RU2310674C1 - Well-killing fluid - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: well-killing fluid contains 85-95% petroleum and 5-15% additive, which consists of at least two components selected from group represented by tall oil, petroleum processing waste, and castor oil and additionally contains phosphoric acid ester.

EFFECT: reduced fire and explosion risk and reduced cost due to use of inexpensive components.

2 cl, 1 tbl, 11 ex

Description

The invention relates to the oil and gas industry, in particular to killing oil and gas wells with hydrocarbon-based liquids.

In world practice, hydrocarbon-based fluids are becoming increasingly widespread in overhaul of wells. This is due to the fact that in many oil and gas producing regions, reservoir pressures are reduced by 15-25% from the initial value. When killing wells with reservoir pressures below hydrostatic, the most effective is the use of marketable oil-based hydrocarbon systems. Its main disadvantage is that oil contains volatile fractions, which, concentrating above the surface, provide it with a low flash point and pose a serious fire hazard.

An assessment of the fire and explosion hazard of oil consists in determining a number of indicators, the main of which is the flash point - this is the lowest temperature of a substance at which, under special tests, vapors and gases are formed above its surface that can flash in air from an external ignition source.

At the flash point, stable combustion of the liquid does not yet occur, since the flash time does not ensure the heating of the surface layer of the liquid to the required temperature and the generation of vapors sufficient to maintain stable combustion. Flash point is an express parameter, tentatively showing the temperature conditions under which a combustible substance becomes flammable in an open vessel or during a spill.

Known fluids for killing wells on a hydrocarbon basis, such as oil (Interval, 2002, No. 10, p. 71).

The disadvantage of such a liquid is its fire and explosion hazard.

A known method of protecting hydrocarbon fuels from fire by adding a phlegmatizer in them in the form of an organohalogen compound, which is introduced into the fuel in an amount of 1-10% of its volume. However, organohalogen compounds are scarce, expensive components that can adversely affect the environment, and are unacceptable for use in workover work (see patent RU 2254492, 2005).

Known liquid for killing a well on a hydrocarbon basis, for example oil or oil products containing an additive in the form of natural fatty acids, caustic soda and mineral filler (see patent RU 2253664, 2005).

The disadvantage of such a liquid is its fire and explosion hazard.

The objective of the invention is to reduce the fire and explosion hazard of a fluid for killing a well using non-deficient, environmentally friendly substances.

The problem is solved in that the fluid for killing a well containing oil and an additive, as an additive, contains a mixture of at least two components selected from the group: tall oil, OPN oil processing waste, castor oil, in the following ratio of liquid components, about.%:

oil 85-95 specified additive 5-15

The specified additive further comprises an ester of phosphoric acid.

In the invention, arrears based on cycloparaffins and fatty acids are used.

As the phosphoric acid ester, for example, TBP tributyl phosphate, tri- (2,3-dibromopropyl) phosphate are used.

The specified additive exhibits the property of a phlegmatizer and provides a liquid with an increase in flash point. The selection of liquid formulations is carried out depending on the properties of the hydrocarbon base, for example, oil of various fields. The increased vapor pressure of crude oil is determined by the presence of hydrocarbons: ethane, propane, butane, which are fire and explosion hazard components. The introduction of these additives of a certain formulation allows the flash temperature to shift upward by reducing the partial pressure of the gas components in the liquid.

Thus, a technical result is achieved in the form of increased fire and explosion safety of the fluid for killing a well through the use of non-deficient and environmentally friendly materials.

Well killing fluid was obtained by mechanically mixing the components. As a hydrocarbon base, oil of various fields was taken.

To obtain the express parameter — the flash point for various liquid compositions, it was studied on a device for determining the flash point in a closed TVZ crucible in accordance with GOST 12.1.044-89.

To obtain reliable data, the test liquid was pre-cooled in the climate chamber "Fetron" type 3001 to a temperature of -25 ° C.

Examples of liquid preparation in the laboratory.

