RU2450865C2 - Drilling mud processing and decontamination mobile plant - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to oil industry, particularly, to mobile plant for drilling mud and wastes treatment. Propose mobile plant comprises solid phase washing unit furnished with vibrating sieve, and cleaned water collection tank. Solid phase washing unit comprises cyclone-type sand separator incorporated with linear shale shaker-desander separator, and, at least, one buffer tank. Said vibrating sieve and shale shaker-desander separator are provided with water sprayers arranged above screen surfaces. Additionally, proposed plant comprises sold-phase loading unit provided with bin communicated with purified water collection tank and inclined screw conveyor to discharge deposited mud from bin. Besides, this plant includes liquid phase coagulation unit including steam heat exchanger communicated with, at least, one settling tank, sediment dewatering unit furnished with centrifuge, centrate collection tank, thermal desalting unit with reverse-osmosis membrane module and evaporation apparatus. Said units are communicated by pipelines and provided with pumps and gates. ^ EFFECT: higher efficiency. ^ 12 cl, 1 dwg

Description

The present invention relates to the field of the oil and oil industry, in particular to mobile installations for the processing and disposal of drill cuttings and drilling waste resulting from the production activities of oil and drilling companies.

A well-known installation for processing drill cuttings (RU, patent 90068, IPC C02F 11/00, publ. 12/27/2009) containing at least one hydrocyclone, a two-level tank for drill cuttings, where the levels are connected to each other through an opening in the bottom the upper level, the upper level is used for primary processing of sludge, and the lower is connected to the hydrocyclone through a pump.

A well-known installation for processing drill cuttings (RU, patent 54036, IPC C02F 11/14), containing a hopper, mixer, loading mechanism for simultaneously feeding into the hopper additives in the form of urea foam and drill cuttings, a screw mixer and a mechanism for unloading recycled drilling sludge.

The above installations do not allow the neutralization of drilling waste.

A well-known complex of industrial installations and devices for the processing of oily sludge (RU, patent 81444, IPC V03V 9/06, publ. 03/20/2009), including collectors, tank equipment, mixers, dispensers, pumps, interconnected by pipelines with shut-off and control valves Moreover, the complex is equipped with a unit for collecting oil from the surface of the barn, connected to a collection of oil products, a pumping unit for the aqueous phase, which is connected to a heated water collector, the outlet of which is directed to a hydraulic monitor for erosion and repulp drill cuttings directly in the drill barn, the complex is also equipped with a device for introducing Portland cement from the surface of the barn, a device for mixing the resulting mixture, a system for receiving and placing drill cuttings treated with Portland cement at the production site, the production site with cured drill cuttings has a technological connection with vehicles for the delivery of cured bulk drill cuttings to a stationary redistribution having a storage tank connected to a metering hopper directed to a mixer, to which a measuring device is connected, connected to a limestone feed tank connected to a natural limestone crushing and grinding unit, the outlet from the mixer is directed to a rotary calcining furnace equipped with a furnace, connected to a collection of oil products, the discharge device of the calcining furnace is connected via a conveyor belt to a crushing and grinding department having a storage tank, the output of which is through a flow-lock of reinforcement forms two streams of marketable Portland cement, one of which is directed to a metering hopper, technologically connected to a device for adding Portland cement to the surface of the oil barn, and the other is directed to a filling machine.

The complex is designed to collect oil from the surface of the barn. A known complex for the processing and disposal of drilling oil-containing sludge (RU, patent 93304, IPC B03B 9/06, publ. 15.12.2009) containing an oil intake device connected to an oil tank, the complex is additionally equipped with a sludge intake device consisting of a soil pump with a coarse filter and a hydraulic wash pump designed to wash out bottom sediment in the area of drill cuttings intake, both pumps are located on a frame mounted on pontoons and with a boom mounted on it with a varying geometry, on which the pipelines of the pumps are heated, while the soil pump is connected to a hydrocyclone, one outlet of which, designed for water outlet, is connected by a pipeline to a water treatment and return water supply device, consisting of a feeder connected to a water tank, one outlet of which is connected to a wash pump, the second is intended for the final discharge of water, while the second outlet of the cyclone, designed to exit the soil, is connected to a soil treatment device consisting of a vibratory tray and two feeders connected to the mixer, while one of the feeders is designed to supply coagulant, and the other to supply sand, the mixer output is connected to the receiving hopper.

