RU2367618C2 - Titanous coagulant used for purification of oil-containing oilfield saltwater up to potable water quality, method thereof (versions) and complex system thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method lies in usage of titanous coagulant containing oxides, hydroxides, sulphates, titanium oxyhydrosulphates, chlorides and titanium, aluminium and silicon oxyhydrochlorides for purification of oil-containing oilfield saltwater up to potable water quality. The purification technology includes coagulation and clarification; at first the two-stage floatation is carried out including water purification from oil products in the first stage and adding of the water solution of flocculent - calcined soda and/or lime in the amount not less than 100 g of calcined soda and not less than 100 g of lime on a dry basis per 1 m³ of the purified water on the second stage; after completing the second stage the purified water settling is carried out up to precipitation of the mechanical admixtures and hardness salts, then coagulation is implemented by adding to the clarified oilfield water of the titanous coagulant solution as in point 1 in the amount not less than 20 g on a dry basis per 1 m³ of the purified water up to decrease of oil products content in the purified water up to less than 0.05 g/m³. Then the final water purification is carried out by method of reverse osmosis up to achieving of potable water quality. The complex system for purification includes the devices needed for methods implementation with contact clarifier being connected through high-pressure pump with membrane units of reverse osmosis, settler being connected with inclined floatator having not less than 10 floatation chamber. The pipe-line connecting the contact clarifier with settler is provided with not less than 4 coupling positioned on the distance not less than 1 m of the contact clarifier inlet and intended for flocculent feed.

EFFECT: decontamination and decrease of oil products content in the purified water up to value best than 0,05 mg/l corresponding to the standards of environmental safety without excessive capital and operating costs.

8 cl, 2 dwg, 14 tbl, 11 ex

Description

The invention relates to the field of treatment of brine salt water and can be used to produce boiler or potable water from oil-containing brine salt water using membrane technologies, as well as to improve the condition and maintain human health and environmental protection; the invention can be attributed to the priority strategic direction of development in Russia “Health of the nation”.

There is a method of complex processing of associated water in oil fields (1), which includes preliminary purification of water from mechanical impurities and oil, followed by sequential extraction of magnesium, lithium, boron, iodine, bromine and other components, after the removal of which water is sent to the reservoir pressure maintenance system for re-injection into the reservoir. However, the known purification method does not allow to achieve a high level of purification to potable quality, since the purification technology is not high enough and boils down mainly to the extraction of inorganic components, after which the purified water is only suitable for pumping it into the reservoir according to the degree of purification.

A known method of removing contaminants from the incoming stream (2), which relates to the treatment of produced water from the installation of crude oil production by the thermal method. However, the known method provides the purification of produced water only to prevent scale formation in the distillation unit.

A known method of removing colmatizing formations from hydrocarbon-containing formations (3), in which the polymer colmatizing formations are removed using chemical reagents. However, the known method of cleaning is aimed at eliminating complications during the drilling of wells, treatment of the wellbore before the secondary opening of reservoirs.

A known method and installation for the purification of liquid effluents, containing, in particular, in suspension suspended pollutants (4), providing means for separating the gravitational action and means for membrane separation used at the stage of final cleaning. However, the known method has a limited scope and quality of treatment for liquid effluents with suspended contaminants.

Known automatic complex for the purification of oily wastewater (5), which is intended for physico-chemical purification of oily wastewater. The automatic complex contains a means for supplying source water, pre-treatment units, collectors and pipelines for returning pre-treated source water, an automatic control unit for the cleaning process. The well-known complex solves the technical problem posed during its creation, according to which this development, compared with the selected prototype (6), increases the degree of purification of the source water to reuse for technical purposes due to the presence of the operation of removing salts (chlorides) in it. However, the well-known automatic complex is designed according to its technology for wastewater treatment and, at the outlet, the purified water does not achieve drinking quality. In addition, from the description of the invention it does not follow what quality of treatment the source water at the outlet reaches and how suitable it is for use in boiler plants: the description does not provide comparative quantitative and / or qualitative parameters of the source and purified water. In addition, the well-known automatic complex is expensive due to its complex design, as well as time-consuming in carrying out the cleaning process and technological maintenance of this process.

Known thin-walled sump (7), designed for the treatment of produced water, however, with this device, the original produced water is purified only from suspended particles, and therefore the degree of purification to the drinking quality is not achieved.

Known flotator (8), designed for the treatment of industrial and domestic wastewater, however, the degree and quality of treatment of the source water is low, since only proteins, fats, oil products, surfactants and other impurities are removed from the source water, which does not provide a sufficient quality of treatment water before drinking.

The known technology for treating produced water and an installation for its implementation (9), which is closest in solving the technical problem to the method proposed in the invention. The known method allows the purification of oil-containing formation salt water to drinking quality and includes a technological operation of coagulation and clarification of the source water.

The disadvantage of this method is the degree of purification of produced water to the oil content in it in an amount of not more than 15 mg / l, which is not enough to obtain high drinking quality water at the outlet.

A known installation for treating formation water (9), which is closest in solving the technical problem to the proposed in the invention a comprehensive system for treating formation water. The known installation, which is based on the sequential clarification of the source water, allows the purification of oil-containing formation salt water to drinking quality, however, the degree of purification of formation water in the known installation allows the removal of oil-containing products in it to a content of not more than 15 mg / l, which is insufficient for receiving at the exit of water of high potable quality.

Known coagulant for treating industrial wastewater using coagulants (10) containing natural aluminosilicate, having in its composition a ratio of silica to alumina 3.9-4.16 and a ratio of natural aluminosilicate to mineral acid in a ratio of 0.07-0, 25. However, the known coagulant has an insufficiently high degree of purification.

