Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FLOW TEE ASSEMBLY FOR OIL WELLS
This invention is in the field of oil field equipment, and in particular
pumping equipment
and related mechanisms used for producing oil from a well.
BACKGROUND
Common oil well pumping equipment includes a polish rod connected at a top end
1o thereof to a drive and at a bottom end thereof to a pump located in an
underground
reservoir of production fluid. The producing oil well comprises a cased hole
extending
from the surface down to the reservoir and sealed at the surface by a wellhead
assembly.
A production tube is anchored to the wellhead assembly at the top of the cased
hole and
extends down to the pump where it is connected to the pump output such that
production
fluid moves up the tube. A flow tee is connected to the tap output end of the
production
tube and to a lateral production conduit that carries the production fluid
laterally from the
well to a pipeline, surface storage tank, or like facility.
The polish rod passes through the wellhead assembly and flow tee into the top
end of the
2o tube and down through the tube to drive the well. The production fluid
passes up through
the annulus formed between the inner wall of the production tube and the
outside of the
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polish rod. The polish rod may rotate or move up and down, depending on the
type of
system in use, but in any event the polish rod is moving as it passes through
the wellhead
assembly into the tube, and since the production fluid is moving up the tube
under
pressure, the polish rod must be sealed to the wellhead assembly to prevent
leaks. A
stuffing box is thus typically provided above the flow tee to seal against the
outside of the
moving polish rod. The stuffing box is exposed to the flowing production fluid
which
often contains a sign~cant amount of abrasive sand which gets between the
packing of
the stuffing box and the polish rod, and causes wear and failure of the
stuffing box
resulting in production fluid leaking out of the stuffing box.
to
SUM1VIARY OF THE INVENTION
It is an object of the present invention to provide a flow tee apparatus that
overcomes
problems in the prior art.
t5
The present invention provides, in a first embodiment, a method of reducing
the wear on
the stuffing box by diverting flow through the flow tee toward the lateral
production
conduit extending substantially horizontally from the flow tee.
Conventionally, the
production fluid flows vertically up the production tube into the flow tee,
where it exerts
20 pressure directly on the bottom of the stuffing box as it changes direction
to flow
horizontally out through the lateral production conduit. By diverting the flow
of
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production fluid horizontally toward the lateral production conduit prior to
the production
fluid contacting the bottom of the stuffing box, the force urging production
fluid and sand
into the stuffing box is reduced, with a resulting reduction in wear and
failure of the
stuffing box.
s
Conventional efforts to improve the life and function of the stuffing box have
been
directed to the stuffing box itself, rather than to the flow tee below the
stuffing box.
The present invention, in a second embodiment, provides a flow tee apparatus
that
includes at least one diverter member oriented and configured such that the
polish rod
passes through the center thereof, but the production fluid flowing up the
annulus
between the polish rod and the inner wall of the production tube strikes the
diverter
member and is directed toward the lateral production conduit.
DESCRIPTION OF THE DRAWINGS
While the invention is claimed in the concluding portions hereof, preferred
embodiments
are provided in the accompanying detailed description which may be best
understood in
conjunction with the accompanying diagrams where like parts in each of the
several
2o diagrams are labeled with like numbers, and where:
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Fig. 1 is a schematic side view of a flow tee assembly of the invention for
diverting the flow of production fluid away from the stuffing box and toward a
lateral production conduit;
Fig. 2 is a schematic sectional view along line 2-2 in Fig. 1.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS:
Fig. 1 schematically illustrates a flow tee assembly 1 of the present
invention, and the
orientation of the flow tee apparatus 1 in a typical well head. The flow tee
assembly 1 is
mounted under the stuffing box 3 and is connected to the top output end of the
production
tube 5. A polish rod 7 extends downward through the stuffing box 3, flow tee
assembly
1, and production tube 5. A lateral production conduit 9 extends horizontally
from the
flow tee assembly 1. The connections of the various parts are by conventional
means
such as male/female threads, flanges, or the like, and are not illustrated.
Lower and upper diverter plates 11 and 13 are oriented at opposite angles as
illustrated in
Fig. l, and are configured as illustrated in Fig. 2 to partially close the
annulus 15 between
the polish rod 7 and inner wall of the flow tee assembly 1. Production fluid,
as indicated
by the arrows in Fig. l, thus flows up the annulus 17 between the inner wall
of the
production tube 5 and the polish rod 7 into the bottom of the flow tee
assembly 1 and
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contacts the lower diverter plate I1 and is diverted to the right side of the
flow tee
assembly 1 where it passes through the gap 19 between the end of the lower
diverter plate
11 and the wall of the flow tee assembly 1. The production fluid then flows
upward
adjacent to the right wall of the flow tee assembly 1, and contacts the upper
diverter plate
13 and is diverted toward the opening on the left side of the flow tee
assembly 1 that is
connected to the lateral production conduit 9 where it passes into the lateral
production
conduit 9 and out to transport or storage.
By diverting the flow of production fluid away from the bottom of the stuffing
box 3, less
1o sand will be forced into the stuffing box 3. It is also contemplated that
the size of the
lateral production conduit 9 should be larger than the annulus 17 between the
inner wall
of the production tube 5 and the polish rod 7, such that the production fluid
will flow
readily into the lateral production conduit 9, and back pressure in the flow
tee assembly 1
is minimal.
It is contemplated that other means of diverting the production fluid toward
the lateral
production conduit 9 and away from the bottom of the stuffing box 3 could be
devised by
those skilled in the art and all such means are contemplated to fall within
the scope of the
present patent. For example by providing only the upper diverter plate in the
flow tee
assembly 1 of Fig. 1, the flow of production fluid will be diverted somewhat,
with a
consequent reduction in sand and the like being forced into the stuffing box
3. By
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providing lower and upper diverter plates 11 and 13, the diversion is
improved, and the
reduction is increased.
The foregoing is considered as illustrative only of the principles of the
invention.
Further, since nurnerous changes and modifications will readily occur to those
skilled in
the art, it is not desired to limit the invention to the exact construction
and operation
shown and described, and accordingly, all such suitable changes or
modifications in
structure or operation which may be resorted to are intended to fall within
the scope of
the claimed invention.
