[go: up one dir, main page]

US20050085395A1 - Process for transporting a multiphase system through a pipeline - Google Patents

Process for transporting a multiphase system through a pipeline Download PDF

Info

Publication number
US20050085395A1
US20050085395A1 US10/501,740 US50174004A US2005085395A1 US 20050085395 A1 US20050085395 A1 US 20050085395A1 US 50174004 A US50174004 A US 50174004A US 2005085395 A1 US2005085395 A1 US 2005085395A1
Authority
US
United States
Prior art keywords
polymer
olefin
monomer units
process according
ethylene
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/501,740
Inventor
Herman Dikland
Michel Van Boggelen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DSM IP Assets BV
Original Assignee
DSM IP Assets BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DSM IP Assets BV filed Critical DSM IP Assets BV
Assigned to DSM I.P. ASSETS B.V. reassignment DSM I.P. ASSETS B.V. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: VAN BOGGELEN, MICEL PAUL, DIKLAND, HERMAN GERARD
Publication of US20050085395A1 publication Critical patent/US20050085395A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17D—PIPE-LINE SYSTEMS; PIPE-LINES
    • F17D1/00—Pipe-line systems
    • F17D1/005—Pipe-line systems for a two-phase gas-liquid flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17D—PIPE-LINE SYSTEMS; PIPE-LINES
    • F17D1/00—Pipe-line systems
    • F17D1/08—Pipe-line systems for liquids or viscous products
    • F17D1/16—Facilitating the conveyance of liquids or effecting the conveyance of viscous products by modification of their viscosity
    • F17D1/17—Facilitating the conveyance of liquids or effecting the conveyance of viscous products by modification of their viscosity by mixing with another liquid, i.e. diluting

