RU2564839C1 - Method of recultivation of lands occupied with sludge sump - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: for recultivation of lands occupied with sludge sump to the drilling wastes the addition is injected on the basis of 50% of their volume, then its mixing is performed over the entire volume of wastes. Then to the sump levelling layers are loaded, which level the sump area with adjacent relief of the ground, and seeds permanent crop are seeded. The carbon sorbent-decomposer, phosphogypsum, construction sand or sand-clay fraction at the following compositions ratio in wt % are used as the addition: carbon sorbent-decomposer 1-3; phosphogypsum 1-5; construction sand 25-48; drilling wastes 50-70. Compound of oxide of silicon and carbon is used as the sorbent-decomposer at the following composition in wt %: oxide of silicon 10-55; carbon 45-90.

EFFECT: invention ensures high effective lands recultivation to the production or to the natural biocenosis.

2 cl, 1 tbl, 1 ex

Description

The invention relates to the oil industry and may find application in the reclamation of sludge pits formed as a result of drilling oil wells.

A known method of disposal of drilling waste products, according to which drill cuttings resulting from drilling operations, waste technological solution and wastewater are mixed in a sludge barn with mineral additives - loam and / or sand or a sand-clay fraction until a homogeneous mass is applied to The inner surface of the barn is a gas torch installation. In the flame of a gas-flare installation, thermal firing is carried out in order to obtain building material for use in equipping well pads and construction of infield roads (Patent for the invention No. 2425815 of 05.07.2010, C04B 33/06).

The method is characterized by significant disadvantages:

- fire and explosion hazard due to the use of gas;

- violation of the soil structure near the barn as a result of heat treatment.

A known method of reclamation of earthen barns containing drilling waste, including cleaning the barn water by coagulation using cement, its sedimentation and pumping. After the precipitate is formed by encapsulation, it is taken out to the slopes of bush sites or highways and the barn is covered with soil, followed by grass sowing (Patent for invention No. 2347908 of March 27, 2007, E21C 41/32).

The method is characterized by the following disadvantage:

microbiological decomposition of oil products and organic compounds that are part of drilling fluids and pose an environmental threat to nature does not occur.

Closest to the proposed invention is a method of reclamation of land occupied by sludge pits, in which the additive - bentonite clay is stirred throughout the volume of drilling waste to a homogeneous state of the contents of the barn. After the process of thickening the waste is completed, with stirring, a peat-sand mixture is poured into the barn until the barn area is aligned with the adjacent terrain, after which, on this area, a second layer of peat-sand mixture containing fertilizers is poured and the seeds of perennial crops are sown ( Patent for invention No. 2479364 dated 05.16.2012, B09C 1/08).

The method is characterized by the following disadvantages:

- bentonite clay does not provide the process of encapsulation of waste and environmentally hazardous components contained in them, which can be carried into the surrounding groundwater and soil;

- there is no microbiological decomposition of oil products and organic compounds that are part of drilling waste and pose an environmental threat to nature;

- agricultural land is not fully restored to be ready for use.

The objective of the invention is to provide a method that allows for highly efficient reclamation of sludge pits for the introduction of used land in production or in a natural biocenosis.

The problem is solved by the method of reclamation of land occupied by sludge pits, in which an additive is added to the drilling waste at the rate of 50% of its volume, after which it is mixed throughout the volume of the waste, then leveling layers are poured into the barn to ensure that the barn area is aligned with the adjacent relief terrain and sow seeds of perennial crops.

New is that as an additive use a carbon sorbent-destructor, phosphogypsum, building sand or sand-clay fraction in the following ratio of components, wt.%:

carbon sorbent destructor 1-3,

phosphogypsum 1-5,

building sand or sand-clay fraction 25-48,

drilling waste 50-70.

Also new is that as a carbon sorbent-destructor use a compound of silicon oxide and carbon, in the following ratio of components, wt.%:

silicon oxide 10-55,

carbon 45-90.

The specified set of essential features ensures the transformation of drilling waste into an environmentally friendly soil, which does not require the arrangement of specially equipped landfills for environmentally harmful substances, improves environmental friendliness and improves the water-physical properties of the land. Also, the economic and financial effect of the invention is due to the elimination of the need for calculations of environmental payments for the negative impact on the environment (taxes) during the disposal of drilling waste.

Using additives carbon sorbent-destructor, phosphogypsum, building sand or sand-clay fraction with a ratio of components, wt.%:

carbon sorbent 1-3,

phosphogypsum 1-5,

building sand or sand-clay fraction 25-48,

drilling waste 50-70,

provides reclamation of drilling waste without preliminary dehydration, which saves energy and labor. At the same time, the processed waste serves as a breeding ground for bacteria that absorb organic compounds.

