SU1388414A1 - Drilling fluid - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells. The purpose of the invention is to increase the heat resistance of the solution to 200.C, reduce the consumption of diesel fuel and increase the stability of the borehole walls. The solution contains ingredients in the following ratio, wt.%: Diesel fuel 5.0–20.0; complex, ester of unsaturated higher acid and polyhydric alcohol 0.1-3.0; cellulose non-ionic esters 0.1-3.0; water the rest. The solution is prepared by introducing into the calculated amount of a solution of ester of unsaturated higher acid and polyhydric alcohol while stirring the calculated amount of the solution of non-ionic cellulose ethers. Stirring is continued for 5-60 minutes, after which the solution is ready for use. If necessary, the solution can be reduced to a given density and saline to the desired salinity. The introduction of cellulose into the solution increases its heat resistance. 2 tab. o (l

Description

one

The invention relates to the drilling of oil and gas wells.

The aim of the invention is to increase the heat resistance of the drilling fluid to 200 seconds, reduce the consumption of oil and increase the stability of the borehole walls,

The drilling fluid containing water, petroleum and emulsifier - complex JQ ester of unsaturated high acid and polyhydric alcohol, additionally contains non-ionic cellulose ethers as an additive in the following ratio, wt.%: 15 Oil product 5.0-20.0 Ester unsaturated higher acid and polyhydric alcohol 0.1-3.0 20 Non-ionic cellulose ethers, 0.1-3.0

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As ester.nenasy-. high acid, and. many atomic-25 alcohol can be used, for example, emultal, pentol, ukramin.

The test results of drilling fluids are presented in table. 1 and 2.

Drilling fluids are prepared in the following way.

, B, the calculated amount of a solution of an ester of an unsaturated higher acid and a polyhydric alcohol in an oil product (petroleum, diesel fuel) with stirring, water, the calculated amount of an aqueous solution of non-onenogenic cellulose ethers. Stirring is continued for 5-60 minutes, after which the drilling fluid is ready for use Q. If necessary, it can be reduced to a given density and saline to the desired mineralization.

Example. 80 ml of a 2% aqueous solution of hydroxyethylcellulose (OEC) are injected with stirring in 20 ml of a 2% solution of emultal in diesel fuel. Stirring is continued for 10 minutes.

PRI mme R 2. First, 90 ml of a 2% aqueous solution of hydroxyethylcellulose containing 30% NaCl and 8% CaClr is prepared. Then in 10 ml of 2%

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lulose (MC) with 5 ml of a 2% aqueous solution of emultal in diesel fuel and mixed.

PRI me R 4. Mix 84.5 ml of a 1.7% aqueous solution of methylcellulose with 12.5 ml of a 12% aqueous solution of emultal in diesel fuel. Then, 30% sodium chloride and 8% calcium chloride, by volume of the solution, are introduced into the resulting solution and mixed.

All other samples of drilling fluids, technological parameters of which were obtained in a similar way (t is conditional viscosity, s; Y is density, g / cm; Q, / Q-, O; static shear stress. Pa; F - filtering, cm; s - coefficient of stability of clay rocks, day stability are given in Tables 1 and 2. The stability of drilling fluids was determined by the method of electrical conductivity.,

These drilling muds are characterized by high sedimentation STABILITY, the precipitation of the dispersed phase was not observed during the entire observation time.

The stability of clay rocks is determined by the swelling of clay rocks by the analytical method proposed by B.D. Gorodnov.

50

With 5pZ (, fr, ° and sp

where is the swelling rate, m / s;

P is the ultimate shear stress. Pa;

Ф - filtrate; b - distilled water.

From the results presented in table. 1 and 2, it follows that the introduction of nonionic cellulose ether as an additive can significantly increase the thermal stability of the drilling fluid up to 200 ° C, reduce the oil product consumption by 30% and increase the stability of the borehole walls.

The introduction of non-ionic cellulose ethers less than 0.1% does not affect the improvement of the properties of the drilling fluid, and their concentration above 3.0% does not lead to a significant improvement in the thermal resistance of the mud and an increase in the stability of the borehole walls.

solution of emultal in diesel top

A salted aqueous solution of ec- etyl cellulose is added with stirring. PRI me R 3. Mix 94.8 ml of 0.11% aqueous solution of methylcel Q

,

0

five

With 5pZ (, fr, ° and sp

where is the swelling rate, m / s;

P is the ultimate shear stress. Pa;

Ф - filtrate; b - distilled water.

From the results presented in table. 1 and 2, it follows that the introduction of nonionic cellulose ether as an additive can significantly increase the thermal stability of the drilling fluid up to 200 ° C, reduce the oil product consumption by 30% and increase the stability of the borehole walls.

The introduction of non-ionic cellulose ethers less than 0.1% does not affect the improvement of the properties of the drilling fluid, and their concentration above 3.0% does not lead to a significant improvement in the thermal resistance of the mud and an increase in the stability of the borehole walls.

Claims (1)

Invention Formula The drilling fluid containing water, diesel fuel and emulsifier is an ester of high-purity high-acid and polyatomic alcohol, characterized in that, in order to increase its heat resistance up to 200 ° C, reduce diesel consumption and increase the stability of the borehole walls, it also contains as an additive, nonionic cellulose ethers with the following co-ingredients, wt.%: Diesel fuel 5.0-20.0 Ester of unsaturated higher acid and polyhydric alcohol O, 1-3.0 Non-ionic esters cellulose 0.1-3.0 WaterEverything