RU1778298C - Composition and method for making artificial rock core - Google Patents

Abstract

Usage: rock modeling, mainly for testing perforating and explosive equipment: SUMMARY OF THE INVENTION: the composition contains a quartz filler and an organosilicon binder. A highly condensed modified polyethoxysiloxane resin was used as a binder. f The ratio of components, wt.%: quartz filler 86-95 ,. binder 5-14. An alkaline alcohol solution is introduced as a resin modifier. The alkali content is 0.15-0.45% of the resin content. For the production of core from the composition of its sleep-; chal form in a snap. The core is then solidified in a 25% aqueous ammonia solution. The cured kerahs are dried with a gradual increase in temperature from 40 to 120 ° C. 2s and 1 ep f - ly, 3 tab. next to h 00 ke

Description

The invention relates to mining, and in particular, to the creation of artificial rock samples (artificial cores) simulating in their chemical composition natural rocks of various oil fields.

Various compositions and methods are known for preparing artificial rock samples from powders of minerals of various grain sizes by sintering during firing or gluing with - using a binder.

Lime, for example, is an artificial core containing quartz sand, pulverized silica and liquid sodium glass as a binder. The manufacturing method consists in thoroughly mixing the components with liquid glass, diluted

1/3 water, filling and tamping in the form of each serving. The core sample is dried in air for 24 hours, kept in an oven at 50 and 150 ° C for 2A hours in each mode, and then subjected to heat treatment at 600-650 C using a special technology.

The closest to the invention in terms of technical nature and the achieved effect is a composition containing a filler (silica sand and pulverized silica) and, as a binder, hydrolyzed tetraethylorthosulfate ikat, prepared immediately before the mixture and core production. The pressed sample cures within 1 day at room temperature, then in an oven at 85-90 ° С for 2 hours, at 200-250 ° С for 1 hour and calcination in a muffle furnace at 550 С for 4 hours with gradual cooling. A core made in this way has a structure similar in mineralogical composition and geometry of the threshold space to natural quartz sandstones.

The disadvantages of samples of this composition are insufficient mechanical strength due to the impossibility of introducing an increased (providing the necessary strength) amount of binder without destroying the resin structure, the presence of a complex chemical reaction of ethyl silicate hydrolysis during its manufacture, and the duration and high energy intensity of the manufacturing process due to an operation for calcining cores at 550-600 ° C.

The aim of the invention is to increase the accuracy of modeling the physicomechanical properties of large diameter cores while reducing the energy consumption of core production.

This goal is achieved by the fact that in the composition for modeling core rock, including a quartz filler and an organosilicon binder, the highly condensed modified polyethoxysiloxane resin is used as the latter in the following ratio of components, wt.%:

Quartz filler 86-95

Binder 5 14,

Before mixing the filler and binder, the binder is modified, mixing is carried out no earlier than 15 hours after modification, and curing of the core is carried out by holding it in a 25% aqueous ammonia solution until it is completely saturated and then dried with a gradual increase in temperature from Ш) to 120 С

Comparative analysis with the prototype allows us to conclude that the proposed composition differs from the known one by the introduction of new components, namely, a polyethoxysiloxane resin modified with an alcohol solution of alkali is used as a binder.

When using the product 111-228 (TU 6-02-1339-86) as a binder during the manufacturing of artificial cores with an increase in their sizes to f 90 mm and 1 200-230 mm, incomplete curing is observed in the center of the samples. The introduction of a modifier (alcohol solution of alkali) in an amount of from 0.15 to 0.5% into the product 111-228 promotes the complete hydrolytic polycondensation of the binder throughout the entire volume of the core, which makes it possible to obtain fully cured core samples.

The test results for the degree of cure are shown in Table 1.

The degree of cure, and depending on the amount of modifier introduced, was determined by the end face section on the core 6 90 mm according to the following formula:

Q - 100,

where Q is the degree of cure,%;

V, is the volume of curing part of the core, m3;

 core volume, m3. When the modifier is introduced in a binder in an amount of less than 0.15%, complete curing does not occur (the middle of the cheese core is loose), and when more than 0.5% is introduced, incomplete curing and surface shedding of pulverized quartz occurs. The use of a modifier from 0.15 to 0.45% binder allows for fully cured core samples.

In the manufacture of a modified binder, not only the quantitative ratio of the modifier, but also the preparation time of the modified binder has a significant effect on the degree of cure. The test results are given in table. 2.