Example 1. To 95 ml (95 vol.%) Of oil was added 5 ml (5 vol.%) Of arrester. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 1.

Example 2. To 90 ml (90 vol.%) Of oil was added 10 ml (10 vol.%) Of tall oil. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 2.

Example 3. To 95 ml (95 vol.%) Of oil was added 5 ml (5 vol.%) Of a mixture (8: 2) of arrester and tall oil. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 3.

Example 4. To 85 ml (85 vol.%) Of oil was added 15 ml (15 vol.%) Of castor oil. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 4.

Example 5. To 90 ml (90 vol.%) Of oil was added 10 ml (10 vol.%). mixtures (1: 1) of arrester and TBP. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 5.

Example 6. To 85 ml (85 vol.%) Of oil was added 15 ml (15 vol.%) Of a mixture (1: 1) of tall oil and TBP. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 6.

Example 7. To 85 ml (85 vol.%) Of oil was added 15 ml (15 vol.%) Of a mixture of (6: 1: 3) OPN, tall oil and TBP. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 7.

Example 8. To 85 ml (85 vol.%) Of oil was added 15 ml (15 vol.%) Of a mixture (9: 1) of arrester and castor oil. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 8.

Example 9. To 90 ml (90 vol.%) Of oil was added 10 ml (90 vol.%) Of a mixture (1: 1) of tall and castor oils. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 9.

Example 10. To 85 ml (85 vol.%) Of oil was added 15 ml (15 vol.%) Of a mixture (1: 8: 1) of tall oil, arrester and castor oil. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 10.

Example 11. To 85 ml (85 vol.%) Oil was added 15 ml (5 vol.%) Of a mixture (1: 1) of castor oil and TBP. Mixing of the liquid was carried out for 25 minutes. The test results, see table 1, experiment 11.

As can be seen from table 1, the oil itself can have a low flash point and even at subzero temperatures are dangerous in relation to the formation of fire and explosion hazard mixtures. The examples presented in table 1 show the possible uses of additives that shift the flash point to safe temperatures. The specified technical result is achieved with different options presented in the table of mixtures. The best technical result is achieved when using as a additive a mixture of at least two components selected from the group: tall oil, arrester waste oil, castor oil. The inventive combinations of substances that form an additive to the hydrocarbon base upon interaction with each other acquire the property of a phlegmatizer, not determined by their total effect, as can be seen from the quantitative data of the research results. The present invention allows the use of domestic, inexpensive, environmentally friendly reagents as phlegmatizers, which increase fire and explosion safety and expand the temperature range of application of hydrocarbon liquids, for example, based on marketable oil, which ensures well killing in safe temperatures.

Table 1 No.
experience Fluid composition Flash point in ° C, at a reagent concentration in% (vol.) Increase
temperature
flash, Δ 0 5 10 fifteen one. Oil Aganskaya + OPN -25 -6 - - 19 2. Oil Anastasievsko- +37 - +56 - 19 Trinity + tall oil 3. Oil Krasnodar + mixture -5 +12 17 Arrester and tall oil four. Oil Anastasievsko- +37 +62 25 Trinity + castor oil 5. Oil Krasnodar + mixture -5 - +17 - 22 OPN and TBF 6. Oil Krasnodar + mixture -5 +20 25 tall oil and TBP 7. Oil Krasnodar + mixture -5 +26 31 Arrester, tall. oils and TBP 8. Oil Krasnodar + mixture -5 +22 27 Arrester and castor oil 9. Oil Novopokurskaya + mixture -25 +11 36 tall and castor oils 10. Oil Novopokurskaya + mixture -25 +18 43 tall, arrester and castor oils eleven. Oil Krasnodar + mixture -5 +24 29th castor oil and TBP

Claims (2)

1. Killing fluid containing oil and an additive, characterized in that as an additive it contains a mixture of at least two components selected from the group: tall oil, waste oil, castor oil in the following ratio of liquid components, about .%: oil 85-95 specified additive 5-15 2. The liquid according to claim 1, characterized in that said additive further comprises a phosphoric acid ester.