RU2230769C2 - Lubricating additive for drilling fluids - Google Patents

Abstract

FIELD: well boring.

SUBSTANCE: lubricating additive containing triglyceride fatty acids with number of carbon atoms 14-24, neutralization agent, and water additionally contains substituted fatty acid ammonium salts with number of carbon atoms 10-26 to ensure following percentages of ingredients: 50-80% triglyceride fatty acids, 3-6% neutralization agent, 5-40% substituted fatty acid ammonium salts, and water to 100%. Using such additive preserves high characteristics of lubrication properties such as reduction of friction factor on the metal-metal interface, improves antifriction properties such as reduction of coefficient of potential catch-up on metal-clay crust interface in fresh and mineralized drilling fluids, and simultaneously improves surface-active properties of drilling fluid filtrate.

EFFECT: improved performance characteristics.

2 tbl

Description

The invention relates to the drilling of oil, gas and exploration wells, and in particular to lubricating additives - lubricants of drilling fluids.

It is known to use as a lubricant additive for drilling fluids a mixture [1], consisting of the following components, wt.%:

Fatty acid

synthetic and / or natural

with C ₇ and above 20-85

Lower monohydric alcohols

with C _2-5 , polyethylene glycols,

polypropylene glycols 10-40

Inorganic bases

and mixtures thereof as

neutralizing agent 1-8

Nitrogen-containing organic

bases and mixtures thereof 0.1-20

Water Else

The specified composition has low toxicity, improves the lubricating properties of the drilling fluid (friction coefficient of the metal-metal pair). However, the drilling fluid treated with the above composition has low anti-stick (anti-friction) properties of the drilling fluids (potential sticking coefficient - Kp of the metal-clay-peel pair), and also has a slight effect on the surface tension of the drilling fluid filtrate.

The closest analogue is a lubricant additive [2] to drilling fluids, containing, wt.%:

Fatty acids with number

carbon atoms from 16 to 18

ethoxylated 6-12 moles

ethylene oxide 15-40

Fatty acid

with the number of carbon atoms

from 14 to 24 50-80

Neutralizing agent 3-6

Water Else

However, the known composition, along with high lubricating properties of the drilling fluid (metal-metal pair), does not have sufficiently high antifriction properties (metal-clay-peel pair).

The technical task of the invention is the preservation of high rates of lubricating properties, such as a decrease in the coefficient of friction at the metal-metal boundary, an increase in antifriction properties, such as a decrease in the coefficient of potential sticking at the metal-clay crust boundary in fresh and mineralized drilling fluids and at the same time increasing the surface-active properties of the mud filtrate.

The problem is solved in that the lubricant additive for drilling fluids containing fatty acids of triglycerides with the number of carbon atoms from 14 to 24, a neutralizing agent and water, additionally contains substituted ammonium salts of fatty acids with the number of carbon atoms from 10 to 26 in the following ratio of ingredients, wt.%:

Triglyceride Fatty Acids

with carbon number

atoms from 14 to 24 50-80

Neutralizing agent 3-6

Substituted ammonium salts

fatty acids with the number

carbon atoms

from 10 to 26 5-40

Water Else

The compositions of the claimed lubricant additives (examples 2-6), beyond and known (examples 1, 7-9) are shown in table 1.

The claimed lubricant additive is prepared as follows.

A natural fat mass containing triglyceride fatty acids is loaded into the reactor, heated, for example, to 40-50 ° C, then a calculated amount of a neutralizing agent (KOH or another) is added to the reactor to partially neutralize free acids. The mass is stirred for 45-90 minutes. In the process of mixing, the calculated amount of substituted ammonium salts of fatty acids with the number of carbon atoms from 10 to 26 is introduced, the temperature is brought to 60-70 ° C and stirred for 1.5-2.0 hours. The finished product is poured into a container.

Example No. 1 (table 1, composition No. 2): to prepare 1 l of a lubricant additive, take 500 ml of natural fat mass containing triglyceride fatty acids and heat to 40-50 ° C, then add 6 g of KOH. The mass is stirred for 60 minutes on a laboratory stirrer. In the process of mixing, 400 ml of substituted ammonium salts of fatty acids with the number of carbon atoms from 10 to 26 are introduced. The mixture is heated to 60-70 ° C and stirred on a laboratory stirrer for 2.0 hours. Other compositions are similarly prepared, are shown in table 1.

To evaluate the effectiveness of the proposed lubricant additives in laboratory conditions, preliminary studies have been carried out. The influence of the ratio of all the starting ingredients on the technological properties of the fluids on standard instruments was studied in accordance with the methodology for monitoring the parameters of drilling fluids RD 39-22-645-81.

The surface tension (σ, mN / m) of a 0.5% aqueous solution of a lubricant additive at the border with kerosene was determined by the stalagmometric method. The test results of the samples are shown in table 2.

Lubricating properties were determined by the coefficient of friction (Ktr) of the metal-metal pair on an instrument manufactured by NL Baroid (USA) in accordance with the international standard API R13B (at a load of 1.03 MPa, 60 rpm).

The foaming ability of the samples of lubricant additives was evaluated in 1% aqueous solutions, mixed for 3 min at 9500-11000 rpm. Foaming activity (P, cm ³ ) was determined as the difference between the volumes of the foamed solution after 3 min of settling (Vp) and the volume of the initial solution (200 cm ³ ) according to the formula P = Vr-200 cm ³ . Foaming (V,%) of an aqueous solution was calculated by the formula

The antifriction properties were determined by the potential sticking coefficient (Kp) of the metal – clay peel pair on a Sticking Tester from NL Baroid (USA) at a pressure of 3.34 MPa.

Comparative tests of samples 2-6 (Table 1-2) showed the high efficiency of the introduced substituted ammonium salts of fatty acids with the number of carbon atoms from 10 to 26. A decrease in the friction coefficient by 20-25%, the coefficient of potential pipe sticking by 50-60%, and surface tension at the border with the hydrocarbon by 40-50% compared with known lubricating additives (example 1, 7-9, table. 1-2).

Sources of information

1. RF patent No. 2163617, C 09 K 7/02

2. RF patent No. 2106382, C 04 K 7/02, 1998.

Claims (1)

A drilling fluid lubricant additive containing fatty acids of triglycerides with carbon atoms from 14 to 24, a neutralizing agent and water, characterized in that it additionally contains substituted ammonium salts of fatty acids with carbon atoms from 10 to 26 in the following ratio of ingredients, wt .%: Fatty acids of triglycerides with the number of carbon atoms from 14 to 24 50-80 Neutralizing agent 3-6 Substituted ammonium salts of fatty acids with the number of carbon atoms from 10 to 26 5-40 Water Else