US3599400A

US3599400A - Centrifugal crude oil separator

Info

Publication number: US3599400A
Application number: US876414A
Authority: US
Inventors: Pierre P Orieux
Original assignee: Compagnie Francaise des Petroles SA
Current assignee: Total Compagnie Francaise des Petroles SA
Priority date: 1968-11-14
Filing date: 1969-11-13
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17
Also published as: CA956897A; DE1956275A1; GB1241748A; NL6917002A; FR1591780A

Abstract

An oil and gas separator for underwater installation receives crude oil at one end of an octagonal toroidal-shaped container and discharges the centrifugally separated oil and gas at the other end. Supports are designed to facilitate the connection of the separator to a wellhead.

Description

United States Patent [72] inventor Pierre P. Orleu Paris, France 2 I] Appl. No. 876,414

[22] Filed Nov 13,1969

[45] Patented AI. 17, 1971 [73] Assignee Commie Francoise Des Petroles Paris, France [32] Priority Nov. 14, 1968 [33] France [54] CENTRIFUGAL CRUDE OIL SEPARATOR [50] FieldolSeareh 55/52 I99, 201,207. I77. [91,205

Primary Examiner-Reuben Friedman Assistant Examiner- R. W. Burks Attorney-Sughrue, Rothwell, Mion, Zinn & MAC PEAK ABSTRACT: An oil and gas separator for underwater installation receives crude oil at one end of an octagonal toroidal- 9hhn" shaped container and discharges the centrifugally separated [52] US. Cl. 55/203 oil and gas at the other end. Supports are designed to facilitate [51 Int. Cl. 801d 53/24 the connection of the separator to a wellhead.

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' F I3 7 i 52 1 I 41 79 tifi CENTRIFUGAL CRUDE OIL SEPARATOR BACKGROUND OF THE INVENTION enter a separator so as to undergo a degassing operation. The 1 usual underwater separators consist of a body with a generally cylindrical shape having a number of deflection plates whose function it is to facilitate the release of the enclosed gases through the impact of the crude oil against these plates. These apparatuses usually include a certain number of control instruments for the purpose of adjusting the flow rate of the crude, the gas and the degassed oil.

A recently introduced separator has been specifically designed to treat the crude oil received at the head of a submarine well and contains various flow-rate control instruments that are placed in a removable instrument capsule connected'with the help of a suitable connecting device to the separation unit. Generally speaking, the exterior appearance of this separator does not differ from that of the usual separators. Its production output is similar to known separator units and its installation on the ocean bottom involves the same problems by virtue of the distance of pipelines of acertain length and by the required dimensions of the separator. The size of the separator requires considerable support area which makes the operation and servicing of the installation under water rather impractical. The output of conventional horizon- .tal separators can improve to a certain point as their volume increases, however, beyond a certain volume, the resultant gains .in output are negated by the installation problems and the desirability of having a compact unit.

SUMMARY OF THE INVENTION An object of this invention thus consists in providing a separator which is both compact and which provides a larger output than the conventional separators. The separator of this invention is characterized by the fact that the crude and gaseous products are channeled by the walls of the apparatus in a generally curved direction, thus engendering a centrifugal force to improve the separation. Since the resultant output of the separator is greater than the conventional separator, it is possible to replace a separator of the same length with the reduced-volume separator of this invention andconsequently the advantages of thinner steel plates are possible.

Another object of this invention is to provide a separator whose general direction comes in the form of an open ring so that the pipeline systems for the entry of the crude oil into the separator and the evacuation of the gas and the degassed oil are as close together as possible. This is accomplished by introducing the pipeline system for the crude oil through a wall of the separator practically perpendicular to the general direction of the ring formed by the lateral walls of the separator. The walls through which the crude oil is introduced will thus constitute one of the ends of the rings. The gas and the degassed oil will be removed through a pipeline system at the other end of the separator which terminates adjacent the first end. With this arrangement the ring-shaped separator will incorporate two adjacent ends that enable relatively easy connections to be made to the three pipeline systems consisting of the crude, gas and oil to an instrument capsule controlling the flow rates and levels of the separator.

Another object of the invention is to provide a separator that along with its support and the wellhead furnishing the crude oil to be treated will constitute a stable and compact structure. This is accomplished by having the base of the wellhead constructed in one piece with the support of the ringshaped separator and having the ring-shaped separator surrounding the head of the well. This arrangement provides a separator which is particularly easy to place in position since the connection between the separator and the wellhead is made removable by arranging, the base of the wellhead, an assembly of radial supports having at their ends supports in the form of a stirrup in order to receive said ring-shapediseparator, the upper part of the ring-shaped wall of the separator containsattachment means which are articulated arms connected to the removable attachments fixed on a collar mounted at the upper portion of the wellhead. With this arrangement, an economical, compact, higher yield separator has been constructed offering the advantage of being easily installed around a submarine well or being withdrawn from it.

