RU2359733C1 - Multifunctional instrument for oil preparation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to petroleum industry and can be used at preparation of oil at compact oil extraction objects and at restricted conditions, for instance at offshore structure. Instrument consists of standard modules, in each of there is an sediment area and module of prepared oil accumulation. In sediment area of each module there are implemented partitions, levels of top edges of which in each following module are biased down as compared to previous. Out of dividing partitions of the case forward the flow there are located mixtures, used for oil blending with washing and other components, herewith into the following module oil is overflowing from the bottom part of accumulation section of the previous module. Top part of dividing partitions allows channels for communicating of gas spaces of all modules for gas withdrawal from the instrument.

EFFECT: providing of high quality of oil preparation in complicated conditions.

2 cl, 1 dwg

Description

The invention relates to the oil industry and can be used in the preparation of oil at compact oil production facilities and in cramped conditions (for example, on offshore platforms).

For the preparation of oil at production facilities, separators are usually used for gas separation, sedimentation tanks for dehydration, desalination, purification from mechanical impurities and other harmful or ballast components.

A known apparatus for dehydration and desalination of oil (patent RU No. 41987 of 2007.07.19, class B01D 17/028), consisting of a horizontal housing with nozzles for the input of purified oil, water and oil output. Two transverse partitions are installed inside, dividing the casing into three zones: a receiving zone, a desalination zone, and a settling zone. In this case, the transverse partition placed between the receiving zone and the desalination zone is made blind from the bottom and with a gap to the upper generatrix of the housing, and the partition separating the desalination zone and the settling zone is made blind from above and simultaneously with a gap to the lower generatrix of the housing. A hydrocyclone is installed in the intake zone, the inlet of which is connected to the input pipe of the oil being cleaned, a coalescent grate located vertically, and a water output pipe.

In the desalination zone, desalination trays are made in the form of corrugated gutters, and a number of fresh water supply units and distribution nozzles emerging from it. The trays are installed obliquely and secured, alternating, with one end in the transverse partition, and the second end of all trays remains free.

In the settling zone, a coalescence grill is installed, located horizontally with an offset to the upper part of the body. Oil and water outlet pipes are installed in the upper and lower parts of the housing, respectively. In the receiving and settling zones, phase separation level gauges are installed, and in the upper wall of the body of the desalination zone, a pressure gauge and a common level gauge are installed.

The disadvantage of the apparatus is that it does not allow using it as a gas separation stage, and the compartments for dehydration and desalination do not have structural elements for carrying out these processes, two compartments are used for desalination (mixing and dehydration separately), which irrationally complicates the apparatus.

Known three-phase apparatus for dehydration of oil (patent RU No. 2077918 from 11.17.1994, class B01D 17/028), including a horizontal cylindrical tank with transverse baffles located in the middle part of the cross section of the housing, and a compartment for the accumulation of dehydrated oil, a pipe supplying water-oil the mixture from one end of the body and the discharge gas, water, oil nozzles, regulators of oil and water levels, while the lower and upper edges of each subsequent partition in the direction from the supplying water-oil mixture pipe to the discharge pipes s down relative to the previous partition.

The apparatus allows highly efficient separation of free gas, dehydration of oil and its purification from mechanical impurities.

The disadvantage of the apparatus is the inability to perform the process of desalination and other processes of additional oil purification, for example, of hydrogen sulfide, which require the execution (sequentially, after the dehydration process) of additional input of washing liquid or another agent, mixing them with dehydrated oil and re-dehydration.

A known installation for oil refining (patent RU No. 2118198 of 1997.10.16, class B01D 17/028). The installation includes a settling tank with partitions, a compartment for the accumulation of refined oil, nozzles for supplying purified oil, nozzles for draining oil and water, gas, oil and water level regulators. In this case, the upper edges of the partitions are located at the same level. The compartment for the accumulation of refined oil is formed by the last partition. At the top of the sump, a spray is installed to supply flushing water. The pipe for supplying the oil to be cleaned is placed with its open end up at the level of the lower edge of the first partition, the pipe for draining settled water is located in the lower part of the sump in front of the last partition and is connected to a water seal.

The design drawback is that the installation allows it to be used to desalinate oil or to purify it separately from hydrogen sulfide. The simultaneous implementation of these operations in the above installation is not provided

Closest to the proposed device is an oil treatment unit (patent RU No. 44531 of 2004.07.27, class B01D 17/00, C10G 33/00), including a horizontal technological tank, separated by a blank screen from below, into a pre-treatment section with a fresh water spray and oil deep purification section with a coalescing unit, emulsion input and output units of separated phases, measuring, control and regulation means, preliminary and deep oil purification sections, which are interconnected by a mixer, are placed under the sprayer of fresh water and mounted in the lower part of the separation partition.

However, the design of the installation is not technologically advanced, since it includes a wide variety of unified units that do not provide efficient mixing and subsequent sedimentation of oil. The device is equipped with a heater in the form of a flame tube, which will periodically burn, which will lead to a stop of the device for repair. For uninterrupted operation, a redundant apparatus is required.

The dehydration process takes place along the entire height of the liquid column, therefore, in the presence of free gas, its separation from the liquid medium prevents the sedimentation of water and reduces the efficiency of dehydration.

A coalescing network in a liquid medium does not work efficiently, since a fine network quickly clogs, and a large network does not impede the passage of small water globules and coalescence does not occur.

Oil from the dehydration section to the desalination section flows through the mixer, and oil enters the mixer through the open upper end of the mixer pipe, which is at the level of the upper oil layer in the dewatering section. In this case, due to oil leakage to the open end of the mixer, the sludge regime is violated, since insufficiently dehydrated oil and gas from the gas space are entrained in the flow.

In the desalination section, the oil supply through the distributor in the lower part of the section prevents the sedimentation of water, since there is a flow of liquid against the movement of water globules.

The intake of refined oil from the top layer of oil in the desalination section does not guarantee the withdrawal of only oil purified from water, since gas is carried away from the gas from the gas space.

The aim of the invention is the development of a multifunctional apparatus for the preparation of oil, which provides the cleaning of oil from gas, water, salts and other harmful or ballast components.

As a result of solving this problem, it becomes possible to obtain technical results, consisting in the fact that the proposed device provides the preparation of oil of the required quality in one unit with minimal time and money.

The problem is solved in that in the known apparatus for the preparation of oil, including a horizontal housing, divided by a partition into blocks that are interconnected through a pipe with a mixer for mixing dehydrated oil with fresh water, mounted in the lower part of the separation wall, a pipe for supplying the oil to be prepared , nozzles for the output of oil, gas and water with mechanical impurities, nozzles for placement of level gauges, according to the invention, two or more unified block division are formed by an inner cavity of the housing unit dividers dully connected to the lower and upper part of the housing. In this case, partitions are installed in each block, creating a sludge zone, and an overflow partition, tightly connected to the lower part of the hull, creating a compartment for oil accumulation. The levels of the upper edges of the partitions that create the zone of sludge in each subsequent block are shifted down compared to the previous block. The mixers are located behind the partition walls of the housing in the direction of flow so that oil enters the next block from the bottom of the storage compartment of the previous block through the pipe at the bottom of the partition and the mixer, and the top of the partition has channels for communicating the gas spaces of all blocks for output gas from the apparatus.

The implementation of a multifunctional apparatus from standardized units, allowing each individually to perform the operations of free gas separation, dehydration, desalination, and cleaning of mechanical and other ballast impurities at the same time, expands the scope of the apparatus, providing high quality oil preparation in difficult conditions, simplifies the manufacturing process of the apparatus.

The efficient operation of the multifunctional apparatus is ensured by the intensification of processes in each unit as a result of the use of a system of partitions that create a favorable hydrodynamic regime of fluid flow during sedimentation.

In the absence of the need for additional special preparation, the subsequent unit can be used as the second stage of preparation in the previous unit, which will increase the throughput of the apparatus with increased quality of the prepared oil.

The supply of each block with a compartment for the accumulation of prepared oil ensures a clear separation of the prepared part of the oil, and prevents its repeated mixing with the undeveloped part.

The selection of oil, prepared in the previous block, for direction to the next block, from the lower part of the storage compartment through the pipe in the separation wall prevents gas from entering the gas flow into the oil stream and re-mixing it with gas, there is no disturbance in the sludge zone and the mode is not violated sludge.

Performing the level of the upper edges of the partitions in the zone of sludge blocks with a shift down relative to the previous block provides the flow of oil sequentially from the previous block to the next without the use of any means of pumping.

This embodiment of the apparatus allows you to perform basic oil treatment operations, such as gas separation, dehydration, purification from mechanical impurities, desalination, purification from other ballast and harmful impurities, for example, hydrogen sulfide in one compact apparatus.

The drawing shows a General diagram of the inventive multifunctional apparatus for the preparation of oil.

The multifunctional apparatus for oil preparation consists of a housing 1, dividing walls 2, which are tightly connected to the lower and upper part of the housing and dividing the housing 1 into blocks for performing individual oil preparation operations. In the upper part of the dividing partitions 2, channels 3 are made for communicating the gas spaces of the blocks; in the lower part, pipes 4 are mounted for oil from the previous block to the subsequent block.

In each block, partitions 5 are installed, creating a sludge zone

oil and dull bottom overflow partitions 6 separating the zone of oil sludge from the compartment for oil accumulation. The upper level of partitions 5 and 6 in each block is the same in height, but in this case, in each subsequent block, partitions 5 and 6 form a step down (in the height of their installation) relative to the previous block, which allows oil to flow from one block to another.

Mixers 9 are installed on the nozzles 4, which serve to mix the oil with the wash water or other components that enter the mixer through the nozzle 10 into the unit provided for this purpose in accordance with the technological process.

The gas released as a result of separation in each block, through channels 3 is communicated with the subsequent block and through the pipe 11 is removed from the apparatus. Water that accumulates in the blocks as a result of sludge is discharged through nozzles 12.

The nozzles 13 are used to house the level gauges. Through manholes 14 inspect the internal state of the blocks.

The multifunctional apparatus for the preparation of oil works as follows.