Known coagulant for the treatment of natural and wastewater (11), closest to the proposed invention according to the achieved technical result and selected as a prototype. The coagulant contains compounds of aluminum, calcium oxide, silicon oxide, iron oxide, magnesium oxide and sulfur dioxide.

The disadvantages of the known coagulant are obtaining insufficiently high degree of purification and instability of its disinfecting properties.

The technical result achieved by the invention is common to the entire group of claimed inventions (titanium coagulant used for purification of oil-containing formation salt water to drinking quality water, a cleaning method and an integrated system for purification of oil-containing formation salt water to drinking quality water), it consists in increasing the efficiency of cleaning to boiler and drinking quality and disinfection of natural and wastewater is not lower than the established standards (12, 13), as well as in reducing the cost this process cycle and reducing the complexity of the purification water reservoir.

The specified technical result is achieved by a new titanium coagulant used for purification of oil-containing formation salt water to potable water, which contains oxides, hydroxides, sulfates, oxyhydrosulfates, chlorides, oxyhydrochlorides of titanium, aluminum and silicon, and these ingredients are contained in terms of oxides in the ratio:

aluminum oxide - not more than 76.5 wt.%,

titanium oxide - not less than 10.6 wt.%,

silicon oxide - not less than 5.0 wt.%,

impurity compounds of sulfur, iron, calcium, chlorine - not more than 0.5 wt.%, water - not more than 7.4 wt.%.

The indicated technical result is also achieved by a new method of purification of oil-containing formation salt water to drinking water according to the first embodiment, including their coagulation and clarification, according to which, before coagulation and clarification, two-stage flotation is performed, at the first stage of which oil-containing formation salt water and its preliminary cleaning of oil products, at the second stage of flotation, an aqueous solution of flocculating chemical reagents is added to it - calcined soda and / or lime in an amount of at least 100 g of soda ash and at least 100 g of lime in terms of dry matter per 1 cubic meter of purified formation water, after the second flotation stage, the purified water is sedimented until mechanical impurities and hardness salts precipitate and coagulation is carried out by adding to the produced water after settling the solution of titanium coagulant solution according to claim 1 in an amount per 1 cubic meter of cleaned at least 20 g in terms of dry matter to reduce the oil content in 1 cubic meter of cleaned bottled water is not more than 0.05 g, after which the final water purification is carried out by the reverse osmosis method until drinking water quality is achieved.

The specified technical result is also achieved by a new method of purification of oil-containing formation salt water to potable water according to the second embodiment, including coagulation and clarification, in which, in accordance with the invention, two-stage flotation is carried out before coagulation and clarification, in the first stage of which an oil-containing formation is supplied salt water and its preliminary purification from oil products; at the second stage of flotation, an aqueous solution of flocculating chemical of agents - soda ash and / or lime in an amount of at least 100 g of soda ash and at least 100 g of lime in terms of dry matter per 1 cubic meter of purified soda water, after the second flotation stage, the purified water is sedimented until mechanical impurities precipitate and hardness salts, and coagulation is carried out by adding to the produced water after settling a mixture of a titanium coagulant according to claim 1 and titanium dioxide in an amount of at least 20 g / cubic meter in terms of dry matter until the oil content decreases products in 1 cubic meter of treated formation water not more than 0.05 g, after which the final water treatment is carried out by the reverse osmosis method until drinking water quality is achieved.

In addition, the specified technical result is achieved by the fact that in the process of coagulation using a mixture of titanium coagulant with powdered titanium dioxide in a mass ratio, respectively, equal to 20: 1.

The specified technical result is also achieved using an integrated system for the purification of oil-containing formation salt water to potable water containing contact clarifier, in which, in accordance with the claimed invention, the contact clarifier is connected, on the one hand, through a pipeline having fittings for supplying flocculent chemical reagents, with a sump equipped with a blind vertical partition, the height of which is below the level of the upper edge of the sump, on the other hand, contact clarification Itel is connected through a high pressure pump to reverse osmosis membrane units, and the sump is connected to an inclined flotator, in the upper part of the first chamber of which oil-containing formation salt water enters.

In addition, the specified technical result is achieved by the fact that the contact clarifier has a gravel load.

In addition, this technical result is achieved in that the flotator has at least 10 flotation chambers.

In addition, this technical result is achieved by the fact that at least 4 fittings for supplying flocculating chemicals are located on the pipeline connecting the contact clarifier and the settler at a distance of at least 1 meter from the entrance to the contact clarifier.

From a comparative analysis of the known solutions it follows that the identical group of the claimed inventions, united by a single technical result indicated above, was not found by the applicant.

The technology of purification of oil-containing formation salt water to boiler and drinking quality according to the claimed invention is illustrated in Figures 1 and 2, which show a diagram of the claimed integrated system for the purification of oil-containing formation salt water to drinking quality, carried out in two stages.

The first stage of purification of oil-containing formation salt water, presented in the form of a diagram in Fig. 1, is based on two-stage flotation and includes the following elements of the integrated system: pipeline 1 with a nozzle for supplying formation (mine) water for purification with a counter 2 that registers the amount of incoming purification water, a mixer 3 with a tank 4 for soda solution and a pump 5 for pumping it out, a flotation machine 6, in which the first five chambers are used to purify water from petroleum products, and the next second five chambers are softened and alkalized water; a mixer 7 of lime mortar and a metering pump 8 for its supply, a sump system of pumps 9, 10 for pumping contaminants, 11 for pumping purified water by flotation, 12 for pumping insufficiently purified water, a pump system 13 for pumping clean water to “Storage”, 14 - for pumping contaminated water to the sump tank and oil trap, 15 - for pumping insufficiently purified water sump pump 9, 16 - for pumping purified water by flotation to the boiler room, sump tank 17 connected to the tank for collecting oil 18 , and which pump 19 delivers flotated water, a sump 20 of the pump pumping water to the "storage", an oil trap 21 located between a sump and a tank for collecting oil, a set of pumps: 22 for pumping oil for transportation, 23 for sludge, 24 - for pumping clean water, 25 - for pumping sludge, 26 - for pumping water for re-treatment, a car with a tank 27 for oil removal, sump 28 of the pump pumping water for re-treatment.