The disadvantage of this device is not sufficiently effective disposal of drill cuttings.

The present invention is the development of a mobile more efficient installation for the processing and disposal of drill cuttings and drilling waste, which reduces the environmental burden on the environment.

The developed installation for the processing and disposal of drill cuttings (hereinafter referred to as UPOBSH) allows the environmentally friendly and harmless drill cuttings and drilling waste resulting from the production activities of oil and drilling companies. As a result of washing the solid phase (cuttings), waste of the 5th hazard class is obtained, which can be used when filling roads, cluster sites, reclamation, etc. As a result of dehydration of the liquid phase using reagents (coagulants and flocculants), followed by desalination of clarified water, purified water is obtained, which can be used for the needs of a drilling rig or dumped into the nearest water body. Dehydrated sludge (cake) and salt concentrate are used as an inert filler in the reclamation of temporary sludge collectors located on the same industrial site with the drilling rig.

The technical result is achieved by the fact that the installation for the processing and disposal of drill cuttings, including a washing unit for a solid phase, equipped with a vibrating screen, a collection tank for purified water, according to the invention, a washing unit for a solid phase contains a hydrocyclone-type sand separator in a linear sieve-hydrocyclone separator, at least one buffer tank, moreover, the vibrating screen and the sieve-hydrocyclone separator are equipped with shower units installed above the grid surfaces, The lob contains a solid phase loading unit equipped with a hopper connected to a treated water collection tank and an inclined screw conveyor for discharging and transporting deposited sludge from the hopper, a liquid phase coagulation unit containing a steam heat exchanger connected to at least one settling tank, a block centrifuge sediment dewatering, centrifuge collection tank, thermal desalination unit containing reverse osmosis membrane module and evaporator, the blocks are interconnected by a pipeline mi are equipped with pumps and valves. In the upper part of the hopper, a removable grill is installed for loading and erosion of clots of sludge, while a washing installation of pressure mode is located above the grill with the possibility of directing the jet to any section of the hopper and mesh. The vibrating screen and sieve hydrocyclone separator has grids with a mesh of 0.25 mm and 0.16 mm, respectively, and are equipped with a visor to direct the washed sludge to the collection container. The shower unit is designed as a spray. Buffer and slop tanks, equipped with mechanical mixers. The coagulation unit of the liquid phase contains a screw metering pump, and the sludge dewatering unit is equipped with a screw pump with a suction pipe. The thermal desalination unit further comprises a mechanical filter.

Drill cuttings belong to the fourth class of danger for the environment (according to the Criteria for classifying waste as a class of danger to the environment, approved by order of the Ministry of Natural Resources of Russia dated 06.15.2001 No. 511).

The composition of the solid phase of drilling waste is presented in table 1.

Table 1 No. p / p Component Name The content of components,% one Silica 50,5 2 Aluminium oxide 39 3 Iron oxide 1,0 four Water 6.9 5 Potassium chloride 1,0 6 Xanthan gum 0.1 7 Cellulose 1,0 8 Caustic soda 0.2 9 Sodium Polyacrylate 0.3 TOTAL: 100.00

The liquid phase of drilling waste, which is a weakly and medium saline solution with the following main indicators:

table 2 №№ Name of indicator Units rev. amount one Chloride content thousand mg / dm ³ 8-22 2 Density at 20 ° C g / cm ³ 1.10-1.14 3 PH value Units 8-12 four EHF mg / dm ³ 200-300

Figure 1 shows the technological scheme UPOBSH.

The structure of the UPOBSH equipment includes several interconnected technological units.

Solid phase loading unit.

Solid phase flushing unit.

Block coagulation of the liquid phase.

The first settling tank equipped with a mechanical stirrer PM - 2 pcs.

The second settling tank, 40 m ³ .

Sludge dewatering unit.

