Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
• • 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
• • 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
• • 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

• This invention relates to the transportation of waxy oils through pipe-lines, and more particularly pertains to a method for increasing the throughput capacity of pipelines used for transporting crude oils having high wax contents.
• the invention also provides an improved process whereby the energy required to transport a very waxy crude oil through a pipe-line may be materially reduced.
• T is the equilibrium temperature in degrees Fahrenheit
• T is the pour point of the waxy oil, also in degrees Fahrenheit, said. resulting equilibrium temperature being however, above the freezing point of the water.
• One of the main advantages of the present invention is that, when applied to waxy, high pour-point oils, there is no inversion of the oil-in-water suspension as long as the equilibrium temperature thereof is maintain within the above-defined range, which, as stated, depends on the pour point of the waxy oil to be transported, this noninversion persisting even when the throughput of the suspension is increased to the economic maximum for the given pipe-line and/or pumping equipment employed.
• the suspensions produced and transported by the process of the present invention can vary within a wide range insofar as their oil concentration is concerned.
• it has been actually applied to the pumping of suspensions containing as low as about by volume of oil and as high as about 70 to 75% by volume of oil, the transport of highly waxy, high pour-point crude petroleum oils over this entire range of oil content having been proved to be feasible when effected as an oil-in-water suspension in accordance with the process of the present invention.
• the criticality of the oil-to-water ratio may be considered one of economics.
• the pumping of suspensions containing very low oil concentrations may be considered to be uneconomical (at least in some cases) since one is required to expend considerable energy for the transport of large amounts of water for each unit of oil thus conveyed.
• the oil concentration in the suspension is too high, the transportation of such suspension might likewise be uneconomical because of the excessive viscosities of the suspension, which would require expenditure of excessive and possibly impractical amounts of energy to transport such suspension through a given pipeline.
• the practical maximum oil concentration in the suspension is in the neighborhood of 75 by volume.
• the optimum oil content in the suspension (at least from energy requirement point of view) is generally close to the above practical maximum, i.e. about 65-70% by volume. Above this one does not generally have a proper suspension because there is not enough water to permit free movement of the oil particles in the suspension.
• the process of the present invention is applicable to the transportation of petroleum oils, and like water-insoluble liquids, which have high wax contents and high pour points.
• These petroleum oils may have wax contents as low as about 5% by wt. (as measured by mixing the oil with about ten volumes of methyl isobutyl ketone, chilling the solution, with Dry Ice, to l0 C. and filtering).
• wax contents as low as about 5% by wt. (as measured by mixing the oil with about ten volumes of methyl isobutyl ketone, chilling the solution, with Dry Ice, to l0 C. and filtering).
• high pour point oils is intended to refer primarily to those oils which have pour points above about 75 F., the pour points of the oils which may be transported in accordance with the process of the present invention varying from about 75 F. (preferably above about F.) to as high as 110 F. and even higher.
• Petroleum oils, or fractions thereof, which may be transported according to the present process may vary within wide limits insofar as their specific gravities is concerned.
• the high pour point of the oils depends on the wax content.
• some crude oils with high pour points e.g., as high as from F. to F., and even higher, were found to have relatively low specific gravities, e.g., in the order of 0.82 and 0.83.
• the temperature of the water available for the preparation of the suspensions necessary for the transport of said oils, after passing through a water-treatment plant for coagulation and separation of solids is about 85 F.
• suspension temperatures which are reasonably near ground temperatures (80-85 F.)
• the same result was attained by continuously mixing the waxy oil With a large excess of water in a pressure vessel at slightly above 85 F., draining away excess water, and directing the desired amount of congealed oil and water into the pipe-line.
• the intermixing of the oil and water to produce the desired suspension may be effected by the use of various techniques and injection devices.
• one may employ ordinary T arrangements as well as those involving perforated plates in either the oil or water inlet sides, or in both.
• Very satisfactory results have been obtained by the use of concentric injection devices, preferably those in which the oil is introduced through the inner pipe, while the water is conveyed through the annulus between the pipes.
