U.S. patent number 3,735,815 [Application Number 05/163,855] was granted by the patent office on 1973-05-29 for method and apparatus for producing multiple zone oil and gas wells.
This patent grant is currently assigned to Dresser Industries, Inc.. Invention is credited to Nijah F. Myers.
United States Patent |
3,735,815 |
Myers |
May 29, 1973 |
METHOD AND APPARATUS FOR PRODUCING MULTIPLE ZONE OIL AND GAS
WELLS
Abstract
Two or more oil and gas zones are produced by allowing
production from at least one zone to drain down to a common chamber
where production from the zones is comingled and lifted to the
earth's surface. A separate gas bent is provided for each zone to
the earth's surface.
Inventors: |
Myers; Nijah F. (Oklahoma City,
OK) |
Assignee: |
Dresser Industries, Inc.
(Dallas, TX)
|
Family
ID: |
22591868 |
Appl.
No.: |
05/163,855 |
Filed: |
July 19, 1971 |
Current U.S.
Class: |
166/313;
166/105.5; 166/189 |
Current CPC
Class: |
E21B
43/14 (20130101); E21B 43/122 (20130101); E21B
43/38 (20130101) |
Current International
Class: |
E21B
43/12 (20060101); E21B 43/38 (20060101); E21B
43/34 (20060101); E21B 43/14 (20060101); E21B
43/00 (20060101); E21b 043/00 () |
Field of
Search: |
;166/313,189,105.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Prorated Production from Multiple Zones Through a Single Tubing
String, Journal of Petroleum Technology page 54, 1967..
|
Primary Examiner: Leppink; James A.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. In multiple zone well production apparatus comprising:
a well casing passing through upper and lower producing zones in a
well bore, said casing having upper and lower openings through
which production from said upper and lower zones can flow,
respectively, into the well casing;
barrier means in said casing between said upper and lower openings,
said barrier means having a plurality of longitudinal passages and
having means in one of said passages for securing a first tubular
string extending to the top of the well bore to said barrier
means;
chamber means below said barrier means, said chamber means
communicating with said lower zone;
tubular means connected to said barrier means and said chamber
means, said tubular means communicating with said one passage for
conducting fluid in the lower zone to said first tubular
string;
a second tubular string below said barrier, said second tubular
string connecting another of said passages to said chamber for
conducting fluid from said upper zone to said chamber;
means for lifting fluid from said chamber to the top of the well
bore;
a third said passage in said barrier means; and
a third tubular string communicating with said third passage and
extending to the top of the well bore for conducting gas from the
lower zone to the top of the well bore.
2. In multiple zone well production apparatus adapted to be set in
a well casing passing through upper and lower producing zones in a
well bore, the casing having upper and lower openings through which
production from the upper and lower zones can flow, respectively,
into the well casing, the apparatus comprising:
barrier means in the casing between the upper and lower
openings;
said barrier means having a first longitudinal passage with means
for securing a first tubular string to said barrier means, said
first tubular string extending to the top of the well bore;
chamber means below said barrier means, and chamber means
communicating with said lower zone;
tubular means connected to said first longitudinal passage in said
barrier means and said chamber means for conducting fluid in the
lower zone to said first tubular string;
a second longitudinal passage in said barrier;
a second tubular string below said barrier, said second tubular
string connecting said second passage to said chamber means for
conducting fluid from said upper zone to said chamber means;
means for lifting fluid from said chamber means to the top of the
well bore;
a third said passage in said barrier means; and
a third tubular string communicating with said third passage and
extending to the top of the well bore for conducting gas from the
lower zone to the top of the well bore.
3. Apparatus according to claim 2 wherein said chamber means is
located at least as low as the lower zone.
4. Apparatus according to claim 2 wherein said chamber means is
located below the lower zone.
5. Apparatus according to claim 2 wherein said means for lifting
fluid comprises a plunger pump.
6. Apparatus according to claim 2 wherein said means for lifting
fluid comprises gas lift means.
7. The method of producing liquid from a well bore passing through
two producing zones with barrier means in the well bore between the
zones comprising the steps of:
passing liquid from the upper zone into a chamber located below the
barrier means;
passing liquid from the lower zone into said chamber;
lifting liquid from said chamber to the top of the well bore;
and
venting gas from the lower zone to the top of the well bore.