The reduced size of such an installation helps eliminate the risk of collisions or accidents which'are always possible in the ocean between the submarine installationand maritime vessels or other underwater equipment. I

Other characteristics and advantages of this invention will appear in the following specification with reference to the attached drawing in which the ring-shaped form of a. separator is disclosed in one form of the invention by means of eight cylindrical elements connected to each other.

IN THE DRAWINGS FIG. 1 shows a plane view of the ring-shaped separator having ends practically cut away and being assembled on a wellhead;

FIG. 2 is a view of the section along line II-II in FIG. 1;

FIG. 3 shows a cross section of the support of the separator along line Ill-III in FIG. 2; and

FIG. 4 shows a cross section of the same support along line IV-IV in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment the separator has been shown as consisting of two parts, one containing the apparatus for the measurement and control of the various fluids, such as crude, gas and oil. This part generally being designated by the term instrument capsule and the other portion receiving the crude from the instrument capsule in order to perform the'oil-gas separation, and in order to return the finished products into the capsule. A detailed discussion of this arrangement can be found in the French patent application filed on Oct. 9, 1968 under Ser. No. PV 169 (240), for: Instrument Capsule for Control of Submarine Petroleum Installation and in U.S. Pat. application Ser. No. 864,997, filed on Oct. 9, 1969.

Although this type of separator is illustrated as the preferred embodiment, it is obvious that this invention could be illustrated with for example a derived separator of the conventional type.

The wellhead, emerging from the ocean bottom has been designated by reference No. l in FIGS. 1 and 2. The pipeline system 2 moves the crude towards a fixed pipe 3 shown in docket lines, and from there towards a pipeline 4 of a mobile piece 5, capable of turning around its axis of revolution. For greater clarity, the invention has been illustrated in the drawings with the instrument capsule containing the prolonged pipelines, respectively the pipes 4, 6, 7, 8, 9 and 10 of piece 5, along with the fixed piece 11, constituting the connecting device serving for the connection of the instrument capsule, not shown.

After passage through the instrument capsule. the crude is moved into the separator by pipeline systems 8, l2 and I3.

Pipeline system 13 penetrates into the separator through its extreme surface 14, shown in cross section in the drawing and connected by a welded connected element 15, similar to the connection more clearly disclosed at 16, to a first cylindrical section 17. The separator of this invention has a general shape of a ring that is obtained in the illustrated drawings by the juxtaposition of elements such as 18. These elements are cylinders with a circular cross section whose included bases are vertical and symmetrical with respect to a circular cross section. It is thus easy to connect any two successive identical elements l8 and 19 along sections such as 20.

In the illustrated embodiment, the separator consists of seven cylindrical sections whose plane projection constitutes seven elements of an octagonal crown, where the last element contains the pipes of the separator. Thus, the crude that arrives via pipeline system 13 is introduced into the interior of the ring-shaped separator, and undergoes intensive centrifugal action that helps promote the degassing of the final products. The result is that for one and the same production of degassed oil over the same length of a conventional separator, the cross section of the ring-shaped separator may be reduced and consequentially it is possible to utilize thinner plates of steel.

At the end of the separator process, the gases are collected in the upper portion of the separator by pipeline system 21, connected to the extreme surface 22. The gas is moved along by pipeline system 7 to the instrument capsule and passes through pipelines l and 23 from which it may be directed toward a torch. The degassed oil is collected in the lower portion of surface 22 by pipeline systems 24 and 9 and it is moved from there to the instrument capsule from which it emerges through pipelines 6 and 25 in order to supply the proper pipeline system.

A manhole 26 may be provided at the end 22 of the separator. Likewise, the cylindrical element 27, connecting the extreme sections of the separator, incorporates a manhole 28.

Arms

29, 30 and 31 illustrated in FIG. 1, are arranged radially around the wellhead and serve as supports for stirrups 32, as shown in FIGS. 2 and 3. In the illustrated embodiment these stirrups are welded on arms such as 30, as illustrated in FIG. 3. The arm 33, as shown in FIG. 4, reveals a disconnecting device 34 making it possible to support the connector 11 as shown in FIG. 2.

Arms

29, 30, 31 and 33 are held at the base of wellhead l by collar 35. The upper edge of the collar 35 being supported on collar 36 of the base of the wellhead. Collar 35 is attached by screwing it tightly on collar 37 with the help of bolts and nuts, not shown here.

