ₂ such as NaAlO ₂ and KAlO ₂ ; and sodium orthoaluminate such as Na ₃ AlO ₃ ]. In the alkali metal salts of aluminate, M ¹ ₂ O molar ratio of to Al ₂ O ₃ (x) is usually 1.0 to 2.5, preferably 1.0 to 2.0. Among these alkali metal salts, sodium salt is preferable. Sodium aluminate is generally obtained by mixing aluminum oxide hydrate and caustic soda, heating, stirring and reacting. For example,
Aluminum oxide trihydrate and caustic soda at about 100-150 ℃
It can be obtained by reacting at the temperature of 1, and crystallization treatment, but there is no particular limitation on the production method, and any method may be used.

If necessary, an alkali metal carbonate containing potassium carbonate can be used in combination with the compound (b). In the alkali metal carbonate containing potassium carbonate, examples of potassium carbonate include anhydrous salt, monohydrate, dihydrate and pentahydrate. Of these, anhydrous salts are preferred.
In addition to potassium carbonate, other alkali metal carbonates may be contained, and examples of the other alkali metal carbonates include sodium carbonate. Examples of sodium carbonate include anhydrous salt (soda ash), monohydrate and decahydrate, and preferred is soda ash.

The pure content of (a) in the additive for drilling stabilization liquid is usually 15 to 85%, preferably 15 to 85% of the total content of (a) and (b).
30-70%. If it is less than 15%, gelation will occur when cement is mixed, and if it exceeds 85%, gelation will occur when seawater is mixed, and the stability performance will deteriorate in both cases.

The weight ratio of the compound (b) to the alkali metal carbonate containing potassium carbonate is not particularly limited, but is generally 1: 0 to 100.

As a control drilling stabilizing liquid to which the additive of the present invention is added, bentonite, attapulgite, sepiolite,
Examples include inorganic clay-based stabilizers such as sericite and polymer stabilizers having a water-soluble polymer as a skeleton. Of these, the bentonite stabilizing solution is preferable.

The addition amount (net content) of the drilling stabilization liquid additive to the drilling stabilization liquid is usually 0.01 with respect to the total weight of the stabilization liquid composition.
-5%, preferably 005-3%. If it is less than 0.01%, the effect of preventing the deterioration of the stabilizing solution performance due to seawater, cement and other electrolytes cannot be expected, and if it exceeds 5%, the effect of just adding it cannot be expected, which is economically disadvantageous.

When adding the additive of the present invention to the drilling stabilization liquid, the following method may be mentioned as the addition method.

(1) A method in which an inorganic clay, a water-soluble polymer, and the like and the additive for a drilling stabilization liquid of the present invention are simultaneously added to kneading water.

(2) A method in which an inorganic clay, a water-soluble polymer, and the like are put in kneading water in advance and the additive of the present invention is added after swelling these.

Of these addition methods, the method (2) is preferable.

The excavation stabilization additive of the present invention is preferably added while stirring the stabilizing solution. The stable liquid composition for ground excavation thus obtained usually has a specific gravity of 1.01 to 1.35, a funnel viscosity of 21 to 45 seconds, a 10-minute gel strength of 5 lb / 100 ft ² or less, and a dehydration amount of 30 ml or less. Hold.

As an embodiment of carrying out ground excavation using a stable liquid composition, first, the stable liquid composition is prepared by adding the additive of the present invention, an inorganic clay, a water-soluble polymer and the like to water. Next, the ground is excavated by using an excavator while circulating or retaining the stable liquid composition in the excavation portion. In this case, the stable liquid composition always fills the inside of the excavated portion, promotes excavation by absorbing frictional heat, radiating heat, lubricating, etc., and carrying the excavated soil to the ground. Formed to prevent collapse of the borehole wall. After the predetermined excavation is completed in this way, the piles or walls are constructed by filling the excavation section with concrete while inserting the rebar framework appropriately and introducing concrete from the bottom to collect the stabilizing liquid from the excavation groove. The stabilizing liquid replaced with concrete is returned to the tank and reused.

The additive of the present invention contains (a) and (b), but in addition, a dissolution accelerator (for example, ethylene glycol, diethylene glycol, polyethylene glycol, etc.),
A dispersion deflocculant (for example, sodium nitrohumate, tannins, lignin sulfonate, condensed phosphate, etc.) can be appropriately used in combination.

[Examples] Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto. Parts in the examples and comparative examples are based on weight. The temperature of the stabilizing solution is 20 ± 3 ° C. The test methods in Examples and Comparative Examples are as follows.

(1) Funnel viscosity (FV): Measured with a 500 ml funnel viscometer. The unit is seconds. It is an index showing the flow characteristics.

(2) 10 minutes gel strength (10Gel): measured with a fan VG meter. The unit is lb / 100 ft ² . It is an index showing shear stability.

