RU1789545C - Drilling mud - Google Patents

Abstract

Usage: drilling oil and gas wells. The inventive drilling fluid contains, wt.%: Clay 5-20; organic reagent stabilizer 0.5-1.5; bactericidal additive - 1 - (1,3-dihydroxy-2-amino) -propyl-4-nitrobenzene 0.02-0.10, water - the rest. The solution is prepared by sequentially introducing into the clay suspension an organic reagent, a stabilizer and a bactericidal additive. 3 tab. ate with

Description

The present invention relates to the oil industry, in particular to water-based drilling fluids for drilling oil and gas wells.

The polymer stabilizing agents used to treat clay drilling fluids are subject to degradation by the action of microorganisms, as a result of which the parameters of the solution deteriorate (viscosity properties decrease and the filtration rate increases). In addition, sulfate-reducing infusion bacteria (SBB) produce hydrogen sulfide, which leads to the development of corrosion processes and environmental pollution.

Well-known drilling fluid compositions containing bactericidal additives for

suppression of bacterial and fungal microflora.

For example, in solution by a.s. USSR No. 971860, 1,2-di (benzylamino) propane, in solution, is used as a bactericide. n about a.s. USSR No. 933696 - 4,4-dimethyldioxane, and in solution according to A.S. USSR No. 960217-dialkylamines. The disadvantages of these technical solutions are the relatively short period of action of bactericidal additives and the absence of hydrogen sulfide-releasing properties in them. The prototype of the claimed invention adopted drilling mud according to A.C. USSR No. 960217.

The purpose of the invention is to increase over time the stability of the technological properties of the drilling fluid due to the prevention of microbiological decomposition

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components while improving hydrogen sulfide neutralizing ability.

This goal is achieved by the fact that the drilling fluid containing clay, an organic organe reagent - stabilizer, an antibacterial additive and water, as a bactericidal additive contains 1 - (1,3-dihydroxy-2-amino) -propyl-4-nitrobenzene (dextramine ) in the following ratio of ingredients, May,%:.

Clay 5-20

Organic Reagent Stabilizer0.5-1.5

1- {1,3-dihydroxy-2-amino) -propyl-4-nitrobenzene (dextramine) 0.02-0.10

Water Else

Example 1. 50 g of clay are mixed in 944.95 tons of water and stirred for 1 hour until the clay is completely dissolved. Then, 5 g of a polymer stabilizer (e.g., CMC. Starch, HP reagent, metas) is added and stirred for another 0.5 hours, after which 0.05 g of the bactericide dextramine and are introduced. stirred for another 20 minutes

Example 2. 150 g of clay are mixed in 839.5 g of water and stirred for 1 hour until the clay is completely dissolved. Then, 10 g of the polymer Stabilizer is introduced (e.g. CMC, starch, HP reagent, metas) and stirred for another 0.5 hours, after which 0.5 g of dextramine bactericide is introduced and mixed for another 20 minutes.

Example 3 200 g of clay are mixed in 784 g of water and stirred for 1 hour until the clay is completely dissolved. Then, 15 g of a polymer stabilizer (e.g. CMC, starch, HP reagent, metas) are added and stirred for another 0.5 hours, after which 1 g of bactericide-dextramine is introduced and mixed for another 20 minutes.

In the table. 1 shows the compositions of the claimed drilling fluid with the optimal values of the ingredients and the solution adopted for the prototype (according to AS USSR No. 960217).

A comparative assessment of the bactericidal ability of the proposed reagent dextramine and the known reagent die ylamine used in the composition according to A. with. USSR Ne9 60217.

The tests were performed on the museum culture of the SVB Desulfovlbrlo desulfurlcans VKMV-1388. Bactericidal activity against SVB was determined by introducing into the medium containing 1000 bacterial cells in 1 ml of the sample, the test reagent in a certain concentration. Samples were thermostated at a temperature of 32 ° C for 24

hours. Then, 1 ml of liquid was taken from the sample and introduced into vials with a nutrient medium to detect SVB, after which the vials thermostatically flow

7 days As a control, use similar samples from an infected medium without the addition of a bactericidal reagent. The bactericidal effect was evaluated by the amount of biogenic

0 hydrogen sulfide, as well as the amount of precipitate formed of iron sulfide in experimental and control samples. In the table. Figure 2 presents data on the degree of suppression of SVB with additives of the studied reagents. As follows from the data table. 2, the dextramine bactericidal additive used in the inventive drilling fluid effectively suppresses the viability of SSCs, completely preventing their growth already

0 at a concentration of 0.005%. Complete suppression of SVB when using the well-known bactericidal additive - diethylamine (as per AS USSR No. 960217) is noted only at a concentration 10 times higher equal to 0.05%.

5 The compositions of drilling fluids are presented in table. 1, investigated on the stability of technological properties over time, as well as on the hydrogen sulfide neutralizing ability. In the table. 3 presents the results of studies. The technological parameters of the solutions, their absorption capacity with respect to hydrogen sulfide and the number of microorganisms contained in them were measured through

5 24 hours after preparation and after 10 weeks of exposure in a desiccator at room temperature. In compositions 1-3, bentonite was used as a clay material, and CMC was used as an organic reagent-stabilizer; in formulations 4-6, respectively, the Kuganak clay powder and CMC were used; in the compositions of 7–9 local clay (Tereklinsky deposit of Bashkiria) and CMC; .in compositions 10-12, bentonite and starch; at

In 5 formulations 13-15, bentonite and HP reagent (nitron reagent): in compositions 16-18, bentonite and metas; As part of 19 (by the USSR AS No. 960217), bentonite and CMC were used. As follows from the table. 3 data

The inventive drilling fluid containing the dextramine bactericidal additive, irrespective of the type of clay used and the organic stabilizing reagent (formulations 1-18), maintains practically unchanged technological parameters and absorption capacity after 10 weeks exposure as a result of complete suppression of life microorganisms. In the prototype solution (composition 19), after the indicated exposure, there was a sharp increase in the number of microorganisms that cause biological degradation of the organic stabilizing reagent and, thus, destabilization of the technological parameters of the solution. In addition, this solution has a low absorption capacity with respect to hydrogen sulfide.

Thus, the claimed drilling fluid in comparison with the prototype has the following technical and economic advantages: a) the parameters of the solution are maintained at a stable and high quality level

The invention claims a drilling fluid containing clay, an organic stabilizing reagent, a bactericidal additive and water, which are designed to increase the stability of technological parameters of the drilling fluid over time by preventing microbiological decomposition: its components while improving the hydrogen sulfide-neutralizing ability, it is a quality for a long period of time, which will help reduce the consumption of chemical. reagents for processing the solution; b) has a higher absorption capacity for hydrogen sulfide, which will help prevent corrosion processes and thereby increase the durability of the bits; c) the consumption of bactericidal additives (dextramine) in

0 of the claimed solution is 5-10 times less than in the known solution, which will help to reduce the cost of processing and transportation.

A bactericidal additive contains 1- (1,3-dihydroxy-2-amino) -propyl-4-nitrobenzene ol in the following ratio of ingredients, May. %:

Clay5-20 Organic stabilizing reagent 0.5-1.5 1- (1,3-Dihydroxy-2-amino) -propyl-4-nitrobenzene 0.02-0.10 Water Else

Table 1

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table 2

Table 3