Definitions

  • the invention relates to a process for transporting a multiphase system, such as for example a gas-petroleum system or a natural gas-condensate system, through a pipeline.
  • a multiphase system such as for example a gas-petroleum system or a natural gas-condensate system
  • the invention also relates to the multiphase system
  • Said systems are released for example in the production of oil and natural gas at sea, for example on the Continental Shelf of the North Sea.
  • the oil contains large quantities of so-called light components. Because the oil is under high pressure in the soil, these components remain in the liquid phase. During the recovery of the oil however these components evaporate as a result of the pressure reduction that occurs. As a result a gas-petroleum system must be transported in the pipelines from the recovery point to the production platform and from the production platform to the coast.
  • This aim is achieved in that a multiphase system is transported to which an oil-soluble polymer has been added with a weight-average molecular weight (Mw) of at most 1,500 kg/mol.
  • the multiphase system preferably comprises an organic liquid. More preferably the multiphase system is a gas-liquid system.
  • Mw is at most 800 kg/mol.
  • Mw is at most 400 kg/mol.
  • Mw is at least 10 kg/mol and more preferably at least 300 kg/mol.
  • the way in which the multiphase system, such as for example the gas-liquis system, is present in the pipeline is for example dependent on the angle of the axis of the line to the horizontal plane and on the flowrates of the gas and the liquid, respectively, in the pipeline.
  • a liquid layer will often be present with on the liquid layer a gas layer, which flow with different velocity through the line.
  • suitable polymers to be used in the process according to the invention if an organic multiphase system is used such as for example natural gas-condensate or gas-petroleum
  • oil-soluble polymers include for example polysiloxanes, natural rubber, olefin polymers, and polystyrene.
  • Ther preferred polymers are olefin polymers.
  • Suitable olefin polymers are for example polypropylene, polybutene and copolymers of ethylene and an alpha olefin
  • the selected polymer is easily soluble in the liquid of the multiphase system.
  • the selected polymer is a (first) olefin polymer containing monomer units of ethylene and at least one alpha olefin and/or if the selected polymer is a ( second) olefin polymer containing monomer units of ethylene, at least one alpha olefin and at least one non-conjugated polyene.
  • the olefin polymers provide a highly improved transport through the pipeline and furthermore offer the advantage that they have a low sensitivity to mechanical degradation (a high “shear stability”), they are chemically inert, they cause no fouling in or blockage of the pipelines and they can easily be added to the multiphase system due to their relatively low viscosity if they are added in a homogeneous solution ( compared to ultra high molecular weight polymers).
  • the olefin polymers may contain for example monomer units of an alpha olefin of 3-23 carbon atoms. Suitable examples include propylene, 1-butene, 1-pentene, 1-hexene and 1-octene and styrene, monomer units of (alpha, omega) diolefins, such as for example 1,5-hexadiene, 1,6-heptadiene and 1,7-octadiene, branched alpha olefins, such as for example 4-methyl-1-butene, 5-methyl-1-pentene and/or 6-methyl-1-heptene.
  • the monomer units of the alpha olefin monomer units are propylene, 1-butene, 1-pentene, 1-hexene and 1-octene.
  • the olefin polymer contains monomer units of propylene.
  • the (second) olefin polymer contains for example polyene (C), the molecule of which contains a C—C double bond which is polymerisable with for example a Ziegler-Natta catalyst, in addition to at least another C—C double bond and/or polyene (D), the molecule of which contains several C—C double bonds which are polymerisable with a Ziegler-Natta catalyst.
  • C polyene
  • D polyene
  • Polyene (C) and polyene (D) can be both aliphatic and alicylic.
  • Aliphatic polyenes generally contain 3 to 20 carbon atoms.
  • Suitable examples of polyene (C) include 1,4,8-decatrienes, 1,4-hexadiene and/or 4-methyl-1,4-hexadiene.
  • Suitable examples of polyene (D) include 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene and/or 1,4,9-decatriene.
  • Alicyclic polyenes with or without a bridge group, may be both mono- and polycyclic.
  • Suitable examples of alicyclic polyenes (C) include alkylidene norbonenes, in particular the 5-alkylidene-2-norbornenes, in which the alkylidene group contains 1 to 20, and preferably 1 to 8 carbon atoms, and some alkenyl norbornenes, in particular the 5-alkenyl-2-norbornenes, in which the alkenyl group contains 2 to 20 and preferably 2 to 10 carbon atoms and in which the alkenyl group does not contain a terminal double C—C bond, for example 5-(2′-methyl-2′butenyl)-2-norbornene and 5-(3′-methyl-2′butenyl)-2-norbornene.
  • polyene (C) is 5-ethylidene-2-norbornene.
  • Suitable examples of alicyclic polyenes (D) include vinylnorbornene, norbornadiene and the alkyl derivatives, and/or dicyclopentadiene.
  • polyene (D) is dicyclopentadiene, 5-vinyl-2-norbornene and/or 1,5-hexadiene is applied.
  • the (first) olefin polymer contains for example 15-80 mole % monomer units of ethylene and 20-85 mole % of the alpha olefin.
  • the first olefin polymer contains 35-75 mole % monomer units of ethylene and 25-65 mole % of the alpha olefin, still more preferably the olefin polymer contains 50-70 mole % monomer units of ethylene and 50-30 mole % of the alpha olefin, most preferably the olefin polymer contains 55-65 mole % monomer units of ethylene and 45-35 mole % of the alpha olefin.
  • the olefin polymer contains no or only a small quantity of crystallinity, so that an even better solubility in organic liquid systems is achieved.
  • the olefin polymer has a crystallinity of at most 5%, measured with the aid of DSC (differential scanning calorimetry). More preferably the polymer has a crystallinity of at most 1%.
  • the crystallinity is calculated from the heat of crystallisation, derived per se from a DSC curve by heating up a polymer sample at a rate of 20° C./min to a temperature of 200° C., keeping it at that temperature for 5 minutes and afterwards recording the curve while the sample is cooled off at a rate of 5° C./min.
  • the (second) olefin polymer contains 0.1-10 mole % monomer units of the polyene and the monomer units of ethylene and the alpha olefin preferably having the molar ratio of the monomer units of ethylene and the alpha olefin of the first olefin polymer. More preferably the (second) olefin polymer contains 0.2-8 mole %, more preferably 0.5-4 mole %, monomer units of the polyene.
  • the polymerisation may be carried out for example in a solution, in a slurry or in the gas phase.
  • the polymerisation is a solution polymerisation.
  • suitable solvents are linear paraffins with 5 to 8 carbon atoms.
  • hexane is used as the solvent.
  • aromatic hydrocarbons are used as the solvent.
  • aromatic hydrocarbons are used with only one benzene nucleus, such as for example benzene and toluene.
  • saturated cyclic hydrocarbons is also possible to use as solvent, preferably having a boiling point that lies in the the boiling point range of the above-mentioned linear paraffins.
