SU653288A1 - Method of cleaning apparatus in course of petroleum dewatering and desalting - Google Patents

Description

The invention relates to the preparation of oil for processing, in particular, to methods for cleaning equipment for dewatering and desalting oil from sludge deposits. In process equipment for oil preparation during their operation, precipitation and formation of sediments from mechanical impurities coagulated from asphalt-resin substances and paraffin hydrocarbons, which cause a decrease in productivity, accidents and simple equipment, deteriorate the quality of the oil produced. A known method of cleaning the dewatering and desalting of oil from oil refineries involves removing the oil from the device, flushing it with hot drainage water and blowing it with steam 1. There is also a known method of cleaning the oil dewatering and desalting oil from sludge deposits by flushing it with a reagent-demulsifier solution , providing for the filling of the cleaned apparatus with a solution and keeping them in this form for a long time 2. Known methods of cleaning oilfield equipment using detergent The means do not allow penetration of sludge deposits without first clearing the oil from the oil, making them simple, requiring large material costs for reagents, hitting special hatches for installing washing machines. In addition, these operations are very time consuming. The aim of the invention is to simplify the process by combining the cleaning apparatus with the process of oil preparation, i.e. dehydration and desalination. This is achieved in that the washing is carried out by feeding the reagent-demulsifier solution into the oil stream before the apparatus to be cleaned, starting with the latter in the course of the flow followed by feeding the waste solution into the oil stream before the first apparatus to be cleaned. The proposed method of cleaning the apparatus of the oil treatment plant does not disrupt the installation's operation in terms of the quality of the oil being prepared, since it prevents intensive filling of the intermediate layers washed with fur from the walls of the fur with trace impurities and tar P & P (& means to the head of the process (in front of the apparatuses of the initial stupas, i.e., the preliminary release stage, oil dehydration, etc.). Cleaning of the contaminated apparatus with detergent supply is carried out without stopping and installation operation resulting in dispersion, delivery and distribution of the cleaning fluid in oil through contaminated surfaces. This reduces the labor costs of installing and maintaining washing machines, using drainage pipelines and eliminating the need for special communications to recirculate the washing solution. Due to the high detergent and emulsifying properties of the detergent with respect to slime contaminants, they are intensively dispersed and transferred by the flow of emul these at the phase boundary in the settling apparatus (a so-called intermediate layers). The cleaning process is intensified by heating the detergent solution due to the heat accumulated in the oil flow. As sludge deposits accumulate in the intermediate layers, the latter are periodically or continuously withdrawn from the apparatus and disposed of using the trap oil preparation technology. The proposed method of cleaning apparatus installation and oil treatment also provides for the possibility of transferring the point of supply of the washing solution after the passages of the apparatus of the last stage to the initial stage. In the proposed method, the cleaning of the apnarats of the oil treatment installation is combined with the process of dehydration and desalting of oil. This is achieved by using a detergent with a demulsifier in addition to these properties. Therefore, the recommended detergent should include at least a non-ionic demulsifier, which can be, for example, polyacrylamide and liquid glass. Such a combination of a process purification of a: slurry from sludge with processes for the purification of oil from water and chloride salts leads to the fact that not only the need for apparatus is eliminated, but even the standard oil is obtained during the entire cleaning period. The oil on the emulsion from the raw materials park is pumped through heat exchangers and steam heaters. A demulsifier is supplied to receive raw pumps. The oil is heated to the sumps of the thermochemical stage, then the first and second electrohydrators. Desalted oil is removed from the plant through heat exchangers. The installation is cleaned of sludge deposits by feeding an aqueous solution of detergent to the last stage, i.e. in front of the second stage dehydrator. After cleaning this unit, the supply of detergent is carried out before the 1st stage electric dehydrator. After the 1st stage electric dehydrators, an aqueous solution of detergent is fed to the intake of the raw pump, after which the heat exchangers and sumps are cleaned. The spent aqueous solution-detergent is fed to the intake of the feed pump, and sludge deposits along with the separated water are discharged from the sump for disposal. When cleaning a thermochemical plant with two stages, an aqueous solution of detergent is supplied in front of the second stage apparatus. After they are cleaned, the supply of detergent is carried out to receive the raw pump. The cleaning of the single-stage installation is carried out by supplying detergent to the intake of the feed pump. In this case, the demulsifier reagent is not supplied, as the detergent has the properties of a demulsifier. In the process of chemical-mechanical treatment of detergent devices with demulsifier properties, the supply to the last stage of installation and recirculation of the solution to the devices of the initial stages reduces the consumption of non-ionic demulsifiers, usually fed to the intake of raw pumps or gas separators of oil treatment plants. Example 1. The apparatus and communications are cleaned with a single stage heat treatment unit UKPN-2 in the NGDU Oct bryskneft from sludge contamination. Heat exchangers and new septic tanks with connecting pipelines are subjected to cleaning without stopping the installation and emptying the apparatuses. At the same time, an aqueous solution of a detergent is metered to the intake of the raw pump in the following ratio of components, wt.%: Separol 25 Polyacrylamide Liquid glass Up to 100 Water Fresh water is also supplied there. calculating 15% for oil. Then, after mixing in the pump, the oil supply to the mixture passes through heat exchangers, connecting pipes and sedimentation tanks. in the latter, the mixture is divided into oil and water. The washed soils are drained along with the released water. Within three days from the installation, the drainage of contaminated water, then the water gradually brightens and on the 2nd day does not contain any mechanical impurities or any other contaminants. Data on the operation of the installation during the entire cleaning period is given in table 1 (from 1 to 5th day serves detergent solution, from the 10th day the supply of detergent solution is stopped). The application of the method reduces the consumption of non-virogenic Rheagent-demulsifier Separol - 25 from 50 to 18 g / t and washing fresh water for desalting from 12 to 4% for oil. At the same time, oil contains chloride salts of not l / 30 mg / l. Example 2. Cleaning of the 10th Subkhankulov-Samsykskiy merchandise oil pipeline from sludge deposits is carried out with an aqueous solution of detergent in the following ratio of components, wt.%: Separol 255.0 Polyacrylamide 1.0 Liquid glass 4.8 Water 100 Subhankulo-Samsyk oil pipeline The park with a diameter of 10 m and a length of 12 km has not been subjected to any kind of cleaning for 20 years. As a result of the oil agglomeration when pumping through the pipeline, the consumption of the non-ionic demulsifier Separol-25 when desalting oil in the commodity park is 50 g / t with simultaneous consumption of washing fresh water up to 12% of the weight of oil. To clean the pipeline, a washing solution in the amount of i2 m is drained directly into the flow of the Tümensk oil. After the separation of oil and water, an intermediate layer consisting, in wt.%: Mechanical - 17.2, asphalt - 2.3) resins - 1 2, paraffin 42, 2, heavy oils - 19.2, water 7, 4, is removed from the reservoir. The total amount of sludge deposits delivered from the pipeline is about 80 tons. After cleaning the pipeline, the Tyumen oil is transported through it with improved hydraulic performance. Thus, for example, the pouring height of tanks for normal operation at the same time decreases from 4.5 m to 1.5 m. As a result of the flushing of the pipeline complex - raw material tank, the desalination of Tyumen oil for 8 months is carried out at a discharge rate of 25 for desalting 18-30 mg / l "fresh water consumption - 4%. Example 3. The cleaning of a combined electrical desalting plant is carried out. The installation consists of heat exchangers, hollow settlers (stage 1) and two electrical stages of spherical electrohydrators. When desalting oil, the raw material pump receives a mixture of OFA demulsifiers (28.2 g / t) and DAYS - 2 (14.1 g / t) in front of the heat exchangers in normal mode. The mixture is then warmed up and sent to five steam rooms. The separated water from the bottom of the sedimentation tanks is discharged into the oil trap. The dehydrated oil is fed to the electrode g d r atora. To flush the oil, the circulating water is used with the temperature supplied in front of the pumps and electric dehydrators. The separated water from the dehydrators is recycled to the intake of raw material pumps. The cleaning of the installation is carried out without shutting down the apparatuses and their emptying, supplying detergent to the electrical stage for 6 days. The following detergent is used, wt.%: Liquid glass up to 100 The separated water with the remnants of the washing solution is fed to the intake of the raw pump. Next, the supply of detergent is moved to the first stage of the installation while reducing the consumption of detergent. As with the cleaning of the electro-dehydrators, the cleaning of the settling tanks is completed within the first two days, which is determined by the removal of contaminants with drainage water. During the entire refining period, high quality oil is supplied for refining — up to 2–8 mg / l for SOL chloride m. As a result of washing the plant and stopping oil pollution for the next 10 days, oil is only treated with flushing water without supplying demulsifier to the system. Table 2 shows data on the operation of the installation during the cleaning period (before the cleaning started, the detergent is not served, from 1 to 5 days the detergent is supplied to the electrical stage, from 6th to 10th day - the detergent is supplied and 1 stage installation; and from 11 to 0 day - the supply was stopped J. Example 4. The combined electric obedient installation described in prior 2 was cleaned. The cleaning was performed with the same detergent one year after the previous cleaning. The installation was cleaned without switching off the apparatuses and emptying them my directly to the intake of the raw material pump before the first thermochemical stage of the combined installation.