8. The method of producing liquid from a well bore passing through
two producing zones comprising the steps of:
draining liquid from the upper zone into a chamber located at least
as low as the lower zone;
draining liquid from the lower zone into said chamber;
lifting liquid from said chamber to the top of the well bore;
and
venting lower zone gas to the top of the well bore through a
tubular member.
9. The method of claim 8 comprising the additional step of
measuring the volume of gas produced from the lower zone.
10. The method of producing liquid from a well bore passing through
two producing zones comprising the steps of:
draining liquid from the upper zone into a chamber located at least
as low as the lower zone;
draining liquid from the lower zone into said chamber;
lifting liquid from said chamber to the top of the well bore;
and
venting the upper zone gas to the top of the well bore.
11. The method of claim 10 wherein said step of venting the upper
zone gas comprises venting the upper zone gas to the top of the
well bore through the casing annulus.
12. The method of claim 10 comprising the additional step of
measuring the volume of gas produced from the upper zone.
Description
BACKGROUND OF THE INVENTION
The field of the invention relates to multiple zone wells which
require one or more of the zones to be artificially lifted. This
method and apparatus is suitable for wells producing oil,
saltwater, fresh water or other liquid with or without natural gas
in one or more of the zones.
A prior art device is shown in U.S. Pat. No. 2,618,339. This device
discloses apparatus for comingling multiple zone well production.
The apparatus is arranged in the well so that the upper zone
production travels down the casing and allows gas entrained in the
liquid to break out and pass to the surface. No provision is made,
however, for separate handling of the lower zone gas. The device
does not provide a check valve to prevent high pressure in the
lower zone from passing through the tool and into the upper zone
where such liquid may not be recoverable. Also, the pump intake is
positioned above the packer which is not necessarily a desirable
position in the case of a low pressure, low production, lower zone.
A further prior art device, shown in U.S. Pat. No. Re 26,319,
discloses a flow control device for producing multiple zone wells
which have sufficient drive in the producing zones to cause the
fluid to flow into the well bore where it is metered through
predetermined orifices and comingled at a point whereby gas from a
higher pressure zone can assist in lifting production from a lower
pressure zone. An additional prior art device, shown in U.S. Pat.
No. 3,509,941, discloses a confluent production apparatus wherein
one zone or the other or both zones can be produced. Check valves
are provided in the passages from each zone so that flow is
prevented between the zones but no provision is made for separate
handling of gas from the lower zone nor is the position of the pump
intake desirable, because the pump intake is above the packer
between zones and is, therefore, above the lower zone. An
additional prior art device, shown in U.S. Pat. No. 3,559,740
discloses method and apparatus for use with hydraulic pump and
multiple completion well bores. This patent discloses a separate
vent for the lower zone gas. It also discloses various selector
heads which provide production from either one or both of the zones
and provides for chokes to meter production from the zones.
However, none of the prior art devices show or disclose apparatus
which adequately drains production from zones in a multiple zone
well; wherein one or more zones have such low pressure that
production is reduced in total or in part by reason of hydrostatic
pressure in a column of the liquid in the well bore being lifted
from the zone to a pump intake, and also provide separate venting
of gas from each zone.
It is, therefore, a primary object of this invention to provide a
multiple zone producing arrangement which provides for lifting of
one or more low pressure zones.
It is a further object of this invention to provide a multiple zone
production apparatus which provides separate venting of the gas
from each zone.
It is a further object of this invention to provide a multiple zone
production apparatus which provides for separate measurement of the
gas from each zone.
It is a further object of this invention to provide a multiple zone
production apparatus which conserves hydrocarbons and prevents loss
of fluid or gas from a high pressure zone into a lower pressure
zone in the same well bore.
SUMMARY OF THE INVENTION
These and other objects of this invention are fulfilled, broadly,
with a multiple zone producing apparatus and method which provides
a chamber for comingling fluid from the production zones at a point
below the upper zone. As an additional feature, the comingling
takes place beneath the lower zone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view partially in elevation and partially in section of
a well bore with well casing and apparatus according to this
invention which may be used to produce a multiple zone well in
accordance with this invention.
FIG. 2 is an alternative embodiment of FIG. 1 showing gas lift
means to produce the liquid from the well.