  • the polymerisation is a slurry polymerisation, preferably liquid propylene is used as the liquid for the slurry.
  • the olefinic polymer contains polar groups
  • the polar groups may for example be part of the main chain, may be part of side groups on the chain and/or may be side groups. The presence of these polar groups results in reduced corrosion and in an improved dispersion of small solid particles.
  • the polar groups contain at least an oxygen atom and/or a nitrogen atom.
  • the olefinic polymer with polar groups is the above-mentioned olefin polymer being grafted with maleic acid, maleic anhydride and/or an ester of maleic acid.
  • the grafted olefin polymer contains at least 0.01 mole, more preferably at least 0.05 mole, side groups derived from maleic anhydride and/or an ester of maleic acid per 1000 grams of polymer.
  • the grafted olefin polymer contains at most 0.5 mole side groups derived from maleic anhydride and/or an ester of maleic acid per 1000 grams of polymer.
  • the olefin polymer may be grafted with for example acrylic acid, itaconic anhydride, maleic anhydride, N-vinylpyrrolidone or acrylamide.
  • the olefin polymer is grafted with maleic anhydride or the esters of maleic acid with the aid of a free radical initiator, in a solution or in bulk.
  • Suitable free radical initiators include for example peroxides, hydroperoxides and azo compounds for example azobis-isobutyronitrile, dicumyl peroxide and/or 5-dimethylhex-3-yne-2,5-bis-tertiary-butyl peroxide.
  • the initiator may be used for example in a quantity of 0.005-2 weight % (on the basis of the reaction mixture).
  • the grafting is carried out in the absence of oxygen.
  • the maleic anhydride or the maleic acid ester and the free radical initiator is mixed, with a melt of the olefin polymer, for example in an extruder or a mixer.
  • the grafting takes place for example at a temperature between 150° C. and 300° C.
  • the process for grafting the olefin polymer may be carried out both continuously and in a batch process. Preferably however the process for grafting the olefin polymer is carried out in a continuous process. After grafting a subsequent modification, with for example an amine towards an imide, is possible.
  • the polymers having the molecular weights as mentioned above may also be obtained by mechanical or thermal degradation of higher molecular weight polymers
  • the polymer is added to the multiphase system in a quantity between for example 1 and 1000 ppm.
  • this quantity is between 5 and 500 ppm and more preferably this quantity is between 10 and 250 ppm.
  • the polymer is preferably dissolved in a solvent suitable for the polymer.
  • the polymer thus dissolved can be added for example to the multiphase system and mixed with it with the aid of known equipment that is used for adding different additives to multiphase systems, such as for example corrosion inhibitors and additives to counter hydrate formation in petroleum, for example methanol.
  • the process according to the invention is applied preferably for the transport of a multiphase system in pipelines with a stratified flow, an annular flow or a slug flow.
  • annular flow a cross-section of the pipe shows that the whole wall is covered with a liquid layer.
  • stratified flow a cross-section of the pipe shows that part of the wall is covered with a liquid layer.
  • the process according to the invention is applied with a stratified flow.
  • U.S. Pat. No. 5,107,843 discloses the use of a water-soluble drag reducer in a water-oil-gas system.
  • the water-soluble drag reducer is a water-soluble polymer containing polar groups.
  • the present invention is directed to oil-soluble polymers.
  • EP-A-243127 discloses that a polymer may be added to oil to improve the transport through pipelines. However in contrast to the present invention this process is not concerned with a multiphase system and is directed to a pure liquid system, with consequently completely different transport mechanisms being involved. Further, EP-A-243127 teaches precisely that a polymer with a very high molecular weight must be used, with an intrinsic viscosity of even more than 10 dl/g.
  • SU-A-(11)1361308 discloses that a copolymer of ethylene and propylene with a molecular weight of 56000-60000 can be added to petroleum for transport through pipelines.
  • this process is not concerned with a multiphase system because it is directed to a heavy petroleum with a high resin content.
  • the polymer is added as a waxinhibitor to counter the formation of aggregates in paraffin-containing resin-like oils.
  • it is precisely light oils that are concerned and precisely the problem of improving the transport volume is solved, while in SU-A (11)1361308 the emphasis lies on lowering the pressure which is necessary to restart the oil flow through the pipeline after an incident
  • U.S. Pat. No. 3,559,664 discloses a process for transporting liquid hydrocarbons, with the addition of a block copolymer of ethylene and propylene to the hydrocarbons.
  • this process is not concerned with a multiphase system because it is directed to a pure liquid system.
  • a high-molecular weight polymer is used with an intrinsic viscosity of more than 5 dl/g. These polymers are not shear stable and these polymers cannot be used in conventional pumping systems which are used in the present field of application.
  • the polymers used in the Examples I-III are:
  • CO 2 gas to which cyclopentane was added in different ratios was pumped through a pipeline to a storage tank at 25° C. at different flowrates.
  • the CO 2 cyclopentane system served as a model for a natural gas-condensate system.
  • Example I 65 ppm EPM-1 had been dissolved in the cyclopentane whereas in Comparative Experiment A no polymer had been dissolved in the cyclopentane.
  • a steel pipe with a cross-section of 100 mm was used as pipeline.
  • the pressure drop over a section of 5 metres of the line was measured.
  • the temperature amounted to 25° C.
  • Table 1 shows the influence of EPM-1 on pressure drop with CO 2 cyclopentane system. It appears that due to the addition of the polymer (EPM-1) to the multiphase system a relative reduction in pressure drop of up to 11% occurs.
  • Example II and Comparative Experiment B were carried out as Example I and Comparative Experiment A, but instead of EPM-1 EPM-2 was used at 50 ppm concentration. The results are given in Table 2.
  • Table 2 shows the influence of EPM-2 on pressure drop with CO 2 cyclopentane system It appears that by the addition of the polymer (EPM-2) to the multiphase system a relative reduction in pressure drop of up to 24% occurs.
  • Example III and Comparative Experiment C were carried out as Example I and Comparative Experiment A, but instead of cyclopentane a light petroleum with a viscosity of 3 centipoise was used and instead of EPM-1, EPM-3 was used at 50 ppm concentration The results are given in Table 3. TABLE 3 Comp. Exp. C Example III Vsl (m/s) Vsg (m/s) ⁇ Pcomp. exp C (Pa/m) ⁇ Pex. 3 (Pa/m) Eff.
  • Table 3 shows the influence of EPM-3 on pressure drop CO 2 petroleum system It appears that by the addition of the polymer (EPM-3) to the multiphase system a relative reduction in pressure drop of up to 8% occurs.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Water Supply & Treatment (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Pipeline Systems (AREA)

