RU2323293C1 - Drilling mud disposal method - Google Patents

Abstract

FIELD: foundations produced by soil stabilization, particularly to obtain all-purpose mixture for road construction and for fertile land improvement.

SUBSTANCE: method involves mixing drilling mud with previously foamed and hardened carbamide and/or formaldehyde resin; additionally introducing calcium containing and organic additives and following mixing thereof with cement and oxides. The components are taken in the following amounts (% by weight): drilling mud - 30-50, carbamide and/or formaldehyde resin 2-5, calcium containing additives - 2-3, organic additives - 1-10, cement - 3-5, remainder is oxides.

EFFECT: increased strength of obtained material, decreased concrete consumption and reduced recovery costs.

5 cl, 2 ex

Description

The invention relates to the disposal of drill cuttings and can be used to obtain a universal mixture intended as soil for the construction of roads, and to improve the fertile properties of the soil.

The Known Method of utilization of drill cuttings, based on the binding of drill cuttings with urea resin (Bulatov A.I., Makarenko P.P., Shemetov V.Yu. "Environmental protection in the oil and gas industry", M., "NEDRA", 1997, p. 323, tab. 67).

The disadvantage of this method is the high toxicity of the resulting mass.

The closest is a method of disposal of industrial sludge, including mixing sludge with resin, oxides and then mixing with cement (EPO No. 0128966, С02F 11 /, С04В 31/00 from 06/15/83, publ. "Invention in the USSR and abroad ", Issue 52, No. 8, 1984, prototype).

The disadvantage of the above method is the high consumption of cement, the high cost of the recycling process.

The proposed METHOD FOR DISPOSAL OF DRILL Sludges allows eliminating the above disadvantages and obtaining a universal mixture for use as a building material with increased strength and as soil with improved environmental properties, for this it involves the use of drill cuttings, mixing drill cuttings with pre-foamed and cured urea and / or formaldehyde resin, the additional introduction of calcium-containing and organic additives, followed by mixing with ce coping and oxides in the following ratio of components, wt.%:

drill cuttings - 30-50 urea and / or formaldehyde resin - 2-5 calcium containing additives - 2-3 organic additives - 1-10 cement - 3-5 oxides - the rest

As calcium-containing additives, calcium chloride or lime is used, peat and / or pre-decomposed woodworking waste are used as organic additives, and sand is used as oxide. The foaming process of the urea and / or formaldehyde resin is carried out at a temperature of 25-40 ° C for 45-90 minutes, and the curing process of the urea and / or formaldehyde resin is carried out at a temperature of 25-40 ° C for 24-48 hours.

The proposed METHOD FOR DISPOSAL OF DRILLING Sludges is carried out as follows.

The modern oil industry produces a huge amount of oil waste, including drill cuttings. Being a kind of industrial sludge, this waste has a number of distinctive properties, namely fluidity, static, hygroscopic, etc.

In some cases, drill cuttings contain oil and oil products. These inclusions after processing by known methods migrate into the environment, polluting the soil.

The proposed METHOD FOR DISPOSAL OF DRILLING Sludges allows to eliminate the above-mentioned disadvantages, including due to the solidification of drill cuttings and turning them into a state close in physical and mechanical characteristics to natural soil.

To do this, take a urea and / or formaldehyde resin in an amount of from 2 to 5 wt.% And foaming using known foam generators at a temperature of 25-40 ° C for 45-90 minutes Then it is cured by means of an acid-containing catalyst, for example acetic acid, keeping for 24-48 hours at a temperature of 25-40 ° C.

After that, the pre-foamed and cured urea and / or formaldehyde resin is mixed with drill cuttings in an amount of from 30 to 50%, which contains a solid phase of 40-65%, oil no more than 7% and water.

Then, to obtain a universal mixture, calcium-containing additives in the form of lime or calcium chloride in an amount of from 2 to 3%, organic additives from peat and / or pre-decomposed woodworking waste in an amount of from 1 to 10% are introduced. Then add cement in an amount of from 3 to 5% and oxides in the form of sand. Moreover, mixing with sand can be carried out at the place of use of the resulting universal mixture. After mixing all the ingredients, the universal mixture is aged for 2-3 days.

As shown by experiments conducted in the course of work at the Priobskoye oil field, foamed and cured urea and / or formaldehyde resin reduces its consumption. At the same time, the high relative surface of the foamed urea and / or formaldehyde resin sharply increases its sorption ability with respect to such pollutants as oil.

The introduction of calcium-containing additives, for example, calcium chloride, reduces cement consumption by introducing free calcium ions. Without this additive, clay components of drill cuttings bind cement calcium ions, thereby reducing its cementing ability. Adding only 1% calcium chloride reduces cement consumption by half.

Organic additives, such as peat, are used as a cheap sorbent, which adsorb mobile contaminants in drill cuttings, such as petroleum products, heavy metals, salts, thereby preventing their migration to the soil, and thereby improve the fertility of the resulting universal mixture.

Peat and pre-decomposed woodworking wastes have an acid pH characteristic, and drill cuttings have an alkaline environment. Thus, peat and pre-decomposed woodworking waste neutralize the alkaline environment of drill cuttings. In addition, peat contains microflora, which contributes to the decomposition of petroleum hydrocarbons and the binding of heavy metals to inactive compounds, for example, chilate ones. Lime also promotes the formation of chilate compounds.

