FR2568977A1 - FLEXIBLE PIPE - Google Patents

Abstract

THE INVENTION RELATES TO A FLEXIBLE HOSE FOR THE TRANSPORT OF CORROSIVE FLUIDS SO AS TO RESIST AN AVOIDABLE ATTACK BY ACIDS SUCH AS CARBONIC ACID AND HYDROSULFUROUS ACID. THE FLEXIBLE PIPE CONSISTS OF A LAYER 11 IN THE FORM OF AN ELASTOMER RESISTANT TO CORROSIVE FLUIDS, WHICH IS ARRANGED BETWEEN A METAL INNER CARRIER LAYER 12 AND AN EXTERNAL CARRIER LAYER 13; THE PROTECTION OF THE FLEXIBLE PIPE IS PROVIDED BY A LAYER 19 IN THE FORM OF A POLYMER COMPOSITION CONTAINING RED IRON OXIDE, THAT IS TO SAY FERRIC OXIDE; THIS POLYMERIC COMPOSITION MAY CONTAIN FROM 5 TO 100 PARTS OF RED IRON OXIDE PER 100 PARTS OF POLYMER; THE FLEXIBLE PIPE MAY ALSO HAVE A REINFORCING LAYER FLOODED IN A MATRIX SHAPED FROM THE said POLYMER COMPOSITION CONTAINING IRON OXIDE. APPLICATION TO THE TRANSPORT OF CRUDE OIL UNDER HIGH PRESSURE.

Description

The present invention relates to a flexible hose and is more

  particularly, although not exclusively, to a flexible hose suitable for carrying a corrosive fluid such as crude oil under high pressure. In accordance with the present invention, a

  hose comprises a polymer composition

  holding red iron oxide (ferric oxide).

  The polymer composition is usually based on a rubber, to which ferric oxide in the form of particles is incorporated by a conventional operating technique, for example on a machine

  Banbury. Preferably, the polymer composition

  holds from 5 to 100 parts of iron oxide per 100

  of rubber, and preferably from 20 to 50 parts

  ties. Ferric oxide is an inexpensive, readily available material with relatively low toxicity, and its presence can provide two benefits:

  1. It is capable of absorbing the quantities

  mitted with hydrosulfuric acid (resulting from the presence

  hydrogen sulphide) and carbonic acid (resulting from

  both of the presence of carbon dioxide). This is partly

  interesting if the hose also contains materials such as textile cords and / or metal reinforcement (eg wires or cables) and / or fabric layers that would be

  otherwise affected by acid attack.

  2. It can serve as a visual indicator of a con-

  tact with hydrosulphurous or carbonic acid in

from red to black.

  The important feature of the present invention is that the iron oxide-containing polymer composition can form a barrier between a potential source of etching and a

  component of the hose that is necessary to

  to protect against such an attack. The most common attack

  rante is an attack by acids contained in the working fluid in the hose and a metal or textile component of the hose is

  particularly vulnerable to such an attack.

  Because reinforcing layers formed of metals, textile material or glass are commonly

  used in flexible hoses, there are

  which the protection aspect of the present

  invention is particularly applicable.

  In a preferred embodiment of the present invention,

  In this invention, a flexible hose component to be protected is embedded in a matrix of a polymer composition containing iron oxide, which extends radially inwardly and outwardly, respectively having a thickness of minus 1 mm and

  advantageously a thickness of between 2 and 10 mm.

  Usually, the polymer composition containing the iron oxide is in the form of a circumferentially continuous layer and a thickness

substantially uniform.

  In another embodiment of the present invention,

  In this invention, a component to be protected is not embedded in a matrix but is contiguous or similar to a polymer composition containing iron oxide, for example being interposed between two such compositions (with respect to preferred thicknesses

  compositions, reference will be made to the preceding paragraph).

  Although we often refer to this

  In a composition containing iron oxide, it is understood that there is a plurality of such compositions within a flexible pipe structure and for example a hose may have wires or cables. metal embedded in a layer of iron oxide and layers of fabric embedded in another layer of oxide

of iron.

  Other features and advantages of the

  will be highlighted, in the following

  description, given by way of non-limiting example, with reference to the accompanying single drawing in which: Figure 1 is a longitudinal sectional view of a portion of a hose according to the present invention. A hose for transporting crude oil under high pressure comprises a layer 11l of an oil-resistant elastomer, disposed between a metallic inner carrier layer 12 and an outer carrier layer 13o. The outer carrier layer 13 comprises metal cables 18 high

  resistance that are embedded in a matrix of a

  polychloroprene rubber position containing

  parts of iron oxide per 100 parts of

  Chouc. Layer 19 is another carrier layer consisting of a rayon fabric embedded in the same

  rubber composition containing iron oxide.

  The flexible hose also comprises a two-part outer covering layer 20 consisting of an inner layer 20B formed of a polychloroprene rubber composition and an outer layer A formed of the rubber composition containing

  iron oxide which has been mentioned above.

  A section of flexible pipe having this structure

  It was equipped with an inner heating element and the ends were sealed with suitable fittings before filling the 75% hose with crude oil. The remaining volume was filled with a mixture of gaseous hydrocarbons (28%), carbon dioxide (70%) and hydrogen sulphide (2%), and the pressure inside the pipe was increased. flexible

  (up to 6894 kN / m2) by pumping into the gas mixture.

  The pipe was immersed in a 5 C bath and increased

  temperature of the pipe contents by means of the internal heating element up to 100 C,

  void an increase in internal pressure (jus-

  than 20,682 kN / m2). The pipe was allowed to cool and then reheated. This heating / cooling cycle was repeated every 12 hours and the oil charge was changed every two weeks. The trial was stopped after 11 months

  and the pipe was inspected for damage

  rations or leaks; we did not find anything. Flexible hoses of a similar structure but without red iron oxide failed after much shorter periods of time, typically 7 to

14 days.

Claims (10)

  1. Flexible hose, characterized in that it comprises a polymer composition containing iron oxide red (ferric oxide).   2. A flexible hose according to claim 1, characterized in that the polymer composition contains from 5 to 10 parts of red iron oxide per 100 parts of polymer.   3. A hose according to claim 1, characterized   in that the polymer composition contains 20 to 20 parts of red iron oxide per 100 parts of polymer.   4. Flexible hose according to any one of the   1 to 3, characterized in that the polymer composition containing iron oxide forms a layer circumferentially continuous.   5. A hose according to any one of the   1 to 4, characterized in that the composition   polymer containing iron oxide extends radially   up to a thickness of at least 1 mm in the flexible pipe.   6. A hose according to any one of the   1 to 4, characterized in that the composition   polymer containing iron oxide extends radially   to a thickness of at least 2 mm and up to mm in the hose.   7. Flexible hose according to any one of the   1 to 6, characterized in that it also includes a reinforcement layer.   8. A hose according to claim 7, characterized   characterized in that the reinforcing layer is formed of a metal.   9. Flexible hose according to one of the claims   7 or 8, characterized in that the reinforcing layer is embedded in a matrix of the polymer composition containing iron oxide.   10. Flexible hose according to any one of the   1 to 9, characterized in that it comprises a component embedded in a matrix of the composition   polymer containing red iron oxide.