Abstract

The invention relates to a process for transporting a multiphase system through a pipeline. An oil-soluble polymer with a weight-average molecular weight (Mw) of at most 1,500 kg/mol has been added to the system. Preferably the process is applied for the transport of a natural gas-condensate system or for the transport of a petroleum-gas system. The polymer may be an olefin polymer which contains monomer units of ethylene and at least one alpha olefin or an olefin polymer which contains monomer units of ethylene, at lease one alpha olefin and at least one non-conjugated polyene.

Description

  • The invention relates to a process for transporting a multiphase system, such as for example a gas-petroleum system or a natural gas-condensate system, through a pipeline. The invention also relates to the multiphase system
  • Said systems are released for example in the production of oil and natural gas at sea, for example on the Continental Shelf of the North Sea. Often the oil contains large quantities of so-called light components. Because the oil is under high pressure in the soil, these components remain in the liquid phase. During the recovery of the oil however these components evaporate as a result of the pressure reduction that occurs. As a result a gas-petroleum system must be transported in the pipelines from the recovery point to the production platform and from the production platform to the coast.
  • It also occurs that during the recovery of natural gas a condensate is formed of so-called heavy components in the natural gas, for example because before its recovery the gas in the soil has a high temperature and after the recovery cools off or because a condensate is formed due to pressure reduction of the gas (also referred to as “retrograde condensation”). Also in this case a multiphase system is transported then, now in the form of a natural gas-condensate system, from the recovery point to the production platform and from the production platform to the coast.
  • It is of course also possible that such systems are transported by pipelines overland, for example from a well to a processing plant where gas and liquid are separated.
  • Said transport operations take place over great distances. Thus, the distance between the well or the recovery point and the platform has increased to dozens of kilometres as a result of the advanced production techniques. The distance between the production platform and the coast can easily increase to a hundred kilometers or even hundreds of kilometers. Therefore the transport of the gas-petroleum and the natural gas-condensate systems is a critical factor in the recovery of petroleum and natural gas. To increase the transport volume a higher pressure drop and/or lines with a larger diameter would have to be used. In both cases much larger investments in the installations are required.
  • It is the object of the invention to provide a process for increasing the transport volume without the above-mentioned disadvantage.
  • This aim is achieved in that a multiphase system is transported to which an oil-soluble polymer has been added with a weight-average molecular weight (Mw) of at most 1,500 kg/mol.
  • The multiphase system preferably comprises an organic liquid. More preferably the multiphase system is a gas-liquid system.
  • According to a preferred embodiment of the invention Mw is at most 800 kg/mol.
  • According to a further preferred embodiment of the invention Mw is at most 400 kg/mol.
  • Preferably Mw is at least 10 kg/mol and more preferably at least 300 kg/mol.
  • By adding the polymer it becomes possible to transport a larger volume of the multiphase system per unit of time through the pipeline, without it being necessary to increase the pressure drop across the pipeline or to choose a pipeline with a larger transport volume.
  • The way in which the multiphase system, such as for example the gas-liquis system, is present in the pipeline is for example dependent on the angle of the axis of the line to the horizontal plane and on the flowrates of the gas and the liquid, respectively, in the pipeline. Thus, in a pipeline of which the axis is at a relatively small angle to the horizontal plane, a liquid layer will often be present with on the liquid layer a gas layer, which flow with different velocity through the line.
  • If there is more liquid in the line and if the gas velocity is high enough waves can be dormed that fill the entire pipe diameter. These liquid plugs are called slugs and these slugs give rise to a large loss in pressure during the transport.
  • Further it is possible that in the multiphase system solids are present, such as for example sand particles. It is also possible that besides the oil or the condensate a liquid aqueous phase or methanol is present.
  • Examples of suitable polymers to be used in the process according to the invention if an organic multiphase system is used, such as for example natural gas-condensate or gas-petroleum, are oil-soluble polymers. Suitable oil-soluble polymers include for example polysiloxanes, natural rubber, olefin polymers, and polystyrene. Ther preferred polymers are olefin polymers. Suitable olefin polymers are for example polypropylene, polybutene and copolymers of ethylene and an alpha olefin
  • Preferably the selected polymer is easily soluble in the liquid of the multiphase system.
  • Very good results are achieved if the selected polymer is a (first) olefin polymer containing monomer units of ethylene and at least one alpha olefin and/or if the selected polymer is a ( second) olefin polymer containing monomer units of ethylene, at least one alpha olefin and at least one non-conjugated polyene.
  • The olefin polymers provide a highly improved transport through the pipeline and furthermore offer the advantage that they have a low sensitivity to mechanical degradation (a high “shear stability”), they are chemically inert, they cause no fouling in or blockage of the pipelines and they can easily be added to the multiphase system due to their relatively low viscosity if they are added in a homogeneous solution ( compared to ultra high molecular weight polymers).
  • As monomer units of an alpha olefin the olefin polymers may contain for example monomer units of an alpha olefin of 3-23 carbon atoms. Suitable examples include propylene, 1-butene, 1-pentene, 1-hexene and 1-octene and styrene, monomer units of (alpha, omega) diolefins, such as for example 1,5-hexadiene, 1,6-heptadiene and 1,7-octadiene, branched alpha olefins, such as for example 4-methyl-1-butene, 5-methyl-1-pentene and/or 6-methyl-1-heptene.
  • More preferably the monomer units of the alpha olefin monomer units are propylene, 1-butene, 1-pentene, 1-hexene and 1-octene. Most preferably the olefin polymer contains monomer units of propylene.
  • As monomer units of a non-conjugated polyene the (second) olefin polymer contains for example polyene (C), the molecule of which contains a C—C double bond which is polymerisable with for example a Ziegler-Natta catalyst, in addition to at least another C—C double bond and/or polyene (D), the molecule of which contains several C—C double bonds which are polymerisable with a Ziegler-Natta catalyst.