• the pumping may be effected by using any types of pumps, e.g., reciprocating or centrifugal pumps, which may be installed at the head of the line, or disposed at a number of points along the pipe-line. In the latter case it may be advisable to inject additional water into the system at the intermediate or booster stations to re place that part of the external water phase which becomes dispersed as droplets in the oil phase by the shearing action of the pumps.
• pumps e.g., reciprocating or centrifugal pumps, which may be installed at the head of the line, or disposed at a number of points along the pipe-line. In the latter case it may be advisable to inject additional water into the system at the intermediate or booster stations to re place that part of the external water phase which becomes dispersed as droplets in the oil phase by the shearing action of the pumps.
• Example I A waxy crude oil from Indonesia having a pour point of about 105 F. and a wax content of about 36% wt. (as measured at C. by the above-described process which involves dilution with methyl isobutyl ketone), was mixed with water under the following conditions:
• This mixture had an equilibrium temperature of about 93 F. It was found to consist of an oil-in-water suspension having a viscosity of 60 centipoises when transported at a velocity of 3 ft./sec. through /2 pipe. This suspension was readily transported through both large and small diameter pipes (ranging from /1 inch up to 18 inches in diameter) without the necessity of using excessive power and without the suspension becoming inverted.
• Example 11 When the above Indonesian crude oil was mixed with water in the same volumetric ratio, but under temperature conditions such that the equilibrium temperature of the mixture was about 95 F., the mixture was found to be a viscous water-in-oil emulsion, which had a viscosity of about 650 cps. and could be pumped through a /2 inch pipe-line only when very large amounts of energy was applied. Also, the oil proceeded to stick to the sides of the pipe-line.
• Example 111 A waxy petroleum oil having a pour point of F. and a wax content of about 27 /2 wt. (as measured by the above-outlined process), was mixed at 93 F. with Water at 76 F. in a volumetric ratio of 60 parts of oil to 40 parts of water. The resulting mixture had an equilibrium temperature of 85 F. The mixture was an oil-in-water suspension, which was readily and smoothly transported even through a small pipe of /2 inch internal diameter without any inversion, and without the necessity of using high power input. It had a viscosity of 45 centistokes when pumped at rate of 5.6 ft./sec. through the above pipe.
• Example IV A Texas crude oil having a pour point of 85 F. and a wax content of about 17% wt., was mixed at 86 F. with Water at 63 F. in a volumetric oil-to-water ratio of 70:30. The mixture had an equilibrium temperature of 75 F., was an oil-in-water suspension readily transported through a pipe-line.
• the improvement which comprises mixing a waxy liquid petroleum oil having a pour point above about 75 F. with Water to form. a petroleum-in-water suspension, effecting said mixing under conditions whereby the equilibrium temperature of the resulting petroleumin-water suspension is above the freezing point of the water used but below that defined by the general formula wherein T is the equilibrium temperature in degrees Fahrenheit, and T is the pour point of the waxy petroleum, also in degrees Fahrenheit, and passing it through the pipe-line.
• the improvement comprising mixing a waxy liquid petroleum oil having a pour point above about 75 F. with water to form a petroleum-in-water suspension, efiecting said mixing under conditions whereby the resulting petroleum-in-water suspension contains between about 10% and about 75% by volume of the oil and an equilibrium temperature above the freezing temperature of the water used, but below that defined by the general formula wherein T is the equilibrium temperature in degrees Fahrenheit, and T is the pour point of the waxy petroleum oil, also in degrees Fahrenheit, and passing said oilin-water suspension through the pipe-line.
• the process of transporting waxy crude oil through a pipe-line which comprises mixing a waxy oil having a pour point of between about 80 F. and about 110 F. with water to form an oil-in-water suspension, said water being used in such an amount that the resulting suspension contains between about 10% and about 75 by volume of oil, effecting said mixing so that the equilibrium temperature of the suspension is above the freezing point of the water used but below that defined by the general formula wherein T is the equilibrium temperature in degrees Fahrenheit, and T is the pour point of the waxy oil in degrees Fahrenheit, passing said oil-in-water suspension through the pipe-line, raising the temperature of said suspension to effect the substantially complete liquefaction of the oil at the end of its transport, thereby resolving the suspension, and separately recovering the substantially water-free oil.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Water Supply & Treatment (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

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Publications (1)

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Cited By (18)

Citations (3)

• 0
  • NL NL111349D patent/NL111349C/xx active
• 1958
  • 1958-01-14 US US708763A patent/US2981683A/en not_active Expired - Lifetime

Patent Citations (3)

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