(3) Dehydration amount: 3kg / cm ² using a filter according to API standard
The amount of dehydration was measured after 30 minutes under pressure. The unit is ml. It is an index showing the mud wall forming property.

(4) Stability against mixing with cement: 1 part and 3 parts of Portland cement were added to 100 parts of the stabilizing solution and mixed thoroughly,
After 1 day, the stabilizing solution performances of (1) to (3) above were measured.

(5) Stability against seawater contamination: 0.4 parts and 1.2 parts of "Aquamarine S" (manufactured by Yashu Pharmaceutical Co., Ltd.) in 100 parts of stabilizing solution.
After adding 1 part and mixing thoroughly, 1 day later, the above (1)
The stable liquid performances of (3) to (3) were measured.

Examples 1 to 6 and Comparative Examples 1 to 10 Tables 1 and 2 show the compositions of the additives of the present invention (Examples 1 to 6) and comparative additives (Comparative Examples 1 to 10).

Moreover, the polymers 1-5 and the compounds 1-4 in an Example and a comparative example are shown below.

Polymer 1: Sodium polymethacrylate Polymer 2: Methacrylic acid (60) -acrylic acid (40) Sodium copolymer Polymer 3: Sodium polyacrylate Polymer 4: Acrylic acid (50) -Itaconic acid (50) Copolymer Sodium Polymer 5: Methacrylic Acid (50) -Itaconic Acid (50) Copolymer Sodium () The figures in () indicate% based on the total weight of acrylic acid and methacrylic acid.

Compound 1: Magnesium oxide Compound 2: Potassium myoban Compound 3: Sodium aluminate Compound 4: CMC (etherification degree 1.10, degree of polymerization 750) Add 100 parts of fresh water and 6 parts of bentonite [Kunimine Industries Co., Ltd. Kunigel VI] to the juicer mixer, and
Stir for minutes. After standing for 1 day, the additive for excavation stabilization liquid of the present invention shown in Table 1 and its comparative product were added, and further 2
A stable liquid composition was obtained by stirring for a minute. Table 2 shows the results of examining the performance of the stabilizing solution.

The additives of the present invention of Examples 1 to 6 maintain various properties such as fluidity (FV), shear stability (10 Gel), and mud wall forming property (dehydration amount) even when cement h or seawater is mixed. ing. However, in Comparative Examples 1 to 10, when cement or seawater is mixed,
It is shown that these performances, especially the shear stability (10 Gel), are significantly deteriorated.

It was confirmed that the stabilizers of Comparative Examples 3 and 6 had a putrid odor after being left for 1 week and the viscosity was significantly lowered.

[Advantages of the Invention] The drilling stabilization liquid additive of the present invention has the following advantages.

(1) The composition using the additive of the present invention does not significantly change stable liquid properties (dispersion stability, dehydration amount, etc.) even when seawater flows in during excavation.

(2) In the composition using the additive of the present invention, stable liquid properties (dispersion stability, dehydration amount, etc.) hardly change even when cement or the like is mixed. Therefore, it can be used repeatedly.

(3) Since the composition using the additive of the present invention does not contain biodegradable substances such as CMC, it does not easily decompose.

(4) The composition using the additive of the present invention is excellent in dispersion stability of inorganic clays such as bentonite.

(5) The composition using the additive of the present invention has a small amount of dehydration and is excellent in the mud wall forming property, that is, the drill hole collapse prevention performance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Tanaka, 1-11, Hitotsubashi-Honcho, Higashiyama-ku, Kyoto, Kyoto Prefecture Sanyo Chemical Industry Co., Ltd. 1 Sanyo Chemical Industry Co., Ltd. (56) References Japanese Patent Publication No. 4-8470 (JP, B2)

Claims (5)

[Claims] 1. A monovalent salt (a) of an unsaturated carboxylic acid (co) polymer having a degree of polymerization of 5,000 or less, an oxide of a metal of Group II or Group III, sodium alum, potassium alum and ammonium. An additive for a drilling stabilization liquid, which comprises a compound (b) selected from the group consisting of alum. 2. The unsaturated carboxylic acid is acrylic acid and / or
The additive according to claim 1, which is methacrylic acid. 3. The additive according to claim 1, wherein the unsaturated carboxylic acid is a compound selected from the group consisting of crotonic acid, fumaric acid, maleic acid and itaconic acid. 4. The addition according to any one of claims 1 to 3, wherein the monovalent salt (a) is a salt selected from the group consisting of alkali metal salts, ammonium salts and amine salts. Agent. 5. The method according to any one of claims 1 to 4, wherein the pure amount of (a) is 15 to 85% with respect to the total weight of the pure components of (a) and (b). Additive.