The carbon sorbent-destructor has unique properties necessary to achieve the specified technical result, namely, a high sorption capacity due to the fact that the composition of the carbon sorbent-destructor includes silicon and carbon oxides, in the following ratio, wt.%:

silicon oxide 10-55,

carbon 45-90,

on which the sorption and destruction activity necessary for the neutralization of contaminated soils depends.

The proposed method for the restoration of land occupied by sludge pits is as follows.

Large foreign objects from iron, wood, plastics, and other wastes are removed from the sludge pit containing drilling waste of hazard class III-IV. Then, a carbon sorbent-destructor containing silicon oxide and carbon in the ratio of wt.%: 10 ÷ 55; 45 ÷ 90, phosphogypsum, building sand or sand-clay fraction based on at least 50% of the volume of drilling waste in the ratio of components wt.%: 1 ÷ 3; 1 ÷ 5; 25 ÷ 48; 50 ÷ 70, and using the excavator carry out the process of mixing the contents of the barn. Next, a clay layer and a soil layer are poured into the barn until the barn area is aligned with the surrounding terrain and the seeds of perennial crops are sown. As a result of these actions, the hazard class of the treated soil is reduced to class V.

The essence of the method of restoration of land occupied by sludge pits is illustrated by an example of a specific implementation.

Example

Large construction waste (items from iron, wood, plastics, etc.) was removed from the sludge barn. Then directly into the barn containing 221.04 m ^{3 of} drill cuttings of the IV hazard class and oil products (5400 mg / kg), mixed 7.5 tons (2.1 wt.%) Of carbon sorbent-destructor, consisting of 7, were introduced 5 tons (10 wt.%) Of silicon oxide and 7.5 tons (90 wt.%) Carbon, 17.5 tons (4.9 wt.%) Phosphogypsum and 100 m ³ (43.0 wt.%) Sand clay fraction (based on 50% of the waste volume). After the indicated components were added to the sludge barn in the required amount, the contents of the barn are mixed with an excavator. The time required for processing drill cuttings and oil products into environmentally friendly soil is 20-40 days, depending on the ambient temperature. Clay and a layer of soil are poured into the barn until the barn area is aligned with the adjacent relief. Next, sowing seeds of perennial crops. As a result of these actions, the hazard class of the resulting soil is reduced to class V.

Physico-mechanical properties obtained from the processing of environmentally friendly soil (average values are indicated):

- total porosity (%) - 12.0;

- water absorption (%) - 2.5.

An increase in important indicators of the water-air regime is observed, which indicates an improvement in the physical properties of the resulting soil. The acid-base properties of the soil under the action of the resulting soil vary slightly.

The components used provide structuring of the fraction <0.25 mm; in the control version, this fraction is 42%, and when components are added, it corresponds to 17.0%, i.e. the content of microaggregates that are not of agronomic value is reduced by more than 2.5 times.

Acute toxicity of soil samples after reclamation was studied in 50 white outbred mice of both sexes weighing 17-20 g with the oral route of administration. After the introduction of the samples, animals were monitored for 7 days, evaluating the time of death, the number of dead animals, and the clinical picture of intoxication. With the introduction of the studied samples, there were no signs of intoxication, all animals are alive, mobile, and have good appetite. According to the classification of soil samples, the studied samples can be assigned to the fifth hazard class.

The effectiveness of the proposed method was determined by the results of pilot tests (Example) and experimentally by laboratory tests. The tests were carried out under standard conditions: atmospheric pressure 760 mm Hg, air temperature 20 ° C. The hazard class was determined by the method of biotesting water extracts. The test results are given in the table.

Claims (2)

1. A method of reclamation of land occupied by sludge pits, in which an additive is added to the drilling waste at the rate of 50% of its volume, after which it is stirred over the entire volume of waste, then leveling layers are poured into the barn, ensuring the barn area is leveled with the adjacent terrain , and carry out the sowing of seeds of perennial crops, characterized in that as an additive, a carbon sorbent-destructor, phosphogypsum, building sand or sand-clay fraction are used in the following ratio of components s, wt.%:
carbon sorbent destructor 1-3 phosphogypsum 1-5 building sand or sand-clay fraction 25-48 drilling waste 50-70 2. The method according to p. 1, characterized in that as the carbon sorbent destructor using a compound of silicon oxide and carbon in the following ratio of components, wt.%:
silica 10-55 carbon 45-90