Method of preparing hydrocarbon mixture for transporting

FIELD: gas industry.

SUBSTANCE: method comprises separating the mixture into C1 methane fraction with subsequent supply to gas pipeline and C2+ hydrocarbon fraction that are preliminary stabilized by its liquefying by means of preliminary cooling down to a temperature at least 16°C and supplying to the gas pipeline. The pressure is maintained at a level no less than 3,2 MPa.

EFFECT: enhanced reliability of one-phase transporting.

2 dwg

 

The invention relates to methods of preparation for the transportation of the mixture of hydrocarbons and can be used at the enterprises of the gas industry.

It is well known that the production of gas condensate fields is a complex mixture of hydrocarbons of the methane and heavier hydrocarbons. In addition to hydrocarbons in the gases may contain various impurities like hydrogen sulfide, mercaptans, carbon dioxide, nitrogen, helium, etc. One of the most important conditions for successful operation of gas transmission systems is a high - quality preparation of gas. In the preparation process gas is subjected to pre-processing on commercial installations of complex gas treatment plant (GTP) to extract hydrocarbon condensate and finally (to marketable condition) at gas processing plants. In the factory of gas and gas condensate can be obtained from the following valuable products: hydrocarbon fraction (methane, ethane, propane, butane, and others), condensate, NGL, etc. the quality Requirements of the products are determined on the basis of the conditions for their safe transportation, storage and use. For example, the main requirement to the quality of the NGL - to minimize the content of methane and ethane in order to reduce the vapor pressure of the LPG. This allows her to spend sportivnie almost in-phase (liquid) state [Vyakhirev R.I., Gritsenko, A. I., Ter-Sarkisov P.M. Development and exploitation of gas fields. - M.: OOO "Nedra-business Center", 2002. - str-689].

However, there is an interest other consumers in obtaining this valuable raw material as a mixture of hydrocarbons With2+with a high content of ethane fraction (up to 40 wt.%). The problem of transporting such a highly unstable gas-saturated liquid, it is advisable to solve it by pumping it in single-phase state of liquid.

Transporting the mixture of hydrocarbons in liquid form is associated with great difficulties, because under certain temperature and pressure, it can partially or completely switch to a gaseous state; when the gas fills the part of the living section of the pipeline, which leads to a sharp increase in hydraulic resistance and decrease of the capacity of the pipeline.

From known sources of patent and scientific and technical information, information about the transportation of similar mixtures of hydrocarbons, C2+with a high content of ethane fraction (up to 40 wt.%) not found.

Closest to the claimed combination of essential features is the way to prepare for the transportation of the mixture of hydrocarbons in the development process gazokondensatnogo deposits in the region with poor transport infrastructure, C is localsize is the pre-mixture is separated into a liquid phase With a5+and the gas phase C1-C4. The liquid phase stabilized by degassing and pumped into the pipeline. The gas phase is divided into methane C1and the fraction With2-C4. Methane is injected into the main pipeline, and the fraction With2-C4stabilize by throttling in the vortex tube and also served in the main pipeline for joint transportation of the consumer. When entering the consumer this mixture is optionally separated into fractions and components [RF Patent №2171953, MPK7 F17D 1/02, publ. 10.08.2001].

The disadvantage of this method is that the fraction With the2-C4transported together with the methane fraction C1in the form of two-phase flow, which leads to limitation of the scope of the method.

The task of the claimed invention is the provision of transportation of hydrocarbon fractions With2+with a high content of ethane fraction (up to 40 wt.%) in single-phase (liquid) state.

The problem is solved by the claimed method of preparation for the transportation of a mixture of hydrocarbons, in which the pre-mixture is separated into a methane fraction C1with the subsequent flow into the pipeline and the fraction of hydrocarbons With2+that before serving in trubor the water stabilized by transferring the liquid through a pre-cooling to a temperature not higher than 16° With and served in the pipeline, maintaining the pressure at the beginning of the pipeline to be at least 3.2 MPa.

The technical result consists in the creation of optimal conditions - maximum temperature and the minimum initial pressure of the prepared liquid mixture of hydrocarbons, in which precluded the formation of a two-phase mixture in the pipeline during its further transportation.

Figure 1 presents the scheme of installation of low-temperature separation of hydrocarbon gas, illustrating the proposed method.

The apparatus comprises a heat exchanger 1, a propane refrigerator 2, separators 3-6, the heat exchangers of the cooling circuit and condensation of gas 7-10, a Stripping column 11, demethanization 12, consisting of two sections, firming and outrun, turbo-expander unit 13, air cooler 14, propane evaporator 15.