The separator rests on stirrups 32, and the upper portion of the wall of the separator is connected to arms 38 through 41 that are articulated on attachments 42-45. The ends of these arms are attached to the attachments mounted on a collar made up of elements 46 and 47, surrounding the upper portion of the wellhead and kept tightly screwed by nuts and bolts.

The advantage of this arrangement is that it greatly facilitates the placement of the separator since the separator can be lowered above the wellhead while being suspended with the help of articulated arms 38-4l. While the separator rests on stirrups 32, and when connector 11 rests in its housing, the elements 46 and 47 can be connected around the upper part of the wellhead. It is clear that numerous modifications can be implemented in the above-described invention. For example, the floor constituted by tubes 48, FIG. 1, would be eliminated and the apparatus included in the instrument capsule could be installed in the ring-shaped separator. Under these conditions, pipeline system 2, coming from the wellhead, would be directly connected to pipeline system 13. Further, oil pipeline system 24 would be connected to pipeline system 25, and gas pipeline system 21 would be connected to pipeline system 23. Appropriate valves could be added on these pipeline systems.

I claim:

1. A compact separator for separating gas and oil from crude received from a wellhead comprising:

a housing with an opening for receiving the crude, a closed curved channel means in the fonn of an open ring lying substantially in a horizontal plane and connected to the opening for creating a centrifugal force with the flowing crude to encourage separation of gas and oil and output means connected to the open ring for separately removing the oil and gas.

2. A separator as in claim 1, where the open ring ends are closed and one end of the ring receives the crude and the other end discharges the oil and as.

A separator as 1n claim including an infrastructure which is rigidly connected to the wellhead, the ring-shaped separator surrounding the wellhead.

4. A separator as in claim 1 including securing means located on the upper portion of the housing, a collar and arms articulated from the securing means to the collar attached to the wellhead.

5. A separator as in claim 1 including a removable and rigid connection with the upper portion of the wellhead for supporting the separator housing and a rigid support at the base of the wellhead for supporting the separator housing about the wellhead.

6. A separator as in claim 1, where the ring consists of cylindrical juxtaposed sections.

7. A separator as in claim 1, where the housing consists of an assembly of tubular sheaths connected around a head of a well to form a continuous tubular envelope, one of the sheaths including a manhole for access to the interior of the envelope, the ring separator having ends that terminate adjacent the manhole, securement means fixed to the upper portion of the housing, a collar screwed to the head of the well, arms articulated from the collar to the securement means, and a separator supporting means attached to the base of the wellhead.

8. A compact separator for separating gas and oil from crude received from a wellhead comprising;

a housing with an opening for receiving the crude, a closed curved channel means in the form of an open ring connected to the opening for creating a centrifugal force with the flowing crude to encourage separation of gas and oil and output means for separately removing the oil and gas, whereby the open ring ends are closed and one end of the ring receives the crude and the other end discharges the oil and gas through separate conduits.

9. A separator as in claim 8 including an infrastructure which is connected to the wellhead, the ring-shaped separator surrounding the wellhead and supported by the infrastructure.

Claims

2. A separator as in claim 1, where the open ring ends are closed and one end of the ring receives the crude and the other end discharges the oil and gas.
3. A separator as in claim 1, including an infrastructure which is rigidly connected to the wellhead, the ring-shaped separator surrounding the wellhead.
4. A separator as in claim 1 including securing means located on the upper portion of the housing, a collar and arms articulated from the securing means to the collar attached to the wellhead.
5. A separator as in claim 1 including a removable and rigid connection with the upper portion of the wellhead for supporting the separator housing and a rigid support at the base of the wellhead for supporting the separator housing about the wellhead.
6. A separator as in claim 1, where the ring consists of cylindrical juxtaposed sections.
7. A separator as in claim 1, where the housing consists of an assembly of tubular sheaths connected around a head of a well to form a continuous tubular envelope, one of the sheaths including a manhole for access to the interior of the envelope, the ring separator having ends that terminate adjacent the manhole, securement means fixed to the upper portion of the housing, a collar screwed to the head of the well, arms articulated from the collar to the securement means, and a separator supporting means attached to the base of the wellhead.
8. A compact separator for separating gas and oil from crude received from a wellhead comprising; a housing with an opening for receiving the crude, a closed curved channel means in the form of an open ring connected to the opening for creating a centrifugal force with the flowing crude to encourage separation of gas and oil and output means for separately removing the oil and gas, whereby the open ring ends are closed and one end of the ring receives the crude and the other end discharges the oil and gas through separate conduits.
9. A separator as in claim 8 including an infrastructure which is connected to the wellhead, the ring-shaped separator surrounding the wellhead and supported by the infrastructure.