U.S. patent number 3,643,736 [Application Number 04/740,520] was granted by the patent office on 1972-02-22 for subsea production station.
This patent grant is currently assigned to Mobil Oil Corporation. Invention is credited to William A. Talley, Jr..
United States Patent |
3,643,736 |
Talley, Jr. |
February 22, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
SUBSEA PRODUCTION STATION
Abstract
This specification discloses a method and apparatus for the
production of subaqueous deposits of fluid minerals through a
subsea satellite system. The wells are drilled in a circular
pattern through a template on the marine bottom serving also as
base upon which the satellite body is installed. The production and
control passages of each of the wells are connected to production
equipment within the satellite body by separate connector units,
independently lowered into place from a surface vessel, to form
portions of fluid paths between the passages within the subsea
wellheads and the production equipment within the shell of the
satellite. Such an installation permits production through the
satellite, installed on the template base, after only one of the
wells has been drilled and completed. The produced fluids are
separated and/or metered within the satellite prior to being
transported to storage. Flowline tools are programmed to enter the
various subaqueous wells through the connector units. Hydraulic
circuitry and controls are provided for pumping the tools and
chemicals down through the various wells and for retrieving the
tools. Also disclosed is a hot water well utilized in conjunction
with the heat exchanger within the satellite for warming the
separated-off gases to prevent the formation of hydrates.
Inventors: |
Talley, Jr.; William A.
(Dallas, TX) |
Assignee: |
Mobil Oil Corporation
(N/A)
|
Family
ID: |
24976849 |
Appl.
No.: |
04/740,520 |
Filed: |
June 27, 1968 |
Current U.S.
Class: |
166/356; 166/267;
166/357; 166/245; 166/336; 166/366 |
Current CPC
Class: |
E21B
41/08 (20130101); E21B 43/017 (20130101) |
Current International
Class: |
E21B
43/00 (20060101); E21B 43/017 (20060101); E21b
043/01 () |
Field of
Search: |
;166/.5,.6
;175/5-10 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Claims
What is claimed is:
1. A subsea production satellite system comprising: a base template
supported beneath the surface of a body of water; a plurality of
wells completed through said base template, beneath the surface of
said body of water; a fully submerigible production satellite body
releasably mounted on said base template; and means for releasably
fluidly connecting each of said plurality of wells with the
interior of said production satellite body whereby fluids produced
through said plurality of wells are gathered within said production
satellite body.
2. A subsea production satellite system, as recited in claim 9,
wherein said base template has an annular portion extending out
beyond said satellite body installed thereon, said plurality of
wells being completed through said annular portion just outward of
said satellite body.
3. A subsea production satellite system, as recited in claim 1,
wherein said base template extends out beyond said satellite body
installed thereon, each of said plurality of wells being completed
through a vertical well conductor pipe forming a portion of said
base template.
4. A subsea production satellite system, as recited in claim 9,
wherein said production satellite body comprises a watertight shell
enclosing production equipment; means for transferring personnel
into said satellite body through the submerged upper end
thereof.
5. A subsea production satellite system, as recited in claim 1,
wherein said plurality of wells are completed through said base
template in an enclosed pattern.
6. A subsea production satellite system, as recited in claim 5,
wherein said enclosed pattern is a circle.
7. A subsea production satellite system, as recited in claim 9,
wherein said base template has an annular portion through which
said plurality of wells are completed in a circular pattern; means
for releasably mounting said satellite body on said base template,
said mounting means comprising a portion fixed to said base
template and coaxially located with respect to said annular
portion.
8. A subsea production satellite system, as recited in claim 14,
wherein said portion of said mounting means fixed to said base
template comprises a vertical pipe.
9. A subsea production satellite system, as recited in claim 1,
wherein said production satellite body is divided into vertically
separated compartments.
10. A subsea production satellite system, as recited in claim 1,
wherein the lowest of said vertical compartments is a storage area
for well treating fluids and is open to said body of water at the
lower end thereof.
11. A subsea production satellite system, as recited in claim 1,
wherein said production satellite body is a vertically oriented
cylinder having rounded ends; means for releasably mounting said
satellite body on said base template, said releasable mounting
means comprising portions fixed to said base template and to the
lower rounded end of said satellite body.
12. A subsea production satellite system, as recited in claim 11,
wherein said means for releasably fluidly connecting each of said
plurality of wells with the interior of said production satellite
body are connector units angularly spaced around the shell of said
satellite body, each of said connector units comprising at least
one vertical tubing section; means at the lower end of said at
least one vertical tubing section for releasably connecting said
connector unit to at least one tubing nipple extending upwardly
from a subsea wellhead through which one of said plurality of wells
is completed.
13. A subsea production satellite system, as recited in claim 20,
wherein each of said connector units further comprises a curved
tubing section extending between each of said at least one vertical
sections and the vertically oriented cylindrical shell of said
production satellite body, said curved tubing section intersecting
said shell perpendicularly and extending into said production
satellite body to connect a production passage of a subsea wellhead
with production equipment within said production satellite
body.
14. A subsea production satellite system, as recited in claim 13,
wherein said curved tubing section of said connector units is
permanently fixed and extends integrally through said shell of said
production satellite body.
15. A subsea production satellite system, as recited in claim 13,
wherein said at least one vertical section extends above a point at
which said curved tubing section of said respective connector unit
joins said at least one vertical section whereby workover
operations may be performed through the respective subsea wellhead
from above without removing said connector unit or the entire
production satellite body.
16. A method for exploiting subaqueous deposits of fluid minerals
through a subsea production satellite station, including the
following steps:
a. setting a base template, through which a plurality of wells are
to be drilled, on a marine bottom beneath the surface of a body of
water;
b. drilling said plurality of wells through said base template set
on said marine bottom, at least some of said plurality of wells
being directionally drilled;
c. completing said plurality of wells, drilled through said base
template, with subsea wellheads on said base template; and
d. releasably installing a production satellite body beneath the
surface of said body of water on said base template and releasably
connecting said production satellite body with said plurality of
completed wells through subsea wellheads thereof.
17. A method for exploiting subaqueous deposits of fluid minerals
through a subsea production satellite station, as recited in claim
16, wherein subsea wellheads, completing said plurality of subsea
wells, are arranged in a circular pattern on said base
template.
18. A method for exploiting subaqueous deposits of fluid minerals
through a subsea production satellite station, as recited in claim
16, wherein said production satellite body is substantially
simultaneously brought into connection with all of the subsea
wellheads of said plurality of completed wells as said production
satellite body is releasably installed on said base template.
