RU1826996C - Method of steel protection against corrosion in oil field media - Google Patents

Abstract

Use: to protect oilfield equipment from corrosion. Essence: the method includes introducing into the medium at pH 10-11 baked cement dust from electrostatic precipitators, containing, wt.%: CaO 44.00-48.00; SI02 14.58-15.80; Al3O2 2.84-3.6; Re203 2.66-3.29; MdO 1.00-1.86; fcO 1.7-2.36; Na20 0.34-0.55; p.p.p. - the rest, including an admixture of silver 0.5-5.0 g / l. 2 tab.

Description

The invention relates to methods for protecting oilfield equipment, tanks and pipelines operating in aggressive well environments: highly mineralized formation waters, oil (oil-water media), gases containing hydrogen sulfide and carbon dioxide and can be used to protect against corrosion breaks in water systems PPD for the injection into the reservoir of wastewater, oil reservoirs for the transfer of watered oils (in the oil recovery system), during hydrotransport of high viscous oils with a high content sulfur.

The purpose of the invention is to reduce the cost of a reagent-inhibitor, increase its dispersibility and solubility in salt formation waters and water-oil environments, providing both wet and dry dosing, including pipelines, oil pipelines

and gas pipelines for the transportation of crude crude petroleum hydrogen sulfide-containing gas, and tanks, as well as simplifying the processing of steel surfaces of oilfield equipment, pipelines and tanks, eliminating waste from one industry (in this case, cement) and turning them into revenue in another area industry (in this case, oil and gas), increasing the environmental friendliness of the inhibitor.

This goal is achieved in that, as an inhibitor of hydrogen sulfide corrosion in oilfield environments, caking dust from electrostatic precipitators of cement plants is used, which is a waste product - waste from cement plants.

Baking dust from electrostatic precipitators has the following composition, wt.%: CaO 45.2-48.0;

00

yoo yoo che

CX

with

Si02 15.4-15.8; 50c 4.8-6.9; Rv20z 3.21-3.29; 2.84-3.03; K20 1.70-2.38; MdO 1.0-1.5: Na20 0.34-0.55; p.p.p. - the rest. Baking dust can be introduced into the tank or pipe in dry or wet form (solution). The protective concentration of caking dust is 0.3-0.6 g / l, providing a protection effect of up to 99% of total, hydrogen sulfide corrosion and carbon dioxide.

Steel tanks are protected by supplying dry dust or mortar, suspension into the dead space of salt formation water, accumulated as a result of gravitational separation in the lower part of the steel tank, where the lower tanks and bottom are exposed to corrosion damage. The filling dust is pumped through a pipe with a bottom valve or plug, which is passed through the top hatch in the roof of the tank into a dead salt water cushion. The alkaline nature of cement cement bake not only reduces the aggressiveness of formation water, but also passivates steel.

Protection of pipelines of reservoir pressure maintenance systems (PPM), as well as protection of reservoirs during the collection and transportation of waterlogged oil, is carried out by dry or wet dosing of the calculated amount of baked dust with a concentration of 0.3-0.6 g / l.

Gas pipelines are protected by transferring wet petroleum hydrogen sulfide-containing gas by spraying cement cement dust onto the wet surface of the gas pipeline’s interior, where cement cement dust is adsorbed by film moisture, alkalizing it to the values of NW with simultaneous steel passivation. Moreover, the alkaline nature of the wet film on the inner surface of the gas pipeline suppresses biocorrosion and hydrogen sulfide corrosion, especially pitting.

Spraying cement baked dust can be done by detonation spraying or by other means.

The proposed method significantly reduces the cost of reagents and simplifies the technology for treating formation water, water-oil mixtures, and wet transported oil gas using cement cement from electrostatic precipitators as a corrosion inhibitor.

Example 1. The protective effect of cement cement dust at various doses

the levelings at Art. 20 were evaluated on formation water of the Palvantash field of the following chemical composition, g / l: CI 82.5; S042 1.1; HCO3, 17; Ca2 + 5.7; Md2 + 1.6; Na + + K + 44.6, specific gravity 1.0965 at 20 ° C, hydrogen sulfide content 43.8 mg / L, pH 6.6. The test results are presented in table. 1. The test material was plate samples made of steel Art. 20, which were immersed in formation water and kept there for 144 hours. The protection effect was evaluated by the formula

E

I0-I0

X 100%

where I0 and I, respectively, the corrosion rate without baking dust is 1.27 g / m X h and with baking dust.

Corrosion rates were determined by mass loss by the formula

AND

Dp

F -T

g / m2 h

0

5

0

5

0

5

where DM - mass loss, g;

F is the area of the metal sample, m2;

T is the exposure time, h

Simultaneously, a comparison was made with the prototype at appropriate dosages of calcium hydroxide. All experiments were carried out at a temperature of + 20 ° C.