  • Polyene (C) and polyene (D) can be both aliphatic and alicylic. Aliphatic polyenes generally contain 3 to 20 carbon atoms.
  • Suitable examples of polyene (C) include 1,4,8-decatrienes, 1,4-hexadiene and/or 4-methyl-1,4-hexadiene.
  • Suitable examples of polyene (D) include 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene and/or 1,4,9-decatriene.
  • Alicyclic polyenes, with or without a bridge group, may be both mono- and polycyclic.
  • Suitable examples of alicyclic polyenes (C) include alkylidene norbonenes, in particular the 5-alkylidene-2-norbornenes, in which the alkylidene group contains 1 to 20, and preferably 1 to 8 carbon atoms, and some alkenyl norbornenes, in particular the 5-alkenyl-2-norbornenes, in which the alkenyl group contains 2 to 20 and preferably 2 to 10 carbon atoms and in which the alkenyl group does not contain a terminal double C—C bond, for example 5-(2′-methyl-2′butenyl)-2-norbornene and 5-(3′-methyl-2′butenyl)-2-norbornene.
  • Preferably polyene (C) is 5-ethylidene-2-norbornene.
  • Suitable examples of alicyclic polyenes (D) include vinylnorbornene, norbornadiene and the alkyl derivatives, and/or dicyclopentadiene.
  • Preferably polyene (D) is dicyclopentadiene, 5-vinyl-2-norbornene and/or 1,5-hexadiene is applied.
  • The (first) olefin polymer contains for example 15-80 mole % monomer units of ethylene and 20-85 mole % of the alpha olefin. Preferably the first olefin polymer contains 35-75 mole % monomer units of ethylene and 25-65 mole % of the alpha olefin, still more preferably the olefin polymer contains 50-70 mole % monomer units of ethylene and 50-30 mole % of the alpha olefin, most preferably the olefin polymer contains 55-65 mole % monomer units of ethylene and 45-35 mole % of the alpha olefin.
  • Preferably the olefin polymer contains no or only a small quantity of crystallinity, so that an even better solubility in organic liquid systems is achieved.
  • Preferably the olefin polymer has a crystallinity of at most 5%, measured with the aid of DSC (differential scanning calorimetry). More preferably the polymer has a crystallinity of at most 1%.
  • The crystallinity is calculated from the heat of crystallisation, derived per se from a DSC curve by heating up a polymer sample at a rate of 20° C./min to a temperature of 200° C., keeping it at that temperature for 5 minutes and afterwards recording the curve while the sample is cooled off at a rate of 5° C./min. The crystallinity is calculated from the heat of crystallisation being expressed in J/g with the aid of the formula (I):
    % crystallinity=heat of crystallisation/2.94   (I)
  • According to a further preferred embodiment of the invention the (second) olefin polymer contains 0.1-10 mole % monomer units of the polyene and the monomer units of ethylene and the alpha olefin preferably having the molar ratio of the monomer units of ethylene and the alpha olefin of the first olefin polymer. More preferably the (second) olefin polymer contains 0.2-8 mole %, more preferably 0.5-4 mole %, monomer units of the polyene.
  • It is possible to use conventional polymerisation techniques for the polymerisation of the olefin polymer, such as for example polymerisation in the presence of a Ziegler-Natta catalyst or an anionic catalyst. It is also possible to polymerise in the presence of a metallocene catalyst.
  • The polymerisation may be carried out for example in a solution, in a slurry or in the gas phase.
  • Preferably the polymerisation is a solution polymerisation. Examples of suitable solvents are linear paraffins with 5 to 8 carbon atoms. Preferably hexane is used as the solvent. It is also possible to use aromatic hydrocarbons as the solvent. Preferably aromatic hydrocarbons are used with only one benzene nucleus, such as for example benzene and toluene. It is also possible to use saturated cyclic hydrocarbons as solvent, preferably having a boiling point that lies in the the boiling point range of the above-mentioned linear paraffins.
  • If the polymerisation is a slurry polymerisation, preferably liquid propylene is used as the liquid for the slurry.
  • In one preferred embodiment of the invention the olefinic polymer contains polar groups The polar groups may for example be part of the main chain, may be part of side groups on the chain and/or may be side groups. The presence of these polar groups results in reduced corrosion and in an improved dispersion of small solid particles.
  • Good results are achieved if the polar groups contain at least an oxygen atom and/or a nitrogen atom.
  • Preferably the olefinic polymer with polar groups is the above-mentioned olefin polymer being grafted with maleic acid, maleic anhydride and/or an ester of maleic acid. Preferably the grafted olefin polymer contains at least 0.01 mole, more preferably at least 0.05 mole, side groups derived from maleic anhydride and/or an ester of maleic acid per 1000 grams of polymer. Preferably the grafted olefin polymer contains at most 0.5 mole side groups derived from maleic anhydride and/or an ester of maleic acid per 1000 grams of polymer.
  • The olefin polymer may be grafted with for example acrylic acid, itaconic anhydride, maleic anhydride, N-vinylpyrrolidone or acrylamide.
  • Preferably the olefin polymer is grafted with maleic anhydride or the esters of maleic acid with the aid of a free radical initiator, in a solution or in bulk.
  • Very good results are achieved if grafting is carried out in a solution with for example hexane as the solvent. This reaction is carried out at a temperature in the range of for example 100° C. to 250° C. and preferably in the range of 120° C. to 190° C. and still more preferably in the range between of 150° C. to 180° C.
  • Suitable free radical initiators include for example peroxides, hydroperoxides and azo compounds for example azobis-isobutyronitrile, dicumyl peroxide and/or 5-dimethylhex-3-yne-2,5-bis-tertiary-butyl peroxide. The initiator may be used for example in a quantity of 0.005-2 weight % (on the basis of the reaction mixture).
  • Preferably the grafting is carried out in the absence of oxygen.
  • If the olefin polymer is grafted in bulk, the maleic anhydride or the maleic acid ester and the free radical initiator is mixed, with a melt of the olefin polymer, for example in an extruder or a mixer. The grafting takes place for example at a temperature between 150° C. and 300° C.
  • The process for grafting the olefin polymer may be carried out both continuously and in a batch process. Preferably however the process for grafting the olefin polymer is carried out in a continuous process. After grafting a subsequent modification, with for example an amine towards an imide, is possible.
  • The polymers having the molecular weights as mentioned above may also be obtained by mechanical or thermal degradation of higher molecular weight polymers
  • Good results are achieved if the polymer is added to the multiphase system in a quantity between for example 1 and 1000 ppm. Preferably this quantity is between 5 and 500 ppm and more preferably this quantity is between 10 and 250 ppm.
  • For the addition to the multiphase system the polymer is preferably dissolved in a solvent suitable for the polymer.