19. A method for exploiting subaqueous deposits of fluid minerals
through a subsea production satellite station, as recited in claim
16, wherein said plurality of wells are drilled and completed, and
said production satellite body is installed substantially from a
floating station.
20. A subsea system comprising in combination:
a. an underwater satellite body positioned at a relative central
position, said satellite body having a compartment capable of
sustaining human life;
b. a plurality of underwater wells surrounding said satellite and
spaced therefrom;
c. coupling means for connecting at least one of said wells to said
satellite body, said coupling means being adaptable for the passage
of materials and through-flowline-tools between said satellite body
and said at least one well; and
d. means in said satellite body cooperable with said coupling means
for supplying a well servicing tool to said coupling means whereby
said well servicing tool may pass from said satellite body, through
said coupling means, and into said well.
21. A base template for releasably supporting a subsea production
satellite on a marine bottom comprising:
a support means comprising a generally flat annular member;
a plurality of guide means through said annular member, each of
said guide means comprising a vertical well conductor pipe and each
being spaced on said annular member from others of said guide
means, each of said guide means extending at least partially
through said annular member and each being adapted to have a well
drilled and completed therethrough; and
means on said support means for supporting and releasably fixing a
fully submerged, production satellite body on said base template so
that said satellite is in a fixed relationship to wells drilled and
completed through said guide means when said satellite is in
position on said base template, said fixing means comprising a
central vertical pipe within said annular member fixed thereto by
an open framework.
22. A base template, as recited in claim 21, wherein said central
vertical pipe is a well conductor pipe whereby a water well is
drilled in a location which will be directly beneath a satellite
body to be installed thereover.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a subsea satellite station in which the
problems associated with laying underwater flowlines are alleviated
by the drilling and completing of individual wells in groups
closely encircling subsea satellite stations. More particularly,
the invention relates to a subsea satellite station designed in
such a manner that groups of wells are drilled and completed
adjacent an installed satellite body.
2. Description of the Prior Art
Since its inception, the offshore oil and gas industry has used
bottom-supported above-surface platforms as the principal mechanism
for the installation and support of the equipment and services
necessary for the production of the subaqueous mineral deposits. As
the industry has developed over the years, it has extended its
search for offshore minerals from its birthplace, producing oil and
gas in the shallow coastal waters off California, and the Gulf of
Mexico, into areas where, because of excessive water depth and/or
other local conditions, the bottom-supported platform is not as
economically or technologically feasible.
While theoretically there is no limit to the depth for which a
bottom-supported platform can be designed and installed, experience
to date indicates that platform costs increase almost exponentially
with the increase in water depth. Thus, the presently estimated
costs of a platform to carry the production facilities for a field
in 400 feet of water or more are so high as to indicate that such
an installation cannot be justified economically for any but the
most productive fields. Furthermore, the few bottom-supported
above-surface platforms that have been designed and built for use
in 300 feet or more of water depth have almost invariably suffered
leg failures of one type or another.
A possible solution is to install the production facilities on a
floating platform, as is described in the H. D. Cox U.S. Pat. No.
3,111,692, issued Nov. 26, 1963, which can be maintained in
position in a field by either a fixed multipoint mooring system of
anchors and anchor lines, or by a dynamic positioning system. The
above solution involves the expense of continuous maintenance and
surveillance of the locating system as well as the associated
problems and expense of maintaining the multiple flexible lines
connecting wellheads on the marine bottom with the continuously
moving floating production platform, and the potential hazard, of
this system, to the hoses, in the event of a failure of the fixed
mooring or dynamic positioning systems.
Another consideration is that, in many areas of the world, local
conditions other than water depth impose critical limitations on
the use of bottom-supported production platforms. In arctic areas,
a bottom-supported platform must be built to withstand the forces
imposed by ice that forms on the water surface during the winter
months of the year, and in many such areas all year long.
Furthermore, any above-water production platform is subject to the
mercy of the wind and waves, especially those occurring during
hurricanes and other violent storms. In the arctic areas these
storms can be exceeded by the forces exerted against the platform
by movement of the thick ice layers that freeze on the surface of
the water. For example, in Cook Inlet, Alaska, the local extremely
high tidal movements on the order of 30 feet or more cause very
fast tidal currents in the Inlet, with velocities of up to 8 to 10
miles an hour or more. These very rapid currents carry with them
the heavy pack ice that forms on the surface of the Inlet, so that
it bears with tremendous force against any fixed structure, such as
a production platform, that should be installed in its path.
In still other areas it is not adverse natural, but manmade,
conditions that restrict the use of bottom-supported above-surface
production platforms. Among such conditions could be listed
official and/or public objection to oil production facilities near
public recreational or residential areas, and the presence of heavy
marine traffic as in harbors, channels, rivers, and other
navigatable bodies of water which make it necessarily advantageous
to install as much of the production equipment beneath the water
surface as possible. For example, the first known use of subsea
wellheads is in Lake Erie where gas is produced from subaqueous
formations beneath the heavily traveled lake.
Therefore, it would appear that where there is extremely deep water
and/or adverse surface conditions, a fully subsea installation
would be the most advisable solution. One method, as is shown by
the J. A. Haeber U.S. Pat. No. 3,261,398, issued July 19, 1966, is
to locate the individual pieces of production equipment on the
marine bottom. Such an installation almost necessitates the use of
robots such as shown in the G. D. Johnson U.S. Pat. No. 3,099,316,
issued July 30, 1963. However, such instrumentalities are expensive
and not without their own limitations and maintenance problems.
Another solution is suggested by the H. L. Shatto, Jr. et al. U.S.
Pat. No. 3,221,816, issued Dec. 7, 1965, wherein the production
equipment for a plurality of wells is grouped within a satellite
chamber adapted to be raised to the surface for repair and/or
maintenance.
To utilize a subsea system, such as shown in the H. L. Shatto, Jr.
et al. U.S. Pat. No. 3,221,816, discussed above, or the subsea
system shown in the application of Warren B. Brooks et al., Ser.
No. 649,959, filed June 29, 1967, where the individual wells are
spaced out from the satellite station, requires long flowlines
between each of the subsea wellheads and the satellite station. All
of the problems associated with laying flowlines in deep water have
not been solved yet, and furthermore, such operations even when
technologically feasible are very expensive, prohibitively so for
all but the most prolific of fields. Another problem is that of
locating a particular subsea wellhead for repair or workover
operations. Locating an object, such as a wellhead, in deep water
requires sophisticated equipment and a great deal of time. By
spacing a number of subsea wellheads across the marine bottom, the
difficulties involved are compounded. One solution to the problem
is shown in the Townsend application, Ser. No. 521,745, filed Jan.
