RU2479364C1 - Reclamation of lands occupied by slime pits caused by oil-and-gas production - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to reclamation of lands contaminated in oil-and-gas production, particularly, those occupied by slime pits. Proposed method comprises introducing thickener into oil-and-production wastes and mixing it over entire volume thereof to homogeneous state. Said thickener represents a bentonitic clay and is taken in amount of 50% of total volume of pit wastes. Thickening and mixing over, peat-sand mix is filled in pit to make it surface level with surrounding terrain relief. Then, second layer of peat-sand mix premixed with ammonium nitrate in amount of 180-220 kg/hec and potassium salt in amount of 130-170 kg/hec is placed onto said surface area. Now, seed of permanent cultures are sown taken in amount of 120-150 kg/hec.

EFFECT: better ecological compatibility of lands and water-physical properties.

2 ex

Description

The invention relates to the field of restoration of lands contaminated in the process of oil and gas production, and specifically, to a method for the reclamation of sludge pits formed as a result of oil and gas production.

There is a known method of reclamation of disturbed soils, including the introduction of a huminomineral ameliorant into disturbed soils, while before it is applied, the soil is previously loosened to the depth of the root layer, then it is evenly watered with a huminomineral ameliorant, and then the soil with humic mineral ameliorant applied to its surface is mixed (RU 22157, 69, 11157 .2003).

A known method of cleaning soil contaminated during oil and gas production by adding a composition based on bentonite clay to the indicated soil (JP 2001-079538, 03/27/2001).

Closest to the proposed invention is a method of restoring land occupied by sludge pits formed as a result of oil and gas production, in which a thickener is added to the oil and gas waste, and the thickener is mixed throughout the volume of liquid waste until the contents of the barn are homogeneous (RU 2162918 C1, B09B 1/00, 2001).

The disadvantage of this method can be attributed to the fact that agricultural land is not fully restored, so that they are ready for use for this purpose.

All waste generated as a result of oil and gas production stored at the places of their collection and temporary storage (emergency technological barns, drill slurry barns, spent quarries, etc.), as well as oil-contaminated soils collected from the places of emergency oil spills, shall be neutralized.

The technical problem solved by the developed method is to develop a technology for the reclamation of sludge pits for introducing these lands into production or introducing them into a natural biocenosis.

The technical result of the invention is to increase the environmental friendliness of the land, improving its water-physical properties through the use of natural material that is environmentally compatible with soil - bentonite clay, and the method can be actively applied in the Far North and in places with a more moderate climate.

Bentonite clay has unique properties necessary to achieve the specified technical result, namely high hydrophilicity, which is due to the fact that the composition of bentonite clay in an amount of more than 70 percent includes a mineral belonging to the group of montmorillonite, which in turn is included in the group of highly dispersed layered aluminosilicates , the high hydrophilicity necessary for the neutralization of contaminated soils depends on the level of their content.

The proposed technical result is achieved due to the fact that in the method of restoration of land occupied by sludge pits formed as a result of oil and gas production, in which a thickener is added to the oil and gas waste and the thickener is mixed throughout the volume of the waste until the contents of the barn are homogeneous, bentonite clay is used as a thickener in the form of a powder with a volume of 50% of the volume of waste contained in the barn, after completion of the process of thickening the waste with stirring, pour peat into the barn - sand mixture until the barn area is leveled with the adjacent terrain, after which a second layer of peat-sand mixture, pre-mixed with ammonium nitrate in an amount of 180-220 kg / ha and potassium salt in an amount of 130-170 kg / ha, is poured onto this area; and sowing seeds of perennial crops at the rate of 120-150 kg / ha.

The technological process of reclamation of sludge pits formed as a result of oil and gas production is carried out as follows.

Large foreign objects such as iron, wood, plastic and other wastes are removed from the sludge barn that contains contaminated soil of hazard class III located in the territory of oil or gas fields. After that, bentonite clay is added directly to the barn containing oil and gas production wastes. At the same time, clay is added in an amount of 50% of the volume of waste contained in the barn. After the required amount of bentonite clay has been added to the sludge barn, the mixing process of the barn is carried out using an excavator, after which a peat-sand mixture is poured into the barn. In this case, the mixture is added in the amount necessary to level the barn area with the adjacent terrain. In parallel, a mixture is prepared in a concrete mixer consisting of a peat-sand mixture and mineral fertilizers. As mineral fertilizers use a mixture of ammonium nitrate and potassium salt. The components of the mixture are used in the following amounts: ammonium nitrate - 180-220 kg / ha, potassium salt - 130-170 kg / ha, and the peat-sand mixture is used in the amount necessary so that after preparation it covers the area intended for reclamation with a layer of at least 15 cm. The last stage is the sowing of seeds of perennial crops in an amount of 120-150 kg / ha from the area to be recultivated. As a result of these actions, the hazard class of the cultivated soil is reduced to IV-V classes.

The acceleration of the efficiency of the process of reclamation of sludge pits contaminated with oil and oil products in the areas of oil production and gas production is due to the use of bentonite clay and the introduction of mineral fertilizers, sowing seeds of perennial crops in combination with agricultural techniques for soil treatment.

The proposed method of reclamation of sludge pits is illustrated by the following examples.

Example 1

From the sludge barn with a volume of 10 cubic meters, which contains contaminated soil of hazard class III located in the territory of the oil fields, the liquid fraction is pumped out and large foreign objects such as iron, wood, plastic and other waste are removed.

After that, bentonite clay is added directly to the barn containing oil production wastes. At the same time, clay is added in an amount of 50% of the volume of waste contained in the barn. After bentonite clay has been added to the sludge barn, the barn is mixed using an excavator.

Then a peat-sand mixture is poured into the barn. In this case, the mixture is added in the amount necessary to level the barn area with the adjacent terrain.

After the process of filling the barn with a peat-sand mixture or in parallel with this process, a mixture is prepared in a concrete mixer consisting of a peat-sand mixture and mineral fertilizers. As mineral fertilizers use a mixture of ammonium nitrate and potassium salt. In this case, the components of the mixture are used in the following amounts: ammonium nitrate - 220 kg / ha, potassium salt - 170 kg / ha, and the peat-sand mixture is used in the amount necessary so that after preparation it covers the area intended for reclamation 20- centimeter layer.

The last stage is the sowing of seeds of perennial crops in the amount of 150 kg / ha from the area to be recultivated.

As a result of these actions, the hazard class of the treated soil is reduced to IV-V class.

Example 2

A liquid fraction is pumped out from the sludge barn with a volume of 15 cubic meters, which contains contaminated soil of hazard class III located in the gas fields, and large foreign objects, such as iron, wood, plastic and other waste, are removed.

After that, bentonite clay is added directly to the barn containing gas production wastes. At the same time, clay is added in an amount of 50% of the volume of waste contained in the barn. After bentonite clay has been added to the sludge barn, the barn is mixed using an excavator.

Then a peat-sand mixture is poured into the barn. In this case, the mixture is added in the amount necessary to level the barn area with the adjacent terrain.

After the process of filling the barn with a peat-sand mixture or in parallel with this process, a mixture is prepared in a concrete mixer consisting of a peat-sand mixture and mineral fertilizers. As mineral fertilizers use a mixture of ammonium nitrate and potassium salt. In this case, the components of the mixture are used in the following amounts: ammonium nitrate - 200 kg / ha, potassium salt - 150 kg / ha, and the peat-sand mixture is used in the amount necessary so that after preparation it covers the area intended for reclamation 15- centimeter layer.

The last stage is the sowing of seeds of perennial crops in the amount of 120 kg / ha from the area to be recultivated.

As a result of these actions, the hazard class of the treated soil is reduced to IV-V class.

It can be seen from examples 1 and 2 that the proposed method for reclamation of sludge pits formed as a result of oil and gas production is effective and can be actively applied both in the Far North and in places with a more moderate climate.

Claims (1)

A method of restoring land occupied by sludge pits formed as a result of oil and gas production, in which a thickener is added to the oil and gas waste, and the thickener is stirred throughout the volume of the waste until the contents of the barn are homogeneous, characterized in that bentonite clay in the form of a powder is used as a thickener in the calculation 50% of the volume of waste contained in the barn, after the process of thickening the waste with stirring, the peat-sand mixture is poured into the barn until the barn area is leveled with an adjacent terrain, after which a second layer of peat-sand mixture, pre-mixed with ammonium nitrate in an amount of 180-220 kg / ha and potassium salt in an amount of 130-170 kg / ha, is poured onto this area, and seeds of perennial crops from calculation of 120-150 kg / ha.