Fugate collection capacity, 40 m ³ .

Block of thermal desalination.

The capacity for collecting purified water, 40 m ³ .

The solid phase loading unit includes a hopper 1 connected via a pipeline to a collection tank for purified water 17. A removable grate (not shown) is installed in the upper part of the hopper 1 for loading and erosion of sludge clots. Above the grate there is a pressure setting washing unit with the possibility of directing the jet to any section of the hopper and net, for example a hose. To withdraw and transport the deposited sludge from the hopper 1, the loading unit contains an inclined screw conveyor 2 (KS).

The washing unit solid phase 2 includes:

- vibrating screen 3 (BC-1) with a mesh of 0.25 mm, equipped with a visor (not shown) for guiding the washed sludge into a collection container;

- sand separator 4 of the hydrocyclone type PG as part of a linear sieve-hydrocyclone separator (vibrating screen) 5 (BC-2) having a mesh with a mesh of 0.16 mm, equipped with a visor (not shown) to direct the washed sludge to the collection container;

- buffer tanks 6 (BE-1) and 7 (BE-2), volume 20 m, equipped with mechanical mixers 8 (PM);

- one or more sectional shower units 9, which are installed above the grid surface of the vibrating screen 3 (BC-1) and 5 (BC-2), for example in the form of a spray (Br);

- NTs-1 pump for supplying washing water to the sand separator 4;

- pumps NTs-5 and valves for supplying and adjusting the washing solution to the installation 9;

- NTs-2 pump for supplying fluid to the coagulation unit.

The coagulation unit of the liquid phase includes:

- a centrifugal pump NTs-3, equipped with a suction pipe for supplying the liquid phase of drill cuttings to the coagulation unit;

- steam heat exchanger 10 (TO);

- screw dosing pump NV-1;

- gate valves for adjusting the high-speed flow of mixed liquids.

The first 11 and second 12 slop tanks are equipped with mechanical mixers 8 (PM).

Sludge dewatering unit includes:

- HB-2 screw pump with intake pipe;

- centrifuge 13 (CF);

- adjusting latches.

The centrifugal collection tank is equipped with a NTs-4 centrifugal pump for supplying purified water to the thermal desalination unit.

The thermal desalination unit includes:

- reverse osmotic membrane module 14 (MM);

- evaporator apparatus 15 (VA);

- mechanical filter 16 (MF).

The collection capacity of purified water 17 is equipped with a centrifugal pump NTs-5.

Installation works as follows.

At the existing drilling site, the liquid phase of the drilling waste is discharged into special sealed steel tanks, from where they are pumped by vacuum units on a car chassis into tankers and transported to the UPOBS unit. The solid phase of drilling waste is discharged into special steel half-boxes, from where they are transported to the UPOBSH unit using a forklift. The equipment used for transporting drilling waste must have airtight shutoff valves on the tanks to prevent leakage of drilling waste.

The solid phase of drilling waste is drill cuttings (hereinafter referred to as cuttings), in portions of up to 1.5 m ³ with a front-end loader, they are fed to the grate with a mesh size of 50 × 50 mm of hopper 1 of the loading unit. The soil is washed with clarified and demineralized water from a container with a volume of 40 m ^{3 of} collection of purified water 17. With the NTs-5 pump, water is fed to the loading unit, where the operator blurs a portion of the sludge lying on the grate of the loading unit with a hose. The flow of the solution is controlled by a valve.

The washed-out sludge passes through the lattice mesh into the hopper 1, from where it is fed by an inclined screw conveyor 2 (KSh) to the washing unit on a vibrating screen 3 (BC-1) with a mesh of 0.25 mm. The performance of the screw conveyor 2 is regulated by a four-speed gearbox at the drive station. The slurry passing through the surface of the grids 3 (BC-1) is washed with purified water through two rows of spray 9 (Br). The supply of the cleaning solution to the spray 9 is carried out by the NTs-5 pump and is regulated by valves.