The production of oil wells in the form of a gas-liquid mixture is supplied through pipe 7 to the first block of housing 1. In this case, the gas-liquid mixture is already prepared for separation into components, since it contains the necessary chemicals, usually added to the pump in the well and, if necessary, to the collector of the collection system well production.

The incoming production of wells fills the first block of the housing 1. After the liquid overlaps the lower edge of the partitions 5 of the housing 1, the production of wells begins to separate into the water and oil phases. The aqueous phase descends to the lower part of block I, and the oil phase accumulates in front of the partitions 5 and, reaching the level of the upper edge of the partitions 5, moves a thin layer above the partitions 5. Gas, water and mechanical impurities are intensively released from the thin layer of the emulsion. The gas released takes up space above the liquid level, oil purified from free gas, water and mechanical impurities is poured over the overflow partition 6 and accumulates in the compartment between the overflow partition 6 and the separation partition 2. Water released in the first block is removed through the pipe 12 in front of overflow partition 6. Together with water, mechanical impurities are also removed.

The oil purified in the first block through the pipe 4 enters the mixer 9 located in the second block. If the second block is intended for desalting oil, then fresh water is supplied to the mixer 9 through the pipe 10 (simultaneously with dehydrated oil). With intensive mixing of oil with fresh water, the existing salt in the oil is washed out. Oil mixed with fresh water fills the second block in the housing 1 of the apparatus. At the same time, as in the first block, the oil phase moves above the partitions 5, and the aqueous phase moves below the partitions 5. In the second block, when washing above the partitions 5, flushing water and gas and mechanical impurities present in the oil are released. The released gas enters the gas space above the liquid level, oil washed from salts, overflowing overflow partition 6, enters the compartment between the overflow partition 6 and the separation wall 2 of the second unit. Wash water, saturated with salts, accumulates in the lower part of the second block and is removed through the pipe 12. Together with the water, mechanical impurities released in the second block are also removed.

Desalted oil from the second block through the pipe 4 enters the mixer 9, located in the third block. If it is necessary to purify oil from hydrogen sulfide, a water-based reagent for absorption of hydrogen sulfide is supplied to the mixer 9 through the nozzle 10. When oil is mixed with a water-based reagent, hydrogen sulfide is absorbed. Oil fills the third block and settles in the sludge zone with partitions 5. The gas phase in the oil is separated and occupies the gas space. Oil moves in a thin layer above the partitions 5, while water with a reagent and absorbed hydrogen sulfide is precipitated, and the refined oil, overflowing over the overflow partition 6, occupies the compartment for refined oil. Separated water occupies the lower space of the third block to the overflow partition 6. Gas is removed from the gas space through the pipe 11, oil is discharged through the pipe 8, water through the pipe 12.

The level of the oil-water interface is monitored in each block by level gauges installed in the nozzles 13, the oil level is controlled by a level gauge installed only in the compartment behind the partition 6 of the third block. The oil level in other parts of the apparatus is set in accordance with the height of the overflow partitions 6, which reduces the capital costs of the level gauges and means for regulating the oil level in the apparatus.

The quality of the oil being prepared is regulated by changing the technological parameters of the process, as well as by changing the level of the oil-water interface in blocks. The presence of several blocks in one apparatus allows to prepare oil for all quality indicators, including those indicators for which special conditions of preparation are required.

A separate unit with a mixer can also be used to heat oil in the apparatus by supplying coolant in the form of hot oil, water, etc. to the mixer.

In addition, the necessary reagent can be supplied to any unit of the apparatus through a mixer to increase the efficiency of the technological process and the quality of the oil being prepared.

The presence in each block of the compartment for the accumulation of prepared oil ensures the reliable operation of each block and allows you to control the quality of the prepared oil.

Thus, the multifunctional apparatus for the preparation of oil is universal. If necessary, the number of blocks can be increased. In the absence of oil preparation in separate blocks, free blocks can serve as an additional step in the oil preparation operation in the previous block. At the same time, an increase in the throughput of the apparatus, a high quality of oil preparation with minimal capital and operating costs are achieved.

Claims (2)

1. Multifunctional apparatus for oil preparation, including a horizontal housing, divided by dividing walls into blocks interconnected through a pipe mounted in the lower part of the dividing wall, with a mixer installed on it, a pipe for supplying the oil to be prepared, pipes for the output of oil, gas and water with mechanical impurities, pipes for placement of level gauges, characterized in that two or more standardized units are made in the device’s body, in each of which there are installed The walls creating the sludge zone and the overflow partition creating a compartment for the accumulation of prepared oil, the upper edges of the partitions creating the sludge zone, in each subsequent block are shifted down compared to the previous block, the mixers are located behind the body dividing walls in the direction of flow, that in the next block the oil comes from the lower part of the storage compartment of the previous block through the pipe in the lower part of the separation wall and the mixer, while the upper part of the separation the partitions have channels for communicating the gas spaces of all the blocks for removing gas from the apparatus. 2. The multifunctional apparatus for oil preparation according to claim 1, characterized in that the dividing partitions are deafly connected to the upper and lower parts of the apparatus body, and the overflow partition is deafly connected to the lower part of the case.