As practice shows, the use of peat and pre-decomposed woodworking waste as part of the proposed universal mixture can reduce cement consumption by 20-30%, which increases its viscosity and quality.

Mixing the components of the universal mixture with sand at the place of its use can significantly reduce the cost of transporting sand, which, as a rule, is sufficient for places where the universal mixture is used.

The resulting universal mixture is low-flowing, which allows it to be transported in open dump trucks without sealing the body and thereby reduce the cost of its transportation and eliminate environmental pollution during its transportation.

An increase in the amount of drill cuttings over 50% in the composition of the universal mixture leads, among other things, to a deterioration in the quality and environmental properties, and the use of drill cuttings less than 30% is environmentally and economically disadvantageous.

The work carried out on the proposed METHOD FOR DISPOSAL OF DRILLING Sludges showed that the resulting universal mixture can be used:

- as a building material - to strengthen road slopes, which allows you to save roads, for example, from erosion during heavy rains, to strengthen construction sites, including those with heterogeneous and unstable soil composition;

- simultaneously as a building material and as a soil - to strengthen the slopes of the roads and to obtain soil cover on the slopes of the roads;

- as a soil by introducing it, for example, into sandy soil, into a soil with a high clay content to improve the fertile properties of the soil.

The essence of the proposed solution can be illustrated by the following examples.

Example 1

Formaldehyde resin in an amount of 4 wt.% (40 kg) was poured into a container with a mixing device, which was previously foamed with a foam generator and cured by means of acetic acid. Then added drill cuttings in an amount of 35 wt.% (350 kg) containing a solid phase of 55%, oil 7%, and mixed.

After mixing drill cuttings with foamed and cured formaldehyde resin, calcium chloride in the amount of 2 wt.% (20 kg), peat in the amount of 6 wt.% (60 kg), cement in the amount of 4 wt.% (40 kg) were added to the tank sand in an amount of 49 wt.% (490 kg), and all this was mixed.

The resulting universal mixture was kept for 3 days and then taken to a dumping site on a dump truck. There, they were dumped by means of vehicles, they were tamped with a skating rink and kept for 30 days, after which they received a dense, solid construction site that did not let water through.

Example 2

A urea resin in an amount of 5 wt.% (50 kg) was poured into a container with a mixing device, which was pre-foamed with a foam generator and cured with acetic acid, and drill cuttings in an amount of 44 wt.% (440 kg) containing 65% solid phase, oil 5%. The urea resin and drill cuttings were mixed.

After mixing drill cuttings with foamed and cured urea resin, lime was added to the tank in an amount of 3 wt.% (30 kg), pre-decomposed wood chips in an amount of 10 wt.% (100 kg), cement in an amount of 5 wt.% (50 kg ), sand in an amount of 40 wt.% (400 kg), and all this was mixed.

The resulting universal mixture was kept for 2 days and then taken out with a dump truck to the slopes of the road. On the slopes of the roads, the universal mixture was dumped by means of vehicles, it was rammed with a skating rink and kept for 29 days. Then the upper layer of the universal mixture on the slopes of the roads was loosened and sown with grass seeds, after 15 days the grass sprouted and the slopes on the roads turned out to be dense, strong with a vegetative cover in the upper layer.

During the operation of the obtained universal mixture, there was no migration of pollutants from it to the soil.

To implement the proposed METHOD FOR DISPOSAL OF DRILLING Sludges, well-known technical devices, including transport ones, were used.

The application of the claimed METHOD FOR DISPOSAL OF DRILLING Sludges allowed

reduce the toxicity of the resulting universal mixture by neutralizing the toxic components of drill cuttings,

reduce the cost of the disposal of drill cuttings by reducing the use of expensive components,

to obtain a universal mixture for use in road construction as a building material with increased strength and as soil with improved environmental properties due to the neutralization of toxic components of drill cuttings.

Claims (5)

1. The method of disposal of drill cuttings, including mixing the cuttings with resin, oxides and cement, characterized in that when mixing use pre-foamed and cured urea and / or formaldehyde resin, drill cuttings are used as cuttings, then calcium-containing and organic additives are added then cement and oxides are added in the following ratio of components, wt.%: Drill cuttings  30-50 Urea and / or formaldehyde resin  2-5 Calcium supplements  2-3 Organic supplements  1-10 Cement  3-5 Oxides  rest. 2. The method of disposal of drill cuttings according to claim 1, characterized in that peat and / or pre-decomposed woodworking waste are used as organic additives. 3. The method of disposal of drill cuttings according to claim 1, characterized in that calcium chloride or lime is used as calcium-containing additives. 4. The method of disposal of drill cuttings according to claim 1, characterized in that sand is used as the oxide. 5. The method of disposal of drill cuttings according to claim 1, characterized in that the foaming process of the urea or formaldehyde resin is carried out at a temperature of 25-40 ° C for 45-90 minutes, and the curing process of the urea or formaldehyde resin is carried out at a temperature of 25-40 ° C for 24-48 hours