  • The polymer thus dissolved can be added for example to the multiphase system and mixed with it with the aid of known equipment that is used for adding different additives to multiphase systems, such as for example corrosion inhibitors and additives to counter hydrate formation in petroleum, for example methanol.
  • Very good results are achieved if as multiphase system, a natural gas-condensate or a gas-petroleum system is transported with the aid of the process according to the invention. Most preferably the process is applied to a natural gas-condensate system, because a very large reduction in pressuredrop is achieved in that case.
  • The process according to the invention is applied preferably for the transport of a multiphase system in pipelines with a stratified flow, an annular flow or a slug flow. In the case of annular flow a cross-section of the pipe shows that the whole wall is covered with a liquid layer. In the case of stratified flow a cross-section of the pipe shows that part of the wall is covered with a liquid layer.
  • Most preferably the process according to the invention is applied with a stratified flow.
  • U.S. Pat. No. 5,107,843 discloses the use of a water-soluble drag reducer in a water-oil-gas system. The water-soluble drag reducer is a water-soluble polymer containing polar groups. In contrast the present invention is directed to oil-soluble polymers.
  • EP-A-243127 discloses that a polymer may be added to oil to improve the transport through pipelines. However in contrast to the present invention this process is not concerned with a multiphase system and is directed to a pure liquid system, with consequently completely different transport mechanisms being involved. Further, EP-A-243127 teaches precisely that a polymer with a very high molecular weight must be used, with an intrinsic viscosity of even more than 10 dl/g.
  • SU-A-(11)1361308 discloses that a copolymer of ethylene and propylene with a molecular weight of 56000-60000 can be added to petroleum for transport through pipelines. However in contrast to the present invention this process is not concerned with a multiphase system because it is directed to a heavy petroleum with a high resin content. The polymer is added as a waxinhibitor to counter the formation of aggregates in paraffin-containing resin-like oils. In the multiphase systems that are used in the process according to the present invention it is precisely light oils that are concerned and precisely the problem of improving the transport volume is solved, while in SU-A (11)1361308 the emphasis lies on lowering the pressure which is necessary to restart the oil flow through the pipeline after an incident
  • U.S. Pat. No. 3,559,664 discloses a process for transporting liquid hydrocarbons, with the addition of a block copolymer of ethylene and propylene to the hydrocarbons. However in contrast to the present invention this process is not concerned with a multiphase system because it is directed to a pure liquid system. Further a high-molecular weight polymer is used with an intrinsic viscosity of more than 5 dl/g. These polymers are not shear stable and these polymers cannot be used in conventional pumping systems which are used in the present field of application.
  • The invention will now be elucidated by means of the following non-restrictive examples.
    • EXAMPLES I-III AND COMPARATIVE EXPERIMENTS A-C
  • The polymers used in the Examples I-III are:
      • EPM-1: an ethylene propylene copolymer having an ethylene content of 58 mole % grafted with maleic anhydride and capped with N-phenyl para phenylene diamine (NPPDA) and Mw 90,000 g/mol
      • EPM-2: an ethylene propylene copolymer having an ethylene content of 58 mole % and Mw of 140,000 g/mol.
      • EPM-3: an ethylene propylene copolymer having an ethylene content of 58 mole % and Mw of 90,000 g/mol
    EXAMPLE I AND COMPARATIVE EXPERIMENT A
  • In a test rig CO2 gas to which cyclopentane was added in different ratios was pumped through a pipeline to a storage tank at 25° C. at different flowrates. The CO2 cyclopentane system served as a model for a natural gas-condensate system.
  • In Example I, 65 ppm EPM-1 had been dissolved in the cyclopentane whereas in Comparative Experiment A no polymer had been dissolved in the cyclopentane.
  • A steel pipe with a cross-section of 100 mm was used as pipeline. The pressure drop over a section of 5 metres of the line was measured. The temperature amounted to 25° C.
  • The results are shown in the Table as a function of the superficial velocity of cyclopentane (vsl) and the superficial velocity of the CO2 (vsg). Also shown are the pressure drop per metre of pipeline (ΔPex. 1, in Pa/m) measured in accordance with the example on the multiphase system to which the polymer had been added, and the pressure drop per metre (ΔPcomp. exp.A, in Pa/m) measured in accordance with the associated comparative experiment on the corresponding multiphase system without the polymer.
  • The effect of the presence of the polymer on the decrease in the pressure drop has been calculated according to the formula (II):
    Eff%=(ΔPcomp. exp A-ΔPex. 1)/ΔPcomp. exp A×100%   (II)
    TABLE 1
    Comp. Exp. A Example I
    Vsl (m/s) Vsg (m/s) ΔPcomp. exp A (Pa/m) ΔPex. 1 (Pa/m) Eff. (%)
    0.06 5.5 27 24  9
    0.06 8 52 47 10
    0.09 5.5 37 33  9
    0.09 8 63 57 11
  • Table 1 shows the influence of EPM-1 on pressure drop with CO2 cyclopentane system. It appears that due to the addition of the polymer (EPM-1) to the multiphase system a relative reduction in pressure drop of up to 11% occurs.
    • EXAMPLE II AND COMPARATIVE EXPERIMENT B
  • Example II and Comparative Experiment B were carried out as Example I and Comparative Experiment A, but instead of EPM-1 EPM-2 was used at 50 ppm concentration. The results are given in Table 2.
    TABLE 2
    Comp. Exp. B
    ΔPcomp. exp A Example II
    Vsl (m/s) Vsg (m/s) (Pa/m) ΔPex. 2 (Pa/m) Eff. (%)
    0.03 4 9 9 0
    0.06 4 13 12 5
    0.09 4 18 17 4
    0.03 5.5 17 16 4
    0.06 5.5 24 20 14
    0.09 5.5 33 27 17
    0.03 6.7 26 23 12
    0.06 6.7 33 27 18
    0.09 6.7 45 36 21
    0.03 8 38 33 13
    0.06 8 49 39 21
    0.09 8 55 42 24
  • Table 2 shows the influence of EPM-2 on pressure drop with CO2 cyclopentane system It appears that by the addition of the polymer (EPM-2) to the multiphase system a relative reduction in pressure drop of up to 24% occurs.
    • EXAMPLE III AND COMPARATIVE EXPERIMENT C
  • Example III and Comparative Experiment C were carried out as Example I and Comparative Experiment A, but instead of cyclopentane a light petroleum with a viscosity of 3 centipoise was used and instead of EPM-1, EPM-3 was used at 50 ppm concentration The results are given in Table 3.
    TABLE 3
    Comp. Exp. C Example III
    Vsl (m/s) Vsg (m/s) ΔPcomp. exp C (Pa/m) ΔPex. 3 (Pa/m) Eff. (%)
    0.03 4 23 23 0
    0.06 4 27 27 0
    0.09 4 33 33 0
    0.03 5.5 28 28 0
    0.06 5.5 33 32 3
    0.09 5.5 38 36 4
    0.03 6.7 38 37 4
    0.06 6.7 43 40 6
    0.09 6.7 49 46 7
    0.03 8 48 46 5
    0.06 8 54 50 8
    0.09 8 59 54 8
  • Table 3 shows the influence of EPM-3 on pressure drop CO2 petroleum system It appears that by the addition of the polymer (EPM-3) to the multiphase system a relative reduction in pressure drop of up to 8% occurs.