The second stage of treatment of brine salt water, presented in the form of a diagram in Figure 2, is based on the subsequent sedimentation of the treated source water, coagulation and final purification of brine salt water using membrane technology - the reverse osmosis method, and includes the following elements: the first section 29 of the tank sedimentation tank 17, pipeline 30, through which water purified from flotation is supplied to the sedimentation tank 17, the second section of the sedimentation tank 17, pipeline 31 with sludge supply fittings, contact clarifier 33, water collection tank 34, system p compressed air supply 35, a pump 36 for pumping water to the contact clarifier for flushing it, a water meter 37, a mixer 38 for preparing a coagulant solution, a high pressure pump 39 for supplying water after cleaning on a contact clarifier, a metering pump 40 for supplying a coagulant solution , reverse osmosis membrane blocks 41, pipe 42 for purified water (for consumers), pipe 43 with a fitting for draining into the sewer, a contact clarifier, a pump 44 for pumping purified water to a contact clarifier.

The work of an integrated system for implementing the claimed method for the treatment of formation salt water is as follows.

In the first stage (Figure 1)

The initial oil-containing formation salt water 1 is fed through a counter 2, which registers the volume of the source water, to the flotation machine 6, sequentially to the first five chambers of the flotation machine 6, then to the second five chambers of the flotation machine 6; From the soda solution tank 4, a soda solution is supplied by a pump 5 through a soda solution mixer 3 and a lime solution is supplied through a lime mixer 7 using a metering pump 8. Contaminants through sump No. 1 of pump 9 and sump No. 2 of pump 10 are directed to the sump tank 17 or to the oil trap 21. Using pump 13, clean water is pumped to the “storage” through the sump of pump 20 and pump 24. Contaminated water through pump 14 fed to the settling tank 17 and then to the oil trap 21. Insufficiently purified water from the flotation machine 6 is pumped to pump 24 by pump 15. Oil products recovered at the flotation stage are sent to oil collection tanks 18 and pump 22 is pumped to the tank of the vehicle for oil export 2 7. The water 21 purified in the oil trap is sent to the sump of the pump pumping water to the flotation machine 6 and re-cleaning 28, and is pumped out by the pump 26 for re-cleaning. Formed in the sump tank 17, the sludge pump 25 is sent to the "storage" 23.

The oil-containing formation salt water 30 purified at the flotation stage is fed through the sump of the pump 16 to the first section of the settling tank 29, and then sent to the second section of the settling tank 31. The sludge formed in the settling tank 17 is sent to the “storage” 32. After the settling stage 32 formation salt water by a pump 44 through a water flow meter 37 is supplied to the contact clarifier 33. When flushing the contact clarifier 33, compressed air is supplied through the system 35 to the pipeline connecting the contact clarifier 33 and the second section of the settling tank 31, having at least 1 meter from the entrance to the contact clarifier 33 fittings; from the mixer 38 for the preparation of a coagulant solution, the pump 40 feeds flocculating chemicals. The water purified on the contact clarifier 33 is supplied to the purified water collection tank 34. The water supplied by the pump 36 to the contact clarifier 33 for washing it is sent to the sewer 43. From the water collection tank 34, water is supplied through the high pressure pump 39 to the return membrane unit osmosis 41, after which the purified water of boiler and drinking quality is pumped to the appropriate consumers by the pump 42.

The treatment of produced water is currently one of the pressing global problems in the oil industry. At the same time, the trend in the world is such that environmental requirements for emissions are being tightened. Therefore, it requires a search for more and more new technologies that could effectively treat the produced water to the level of boiler and drinking quality. As you know, more stringent environmental requirements for the quality of drinking water are increasing: for example, new initiatives - the Convention for the Protection of the Marine Environment in the North-East Atlantic, the Kyoto Agreement and others - have led to the revision of environmental requirements already within the industry as applied to oil emissions. The main goal pursued by all new technologies and devices aimed at water purification is to achieve a zero approximation in the content of oil in the initial purified water and the minimum presence of solid particles, hardness salts and other pollutants.

The invention is aimed at achieving such a result.

The following are examples of specific implementations of the claimed group of inventions.

In the claimed method, a titanium coagulant solution is used, because at all water utilities where experimental and production tests took place, a water treatment scheme using a working solution prepared from dry matter is used. In dry form, titanium coagulant can also be used, but subject to the purchase of new equipment by water utilities, as well as the attraction of additional labor.

Production tests were carried out at the processing plant of the Production Service Department of LUKOIL-Komi LLC, located on the industrial areas of the oil mine No. 3 of the LUKOIL-Ukhtaneftegaz TPP LUKOIL-Komi LLC in June-July 2007.

Examples of the implementation of the claimed method

Example 1

In accordance with the invention, flotation has two stages. The first of them is an intensive purification of the original oil-containing formation salt water from oil products. During the first stage of flotation, a steady decrease in the content of oil products was observed on average with an efficiency of up to 96.2% with respect to the initial content of oil products of the treated water. Such preliminary cleaning in the first stage of flotation makes it suitable for further processing in the second stage of flotation.

