RU2217463C2 - Drilling solution - Google Patents

Abstract

FIELD: hole drilling. SUBSTANCE: invention relates to opening water-bearing stratum represented by sandy deposits. Drilling solution for opening water-bearing stratum contains carboxymethylcellulose, dextrin granules, perlite and water. Solution contains additionally lignin in the following ratio of components, wt.-%: carboxymethylcellulose, 0.5-2.0; dextrin granules mixture carbohydrates formed in hydrolysis of potato and maize starch, 0.5-3.0; perlite, 0.1; lignin, 0.1-0.2; water, the balance. EFFECT: enhanced quality of water-supply well opening. 1 tbl

Description

The invention relates to the field of drilling, in particular for opening aquifers, represented by sandy sediments.

Known drilling fluid containing in its composition carboxymethyl cellulose (CMC), dextrin grits and water (Russian patent 2012584 from 05.15.94, IPC C 09 K 7/02, publ. 05/15/1994). Also known is a drilling fluid containing CMC, lignin and water (Russian patent 2155203 from 08/27/00, 09 K 7/02, publ. 08/27/2000). These drilling fluids include CMC, lignin, dextrin grains - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches, and water. The disadvantage of these solutions is that the polymer crust formed on the walls of the aquifer is extremely poorly wedged after setting up the filter column, which ultimately reduces the specific flow rate of hydrogeological wells.

The closest analogue is a drilling fluid containing CMC, dextrin grains - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches, perlite and water (Russian patent 2141991, С 09 К 7/02, publ. 11/27/1999).

The task of improving the quality of opening the aquifer can be solved by reducing the depth of penetration of particles into the reservoir and creating a high-quality elastic, thin, polymer film on the walls of the aquifer. This is achieved by the fact that in the drilling fluid containing CMC, dextrin grains - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches, perlite, lignin is additionally introduced at a ratio of components, wt.%:

CMC 0.5-2.0

Dextrin nibs - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches 0.5-3.0

Perlite 0.1

Lignin 0.1-0.2

Water Else

and carry out mixing in a clay mixer.

Improving the quality of opening is achieved due to the fact that lignin particles together with CMC, dextrin grains and perlite create a thin elastic polymer crust, which significantly reduces the degree of penetration of the drilling fluid into the aquifer. Lignin gives this property to the crust. In the process of wedging out a well, this crust can be easily destroyed by the hydromechanical method.

Lignin is a loose powder of brown color, which is one of the three high molecular weight components of wood. Wood lignins are obtained by conventional sulphite cooking of coniferous species at a pH of 1-2 and a temperature of 135 ° C. At the same time, about half of the monomer units are attached to sulfo groups and about 90% of lignin becomes water soluble. In significant quantities, lignin is formed as a by-product in the production of cellulose and in the hydrolysis of plant materials. The molecular weight of lignin varies from 800 to 10 ⁶ .

The proposed solution differs from the known in that it additionally contains lignin. The use of additional lignin in the solution increases the water loss of the formation, since it is precisely this composition of the components that contributes to the formation of a thin, elastic film on the walls of the aquifer, which significantly reduces the likelihood of penetration of the drilling fluid into the aquifer, and reduces the degree of clogging. The resulting film is much faster to clay out, which contributes to an increase in the specific production rate of hydrogeological wells.

To prepare the proposed solution, water is collected in a container, added, stirring, first CMC, then lignin and perlite, and finally dissolve the crumb. After that, bring the volume of the solution with water to the required value and mix until all components of the solution are completely dissolved.

When using this solution for opening aquifers, represented by loose sediments, a protective thin elastic polymer crust is formed on their walls, which prevents clay particles from penetrating deep into the formation, thereby increasing its water yield, and at the same time keeps the formation walls upright, which is very important when lowering the filter column. Subsequently, this crust is easily destroyed by the hydromechanical method of wedging.

The practical application of this solution in wells drilled in the Rostov Region showed that the solution containing,%: CMC 2.0; dextrin nibs 2.0; perlite 0.1; lignin 0.2; water is the rest.

The use of this solution allows to obtain a specific rate of hydrogeological wells on average 30% more than in wells drilled using a solution containing CMC, dextrin grits and perlite. Well drilling was carried out in one area using a single technology (see table of comparative data).

Claims (1)

Drilling fluid for opening an aquifer containing carboxymethyl cellulose, dextrin grains - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches, perlite and water, characterized in that the solution additionally contains lignin in the following ratio of components, wt. %: Carboxymethyl cellulose 0.5-2.0 Dextrin nibs - a mixture of carbohydrates formed during the hydrolysis of potato and maize starches 0.5-3.0 Perlite 0.1 Lignin 0.1-0.2 Water Else