It was found that the complete curing of the manufactured cores occurs when using a modified binder no earlier than 15 hours after the moment of its manufacture.

For experimental verification of the proposed method, 8 compositions were prepared with various percentages of ingredients. As a binder, a specially prepared solution of resin 111-228 (TU 6-02-1339-86) with a different modifier content (0.15-0.45%) was used. The modifier is an alkaline alcohol solution. As a filler, a mixture of Lyubertsy quartz sand and powdered quartz of the KP-3 grade was used.

The sequence and modes of ligation of the proposed compositions and the method of manufacturing artificial cores are as follows.

First, filler fractions are mixed in the required proportions in 018M type mixed-run runners for 20 minutes; then, in the process of mixing the filler. (silica sand and pulverized quartz), a modified binder that has been prepared and aged for at least 15 hours is introduced into the mixer. Cladding time: no binder for 20-30 minutes, after which the mixture is ready to form core samples.

Metal core was used to form core samples. Any methods of dynamic compaction of mixtures, namely, pressing, manual, etc., can be used for their manufacture. In this case, the compaction of the compositions was carried out by double-pressing in a mold with holding under pressure of 4 MPa for 1, 5 min on each side. The obtained crude cores were cured by immersing them in a 25% aqueous solution of ammonia on 20 hours. The cured cores were successively dried at 50, 70, 100, and 120 ° C for 8 hours at each temperature.

Finished cores made by the proposed method were tested

17782986

Their strength characteristics are shown in table.3.

The tests show that

0

5

0

it is advisable to use sandstone with a binder content of up to 10%, which provides the necessary strength parameters.

The implementation of the invention will make it possible to use it instead of natural rock samples in special combined targets for studying and testing the breakdown ability of perforators under conditions of high pressures and temperatures, in studying patterns of rock destruction during explosive loading, in modeling productive oil fields, and also when opening the oil reservoir, while studying the processes of filtration and the displacement of oil by water from a porous medium.

The characteristic technical and economic indicators of the new method of manufacturing artificial core is the possibility of obtaining homogeneous and heterogeneous samples with predetermined reservoir properties, which in their chemical composition simulate natural rocks of various oil fields, allowing the use of artificial core repeatedly to verify the reproducibility of the results obtained. The use of artificial cores will make it possible to reduce energy consumption during production, eliminate the use (or significantly reduce) of expensive and hard-to-obtain natural cores, and reduce the cost of the testing of flash-burst equipment (PVA).

Formula, Inventions

 1. A composition for the manufacture of artificial rock core, comprising a quartz filler and an organosilicon binder, characterized in that, in order to increase the accuracy of modeling the physicomechanical properties of large diameter cores, a highly condensed modified polyethoxysiloxane resin is used as an organosilicon binder in the following ratio of components, wt.%:

0

5

Quartz filler 86-95;

Modified Polyethoxysiloxane

resin 5-14.

2. The composition according to claim 1, with the exception that the alcohol solution of alkali is introduced as a modifier in an amount of 0.15-0.45% of the content of the modified resin.

3. A method of manufacturing an artificial core, comprising mixing a quartz filler and a silicon-organic binder, molding

snap core, compaction of the composition and curing of the core, characterized in that, in order to reduce

the energy intensity of the core manufacturing process, before mixing the filler and binder, the binder is modified, the components are mixed in at least 15 hours

after modification, and curing of the core is carried out by holding it in a 25% aqueous solution of ammonia until it is completely saturated and then dried with a gradual increase in temperature from 40 to 120 ° C.

Table 1

Binder Composition

The content of the modifier in the binder, wt.%

resin TTT-228

Resin 111-228 mo- 0.198

differentiated 0.15100

0.2100

0.3100

Oh, A100

0.45100

0.597

table 2

Cooking time Degree of non-modified wait for core binder, h% vol.

130

550

1070

14 96 ...

15YuO 24100

Table 3

The ratio of quartz content of modified sv sand to pulverized,%

quartz in the filler,% ---..--.

4 5 | TO th | 15 Bending strength, MPa

80 / 201,703,102,502,301,90

60 / 401,302,705,805,203,10

50 / 501,102,407,207,607,30

40 / 600,902,07,808,908,40

20 / 800,601,808,309,509,10

The degree of curing of the core, vol.

ABOUT

thirty