Example 2. In the RVS-1000 technological tank in the lower section 2 m high from the bottom, formation water was accumulated as in Example 1, a 6 m thick oil layer was separated on top. A plastic polyethylene pipe 0 80 mm was passed through the upper inspection hatch, the lower end of the pipe had plug valve, opened by a cord passed through the body of the pipe or inside the pipe. The opposite end of the pipe has a funnel for loading baking dust so that the concentration in produced produced water is 0.5 g / l. Cement dust can also be injected in the form of a concentrated slurry solution so that the concentration of cement dust is also equal to 0.5 g / l. Concentrated working solutions of baked dust can be 5-10% concentration, and the concentration of baked cement dust in produced bottom water can be in the range of 0.3-0.6 g / l with a pH value of 10-11. In this example, the concentration of baked dust is 0.5 g / l at a pH of 10.6.

At the same time, the corrosion rate in the reservoir water is 1.27 g / m2hh to OOI g / m2 hh, which provides a protection effect of 92.1% and prevents the perforation of the lower part of the reservoir where salted bottom water accumulates.

Example 3. In a gas pipeline with a wet inner wall, an ejector with a nozzle under pressure of compressed gas is injected and sprayed baking dust along the gas pipeline, which is adsorbed on the wet inner surface of the pipe and alkalizes it to a value of 10.6 (pH 10.6), which corresponds to the concentration 0.5 g / l Crude oil gas containing 4.5 vol.% Hydrogen sulfide and carbon dioxide 3.5 vol.% Is pumped through the pipeline. Moreover, not only does the corrosion rate decrease from 1.4 mm / year to 0.06 mm / year, but the hydrogen embrittlement of steel also decreases. The effect of protection against water loss by the loss of ductility of metal samples of U8A steel was 99% with a corrosion protection effect of 96%.

EXAMPLE 4 A calculated amount of caking dust is loaded into the central gravity collector, oil-transporting oil transporting 80% through a measuring device in the head of the runway for streams from wells, in such a way that the concentration per liquid is 0.6 g / l. Without an inhibitor, prior to feeding it into the stream, the corrosion rate measured using a polarization type UK-1 device was 1.47 mm / year, and after the introduction of caking dust, the corrosion rate was 0.01 mm / year, which gives a 99% corrosion protection effect.

Example 5. The bottom-hole oilfield water from the technological reservoirs of the oil recovery point after demulsification containing 193 mg / l of petroleum products, 380 mg / l of strontium and 26 mg / l of lithium is treated with grout cement dust from electrostatic precipitators of the Akhangaran cement plant with the composition, wt.%: CaO 44.65-46.18; MdO 1.04-1.86; SI02 14.59-15.50; 3.10-3.60; ResOz 2.66-3.17; R2U3 2.39-3.81; Hell 2.5 g / t. The initial corrosion rate in commercial oilfield wastewater prior to treatment is 1.72 g / m2 X h with a content of sulfate reducing bacteria (BSC) of 10 cells / ml BSC, pH 6.2, and a hydrogen sulfide content of 168 mg / l. Cement dust (GSP) is introduced into the intake well under the stream, where commercial water comes from process tanks. The well is connected via a pipe to the reaction chamber of the settler, where mixing and contact of the central processing unit with sewage-treated oil water occur, and a clean drain of the settler in the form of clarified water is pumped into the reservoir. Different pH values of the water to be treated are achieved with different dosages of PCP. With increasing doses, the pH value increases. The effect of pH values on the passivation of steel by cement cement binder (PCP) and the quality of clarified water pumped into the reservoir at the outlet of the sump are shown in Table. 2.

Claims (3)

1. A method of protecting steel from corrosion in oilfield environments, comprising introducing a calcium hydroxide inhibitor into the medium to be treated, characterized in that, in order to reduce the corrosiveness of the medium, passivate the steel while improving the quality of the medium, cheapening the processing process, simplifying it and expanding the raw material base , as a calcium hydroxide inhibitor, cement grout from electrostatic precipitators is used. 2. The method according to claim 1, characterized in that the concentration of cement cement in the processed medium is maintained at 0.3-0.6 g / l when the pH reaches 10-11. 3. The method according to paragraphs. 1 and 2, characterized in that the baked cement dust from electrostatic precipitators has the following composition, wt.%: CaO - 44.65-48.00; Si02 14.58- 15.80; - 2.84-36; Rv20z - 2.66-3.29; MdO - 1.00-1.86; K20 - 1.7-2.36; Na20 0.34-0.55; p.p.p. - the rest, including an admixture of silver of 0.5-5 g / t. Note: ZZP - baked cement dust from electrostatic precipitators of the Akhangaran cement plant. table 2 The effect of pH on the passivation of steel (corrosion rate Art. 20) and the quality of the water treated with PZP at 20 ° С