Table 1 shows the results of tests carried out under production conditions, which show a significant decrease in the content of oil products after the first stage of flotation.

Table 1 No. p / p The oil content, mg / DM ³ Source formation water Water after the first flotation stage one 107.36 4.8 2 53.67 3.74 3 102.84 3,55 four 20.61 3.63 5 149.64 2.08

Example 2

In the flotation department of the pilot industrial processing plant, work was carried out to treat the salt waters of the Yarega field using existing flotation machines. The main goal of the work at the second stage of flotation is the maximum reduction in stiffness (Ca ²⁺ and Na ⁺ + K ⁺ ). The tests showed that the dosage of soda ash taken in an amount of less than 100 g / m ³ was insufficient to effectively reduce the hardness of the treated water. The experiments also showed that the optimal dosage of soda ash was 300 g / m ³ in terms of dry soda ash.

Example 3

In the flotation department of the pilot industrial processing plant, work was carried out to treat the salt waters of the Yarega field using existing flotation machines. The main goal of the work at the second stage of flotation is the maximum reduction in stiffness (Ca ²⁺ and Na ⁺ + K ⁺ ). The tests showed that the dosage of lime, taken as the second flocculating chemical reagent in an amount of less than 100 g / m ³ , was insufficient to effectively reduce the hardness of the treated water. The experiments showed that the optimal dosage of lime was 315 g / m ³ in terms of lime in the dry state.

Numerous experiments with different contents of flocculating chemicals indicated in examples 2 and 3 have convincingly shown that when they are used in a ratio of 1 m ^{3 of} treated formation water at least 100 g in terms of a chemical reagent (soda ash and / or lime) in a dry state a stable decrease in the total hardness of treated water on average 57.2% compared with the original. Such preliminary cleaning at the flotation stage makes it suitable for further processing on a contact clarifier.

The results of the production tests indicated in examples 2 and 3 are summarized in tables 2-4, which show samples with different qualitative characteristics of the source water after the second stage of flotation.

table 2 Total rigidity
mg * equiv / dm ³ Ca ²⁺ , mg / dm ³ Na ⁺ + K ⁺ , mg / dm ³ Source formation water 56.0 721.44 3822.34 Water after the second stage of flotation 24.0 280,0 3133.75

Table 3 Total stiffness, mg * equiv / dm ³ Ca ²⁺ , mg / dm ³ Na ⁺ + K ⁺ , mg / dm ³ Source formation water 56.0 721.44 3822.34 Water after the second stage of flotation 20,0 240.0 3446.1

Table 4 Total stiffness, mg * equiv / dm ³ Ca ²⁺ , mg / dm ³ Na ⁺ + K ⁺ , mg / dm ³ Source formation water 56.0 721.44 3822.34 Water after the second stage of flotation 22.0 320,0 2721.6

Table 5 shows the test results with dosages of soda ash and lime insufficient for optimal purification of the source water.

Table 5 Total stiffness, mg * equiv / dm ³ Ca ²⁺ , mg / dm ³ Na ⁺ + K ⁺ , mg / dm ³ The dose of soda ash, g / m ³ 60 The dose of lime, g / m ³ 85 Source formation water 56 721.44 3822.34 Water after the second stage of flotation 42 698.34 3800.15

According to the results of numerous experimental studies with different doses of soda ash and lime, the optimal values were experimentally obtained, which are shown in table 6.

Table 6 Total stiffness, mg * equiv / dm ³ Ca ²⁺ , mg / dm ³ Na ⁺ + K ⁺ , mg / dm ³ The dose of soda ash, g / m ³ 300 The dose of lime, g / m ³ 315 Source formation water 56 721.44 3822.34 Water after the second stage of flotation 20,0 240.0 3446.1

From table 6 it is seen that these dosages of soda ash and lime sufficiently well reduce the hardness of water.

Example 4

Pre-treated initial formation water from oil products and hardness salts has not yet reached drinking quality, since it contains a certain amount of contaminants in the form of oil product residues and hardness salts that are removed in subsequent stages, one of which is cleaning with a contact clarifier.

The tests were carried out on a contact clarifier installed, as mentioned above, directly in the water treatment department of the boiler room of the oil mine No. 3 of the LUKOIL-Ukhtaneftegaz TPP LUKOIL-Komi LLC. Testing was carried out especially carefully, for which experts trained in all stages of water treatment were admitted to the experiment. The main working material of the used contact clarifier was the gravel loading of a certain fraction located in the contact clarifier according to special calculations of their loading, allowing cleaning in the optimal mode, subject to the maximum filter cycle time. Periodically, according to the results of the analysis of purified water, the contact clarifier was washed to ensure its most effective operation.

When treating water with a contact clarifier, flocculating chemicals were added in different experimental ratios, as used in the claimed cleaning method according to the first embodiment, titanium coagulant, and in the claimed cleaning method according to the second embodiment, a mixture of titanium coagulant with titanium dioxide was used as chemical reagents, and also a mixture of titanium coagulant with powdery non-chlorinated (i.e. not having passed the surface treatment stage) titanium dioxide (used an opacifier, a thickener and a disinfectant). During coagulation, an aqueous solution of flocculating chemical reagents in the amount of 1 cubic meter of cleaned formation water of at least 20 g in terms of each chemical reagent in the dry state was added to the produced formation water after settling until the oil products decreased in the amount of 1 cubic meter of cleaned formation water water not more than 0.05 g, after which they proceeded to the final purification of produced water by the reverse osmosis method until its drinking quality was achieved.