The method is as follows.

Supplied raw material gas, pre-dried and cleaned of sulfur compounds and carbon dioxide on previous installations. The hydrocarbon gas stream is cooled, consecutively passing through the heat exchanger 1, a propane refrigerator 2, where it is pre-cooling and partial condensation due to the cold return flow of methane fraction and propane, and then enters the separator 3 for separating the liquid phase. deliveries in the separator liquid hydrocarbons are fed to the power demethanization 12. The gas flow from the separator 3 after cooling and partial condensation in the heat exchanger 7 flows into the separator 4, in which the gas stream is enriched with helium and liquid - ethane. Vapor phase from the separator is directed to complete the condensation in the heat exchanger 8, and then the flow of the supercooled liquid is supplied to the Stripping column 11. Enriched with ethane and liquid separator 4 is delivered to the separator 5. Vapor phase from it is fed to the Stripping column 11 as the Stripping gas, and the liquid is divided into two streams and fed to demethanizer 12, while the main thread after heating in the heat exchanger 9 is supplied to the power of the column, and the other for irrigation.

From the Stripping column 11 otmerenny gas is fed to the further enrichment of helium with the aim of obtaining helium concentrate in the corresponding helium columns (not shown).

With the cube of the first Stripping column 11 is displayed methane fraction of the high-pressure portion through which the heat exchanger 10 is fed to the separation in the separator 6. The gas phase from the separator 6, together with the top product of demethanizer 12, is directed to the expansion in the expander turbine expansion unit 13 with the aim of obtaining cold, and presented with the installation in the form of a commercial product - methane fraction Ci. The liquid from separator 6 is supplied to the irrigation demet is Nistor 12.

In demethanizer 12 is rectification of the incoming fluid with obtaining methane fraction C1as the top product, and hydrocarbon fractions With2+as VAT residue.

The fraction of hydrocarbons With2+output from the cube of demethanizer 12 to a temperature of 50°With, before transportation to the consumer stabilized by cooling to a temperature not higher than 16°With, for example, first in air refrigerator 14, and then in propane evaporator 15, which guarantees its liquid state throughout the length of the pipeline at any time of the year when the pressure at the beginning of the pipeline to be at least 3.2 MPa and 1.8 MPa at the end. Cooling can be carried out in any conventional refrigeration installation, which provides cooling fraction to a temperature not higher than 16°for those applications in which the pipeline is buried in the ground. However, it is preferable to limit the fridge contained a combination of heat exchangers with air or water cooling and conventional cooling installation with a closed cycle and propane as refrigerant.

Example.

Consider the implementation of this method on the example biznesowego transportation to the consumer of a mixture of hydrocarbons With2+The Orenburg field. The helium plant in the cryogenic section of the Oia hydrocarbon gas demethanizer is the separation of a mixture of hydrocarbons methane fraction C 1from the top of the column and the fraction With2+as a bottom liquid.

Waste liquid distant sections of demethanizer 12 represents the fraction of hydrocarbons With2+with a high content of ethane of the following composition, wt.%:

Methane0,784
Carbon dioxide0,002
Ethan38,629
Propane34,383
Isobutane6,644
Butan11,671
Isopentane3,749
Npentane2,707
Hexane + high1,431

Present in the bottom liquid in small amounts of methane and carbon dioxide is completely dissolved and not have a practical effect on the physical properties of the fractions With2+.

To ensure single-phase (liquid) state fraction2+along the entire route of the pipeline and at any period of the year experimentally determined optimum temperature and pressure at the beginning of the pipeline, taking into account characteristics of the pipeline route and the ground temperature under the condition bezmasenoj feed mixture. The initial data for calculations: the temperature of the bottom liquid at the exit of demethanizer - 50°C, process pressure, demethanizer is - 3,2-3,6 MPa, the length of the pipeline 214 km, the pressure at the inlet of the plant-consumer after node degassing is 1.2-1.6 MPa, average soil temperature at the depth of the pipeline in the summer time is 16°C, and in winter - minus 3°C.

You have previously investigated the state of the aggregate fraction C2+obtaining curves of phase transitions, built in the coordinates of the "pressure - temperature". The essence of research is that for a given composition of the mixture at a specified temperature (T) and pressure (p) is determined by its phase state, thereby altering the values of T and p, and interpret the curve of phase transitions. The curve of phase transitions of the mixture of hydrocarbons is presented in figure 2.

In the learning curve phase transitions based technology allocation fraction C2+from hydrocarbon gas defines the minimum initial pressure of 3.2 MPa and a maximum temperature of 16°C fraction C2+at the entrance to the pipeline, providing single-phase transportation at the maximum possible distance (up to 300 km).

The restriction on the initial pressure of the transported mixture is explained by the conditions of the rectification in demethanizer 12 with pressure not less than 3.2 MPa. At lower pressures obtaining the necessary cold on turbodyne for the work of installation is impossible. However, the pressure in the column should provide a "floor" of hydraulic pressure loss as when passing the cubic product through a refrigeration unit prior to being fed into the pipeline, and transportation of the mixture by pipeline to the plant at a distance of 214 km (in terms of the consumer, the pressure of incoming material at the end point of the pipeline at the site of the degassing should not be less than 1.8 MPa, subject to further reduce the pressure to the specified input values to the factory consumer and conditions of the piping temperature of the mixture acquires the temperature of the soil and cannot be above 16°C, which corresponds to the average the soil temperature in summer).

From the graph of phase transitions can be seen that even under the most adverse conditions that may be on the final stretch of pipeline in the summer time, namely when the pressure at the outlet of the pipeline 18 MPa and a temperature of 16°C this mixture of hydrocarbons, C2+will be in equilibrium (the point on the curve). In practice, however, due to the reduced flow rate compared to the maximum design pressure at the outlet of the pipeline significantly exceeds this value (up to 2.5 MPa). In addition, the operating range of demethanizer 3,2-3,6 MPa can further provide a liquid condition C2+ along the length of the pipeline.

Therefore, the initial pressure and temperature, as can be seen from the graphs of the phase transition, even in the summer, provide single-phase (liquid) transporting the mixture to the consumer.

The preparation method for the transportation of a mixture of hydrocarbons, in which the pre-mixture is separated into a methane fraction C1with the subsequent filing of a gas pipeline and the fraction of hydrocarbons With2+that prior to being fed into the pipeline stabilize, characterized in that the fraction of hydrocarbons With2+stabilize by transferring the liquid through a pre-cooling to a temperature not higher than 16°and served in the pipeline, maintaining the pressure at the beginning of the pipeline to be at least 3.2 MPa.



 

Same patents:

FIELD: storage or transporting of natural gas.

SUBSTANCE: method comprises cooling natural gas down to a temperature below the temperature of the ambient air and transporting the cooled natural gas.

EFFECT: enhanced efficiency of storage and transporting.

16 cl, 13 dwg

FIELD: the invention refers to energy-conservation technologies of pipeline transportation of natural gas.

SUBSTANCE: it may be used for controlling the technological process of the main pipeline with simultaneous selection out of gas of valuable ethane, propane, butane components. The technical result of the invention is reduction of energy inputs for maintaining pressure in the main pipeline, provision of stabilization of pressure in the main pipeline. The mode of transportation of natural gas along the main pipeline includes its feeding into the main pipeline on the first and the following compressor stations and giving out natural gas from the main pipeline through gas reducing stations and divide it on two flows one of them is directed into the pipeline of high pressure, and the other into a consumer pipe-bend. At that the gas of consumer pipe-bend is preliminary cooled and cleared from condensed and hard fraction, and then further cooling is executed till the temperature below the point of condensation of methane and division of cryogenic liquid and directed to the user, and out of received cryogenic liquid methane is separated from liquid ethane-propane-butane fraction which is returned into the pipeline of high pressure and further into the main pipeline, and detailed methane is directed into the pipe-bend. At that the gas in the pipeline of high pressure is preliminary additionally cooled, compremirated and returned into the main pipeline.

EFFECT: reduces power inputs.

7 cl, 1 dwg

FIELD: preparation and transportation of petroleum associated and natural gases.

SUBSTANCE: invention relates to preparation of gas for transportation along gas pipeline and separation of heavy fraction condensate from gas. Proposed plant for preparation of petroleum associated gas or natural gas for transportation along gas pipeline and obtaining of liquid hydrocarbons from gas intake line, device to increase and decrease pressure, gas flow line, liquid hydrocarbons extraction line, three-circuit heat exchanger, separator, expansion valve, two regulating valves and swirl pipe whose input is connected through pressure increasing and decreasing device from one side with inlet gas line through first regulating valve and through series-connected second regulating valve and first circuit of heat exchanger, and from other side, with output of expansion valve. Output of cold flow of swirl pipe is connected through second circuit of heat exchangers with gas flow line, output of hot flow of swirl pipe is connected through third circuit of heat exchanger with input of separator whose condensate output is connected with line to remove liquid hydrocarbons, and gas output, with input of expansion valve.

EFFECT: increased degree of separation of condensate of heavy fractions of hydrocarbons from petroleum associated gas or natural gas designed for transportation along gas pipeline.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: device comprises device for enhancing and reducing pressure, receiving gas line for supplying the plant with the gas, discharging gas line through which the gas after purification is supplied from the plant, two vortex pipes, ejector, and condensate collector. The inlet of the first vortex pipe is connected with the receiving gas line and outlet of the cold gas flow of the second vortex pipe through the device for enhancing or reducing pressure. The output of the hot flow of the first vortex pipe is connected with the inlet of the first separator through the ejector, and the condensate outlet of the separator is connected with the inlet of the second vortex pipe. The outlet of the cold flow of the second vortex pipe is connected with the receiving gas.

EFFECT: enhanced quality of purification.

1 cl, 1 dwg

FIELD: pipeline transport.

SUBSTANCE: method comprises intensifying extraction of low-pressure gas in tanks of oil stabilization due to rarefying gas in the inlet gas collector that connects the tank with the inlet of liquid-gas jet compressors by mixing the pumping product with active agent and increasing initial pressure of the low-pressure gas up to the pressure required by a consumer with simultaneous condensation of C5+ fraction. The gas-liquid mixture is supplied to the air cooling apparatus. After the separation of gas from the active agent, purifying and drying the compressed gas is intensified by supplying the compressed gas into the vortex pipe and, then, to the consumer.

EFFECT: improved method.

1 dwg

FIELD: pipeline transport.

SUBSTANCE: power plant is additionally provided with a turbine expander provided with an electric generator. Power generated by the steam plant is directed to the main gas pipeline, and a part of power is directed to the turbine expander with electric generator to produce electric power.

EFFECT: enhanced reliability and efficiency.

1 cl, 1 dwg

The invention relates to techniques for managing operations of the process gas transportation

The invention relates to pipeline transport

The invention relates to transport gas and is used to restore the high concentration of inhibitors

The invention relates to the field of pipeline transport of gas

FIELD: pipeline transport.

SUBSTANCE: power plant is additionally provided with a turbine expander provided with an electric generator. Power generated by the steam plant is directed to the main gas pipeline, and a part of power is directed to the turbine expander with electric generator to produce electric power.

EFFECT: enhanced reliability and efficiency.

1 cl, 1 dwg

FIELD: pipeline transport.

SUBSTANCE: method comprises intensifying extraction of low-pressure gas in tanks of oil stabilization due to rarefying gas in the inlet gas collector that connects the tank with the inlet of liquid-gas jet compressors by mixing the pumping product with active agent and increasing initial pressure of the low-pressure gas up to the pressure required by a consumer with simultaneous condensation of C5+ fraction. The gas-liquid mixture is supplied to the air cooling apparatus. After the separation of gas from the active agent, purifying and drying the compressed gas is intensified by supplying the compressed gas into the vortex pipe and, then, to the consumer.

EFFECT: improved method.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: device comprises device for enhancing and reducing pressure, receiving gas line for supplying the plant with the gas, discharging gas line through which the gas after purification is supplied from the plant, two vortex pipes, ejector, and condensate collector. The inlet of the first vortex pipe is connected with the receiving gas line and outlet of the cold gas flow of the second vortex pipe through the device for enhancing or reducing pressure. The output of the hot flow of the first vortex pipe is connected with the inlet of the first separator through the ejector, and the condensate outlet of the separator is connected with the inlet of the second vortex pipe. The outlet of the cold flow of the second vortex pipe is connected with the receiving gas.

EFFECT: enhanced quality of purification.

1 cl, 1 dwg

FIELD: preparation and transportation of petroleum associated and natural gases.

SUBSTANCE: invention relates to preparation of gas for transportation along gas pipeline and separation of heavy fraction condensate from gas. Proposed plant for preparation of petroleum associated gas or natural gas for transportation along gas pipeline and obtaining of liquid hydrocarbons from gas intake line, device to increase and decrease pressure, gas flow line, liquid hydrocarbons extraction line, three-circuit heat exchanger, separator, expansion valve, two regulating valves and swirl pipe whose input is connected through pressure increasing and decreasing device from one side with inlet gas line through first regulating valve and through series-connected second regulating valve and first circuit of heat exchanger, and from other side, with output of expansion valve. Output of cold flow of swirl pipe is connected through second circuit of heat exchangers with gas flow line, output of hot flow of swirl pipe is connected through third circuit of heat exchanger with input of separator whose condensate output is connected with line to remove liquid hydrocarbons, and gas output, with input of expansion valve.

EFFECT: increased degree of separation of condensate of heavy fractions of hydrocarbons from petroleum associated gas or natural gas designed for transportation along gas pipeline.

1 dwg

FIELD: the invention refers to energy-conservation technologies of pipeline transportation of natural gas.

SUBSTANCE: it may be used for controlling the technological process of the main pipeline with simultaneous selection out of gas of valuable ethane, propane, butane components. The technical result of the invention is reduction of energy inputs for maintaining pressure in the main pipeline, provision of stabilization of pressure in the main pipeline. The mode of transportation of natural gas along the main pipeline includes its feeding into the main pipeline on the first and the following compressor stations and giving out natural gas from the main pipeline through gas reducing stations and divide it on two flows one of them is directed into the pipeline of high pressure, and the other into a consumer pipe-bend. At that the gas of consumer pipe-bend is preliminary cooled and cleared from condensed and hard fraction, and then further cooling is executed till the temperature below the point of condensation of methane and division of cryogenic liquid and directed to the user, and out of received cryogenic liquid methane is separated from liquid ethane-propane-butane fraction which is returned into the pipeline of high pressure and further into the main pipeline, and detailed methane is directed into the pipe-bend. At that the gas in the pipeline of high pressure is preliminary additionally cooled, compremirated and returned into the main pipeline.

EFFECT: reduces power inputs.

7 cl, 1 dwg

FIELD: storage or transporting of natural gas.

SUBSTANCE: method comprises cooling natural gas down to a temperature below the temperature of the ambient air and transporting the cooled natural gas.

EFFECT: enhanced efficiency of storage and transporting.

16 cl, 13 dwg

FIELD: gas industry.

SUBSTANCE: method comprises separating the mixture into C1 methane fraction with subsequent supply to gas pipeline and C2+ hydrocarbon fraction that are preliminary stabilized by its liquefying by means of preliminary cooling down to a temperature at least 16°C and supplying to the gas pipeline. The pressure is maintained at a level no less than 3,2 MPa.

EFFECT: enhanced reliability of one-phase transporting.

2 dwg

FIELD: oil industry.

SUBSTANCE: supersonic tube comprises Laval nozzle, cyclonic separator with the blade, diffuser for discharging dried gas, and diffuser for discharging condensed liquid. The blade is made of deformed plate set in the screw groove made in the inner side of the cyclonic separator. The length of the plate is at least ½ of the pitch of the screw groove. The housing of the tube of the cyclonic separator receives locking members whose faces enters the screw groove. The distance between the adjacent locking members mounted in the screw groove is equal to the length of the plate.

EFFECT: enhanced efficiency.

4 dwg

FIELD: natural gas industry; other industries; production of the gas pipeline blowoff valves.

SUBSTANCE: the invention is pertaining to natural gas industry and is intended for blowing through of the gas pipelines. The technical result of the invention is the increased efficiency of usage of the gas pipeline blowoff valves at augmentation of the quantity of the delivered for utilization of the waste heavy hydrocarbon fractions of the natural gas for their additional condensation in the area of formation of the microswirlings between the exterior funnel-shaped and interior perforated conical walls. In the gas pipeline blowoff valve in the holes of the perforated conical wall there are the curvilinear grooves, which curvature is directed counterclockwise, and the curvature of the guiding vanes is made in the clockwise direction.

EFFECT: the invention ensures the increased efficiency of usage of the gas pipeline blowoff valves.

4 dwg

FIELD: gas conveyance means, particularly gas-main lines, gathering lines and manifolds of gas fields for condensate recovery.

SUBSTANCE: device to prevent condensate plug forming in pipeline comprises pipeline with inclined sections and connection elbows with enclosing channel. Discharge condensate pipe is formed in lower part of connection elbow. Condensate pipe is located in funnel-shaped enclosing channel and is connected to accumulation vessel located below ground freezing level. Condensate removal pipeline is installed in accumulation vessel so that the condensate removal pipeline is coaxially retained in vertical enclosing channel.

EFFECT: possibility to maintain thermal gas pipeline regime, which prevents condensate freezing, to remove accumulated condensate due to usage of steam condensation heat generated during condensation of steam present in conveying gas flow.

1 dwg

Up!