Wash water containing suspended sludge particles with a fraction of up to 0.25 mm, passed through a vibrating screen 3 (BC-1), enters buffer tank 6 (BE-1) with a volume of 20 m ³ of the washing unit. The buffer tank 6 to prevent sedimentation of suspended particles is equipped with a mechanical stirrer 8 (PM). From the buffer tank 6 (BE-1), the washing water is pumped by the NTs-1 pump to the sand separator 4 of the hydrocyclone type PG as part of a linear sieve-hydrocyclone separator 5 (BC-2) having a mesh with a mesh of 0.16 mm.

The slurry passing through the surface of the grids 5 (BC-2) is additionally washed with purified water through one row of spray 9 (Br). The supply of the washing solution to the sprayer 9 is carried out by the NTs-5 pump and is regulated by a valve.

The washed sludge separated on vibrating screens 3 (ВС-1) and 5 (ВС-2) (drill cuttings of the 5th hazard class) is discharged into the boxes located under the vibrating screens and, as they are filled, are transported to the site provided by a front-end loader for its intermediate storage.

Wash water containing suspended sludge particles with a fraction of 0-0.16 mm, passed through a grid of vibrating screens 5 (BC-2), enters the buffer tank 7 (BE-2), a volume of 20 m ³ . The buffer tank 7 to prevent sedimentation of suspended particles is equipped with a mechanical stirrer 8 (PM).

From the buffer tank 7 (BE-2), the washing water is pumped by the NTs-2 pump to the coagulation unit.

The liquid phase of drill cuttings (hereinafter referred to as JBS), delivered to the installation, is pumped by the centrifugal pump NTs-3 of the coagulation unit through the drain pipe of the tank of the vacuum machine using a pressure-suction sleeve connected to the suction pipe of the pump. From the rig, on the site of which the installation is located, it is also possible to lay a pipeline to the suction nozzle of the centrifugal pump NTs-3.

ZhBSh pump centrifugal NTs-3 or washing water from the buffer tank 7 (BE-2) of the washing unit with a centrifugal pump NTs-2, is fed through a steam heat exchanger 10 (TO) to one of the settling tanks 11 or 12 of the installation. When passing through a heat exchanger 10, the fluid is heated to a temperature of 15-20 ° C.

The production of water vapor is carried out using a commercially available steam generator or a mobile field steam installation on an automobile chassis of the PPUA type.

Simultaneously with the supply of ZhBSh or wash water to the flow line of the heat exchanger 10, a HB-1 screw metering pump delivers a 20% solution of coagulant (aluminum sulfate Al ₂ (SO ₄ ) ₃ ) in an amount of 1 to 3 kg per 1 m ^{3 of} ZhBSh.

In this case, the coagulant solution is mixed with JBS and washings. The supply of the coagulant solution (capacity NV-1) and the supply of concrete products (capacity NTs-2 or NTs-3) must be coordinated so that the calculated amount of the coagulant solution is evenly distributed over the entire volume of the reinforced concrete. The flow of the screw pump is regulated by rotating the flywheel on the variator according to the indications of the arrow of the gravitational sensor. The flow of pumps NTs-2 or NTs-3 is regulated by a valve on the pressure pipe.

After filling the tank 11 and / or 12 while maintaining a temperature of 20 ° C for at least two hours, the process of coagulation of suspended particles occurs, as a result of which they settle to the bottom of the tank.

Using a sampler, the height of the sludge layer in the tank 11 and / or 12 is determined. The intake pipe of the suction sleeve of the pump of the screw (HB-2) dewatering unit is installed at a height equal to two heights of the bottom sediment. The clarified water from the tank 11 and / or 12 by the pump (HB-2) is pumped into the collection tank of the centrate 18.

After pumping the clarified water, to reduce the specific gravity of the precipitate remaining in the tank 11 and / or 12 before feeding to the centrifuge 13, the precipitate is mixed with the mechanical stirring 8 with the remaining volume of clarified water.

The suspended sludge from the tank 11 and / or 12 is pumped by a screw pump (HB-2) into a two-phase horizontal sedimentation centrifuge 13 (decanter) (CF), where sludge is dehydrated. The flow of the solution is controlled by a mechanical variator of a screw pump.