19, 1966, now U.S. Pat. No. 3,391,734 wherein the wellheads are
fabricated integrally with the shell of the satellite body. Wells
are directionally drilled through the satellite body and are
completed inside of the shell. Although such a configuration does
away with the exterior flowlines, there is one very important
defect in this type of system-the satellite body cannot be raised
back to the surface for maintenance or repair operations without
cutting all of the well casings hung therein.
SUMMARY OF THE INVENTION
In accordance with the instant invention, a subsea satellite
station, to exploit subaqueous deposits of fluid minerals,
comprises a base template having a circular pattern of upstanding
well conductor pipes affixed thereto through which wells are
directionally drilled and are completed. The satellite body is
releasably installed in a central position on the base template,
encircled by the adjacent subsea wellheads of the wells drilled and
completed through the base template. With the subsea wellheads
close around the satellite body, each of the subsea wellheads can
be fluidly connected to the satellite body with short, rigid
connector units. This arrangement obviates the need for all
individual flowlines except those connecting the satellite station
with a production and/or storage facility. The large satellite
stations, more widely spaced apart than would be individual subsea
wellheads, are also easier to locate for workover and/or repair
operations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a subsea production system in
accordance with the present invention;
FIG. 2 is a partially broken away enlarged view of one of the
satellite stations shown in FIG. 1, illustrating the arrangement of
the equipment therewithin;
FIG. 3 is a schematic representation of a heat exchange system to
be utilized within the satellite station also, but shown in less
detail in FIG. 2;
FIG. 4 is a schematic diagram of the basic circuitry required to
produce a plurality of oil and gas wells within a satellite
station;
FIG. 5 is a schematic diagram of a modified TFL FLUID SUPPLY
SYSTEM;
FIG. 6 is a schematic diagram of a modified PRODUCTION SYSTEM for
producing a field having a high gas-oil ratio;
FIG. 7 is a schematic diagram of a modified PRODUCTION SYSTEM for
producing a field having a medium gas-oil ratio; and
FIG. 8 is a schematic diagram of a modified satellite station
configuration for allowing the satellite body to be installed on a
base template of a satellite station prior to the completion of any
of the wells through the base template.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now looking to FIG. 1, a subsea system for producing fluid
minerals, in particular gas and oil, from a subaqueous field by a
plurality of subsea wellheads is illustrated. A plurality of subsea
production satellite stations, generally designated 10, are spaced
across a marine bottom 12, each satellite station 10 comprising a
satellite body 15 centrally positioned within a circular group of
closely spaced subsea wellheads 14. The produced fluids from the
subaqueous wells are directed through encircling subsea wellheads
14 into the satellite body 15 of the respective satellite station
10. The fluids being produced from the subsea wellheads 14 of each
circular group are combined within the respective enclosed
satellite body 15 and a first stage of separation (gravity) takes
place. At least the liquid portion is then directed to a circular
manifold 16 atop a central bottom-mounted storage tank 17 through a
shipping line 18, one shipping line 18 extending from each
satellite station 10.
A floating master station 20, having power-generating and final
stage separation equipment thereon, as well as being fitted out
with offloading apparatus, is in fluid and electrical communication
with the bottom-supported storage tank 17 through a tensioned
tether pipe 22 extending from the storage tank 17 to a point just
beneath the turbulent surface zone of the body of water and fixed
at this point to a large subsurface buoy 24. A flexible conduit 26,
containing a plurality of electrical and fluid flow paths, extends
from the upper end of the tensioned tether pipe 22 to the floating
master station 20. The produced liquid, collected in the circular
manifold 16, is directed to the master station through a main
shipping line 27 supported along the length of the tether pipe 22,
and a fluid line forming a portion of the flexible conduit 26. The
produced liquid passes through the final stage separation equipment
on the master station 20 where the pressure is normalized and
dissolved gases are removed. The dead liquid is then transported to
storage within the storage tank 17 through a line of the flexible
conduit 26 connected to an axial passage in the interior of the
tether pipe 22.
In the upper left-hand corner of FIG. 1 is illustrated the drilling
of a well through a satellite base template, generally designated
28, which has been previously installed on a marine bottom along
with a shipping line 18' for connecting a satellite station, when
completed in conjunction with the template 28, with the storage
tank 17. A drill string 30 is suspended from above the surface from
a semisubmersible drilling vessel 32 and extends through a blowout
preventer stack 33 mounted on one of a plurality of upstanding well
conductor pipes 34 forming a portion of the template 28.
Illustrated in the lower portion of FIG. 1 is a manned submersible
work vehicle, generally designated 36, of a type to be employed to
assist in the subsea operations and for the dry transfer of
personnel to the satellite station 10. The submersible work vehicle
36 has a pair of articulated arms 38 and 40 carrying a socket
wrench 42 and a vise grip tool 44, respectively. The submersible
work vehicle 36 is further equipped with a pivotable positioning
motor 46 on each side (one shown) to assist in locating the
submersible work vehicle 36 adjacent a satellite station 10 firstly
when subsea operations are to be performed during the drilling
operations and the installation of the satellite body 15
therewithin, and at later times during maintenance and workover
operations. A lower port 48 of the submersible work vehicle 36 is
connected with a rear compartment (not shown) within the shell
thereof to permit a diver to be released at an installation site if
one should be needed. The rear compartment is isolated from the
pilot's compartment, seen through the front view plate 50, so that
a diver after exposure to deep water can be kept in compression in
the rear compartment while the front compartment is maintained at
atmospheric conditions. This general type of submersible work
vehicle is well known in the art and specific vehicles of this type
are more fully described in the application Ser. No. 649,959, filed
June 29, 1967, of Warren B. Brooks, Charles Ovid Baker, and Eugene
L. Jones, and the references cited therein.
Now looking at FIG. 2, the interior of the satellite body 15, as
well as the satellite base template 28, are illustrated in more
detail. The internal equipment comprises that necessary for a high
gas-oil ratio, high-pressure field. The base template 28 comprises
an outer ring 51 to which are rigidly connected the plurality of
upstanding vertical well conductor pipes 34 through which
subaqueous wells have been drilled. As shown, a dual completion
wellhead 14 is mounted on the upper end of each of the well
conductor pipes 34 in completing each of the respective subaqueous
wells. The satellite body 15 is installed after the completion of
all of the wells drilled through the respective base template 28.
The satellite body 15 is shown to be cradled in a plurality of
radially extending spaced arms 41 fixed to the base template 28.