Table 7 shows the results of experimental studies using titanium coagulant with different doses.

Table 7 Source formation water Water treated with titanium coagulant 07.07.07-26.07.07 The dose of titanium coagulant, g / m ³ eighteen one hundred one hundred Total stiffness, mg * equiv / dm ³ 56.0 42 22 twenty The residual iron content, mg / DM ³ 4.17 1,03 0.19 0.13 The residual content of aluminum, mg / DM ³ - 0.6 0.06 0.06 Permanganate oxidation, mg O ₂ / dm ³ 10.08 5.44 4.0 4.0 Color, hail. - 14.8 1,69 1,69 Turbidity, EMF - 7.5 0.83 0.83 Petroleum products, mg / DM ³ 107.36 0.13 <0.05 <0.05

The tests performed showed, as can be seen from table 7, that the dosage of titanium coagulant taken in an amount of less than 20 g / m ³ was insufficient for effective cleaning. The optimal dosage for titanium coagulant was 100 g / m ³ in terms of a chemical reagent (titanium coagulant) in the dry state.

Example 5

When treating water with a contact clarifier, flocculating chemicals were added in different experimental ratios, using titanium coagulant as well as its mixture with titanium dioxide.

Tests using a mixture of titanium coagulant with titanium dioxide showed that dosages of titanium coagulant to titanium dioxide in a ratio of 20: 1, taken in an amount of less than 20 g / m ³ , were also insufficient for effective cleaning. The optimal dosage of a mixture of titanium coagulant with titanium dioxide in the same ratio of 20: 1 was 60 g / m ³ in terms of a mixture of these chemicals (titanium coagulant and titanium dioxide) in the dry state.

The optimal doses of titanium coagulant and its mixture with titanium dioxide taken as flocculating chemicals are shown in table 8.

Table 8 Source formation water Water treated with a titanium coagulant 07.07.2007 Titanium Coagulant Water
07/23/2007 Water treated with a titanium coagulant 07/27/2007 Total stiffness, mg * equiv / dm ³ 56.0 24 22 twenty The residual iron content, mg / DM ³ 4.17 0.29 0.19 0.13 The residual content of aluminum, mg / DM ³ - 0.1 0.06 0.06 Permanganate oxidation,
mg O ₂ / dm ³ 10.08 4.32 4.0 4.0 Color, hail. - 5.54 1,69 1,69 Turbidity, EMF - 1,54 0.83 0.83 Petroleum products, mg / DM ³ 107.36 <0.05 <0.05 <0.05

Numerous experiments with different contents of flocculating chemicals indicated in examples 4 and 5 (titanium coagulant and a mixture of titanium coagulant to titanium dioxide) have convincingly shown that when they are used (with a ratio of titanium coagulant and titanium dioxide as 20: 1) in a ratio of

1 m ^{3 of} purified formation water of at least 20 g in terms of a dry chemical reagent gives a stable decrease in the content of oil products to less than 0.05 g / m ³ , which corresponds to the efficiency of reducing the oil content of the source of purified water to about 99%. Such a high degree of purification allows us to move on to further fine purification based on high membrane technologies (reverse osmosis method), which require a minimum content of oil products.

In the above examples of the purification of oil-containing formation salt water, the results of industrial and experimental studies were obtained using a new titanium coagulant.

Examples of the implementation of titanium coagulant used in the claimed method of purification of oil-containing formation salt water to drinking quality

The claimed titanium coagulant was obtained by the applicant at its production base in the course of targeted pilot studies of the search for the most effective oil-containing formation salt water in terms of the degree of purification. The composition of the new titanium coagulant includes compounds: oxides, hydroxides, sulfates, oxyhydrosulfates, chlorides, titanium, silicon and aluminum oxyhydrochlorides, the content of which in terms of oxides is: aluminum oxide - not more than 76.5 wt.%, Titanium oxide - not less than 10.6 wt.%, Silicon oxide - not less than 5.0 wt.%, Impurity compounds of sulfur, iron, calcium, chlorine account for no more than 0.5 wt.%, And the water content is not more than 7.4 wt.%.

The new titanium coagulant, used to purify oil-containing formation salt water to potable quality, contains the ingredients sulfates, oxyhydrosulfates, chlorides and oxyhydrochlorides of titanium, silicon and aluminum, the quantitative content of which is calculated from the required composition of the content of titanium, silicon and aluminum oxides.

The total content of titanium sulfates and oxyhydrosulfates is not more than 0.03 wt.%, Silicon - not more than 0.005 wt.%, Aluminum - not more than 0.026 wt.%. Thus, the total sulfates and oxyhydrosulfates of titanium, silicon and aluminum are not more than 0.061 wt.%. The content in the total mass of the titanium coagulant of sulfates and oxyhydrosulfates is minimal and their effect on the coagulating properties in the process of water treatment is negligible.

The content of titanium, silicon and aluminum chlorides and oxyhydrochlorides in the titanium coagulant positively affects its coagulating properties and the water treatment process.

The total content of titanium chlorides and oxyhydrochlorides is not less than 2.3 wt.%, Silicon - not less than 0.75 wt.%, Aluminum - not less than 5.2 wt.%. The total amount of titanium, silicon and aluminum chlorides and oxychlorides in the composition of the titanium coagulant is at least 8.25 wt.% (Quite significant relative to the total weight). However, these amounts, calculated on oxides, make up less than a third (2.3 wt.%) And are already included in the total content of titanium oxide, which in the claimed coagulant is at least 10.6 wt.%.