FIG. 3 is an alternative embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment, FIG. 1, casing 10 is shown in a well
bore through two producing horizons 12 and 14. Perforations 16 and
18 in the upper and lower producing zones, respectively, allow
production from these zones to flow into the casing 10. A packer 20
is sealingly engaged with the casing 10 between the perforations 16
and 18 to isolate the producing zones from each other. Gas from the
upper zone 12 flows into the casing 10 through perforation 16 and
is designated UG. Gas may be dissolved and/or entrained in the
upper zone liquid production designated U. Some of the upper zone
gas UG can break out of the liquid U and flow upward through the
casing 10 to be gathered from outlet 22 in the casing at the top of
the well bore. The volume of UG gas passing through this outlet can
be measured and then used for gas lift purposes, sold into a
pipeline, or used for another purpose. Production LG from lower
zone 14 flowing into casing 10 through perforation 18 may flow
upward into a passage 24 in a head or barrier portion 26 connected
to packer 20. This gas can then pass into a tubing string 28 which
extends to the top of the well bore where it may be measured and
disposed of in one of the ways mentioned for the UG gas. Liquid
production U from the upper zone can gravitate or flow downward
through passage 30 and head 26 and thence through tubing 31
connected to passage 30. A check valve 32 is incorporated in the
flow path for liquid U permitting flow into chamber 34 from the
upper zone but preventing back flow from chamber 34 to passage 30.
Lower zone liquid production L flows into casing 10 through
perforation 18 and enters chamber 34 through ball check valve 36
which prevents back flow from chamber 34 to perforation 18. A pump
38 is positioned in the tubing string 40 immediately above chamber
34 where production U and L are comingled and admitted to the pump
intake and lifted to the surface. Pump 38 may alternatively be a
plunger pump operated by sucker rods or a hydraulically operated
piston pump which has a piston-type motor section that operates a
piston-type pump. A hydraulic pump would require an additional
tubular conduit extending from the surface of the well bore to the
pump. The additional pipe could be located inside tubular string 40
as illustrated in FIG. 2 as tubing string 42 which is illustrated
for gas lift purposes. The additional string for the hydraulic pump
could alternately be located beside tubing string 40 in a manner
well known by those with skill in the art.
Referring to FIG. 2, an apparatus used in gas lifting a well
according to this invention is illustrated. A concentric tubing
string 42 is run inside the long tubing string 40 and is used to
inject gas through gas lift valves 44 to lift the comingled liquids
L and U from chamber 34. In this embodiment, gas to lift the
comingled fluid is injected at 46 into tubing 40 and is admitted
through gas lift valves 44 into the concentric tubing string 42 to
lift the comingled fluid through concentric tubing string 42. A
packing arrangement 48 which may be a landing nipple or a packer or
other suitable device is used to seal between tubing string 40 and
tubing string 42 to permit a gas lift arrangement. Other
arrangements for gas lift are well known to those with skill in the
art and any one of a number of arrangements may be used to gas lift
the liquid from chamber 34.
Referring to FIG. 3, an apparatus used in lifting a well according
to this invention, casing 110 is shown in a well bore through two
producing horizons 112 and 114. Perforations 116 and 118 to the
upper and lower producing zones respectively allow production from
these zones to flow into the casing 110. A packer 120 is sealingly
engaged to the casing 110 between the perforations 116 and 118 to
isolate the producing zones from each other. The flow of upper and
lower zone gas and liquid is generally the same as described
hereinbefore except that the head or barrier portion 126 is
simplified to have fewer passages. Lower zone gas LG flows through
passage 124 into tubing string 128 connected thereto. Upper zone
liquid production flows through check valve 132 into passageway 133
in body 126. A tubular string 131 is connected to body 126 in
alignment with passage 133 to conduct upper zone liquid U to
chamber 134. Check valve 136 admits lower zone production liquid L
into chamber 134 and prevents back flow therefrom. Tubing string
140 is sealingly engaged to head 126 by means of a suitable
connection 127. Tubing string 131 is sealingly engaged to tubing
string 140 by a suitable connection 135, so that back flow from
chamber 134 is prevented into the upper zone by check valve 132 and
back flow from chamber 134 is prevented to lower zone by check
valve 136. A suitable plunger pump 138 may be used to lift the
liquid from chamber 134 through tubing string 140. It should be
understood that pump 138 may be a hydraulically operated pump. It
should also be understood that a gas lift arrangement similar to
FIG. 2 could be used to lift fluid from chamber 134 through tubing
string 140 to the top of the well bore. These and other means for
lifting fluid well known to those skilled in the art may be used in
lifting the fluid from chamber 134 according to this invention.
* * * * *