Threaded detent rods 43 extend through each of the arms 41 and
through the shell of the satellite body 15 into receivers 45 fixed
to the inner wall of the shell. The detent rods can be screwed into
and out of engagement with the receivers by means of the socket
wrench 42 of the submersible work vehicle 36. A hex nut 53,
terminating in a conical guide, is affixed to the outer end of each
detent rod 43. Support frames 47, having pillow boxes 49 in which
the detent rods 43 are journaled, allow the use of long detent rods
43 extending radially out beyond the well conductor pipes 34.
A water well 52 is shown as having been drilled through the center
of the base template 28 and is necessarily completed prior to the
installation of the satellite body 15. After all of the wells,
including the water well 52, have been completed, the satellite
body 15 is lowered into place and is leveled and locked into the
base template 28 in any suitable manner. There would be no reason
why one water well could not be drilled through one of the well
conductor pipes 34 on the ring 51 of the base template 28, if this
should prove more convenient. The only disadvantage would be the
elimination of one possible producing well. The W. F. Manning, U.S.
Pat. applications Ser. Nos. 663,799, now U.S. Pat. No. 3,504,740
and 663,798 entitled SUBSEA SATELLITE FOUNDATION UNIT AND METHOD
FOR INSTALLING A SATELLITE BODY WITHIN SAID FOUNDATION UNIT, and
SUBSEA SATELLITE FOUNDATION UNIT AND METHOD FOR INSTALLING A
SATELLITE BODY THEREWITHIN, respectively. disclose alternate
leveling and locking means as well as means for registering the
installed satellite with respect to encircling wellheads.
The water well 52 is designed to provide a heat source for a heat
exchanger unit (to be discussed below) to warm the produced fluids
after a pressure cut has been taken. The well water may also be
directed through radiators in the portions of the satellite body 15
in which personnel are present to raise the interior temperature of
that portion of the satellite body 15 above the ambient temperature
at the marine bottom. In deep water the temperature at the marine
bottom is in the range of 35.degree. to 45.degree. F., too cold for
a man to work for long periods unless he is heavily clothed.
Each of the submerged dual completion wellheads 14 has a pair of
upstanding tubing nipples (not shown), each being in fluid
communication with a producing zone. Each of the pairs of tubing
nipples is adapted to telescope into complementary passages of a
stab-over connector unit, generally designated 54, comprising a
pair of downwardly curving tubing sections 56 extending radially
outward from within the shell of satellite body 15 and terminating
in vertical lubricator sections 58. By means of the stab-over
connector units 54, the production and control passages extending
through the subaqueous wells are connected to manifolds within the
satellite body 15 for the combining of the produced fluids through
the satellite body 15 and/or for the injection of lift gas, or
other fluids utilized in secondary recovery procedures, from the
satellite body 15, to all or selected ones of the subaqueous wells.
As shown in the embodiment of FIG. 2, the stab-over connector units
54 are permanently fixed with respect to the satellite body 15.
Therefore, the satellite body 15 must be radially positioned quite
precisely so that the stab-over connector units 54 can register
with and telescope over the upstanding tubing nipples of the
respective wellheads 14.
An escape hatch 60 is formed within the upper end of the satellite
body 15 to permit the entry of an operator 62 from a diving bell or
travel chamber, as shown in the Townsend application Ser. No.
521,745, filed Jan. 19, 1966, now U.S. Pat. No. 3,391,734, or a
submersible work vehicle 38. The upper portion of the interior of
the satellite body 15, within which the operator 62 is shown
sitting at a panel 64, comprises a control section, generally
designated 66, from which various operations, not normally
programmed, may be controlled and from which stored information can
be retrieved. Below the control section 66 is a production section,
generally designated 68, containing the various equipment necessary
to separate and meter the produced fluids as well as to pump
treating fluids and tools through the various wells.
Beneath the floor of the production section 68 is a treating fluid
storage section, generally designated 70. The treating fluid
storage section 70 generally comprises an open-bottomed tank
defined by the floor 71 of the production section 68 and the outer,
generally cylindrical shell of the satellite body 15. The storage
section 70 can be partitioned to permit the storage of two or more
discrete well treating fluids needed in one or more operations.
Although some plumbing extends through the storage section 70, it
is substantially uncluttered to permit the storage of a large
quantity of well treating fluid.
Centrally located, within the production section 68, is a
cylindrical heat exchanger unit 74. Equiangularly spaced around the
heat exchanger unit 74 are a plurality of spherical separators 72.
The produced fluids normally flow through the shell of the
satellite body 15 by way of the tubing section 56 of the connector
units 54. From a tubing section 56 the fluid is directed by a
branch conduit 76 through an expansion valve (shown in FIG. 3 and
to be discussed with respect thereto) into an upper heat exchanger
manifold 78 located within the upper end of an insulated jacket 79
of the heat exchanger unit 74. Fluids, exiting from the manifold
78, flow down through a central pipe 80, leaving the heat exchanger
unit 74 near the lower end thereof by means of conduits 82 (one
shown) which lead the produced fluids into the individual
separators 72.
The separators 72 in the satellite station 10 are of the gravity
type to permit the separation of the gas from the oil without a
substantial temperature drop in the separators, avoiding hydrate
and paraffin deposition problems therewithin. A loss of 7.degree.
to 8.degree. F. would be normal with such equipment. With a
1-minute retention time within the separator, all of the free gas
will be removed, only the gas, dissolved in the liquid at the
separator pressure, remaining for the secondary, or final,
separation stage. While the separators planned for this
installation have no water knockout feature, provision for removal
of water from the oil could be provided if it was desirable at this
stage of production. The pressure at which the separators 72 are
designed to function may be governed by the depth at which the
satellite station 10 is located since it is desirable to have
sufficient pressure to lift the oil from the marine bottom to the
master station 20 on the surface. In very deep water the produced
oil may have to be lifted, at least in part, by power-driven pumps.
Where the satellite is connecting into a truck pipeline, rather
than being transported away by tanker, the output pressure of the
separators would be governed by the line pressure in the pipeline.
Where the wells are producing with a wellhead pressure of, for
example, 1,500 p.s.i. and the satellite station 10 is located in
2,000 feet of water, a 900-pound pressure drop will be taken, prior
to introducing the produced fluid into the separators 72, to obtain
a pressure of approximately 600 p.s.i., which would be that
necessary to drive the oil from the marine bottom to the surface.
Taking a pressure drop of 900 p.s.i. lowers the temperature of the
produced fluids by more than 50.degree. F. When considering a
10,000-foot well in which the produced fluids at the wellhead would
be at from 150.degree. to 170.degree. F., at 50.degree. F. the
resultant temperature would be well within the formation
temperature of hydrates and paraffins.
The heat exchanger unit 74, as shown more fully in FIG. 3, is
located in the process fluid circuitry between expansion chokes 84,
one located in each of the branch conduits 76, and the separators
72, providing a regulated flow of warm water as a heat source to
increase the temperature of the mixed oil and gas on the downstream
side of the choke 84 where a pressure cut has been taken, to
prevent hydrate formation, minimize excessive paraffin deposition
in the equipment, and restrict emulsion formation. The heat
exchanger unit 74 depends upon well water obtained from the
previously mentioned water well 52 (shown only in FIG. 2). The
water is produced through a normal type of oil well completion and
then flows through a variable choke 86 that regulates the flow and
downstream pressure. In an example, using a 10,000-foot water well,
the water at the upper end of the heat exchanger will also be in
the range of 150.degree. to 170.degree. F. The water from the well
52 is directed upward through a conduit 88, entering the insulated
cylindrical jacket at 79 of the heat exchanger unit 74, through the
upper end thereof. The water travels down through the interior of
the heat exchanger jacket 79, emerging from the lower end thereof
in outlet line 90 from which the water is dumped into the sea. As
the cold produced fluid passes into the manifold 78 within the
upper end of the heat exchanger unit 74, after passing through the
expansion choke 84 and a one-way valve 92, the fluid comes into
indirect contact with the warmer water flowing around the manifold
78. From the manifold 78, the produced fluid flows through a
helical coil 94 extending axially through the heat exchanger unit
74 and into a heat exchanger manifold (not shown) in the lower end
thereof, and then out of the jacket 79 through conduits 82, each
connected between one of the separators 72 and the lower heat
exchanger manifold. A temperature sensor 96 is installed in at
least one of the outlet lines 82 to act as a flow indicator and
monitor mechanism to control the increase or decrease of the water
flowing into the heat exchanger unit 74. By increasing or
decreasing the size of the choke 80, the water flow is regulated to
maintain the required temperature of the produced fluids entering
the separators 72 (FIG. 2). Such a system also acts as a resource
conservation in that large use of produced oil and/or gas to fire
such heater equipment as would be otherwise needed is not
required.
Looking back to FIG. 2, the liquids leave the separators 72 through
respective liquid outlet lines 98, connecting the separators 72
with liquid output manifold 100 centrally positioned around the
lower end of the heat exchanger unit 74. The combined produced
liquid from the plurality of separators 72 is directed from the
manifold 100 through a main oil outlet line 102 which is connected
to the input end of a respective shipping line 18.
The liquid is removed, at the lower end of each of the separators
72, by the respective line 98 so as to also drain off all the
water, entrained sand, and other impurities with the oil These
impurities might otherwise impede the action of the separator 72
and cause a premature malfunction thereof. A shutoff valve 104 in
each of the liquid outlet lines 98 is controlled in conjunction
with a float (not shown) within each of the separators 72, to
regulate the levels of the liquid within the separators 72. As
shown, a mechanical linkage is utilized between the float and the
valve 104. One of the electromechanical systems, well known in the
art, could be substituted for the mechanical linkage. A clean oil
line 108 is connected at a first end thereof into at least one of
the separators 72, above the lower end thereof, to pick up oil from
above the sediment level and below the low level of the liquid to
provide substantially clean oil (with dissolved gas) for pumping a
tool into and down through a selected well. Line 108, at the other
end thereof, is connected to a first inlet of three-way
two-position valve 110, the outlet of which is connected to the
inlet of a gas-driven turbine-pump 112 to provide the clean oil
under pressure to the TFL system. A second inlet of the three-way
two-position valve 110 is also connected to a line 114 having a
pickup head 116 in the fluid storage section 70 of the satellite
body 15 to provide a source of treating fluid for the turbine-pump
112. Gas under pressure, for driving the turbine portion of the
turbine-pump 112, is provided through a turbine gas supply line 118
extending from an auxiliary turbine (not shown in this view) which
is supplied with produced fluid tapped off, through lines 119,
upstream of the chokes 84. The clean oil under pressure from the
pump portion of the turbine-pump 112 is fed into a manifold (not
shown in this view). From this last-mentioned manifold, the oil is
pumped out, being selectively directed into one or more pressure
lines 122, each pressure line 122 being connected into a bypass
conduit section 124 just behind a TFL tool 126 stored therein. Each
bypass conduit 124 is directly connected to a curved tubing portion
56 of a connector unit 54 for pumping the TFL tool 126 therein into
the connected wellhead 14 and down a passage of the respective
well. The separated-out gas, leaving a separator 72 through an
upper pipe or gas outlet line 120, is combined with the
separated-out gas from the other separators 72 in a ring manifold
unit 128 encircling the insulated jacket 79 of the heat exchanger
unit 74.
The separated-out gas can be, in various instances, utilized in
production procedures, stored for eventual transportation to shore,
or disposed of at the site of the offshore production field. A main
outlet line 130, from the ring manifold 128, is shown directing the
gas out of the satellite station 10 for disposal through one or
more distant gas disposal wells (not shown) where the gas will be
injected into shallow sands underlying the marine bottom. A safety
regulator valve 132 is connected in the main outlet line 130 to
allow gas to be bled off through a flare line 134 to the master
floating station 20, if the pressure in the main outlet line 130
should rise above a predetermined value. If the gas obtained in the
primary stage of separation is to be either disposed of by flaring
or is to be stored for future transportation-to-shore facilities,
it is conducted to the master station 20 by shipping line (not
shown), as described with respect to the produced oil. At the
master station 20, the gas obtained from the primary stage of
separation is combined with the gas obtained from the secondary or
final stage of separation on the master station 20. If the gas is
to be flared, a flare stack is erected above the master station 20.
If the gas is to be stored, it is first compressed at the master
station 20 and then is pumped down to a portion of the storage tank
17 or to a separate storage tank (not shown) nearby. As noted
above, the gas from the primary separation stage may also be
utilized in production procedures, the most common of these
procedures being the utilization of the gas under pressure to
provide lift pressure in the producing formations. A gas injection
well for this purpose may be one of the wells drilled through the
ring 51 of the template 28, in which case a separated-out gas is
fed into the wellhead 14 through a respective one of the curved
tubing sections 56 of a stab-over connector unit 54, or the
injection well may be located at a distance from the satellite
station 10, in which case an interconnecting flowline having a
pressure regulator valve and a flare line, as described above with
respect to injecting the gas into shallow sand formations, will be
utilized.
FIG. 4 illustrates, in schematic form, a complete system, with the
exception of a storage means, for the production of a low gas-oil
ratio low pressure field. The fluid is produced in the portion of
the system designated as WELL AND WELLHEAD EQUIPMENT at the TD
(total depth) 136 of a representative well, generally designated
138. In the well 138 is a storm choke 140 placed at approximately a
3,000-foot depth, below the normal lower limit of paraffin
deposition, for safety purposes. Quarter-turned manually operated
valves 142 are mounted on the wellhead 14 outside the satellite
body 15 where they are easily accessible for operation by a man,
robot, or a manned craft such as the underwater submersible work
vehicle 36 illustrated in FIG. 1. In some instances, it may be
desirable to utilize remotely actuatable valves in place of the
manually operated valves 142. A high-low safety valve 144, also
mounted on the wellhead 14 outside the satellite body 15, will
automatically close should the pressure in the well 138 exceed a
specified high pressure or drop below a specified low pressure.
From the upper end of the wellhead 14, the fluid is directed
through connector unit 54 to the portion of the wellhead equipment
within the satellite body 15 where one or more TFL tools are stored
in a storage chamber, designated by block 146. (A TFL storage
device and a paraffin cutting tool, designed to be stored
therewithin, are fully described in the patent application Ser. No.
579,571, of James T. Dean, entitled STORAGE SYSTEM FOR TFL TOOLS,
filed Sept. 15, 1966, now U.S. Pat. No. 3,396,789. In FIG. 3 of the
Dean patent, the incorporation of the described storage device in a
fluid circuit for automatically maintaining a subsea well is
shown.) The TFL storage chamber 146 is located in the previously
described bypass conduit section 124, as is a TFL tool control
valve 148, which remains closed except during TFL maintenance
and/or testing. The branch conduit 76 contains a pressure indicator
150, an orifice meter 152, and a production wing valve 154. The
production wing valve 154 is normally open while the well 138 is
producing and closed during TFL operations. The branch conduit 76,
through which the produced fluid generally flows, provides a path
around the TFL storage chamber 146 and the closed control valve
148. When the well 138 is producing, the fluids flow from TD point
136, up through the storm choke 140, and the series of valves 142
and 144, of the wellhead 14, into the branch conduit 76. The
pressure and flow rate of the fluid at the wellhead 14 are
monitored at all times by the pressure indicator 150 and the
orifice meter 152, respectively, and representative signals are
transmitted to, and recorded within, the control section 66 of the
satellite station 10.
The produced fluid flowing through the branch conduit 76, past the
interconnection with the bypass conduit section 124, leaves the
portion of the system designated in the schematic diagram as
WELLHEAD AND WELLHEAD EQUIPMENT and enters the portion designated
PRODUCTION SYSTEM through a rotary variable choke 156. As the fluid
passes through the variable choke 156, the pressure is lowered from
that at the wellhead 14 to a pressure just above that necessary to
drive the fluid from the marine bottom to the surface. From the
rotary choke 156, the produced fluid is directed through a check
valve 157 into a collector manifold 158. Branch conduits 76', each
having a check valve 157', also shown as leading into the collector
manifold 158, are connected to the wellhead equipment of the
various wells encircling the satellite station 10. A pressure
sensor 160 is mounted in the collector manifold 158 to monitor the
pressure therewithin, a signal representative of which is
transmitted to and recorded within the control portion of the
satellite station 10. The rotary variable choke 156 is controlled
in response to the pressures indicated by the pressure sensors 150
and 160. Three gravity separators 72 are connected, in parallel, to
the collector manifold 158 through inlet lines 162, each having a
shutoff valve 163 therewithin. The liquids, including oil and
water, exit for the most part through lines 98 which empty into
liquid collector manifold 164. This manifold corresponds to the
circular manifold 100 shown in FIG. 3. From the liquid collector
manifold 164, the oil exits through the outlet line 102 and is
transferred to storage through shipping line 18 after passing
through a flowmeter 166. A clean oil outlet line 108, as previously
discussed, extends from a point within each of the separators 72,
from where substantially clean pure oil can be obtained, to a
manifold 175, which empties in turn into the upstream end of a line
174 connected at its downstream end to an inlet port of a three-way
two-position valve 180 in the TFL Fluid Supply System. The gas
accumulating in the separators 72 passes out through a high liquid
shutoff valve 168 located in the upper end of each of the
separators 72, into a gas outlet line 120, which empties into a gas
collector manifold 170. The major portion of the gas leaves the
manifold 170 through the main gas outlet line 130, passing through
an orifice meter 172, and is transferred to storage or disposal
means. By disposal means is meant "flaring" or "shallow sand
injecting" as previously discussed. The fluid pressure supply line
119 is connected between the bypass conduit 124, at one end
thereof, and a manifold 159 at the other end. Lines 119' connect
the bypass conduits of the other wells, which flow through the
satellite station 10, with the manifold 159. The inlet of an
auxiliary separator 161, where only a small pressure cut is taken,
is in fluid connection with the manifold 159 through a
high-pressure line 165. The turbine gas supply line 118 is
connected between the gas outlet of the auxiliary separator 161 and
the inlet of the turbine of the turbine-pump 112 of the TFL FLUID
SUPPLY SYSTEM to supply high pressure gas to the pump portion of
the turbine-pump 112. The pressure-reduced gas, from the gas
discharge, or outlet, of the pump portion of the turbine-pump 112,
is directed through a line 167 into the gas collector manifold 170.
The liquids separated out in the auxiliary separator 161 are
directed through line 169 into the liquid collector manifold 164.
The purpose of the turbine-pump 112 is discussed below. If one of
the separators 72 becomes plugged, the liquid will fill that
separator and force the respective valve 168 to close. With this
possibility in mind, the separators 72 are designed so that any two
are all that are required to process the total amount of fluid
passing through the satellite station 10. With the same rate of
flow of gas through the orifice meter 172, and liquid through the
flowmeter 166, a signal warning of an increase in pressure will be
transmitted to the control portion 66 of the satellite station 10
from the sensor 160 in the manifold 158, indicating that there is a
problem. Furthermore, the closing of a valve 168 can be made to
actuate an electric switch, which in turn will provide a signal
indicating which separator is malfunctioning. The production stream
through the plugged separator 72 would then be cut off by closing
the respective shutoff valve 163 so that the respective separator
72 can be serviced by personnel within the satellite station
10.
The portion of the schematic diagram designated as the TFL Fluid
Supply System contains a fluid storage means 178, which corresponds
to the open-bottomed fluid storage section 70 of the satellite
station 10 as shown in FIG. 2. The storage means 178 is connected
to a first inlet port of the three-way two-position valve 180
through a line 190 having a salt water sensor 188 therein to
provide a signal in the control section of the satellite station 10
indicating that the storage means 178 is empty of treating fluid
and now contains only salt water. The other inlet port of the
three-way two-position valve 180, as previously discussed, is
connected to a source of clean oil through the line 174 extending
from the manifold 175 in the PRODUCTION SYSTEM portion of the
schematic diagram. The outlet of the three-way two-position valve
180 is operatively connected to the inlet of the pump portion of
the turbine-pump 112, the outlet of the pump portion of the
turbine-pump 112 being connected to an inlet of a manifold 182
through a conduit 184. The power for driving the pump portion of
the turbine-pump 112 is provided by gas under pressure obtained
through the line 118 from the auxiliary separator 161, which is fed
with produced fluid at wellhead pressure from the Well and Wellhead
Equipment portion of the system as previously outlined. By opening
and closing a valve 176 in the line 118, the operation of the
turbine-pump 112 may be controlled. From the manifold 182 the clean
oil and/or the treating fluid, under pressure, is pumped through
one or more of the outlet lines 192 at a time, each of the outlet
lines 192 having a check valve 194 and a selectively actuated
cutoff valve 196 therein from which the fluid is directed through
the respective line 122 into the Well and Wellhead Equipment
portion of the schematic diagram where it is directed into the
bypass conduit 124 between the TFL tool storage chamber 146 and the
shutoff valve 148. Outlet lines 192' , each having a one-way check
valve 194' and a shutoff valve 196' therein, are connected to the
bypass conduits of the Well and Wellhead Equipment portions of the
other wells (not shown) producing through the respective satellite
station 10.
To commence a TFL maintenance and/or testing procedure, valves 148
and 154 in the Well and Wellhead Equipment portion would both be
closed. The shutoff valve 176, in the TFL Fluid Supply System,
connected to the input of the turbine-pump 112 would be open to
activate the turbine portion. For paraffin removal, for instance, a
paraffin solvent and corrosion inhibitor stored in the storage
means 178 would first be drawn into the input of the pump section
of the turbine-pump 112 by the proper positioning of the valve 180.
After pumping approximately one barrel of treating fluid through
the valve 180, the position of the valve would be changed so that
the oil from line 174 would then be supplied to the pump portion of
the turbine-pump 112. One or more of the valves 196, 196' would be
open to permit the fluid driven by the turbine-pump 112 to exit
from the header 182 through a line 122 to apply fluid pressure in
the section of the bypass conduit 124, of the Well and Wellhead
Equipment portion, between the valve 148 and the storage means 146.
With the valve 148 closed, the fluid driven through line 122 into
the bypass conduit 124, behind the storage means 146, will cause a
paraffin cutting tool 126 positioned within the storage means 146
to be propelled down through the curved tubing section 56 of the
connector unit 54 and down through the wellhead 14 of the
respective well 138. The piston section of the tool 126 is not
completely sealed within the tubing of the well 138 in which it
moves so that by the time the tool is down in the well, at the
lower end of the paraffin deposition zone, all of the treating
fluid is in the well ahead of the tool. When the tool 126 reaches
the end of its travel, above the storm choke 140, the valve 176, in
the TFL Fluid Supply System portion, controlling the turbine-pump
112, would be shut causing the turbine-pump 112 to cease operation.
The shutoff valve 148 in the bypass conduit 124 is then opened
causing the TFL tool 126 to be returned up the well 138 by the
fluid being produced, which now is directed into the downstream
portion of the branch conduit 76 through the bypass conduit 124.
When the TFL tool 126 has reentered the storage chamber 146, an
indication of this condition will be given in the control section
66. A switching means providing this function is shown in the Dean
U.S. Pat. No. 3,396,789, discussed above. At this time, the valve
148, in the bypass conduit 124, will be shut and the valve 154, in
the branch conduit 76, will be reopened, returning the well to
production through the branch conduit 76. All of the previously
described steps can be sequentially performed by an operator in the
control section 66 of the satellite station 10, by remote control
from the floating master station 20, or by a programmed computer,
or by a combination of the aforementioned methods.
FIG. 5 illustrates a modification in which an electric motor 198 is
utilized for driving a pump 200. With the substitution of the
electric motor 198 and the pump 200 for the turbine-pump 112 (shown
in FIG. 4), the gas line 118 is eliminated and the only exit line
from the manifold 170 is the line 130. The remainder of the TFL
Fluid Supply System (shown in FIG. 5) is identical to that shown in
FIG. 4, therefore being a storage means 178' connected to one inlet
of a three-way two-position valve 180' through a line 190' having a
salt water sensor 188' therein. The other inlet of the three-way
two-position valve 180' is connected to the line 174 as shown in
FIG. 4 which is connected at the other end thereof to a clean oil
source in the separators 72. The outlet of the three-way
two-position valve 180' is operatively connected to the inlet of
the pump 200. The outlet of the pump 200 is in turn connected,
through the line 184, to the header 182, as shown in FIG. 4. The
identical procedure would be followed with the exception that
electrical power would be used to operate the electric motor 198 to
drive the pump 200.
FIG. 6 shows the modified Production System to be used with the
typical high gas-oil ratio high pressure well. This modified
Production System is utilized with the Well and Wellhead Equipment
portion and TFL FLUID SUPPLY SYSTEM portion of the schematic
diagram of FIG. 4. As the produced fluid is directed from the
branch conduit 76 through a variable choke 156' and a check valve
157', it is collected in a primary manifold 202 (generally similar
to the manifold 78 shown in FIG. 2). The produced fluid in the
manifold 202, having a high gas content, is now quite cold due to
expansion in the choke 156'. This cold fluid passes out of the
manifold 202 through a line 204 extending through a heat exchanger
unit 206 (corresponding to the heat exchanger unit 74 of FIG. 2).
The fluid, warmed up in the heat exchanger unit 206, enters a
secondary manifold 208 from which it is directed into three
separators 72'. A pressure sensor 209 and a temperature probe 238
are located in the secondary manifold 208. From the separators 72'
the major part of the produced liquid is collected in the manifold
164' after which it is removed through a line 102' having a
flowmeter 166' therein, the outlet of the flow meter 166' being
connected to the inlet of a shipping line 18 connecting the
satellite station 10 with a distant storage facility. Again, clean
oil is picked up by lines 108' and is directed through line 174' to
the clean oil supply inlet of the three-way two-position valve, as
shown in FIG. 4. The gas exiting from the separators 72', through
lines 120', is collected in the manifold 170' from which it is, in
the main, transmitted through a line 210 from the orifice meter
172, through a safety pop-off valve 214, to a gas injection well
212, for disposal in shallow sand formations. The gas enters the
injection well 212 through the wellhead 216 thereof having a
high-low fail-safe valve 218 and a manually operated valve 220.
There is also a storm choke 222 beneath the marine bottom in the
injection well 212. If the back pressure in the shallow sand
formations being used for disposal should rise above a preset limit
of the pop-off safety valve 214, the gas will be directed instead
through a line 134' to the surface where it will be flared. To heat
the cold fluids within the heat exchanger unit 206, warm water, at
150.degree. to 170.degree. F., is obtained from the TD 228 of a
water injection well 226 producing through a wellhead 227
comprising a manual valve 230 and an automatic setting valve 232,
and a rotary choke 234 having a pressure differential indicating
device 236 located thereacross. The warm water flows through the
heat exchanger unit 206, past a series of coils 205, in the line
104. From the heat exchanger unit 206, the then cooled water is
directed out through line 240 into the surrounding water near the
marine bottom. The rotary choke 234 is operated automatically in
response to a temperature signal obtained from the temperature
probe 238 previously described as located in the primary manifold
208 downstream of the heat exchanger unit 206. As the temperature
sensed by the temperature probe 238 decreases, the choke 234 is
opened further. If the temperature indicated reaches a specified
low level, the satellite station 10 is completely shut in.
FIG. 7 is a schematic diagram of another modification of the
Production System of FIG. 4, for a typical medium gas-oil ratio,
medium pressure well. A well is produced in the same manner as in
the previous two examples utilizing the same type of well and
wellhead equipment. In this modification the fluid, entering the
Production System portion through a branch conduit 76, is directed
through a one-way valve 241 into a heat exchanger conduit 242 which
traverses a heat exchanger unit 244. The produced fluid having been
produced from a TD of 10,000 feet makes its first pass through the
heat exchanger unit 244 at a temperature of 150.degree. to
170.degree. F. Upon exiting from the heat exchanger unit 244, a
pressure cut is taken through a variable choke 245. The now cold
fluids are passed back through the heat exchanger unit 244 by the
traversing heat exchanger conduit 245 to raise the temperature in
the expanded fluid to a prescribed minimum to prevent hydrate
formation and wax deposition. From the conduit 245 the fluid passes
into a collector manifold 246 containing a pressure sensor 238' and
temperature probe 209'. In collector manifold 246, the fluid from
the heat exchanger conduit is combined with the pressure cut fluid
from the other wells of the satellite stations through heat
exchanger lines 245'. The fluid from each well has previously been
directed through the heat exchanger unit 244, had a pressure cut
taken and then been passed back through the heat exchanger unit 244
through separate conduits. The combined fluid in the collector
manifold 246 is directed out through a conduit 247, making a final
pass across the heat exchanger unit 244 into another collector
manifold 248. From the manifold 248, the fluid is divided into
separate streams and directed into separators 72' through lines
249. The remainder of the fluid system is identical to that already
discussed with respect to FIG. 4. If the temperature indicated by
the temperature probe 209' decreases below a specified value, all
the wells of the satellite station 10 are shut in.
The schematic diagrams of FIGS. 4-7 illustrate examples of systems
to be used in specific cases. However, the features of the various
Figures can be combined in different arrangements to suit various
conditions. For instance, the electric-motor-drive-pump 200 of FIG.
5 could be used with the modifications of FIGS. 6 and 7.
FIG. 8 illustrates a modified satellite station 10', similar to the
satellite station 10 of FIGS. 1 and 2, having the added advantage
of being able to be installed prior to completing any of the
production wells through the ring 51' of the base template 28'. In
this embodiment, instead of using cradling arms as illustrated in
FIG. 2, the satellite body is held in the satellite base 28' by a
central sleeve 250 depending from the lower end of the satellite
body 15' and automatic spring-loaded latches (not shown) over the
upper end of the well conductor pipe of the water well 52. The
latches can be disabled by a hydraulic pressure applied through the
conduit 252 extending between a manifold 254, forming a portion of
the framing of the base template 28', at the inner end, and a
quick-disconnect coupling section 256, at the outer end. The outer
end of the conduit is supported by a skeletal frame 258 to displace
the coupling section 256 outward of the well conductor pipes 34'.
The arrangement of the equipment within the satellite body 15' is
substantially the same as the arrangement within the satellite body
15 of the earlier discussed embodiment with the exception of the
orientation of the TFL tool 126 and the associated hydraulic
circuitry. In this instance, the connector units 54' are not
permanently attached to the satellite body 15' but instead are
stabbed-over tubing nipples 260 extending vertically out of the
upper end of the satellite body 15'. When a well is to be completed
through one of the upstanding well conductor pipes 34', a wellhead
14' is first mounted on the respective well conductor pipe 34'. A
connector unit 54' is later lowered from the surface to make the
connection between the wellhead 14' and the satellite body 15'. The
connector unit 54' consists of a curved tubing section 56' and a
vertical lubricator section 58'. The lower end of the lubricator
section 58' is stabbed over the tubing (not shown) extending
vertically out of the upper end of the wellhead 14', while the
outer vertical free ends of the curved tubing section 54' stabs
over the respective ones of the upstanding tubing nipples 260
extending out of the upper end of the satellite body 15'. In this
manner, with each connector section 54' being individually engaged
between the wellhead 14' and the respective upstanding tubing
nipples 260, greater tolerances can be allowed in installing the
satellite body 15'. Furthermore, an individual well can be produced
through the satellite station 10' while the remaining wells are
still being drilled and completed. The vertical orientation of the
tubing nipples 260 extending vertically into the satellite body 15'
presents no problem, each of the TFL storage chambers 146' is
reoriented into a vertical position so as to be coaxial with the
respective tubing nipples 260. The vertical position of the storage
chamber 146' permits the TFL tool 126' stored therewithin to move
easily into respective tubing nipples 260 so that it can be pumped,
under fluid pressure, through a full 180.degree. bend in the tubing
sections 56' of the connector unit 54'. Such a bend, of
180.degree., will not present any insurmountable problems requiring
only that the wells be spaced out far enough from the satellite
body 15' to obtain a 5-foot radius bend in the conduit. Stab-over
connections, as discussed in this application, are more fully
described in the Manning application Ser. No. 663,799 now U.S. Pat.
No. 3,504,740.
Although the present invention has been described in connection
with details of the specific embodiments thereof, it is to be
understood that such details are not intended to limit the scope of
the invention. The terms and expressions employed are used in a
descriptive and not a limiting sense and there is no intention of
excluding such equivalents in the invention described as fall
within the scope of the claims. Now having described the apparatus
and methods herein disclosed, reference should be had to the claims
which follow.
* * * * *