Thus, in view of the foregoing, the applicant, under the concept of “conversion to oxides”, means that the total amount (converted in wt.%) Of the oxides already contains “sulfates, and oxyhydrosulfates, and chlorides, and oxyhydrochlorides of titanium, silicon and aluminum, and therefore, in the claimed titanium coagulant (CT), we consider it appropriate to indicate in the claims the ingredients converted to oxides and taken in the following ratio:

aluminum oxide - not more than 76.5 wt.%,

titanium oxide - not less than 10.6 wt.%,

silicon oxide - not less than 5.0 wt.%,

impurity compounds of sulfur, iron, calcium, chlorine account for no more than 0.5 wt.%, and the water content in the coagulant is not more than 7.4 wt.%.

Below are the quantitative compositions of titanium coagulant from different test batches (without specifying the specific content of sulfates, oxyhydrosulfates, chlorides and oxyhydrochlorides, taking into account the above explanations about their insignificant content).

CT Example (1)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 61.7

aluminum oxide - 20.3

silicon oxide - 11.6

water content - 6.11

impurities - 0.29

CT Example (2)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 65.1

aluminum oxide - 15.3

silicon oxide - 12.5

water content - 6.67

impurities - 0.43

CT Example (3)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 63.3

alumina - 18.1

silicon oxide - 11.9

water content - 6.35

impurities - 0.35

CT Example (4)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 43.7

aluminum oxide - 38.4

silicon oxide - 10.52

water content - 7.25

impurities - 0.13

CT Example (5)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 49.4

aluminum oxide - 32.8

silicon oxide - 12.4

water content - 5.19

impurities - 0.21

CT Example (6)

The titanium coagulant contains, in terms of oxides, the ingredients in the following ratio, wt.%:

titanium oxide - 58.9

aluminum oxide - 21.5

silicon oxide - 13.7

water content - 5.66

impurities - 0.24

The different compositions of the claimed titanium coagulant indicated in the examples of CT (1) -KT (6), combined and presented in the table below for batches No. 1-6, were tested in real production conditions in different regions of the Russian Federation.

List of ingredients The number of the test batch of titanium coagulant with different quantitative composition of ingredients Party number 1 Party number 2 Party number 3 Party number 4 Party number 5 Party number 6 The quantitative composition, wt.% TiO ₂ 61.7 65.1 63.3 43.7 49.4 58.9 Al ₂ O ₃ 20.3 15.3 18.1 38,4 32.8 21.5 SiO ₂ 11.6 12.5 11.9 10.52 12,4 13.7 The rest is
new 6.4 7.1 6.7 7.38 5,4 5.9 Water 6.11 6.67 6.35 7.25 5.19 5.66 Impurities 0.29 0.43 0.35 0.13 0.21 0.24

The claimed titanium coagulant was tested at different drinking and intake water facilities by various Russian pilot industrial research centers and special water treatment laboratories for the level of compliance with sanitary, hygienic, epidemiological and other standards stipulated by GOSTs, and the quality of treated water, the results of which and examples of specific tests are given below.

Example 6

The tests were carried out at the industrial storm water runoff of a machine-building enterprise and at the underground source of domestic and drinking water supply in the village of Karaseozersk, Sverdlovsk Region. The treatment results of the underground water source of this drinking water supply using the claimed titanium coagulant, which includes compounds whose contents in terms of oxides are: titanium oxide - not less than 10.6 wt.%, Silicon oxide - not less than 5.0 wt.%, the compounds of sulfur, iron, calcium, chlorine account for no more than 0.5 wt.%, and Bopak-E aluminum oxychloride showed a more effective purification of the new titanium coagulant in comparison with different coagulants, in particular, in comparison with oxychloride alumina to remove silicon compounds; the residual aluminum content in the treatment of the source water with a titanium coagulant complies with the applicable standards and rules; in the treatment of water with aluminum oxychloride, the residual aluminum content is higher than the required indicators, which corresponds to the current sanitary standards and rules (12-13). The obtained results of multiple industrial tests confirm the effectiveness of the composition and the optimal ratio of the ingredients of the claimed titanium coagulant, as well as the decrease in specific concentrations of the silicon compound in the tested samples (treated water) when using the inventive titanium coagulant by an average of 20%. The content of silicon in the feed water is 13.25 mg / l, aluminum is absent. The test results are shown in table 9.

Table 9
The results of water treatment with a coagulant titanium and aluminum oxychloride. No. of samples one 2 3 four Solution % Titanium Coagulant Powder Solution 1% solution of OXA "Bopak-E" The dose of coagulant for a commercial product, mg / l twenty thirty twenty thirty Filtered water quality Residual aluminum, mg / l 0,089 0,080 0.49 1,54 Residual silicon, mg / l 12.52 11.58 12.76 12.05

Example 7

The technology for using the claimed titanium coagulant has been tested and tested for the quality of purification and disinfection of drinking water (object - Moscow River). The tests were carried out in March 2007 on the basis of the Moscow State Unitary Enterprise MOSVODOKANAL (MGUP MOSVODOKANAL) by the Center for the Improvement of Water Treatment Technology at the Mosvodopodgotovka industrial plant. The results of the tests are presented in table 10.

Table 10 The quality of the source water (Moscow) Experiment Conditions Temperature Hail 6 one Powder titanium coagulant Turbidity mg / l 6.8 2 Coagulant Injection Color Hail 47 3 Quick stir pH 7.79 Speed - 180 rpm Permanganate mg O / L 6.6 3 min time Alkalinity mEq / L 2.9 four Slow mixing Speed - 40 rpm Smell Score 2 rot Time - 20 min. Ammonia mg / l 0.12 5 Settling - 30 min 6 Sample selection 7 Filtering through a paper filter (white tape) Test results No. of samples one Solution 10% solution of powdered titanium coagulant The dose of coagulant for a commercial product, mg / l 60 The volume of injected suspension, ml / l 0.6 The dose of coagulant in Al ₂ About ₃ , mg / l 8.13 Filtered Water Quality: Color, hail eighteen pH 7.62 Turbidity, mg / l 0.10 Ost. Al, mg / l 0.11 P.O., mg O / L 4.24

The test results confirmed the efficiency and technical result of the claimed titanium coagulant for the purification and disinfection of natural waters, which has an optimal mode at a dosage of 60 mg / l and a concentration of 10% with vigorous stirring for 3 minutes.

Examples of testing the claimed integrated system for implementing the method of purification of oil-containing formation salt water to drinking quality

The claimed integrated system for purification of oil-containing formation salt water to drinking quality was repeatedly tested in the same production conditions of the oil mine No. 3 of the LUKOIL-Ukhtaneftegaz TPP LUKOIL-Komi LLC, in which the claimed purification method was tested in order to develop the most optimal and inexpensive at the cost of constructive technical solutions of the main blocks of the integrated system and technical connections between them to ensure optimal system conditions and a high degree of purification of the original Lastova water.

Example 8

Repeated tests of an integrated system for implementing the claimed method for treating formation waters showed that the presence of a standard flotator with less than 10 flotation chambers in this system at the initial stage of treatment does not provide a sufficient degree of reduction of oil products and hardness salts contained in the tested formation waters, therefore, by its numerous experimental tests with different numbers of flotation chambers, the optimal option of a flotator containing at least 10 flotation chambers, which when implementing the method are conventionally divided into two stages, each of which contains five flotation chambers.

Table 11 shows the results of repeated tests, as a result of which the optimal number of flotation chambers, conditionally divided into two stages, was found. As can be seen from table 11, an insufficient number of flotation chambers leads to a slight decrease in the content of oil products in produced water.

Table 11 No. p / p The oil content, mg / DM ³ Source formation water Water after treatment on a flotator having less than 10 flotation chambers Water after treatment on a flotator having 10 flotation chambers one 107.36 48.45 4.8 2 53.67 48.65 3.74 3 102.84 47.35 3,55 four 20.61 13.14 3.63 5 149.64 77.35 2.08

Example 9

Subsequent experimental studies and tests of the produced water purified after flotation chambers were carried out in a sump, in which clarification of the test water was observed for at least 60 minutes, constantly during the tests flowing through the upper part of the blind partition, installed below the upper level of the sump, which facilitated the effective deposition of mechanical impurities and suspensions visually well observed at the bottom of the sump.

Table 12 shows the results of testing, which clearly demonstrate the need for a blank partition in the sump, which allows, after 60 minutes, to visually observe the clarification of produced water.

Table 12 Time min Brightening Area (visual) 10 not observed twenty not observed thirty not observed 40 slight lightening fifty lightening at the top 60 full volume clarification

Example 10

Further tests of the formation water that had already been pre-cleaned after the flotator and settler were carried out in a contact clarifier, where it was supplied under pressure through a pipeline connecting the settler to a contact clarifier. The presence of at least 4 fittings in the pipeline made it possible to introduce periodic dosing of flocculating chemicals into the inlet piping, which contributed to an overall increase in the efficiency of further purification due to intensive flocculation. Through repeated experiments, it was possible to find their optimal location of at least 1 meter from the entrance to the contact clarifier and at an approximately equal distance from each other on the remaining section of the pipeline to the exit of the sump. This design allowed us to achieve high quality purification from petroleum products to a level of less than 0.05 g / m ³ (in comparison, for example, with the prototype, in which this figure is much lower - no more than 15 g / m ³ ).

Example 11

The produced water obtained after the contact clarifier had, as can be seen from Example 8, a high purification quality, however, to bring it to the drinking level, further tests were carried out at the next stage of the claimed integrated system by directing the purified water through a pipeline to high-tech membrane systems in which it was brought to final purification (drinking level) by reverse osmosis.

Tables 13 and 14 show the results of studies, from which it follows that the initial formation water after two stages and final treatment by reverse osmosis corresponds to the required high quality indicators of drinking water.

Table 13 Source formation water Water treated with a titanium coagulant 07.07.2007 Water after final treatment by reverse osmosis Total stiffness, mg * equiv / dm ³ 56.0 24 0.11 The residual iron content, mg / DM ³ 4.17 0.29 0.15 Permanganate oxidation,
mg O ₂ / dm ³ 10.08 4.32 4.0 Color, hail. - 5.54 0.92 Turbidity, EMF - 1,54 0.52 Petroleum products, mg / DM ³ 107.36 <0.05 <0.05 Table 14 Source formation water Water treated with a titanium coagulant 07/27/2007 Water after final treatment by reverse osmosis Total stiffness, mg * equiv / dm ³ 56.0 twenty 0.08 The residual iron content, mg / DM ³ 4.17 0.13 0.02 Permanganate oxidation 10.08 4.0 4.0 Total stiffness, mg * equiv / dm ³ 56.0 twenty 0.08 The residual iron content, mg / DM ³ 4.17 0.13 0.02 Permanganate oxidation, mg O ₂ / dm ³ 10.8 4.0 4.0 Color, hail. - 1,69 0.92 Turbidity, EMF - 0.83 0.52 Petroleum products, mg / DM ³ 107.36 <0.05 <0.05

In accordance with the results obtained, it can be concluded that there is a real possibility of preparing salt water from various fields, in particular, the tested waters of the Yarega field to boiler and drinking water.

As can be seen from the above research results, at the flotation stage, there is a stable decrease in the content of oil products on average from 29-105 to 3.55-4.00 mg / l (the efficiency of reducing the content of oil products to 96.2%) and a decrease in the total water hardness on average from 56 to 24 mg equiv / l (stiffness reduction efficiency 57.2%). The water prepared at the flotation stage is suitable for further processing on a contact clarifier.

From the results of the tests it is seen that during the preparation of water on the contact clarifier there is a stable decrease in the content of suspended solids, color and turbidity of the tested water. The main positive result is a decrease in the content of petroleum products to less than 0.05 mg / l (the efficiency of reducing the content of petroleum products is 99%), which ensures the supply of treated water to a reverse osmosis unit (the main requirement for water quality is the minimum content of petroleum products). In addition, during the preparation of water at the reverse osmosis unit, a steady decrease in all the main indicators below the regulated norms is observed.

The claimed group of inventions of a new treatment technology makes it possible to consider produced water no longer as undesirable sewage polluting the environment, but, on the contrary, consider produced water, which can be cleaned using high-quality technology that meets environmental standards, as an essential reserve of drinking water quality, treatment which does not require excessive capital costs and uneconomic operating costs. It can be assumed that the use of the claimed group of inventions will make it possible in the near future to approach the goal of achieving zero hazardous discharge and solve the problems of treating produced water to drinking quality.

Literature

1. RF patent No. 2189362.

2. RF patent No. 2215871.

3. RF patent No. 2066373.

4. PCT Application: FR 03/00627 (02/26/2003); WO 2004/083132 (09/30/2004).

5. RF patent No. 22235069.

6. RF patent No. 2079437.

7. RF patent No. 2230595.

8. RF patent No. 2301775.

9. The journal "Oil of Russia", No. 6, 2007 (prototype).

10. RF patent No.2019520.

11. RF patent 2195434.

12. Building codes and rules 2.04.02-84. Water supply. External networks and facilities. M., Stroyizdat, 1985. P.23.

13. Building norms and rules 2.04.03-85 Sewerage. External networks and facilities. M. SITP Gosstroy USSR, 1986. P.48.

Claims (8)

1. Titanium coagulant used for the purification of oil-containing formation salt water to potable water, containing oxides, hydroxides, sulfates, oxyhydrosulfates, chlorides, titanium, aluminum and silicon oxyhydrochlorides, and these ingredients are calculated as oxides in the ratio:
aluminium oxide not more than 76.5 wt.%, titanium oxide not less than 10.6 wt.%, silica not less than 5.0 wt.%, impurity compounds of sulfur, iron, calcium, chlorine no more than 0.5 wt.%, water not more than 7.4 wt.%. 2. The method of purification of oil-containing formation salt water to drinking-quality water, including their coagulation and clarification, characterized in that prior to coagulation and clarification, two-stage flotation is carried out, in the first stage of which oil-containing formation salt water is supplied and its preliminary purification from oil products is carried out in the second flotation stage add an aqueous solution of flocculating chemicals - soda ash and / or lime in an amount of at least 100 g of calciners per 1 cubic meter of purified water of soda ash and at least 100 g of lime in terms of dry matter, after the second stage of flotation, the purified water is sedimented until mechanical impurities and hardness salts precipitate, and coagulation is carried out by adding a titanium coagulant solution to the produced water after sedimentation according to claim 1, amount per 1 cubic meter of purified water of at least 20 g in terms of dry matter until the oil content is reduced to 1 cubic meter. m of purified formation water not more than 0.05 g, after which the final purification of water is carried out by the reverse osmosis method until drinking water quality is achieved. 3. A method of purification of oil-containing formation salt water to drinking-quality water, including coagulation and clarification, characterized in that before coagulation and clarification, two-stage flotation is carried out, in the first stage of which oil-containing formation salt water is supplied and its preliminary purification from oil products, in the second stage flotation is added to it an aqueous solution of flocculating chemicals - soda ash and / or lime in an amount of at least 100 g cal cinnamon soda and not less than 100 g of lime in terms of dry matter, after the second stage of flotation, the purified water is sedimented until mechanical impurities and hardness salts precipitate, and coagulation is carried out by adding to the water obtained after sedimentation a mixture of titanium coagulant according to claim 1 and dioxide titanium in an amount of not less than 20 g / cubic meter in terms of dry matter until the oil content is reduced to 1 cubic meter. m of purified water not more than 0.05 g, after which the final water purification by reverse osmosis is performed until drinking water quality is achieved. 4. The method according to claim 3, characterized in that in the process of coagulation using a mixture of titanium coagulant with powdered titanium dioxide in a mass ratio, respectively, equal to 20: 1. 5. An integrated system for purifying oil-containing formation salt water to drinking-quality water, comprising a contact clarifier, characterized in that the contact clarifier is connected, on the one hand, through a pipe having fittings for supplying flocculating chemicals with a sump equipped with a blank vertical partition, the height of which is below the level of the upper edge of the sump tank, on the other hand, the contact clarifier is connected through a high pressure pump to reverse osmosis membrane units, and the toynik is connected to an inclined flotator, in the upper part of the first chamber of which oil-containing formation salt water enters. 6. The complex system according to claim 5, characterized in that the contact clarifier has gravel loading. 7. The integrated system according to claim 5, characterized in that the flotator has at least ten flotation chambers. 8. The integrated system according to claim 5, characterized in that at least four fittings for supplying flocculating chemicals are located on the pipeline connecting the contact clarifier and the settler at a distance of at least 1 m from the entrance to the contact clarifier.

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