The dehydrated sediment separated in the centrifuge 13 is discharged into a container (not shown) located under the block, and the water purified from suspended particles enters the collection chamber of the centrate 18.

As the container is filled to collect the dehydrated sludge, its contents are removed and discharged into a temporary sludge collector during the drilling rig for subsequent lithification.

From the collection chamber of the centrate 18, water purified from suspended particles by the pump NTs-4 is fed through a mechanical filter 16 to the thermal desalination unit.

In the thermal desalination unit, a two-stage purification of clarified water occurs:

- deep purification and desalination of clarified water by the reverse osmosis method on the reverse osmosis membrane module 14 (MM);

- evaporation of the reverse osmosis concentrate in a 3-stage evaporation apparatus 15 (VA).

Salt concentrate from the thermal desalination unit is sent to a temporary sludge collector during the drilling rig for subsequent lithification.

Desalted water from the thermal desalination unit is supplied to the collection tank for purified water 17, from where the pump NTs-3 can be supplied for reuse to the drilling rig or discharged to the nearest water body (stream, river) in accordance with the draft standards for permissible discharges.

As a result of washing the solid phase of drilling waste having a 4th hazard class for the environment, we get drill cuttings having a 5th hazard class (according to the Criteria for classifying waste as a hazard class for the environment, approved by Order of the Ministry of Natural Resources of Russia dated 15.06.2001 No. 511), which can be used when filling roads, bush sites, reclamation, etc.

Dehydrated sludge (cake) and salt concentrate, which have a 3rd hazard class for the environment, are used as an inert filler in the reclamation of temporary sludge collectors located on the same industrial site with the drilling rig. In this case, the neutralization of the solid phase (treatment with hardening compounds) occurs directly on the reclaimed area, i.e. in the most temporary foundation pit in the warmer months.

Water can be used for the needs of a drilling rig or the nearest water body has been discharged.

Claims (12)

1. Mobile installation for the processing and disposal of drill cuttings, including a solid phase washing unit equipped with a vibrating screen, a collection tank for purified water, characterized in that the solid phase washing unit contains a hydrocyclone-type sand separator in a linear sieve-hydrocyclone separator, at least one buffer tank moreover, the vibrating screen and sieve-hydrocyclone separator are equipped with shower units installed above the grid surfaces, the installation further comprises a solid phase loading unit, equipped with a hopper connected to a treated water collection tank and an inclined screw conveyor for withdrawing and transporting deposited sludge from the hopper, a liquid phase coagulation unit containing a steam heat exchanger connected to at least one settling tank, a sludge dewatering unit equipped with a centrifuge, a tank centrifugal collection unit, a thermal desalination unit containing a reverse osmosis membrane module and an evaporator, the blocks are interconnected by pipelines, equipped with pumps and valves. 2. Installation according to claim 1, characterized in that a removable grate is installed in the upper part of the hopper for loading and erosion of sludge clots, while a washing pressure unit is located above the grate with the possibility of directing the jet to any section of the hopper and mesh. 3. Installation according to claim 1, characterized in that the vibrating screen has a mesh with a mesh of 0.25 mm 4. Installation according to claim 1, characterized in that the sieve-hydrocyclone separator has a mesh with a mesh of 0.16 mm 5. Installation according to claim 1, characterized in that the vibrating screen is equipped with a visor for guiding the washed sludge into a collection container. 6. Installation according to claim 1, characterized in that the sieve-hydrocyclone separator is equipped with a visor for directing the washed sludge into a collection container. 7. Installation according to claim 1, characterized in that the shower installation is made in the form of a spray. 8. Installation according to claim 1, characterized in that the buffer tank is equipped with a mechanical stirrer. 9. Installation according to claim 1, characterized in that the settling tank is equipped with a mechanical stirrer. 10. Installation according to claim 1, characterized in that the block of coagulation of the liquid phase contains a screw metering pump. 11. Installation according to claim 1, characterized in that the sludge dewatering unit is equipped with a screw pump with a suction pipe. 12. Installation according to claim 1, characterized in that the thermal desalination unit contains a mechanical filter.

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