In connection with the intensive (salvo) cleaning of heat exchange equipment and distribution devices in the thermochemical stage sumps, the intermediate layers are quickly filled by washing with mechanical impurities and the work of the sump equipment is deteriorated.

Further As a result of the wash-up of soils in the electric dehydrators, the performance of the latter deteriorates, expressed in an increase in the content of dry salts from 10–15 mg / l to 5080 mg / l, which ultimately leads to the breakdown of the technological regime and the need to work on the drainage of intermediate layers from septic tanks and electro-dehydrators in a trap. The use of the proposed method of cleaning the apparatus for preparing oil from sludge deposits makes it possible to clean the apparatus of oil treatment plants without emptying them and stopping to carry out the refining process, which is especially important at the current stage of development of the oil industry due to the rapid growth of oil production rates, the discovery of new deposits and shortage of oil treatment capacity; the possibility of obtaining standard oil in the process of cleaning the apparatus, as well as a sharp decrease in reagent costs and maintenance labor, eliminating the need for steaming and the use of special equipment for cleaning purposes, which greatly increases the efficiency of the method.

That blitz

28.2

ten

ten

ten

ten

ten

table 2

15

Clean

The same is pure

Also -

Claims (2)

1. Bazlov M.N. et al. Oil treatment in pro-industry, M., 1957, p. 22-23. 2. US patent 93258428, cl. 252-1130, 19 €€.