Claims (13)

1-14. (canceled)
15. A process for transporting a multiphase system through a pipeline, wherein a multiphase system is transported to which an oil-soluble polymer has been added with a weight-average molecular weight (Mw) of at most 400 kg/mol.
16. A process according to claim 15, wherein the polymer is an olefin polymer which contains monomer units of ethylene and at least one alpha olefin or the polymer is an olefin polymer which contains monomer units of ethylene, at least one alpha olefin and at least one non-conjugated polyene.
17. A process according to claim 15, wherein the alpha olefin is propylene.
18. A process according to claim 16, wherein the olefin polymer contains 15-80 mole % monomer units of ethylene and 20-85 mole % monomer units of an alpha olefin or the olefin polymer contains monomer units of ethylene, units of an alpha olefin and 0.1-10 mole % monomer units of the polyene wherein the monomer units of ethylene and the alpha olefin have the same molar ratio as in said (first) olefin polymer.
19. A process according to claim 18, wherein the olefin polymer contains 35-75 mole % monomer units of ethylene and 25-65 mole % monomer units of an alpha olefin.
20. A process according to claim 16, wherein the olefin polymer has a crystallinity of at most 5%.
21. A process according to claim 16, wherein the olefin polymer contains polar groups.
22. A process according to claim 21, wherein the olefin polymer containing polar groups is an olefin polymer grafted with maleic anhydride and/or an ester of maleic acid.
23. A process according to claim 15, wherein the multiphase system is a gas petroleum system.
24. A process according to claim 15, wherein the multiphase system is a natural gas-condensate system.
25. A process according to claim 15, wherein the multiphase system has a stratified, an annular flow or a slug flow.
26. A multiphase system wherein the multiphased system an oil-soluble polymer has been added with a weight-average molecular weight (Mw) of at most 400 kg/kmol.
US10/501,740 2002-01-16 2003-01-09 Process for transporting a multiphase system through a pipeline Abandoned US20050085395A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
NL1019759 2002-01-16
NL1019759 2002-01-16
PCT/NL2003/000010 WO2003060375A1 (en) 2002-01-16 2003-01-09 Process for transporting a multiphase system through a pipeline

Publications (1)

Publication Number Publication Date
US20050085395A1 true US20050085395A1 (en) 2005-04-21

Family

ID=19774460

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/501,740 Abandoned US20050085395A1 (en) 2002-01-16 2003-01-09 Process for transporting a multiphase system through a pipeline

Country Status (7)

Country Link
US (1) US20050085395A1 (en)
EP (1) EP1466123B1 (en)
AT (1) ATE365887T1 (en)
AU (1) AU2003202825A1 (en)
DE (1) DE60314593D1 (en)
NO (1) NO20043394L (en)
WO (1) WO2003060375A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050167326A1 (en) * 2003-12-19 2005-08-04 Bhan Opinder K. Systems, methods, and catalysts for producing a crude product
US20070042911A1 (en) * 2003-10-02 2007-02-22 Philip Fletcher Method for reducing the viscosity of viscous fluids
US20090005490A1 (en) * 2005-04-04 2009-01-01 Jeffrey Forsyth Wax-Containing Materials

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2853800A1 (en) * 2013-09-26 2015-04-01 M-I Finland Oy A method and system for delivering a drag reducing agent

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351079A (en) * 1962-09-28 1967-11-07 Dow Chemical Co Low fluid loss compositions
US3559664A (en) * 1967-09-28 1971-02-02 Shell Oil Co Process of reducing friction loss in flowing hydrocarbon liquids
US3687148A (en) * 1971-06-25 1972-08-29 Vitold Kruka Process of reducing friction loss in flowing hydrocarbon liquids and compositions thereof
US5027843A (en) * 1990-06-19 1991-07-02 Conoco Inc. Use of a water soluble drag reducer in a water/oil/gas system
US20020063241A1 (en) * 2000-10-16 2002-05-30 Alink Bernardus Antonius Maria Oude Corrosion inhibitor-drag reducer combinations
US20040030206A1 (en) * 2000-12-01 2004-02-12 Uwe Dahlmann Additives for inhibiting the formation of gas hydrates
US6774094B2 (en) * 2001-04-24 2004-08-10 Baker Hughes Incorporated Drag reduction using fatty acids

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2597487B1 (en) 1986-04-17 1989-09-29 Bp Chimie Sa AMORPHOUS COPOLYMERS OF HIGH MOLECULAR MASS OF ETHYLENE AND ALPHA-OLEFINS.
FI89132C (en) 1990-04-06 1993-08-25 Orion Yhtymae Oy Method for fine-needle biopsy or for performing a tissue marker in conjunction with mammography and arrangements for performing the procedure

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351079A (en) * 1962-09-28 1967-11-07 Dow Chemical Co Low fluid loss compositions
US3559664A (en) * 1967-09-28 1971-02-02 Shell Oil Co Process of reducing friction loss in flowing hydrocarbon liquids
US3687148A (en) * 1971-06-25 1972-08-29 Vitold Kruka Process of reducing friction loss in flowing hydrocarbon liquids and compositions thereof
US5027843A (en) * 1990-06-19 1991-07-02 Conoco Inc. Use of a water soluble drag reducer in a water/oil/gas system
US20020063241A1 (en) * 2000-10-16 2002-05-30 Alink Bernardus Antonius Maria Oude Corrosion inhibitor-drag reducer combinations
US20040030206A1 (en) * 2000-12-01 2004-02-12 Uwe Dahlmann Additives for inhibiting the formation of gas hydrates
US6774094B2 (en) * 2001-04-24 2004-08-10 Baker Hughes Incorporated Drag reduction using fatty acids

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070042911A1 (en) * 2003-10-02 2007-02-22 Philip Fletcher Method for reducing the viscosity of viscous fluids
US7745500B2 (en) 2003-10-02 2010-06-29 Advanced Gel Technology Limited Method for reducing the viscosity of viscous fluids
US20100234253A1 (en) * 2003-10-02 2010-09-16 Advanced Gel Technology Limited Method for reducing the viscosity of viscous fluids
US8178586B2 (en) 2003-10-02 2012-05-15 Oilflow Solutions Holdings Limited Method for reducing the viscosity of viscous fluids
US20050167326A1 (en) * 2003-12-19 2005-08-04 Bhan Opinder K. Systems, methods, and catalysts for producing a crude product
US7628908B2 (en) 2003-12-19 2009-12-08 Shell Oil Company Systems, methods, and catalysts for producing a crude product
US20100055005A1 (en) * 2003-12-19 2010-03-04 Opinder Kishan Bhan System for producing a crude product
US20090005490A1 (en) * 2005-04-04 2009-01-01 Jeffrey Forsyth Wax-Containing Materials
US8357745B2 (en) 2005-04-04 2013-01-22 Oilflow Solutions Holdings Limited Wax-containing materials

Also Published As

Publication number Publication date
WO2003060375A1 (en) 2003-07-24
ATE365887T1 (en) 2007-07-15
EP1466123B1 (en) 2007-06-27
NO20043394L (en) 2004-10-15
DE60314593D1 (en) 2007-08-09
EP1466123A1 (en) 2004-10-13
AU2003202825A1 (en) 2003-07-30

Similar Documents

Publication Publication Date Title
AU2017335817B2 (en) Paraffin inhibitors, and paraffin suppressant compositions and methods
US10619038B2 (en) Copolymers comprising ethylene vinyl esters and esters of (meth)acrylic acid, their formulations and use as pour point depressant, wax inhibitor and flow enhancer for crude oils
US7541315B2 (en) Paraffin inhibitor compositions and their use in oil and gas production
EP0799248B1 (en) Method for preventing fouling in polymerization reactors
US11236282B2 (en) Copolymers comprising a-olefins and olefin dicarboxylic acid esters, production thereof, and use thereof as pour point depressants for crude oils, mineral oils, or mineral oil products
US6946524B2 (en) Methods for producing polyester amides based on polyisobutylenes, polyester amides produced thereby, and uses therefor in stabilizing crude oil
US10125306B2 (en) Asphaltene inhibition
US20110190438A1 (en) Method of improving the cold flow properties of a paraffin-containing fluid
RU2752630C2 (en) Paraffin suppressant compositions and methods
US3957659A (en) Crude oil compositions having improved low temperature flow properties
EP1466123B1 (en) Process for transporting a multiphase system through a pipeline
US20060205603A1 (en) Method for inhibiting hydrate formation
US6815011B2 (en) Alpha olefin monomer partitioning agents for drag reducing agents and methods of forming drag reducing agents using alpha olefin monomer partitioning agents
US5232963A (en) Dispersing gums in hydrocarbon streams with β-olefin/maleic anhydride copolymer
US20040058827A1 (en) Paraffin inhibitor compositions and their use in oil and gas production
US20240076567A1 (en) Composition of additives comprising a copolymer and a resin
US11180588B2 (en) Compositions to stabilize asphaltenes in petroleum fluids
CN117222724A (en) Polymeric pour point depressants for waxy crude oils
Than et al. Synthesis copolymer use to reduce pour point temperature of diamond crude oil
WO2021061903A1 (en) Anhydride-based copolymers
WO2026017479A1 (en) Α-olefins – maleate copolymers, formulations thereof, and their use as pour point depressants or wax deposition inhibitors
BR112023021176B1 (en) Polymeric Pour Point Depressants for Waxy Crude Oils
CA3217341A1 (en) Polymeric pour point depressants for waxy crude oils
Than et al. Study effect of initiators on performance of copolymer used as pour point depressant for Diamond crude oil, Blocks 01 and 02, offshore Vietnam
EA050003B1 (en) ADDITIVE COMPOSITION CONTAINING COPOLYMER AND RESIN

Legal Events

Date Code Title Description
AS Assignment

Owner name: DSM I.P. ASSETS B.V., NETHERLANDS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DIKLAND, HERMAN GERARD;VAN BOGGELEN, MICEL PAUL;REEL/FRAME:016118/0646;SIGNING DATES FROM 20040605 TO 20040617

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION