U.S. patent application number 10/939749 was filed with the patent office on 2006-03-16 for method and apparatus for production logging.
Invention is credited to Francis Michael Heaney, David Lynn Houdek.
Application Number | 20060054316 10/939749 |
Document ID | / |
Family ID | 36032628 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060054316 |
Kind Code |
A1 |
Heaney; Francis Michael ; et
al. |
March 16, 2006 |
Method and apparatus for production logging
Abstract
Method and apparatus are disclosed for performing production
logging in a cased well having a plurality of isolated production
zones and a tubing string which intersects the production zones. An
access device is connected in the tubing string for each of one or
more production zones and an intervention tool is conveyed to and
positioned in the access device associated with the selected
production zone. Production parameters from the selected zone are
measured by sensors in the intervention tool.
Inventors: |
Heaney; Francis Michael;
(Ardrossan, CA) ; Houdek; David Lynn; (Ennis,
TX) |
Correspondence
Address: |
CLARENCE EMILE ERIKSEN
3200 SOUTHWEST FREEWAY, SUITE 2355
HOUSTON
TX
77027
US
|
Family ID: |
36032628 |
Appl. No.: |
10/939749 |
Filed: |
September 13, 2004 |
Current U.S.
Class: |
166/250.01 ;
166/313 |
Current CPC
Class: |
E21B 33/124 20130101;
E21B 47/10 20130101 |
Class at
Publication: |
166/250.01 ;
166/313 |
International
Class: |
E21B 47/00 20060101
E21B047/00; E21B 43/12 20060101 E21B043/12 |
Claims
1. A method of production logging in a cased well having (i) a
plurality of production zones that are isolated from one another,
(ii) a tubing string for conveying production from said production
zones to the earth's surface, and (iii) at least one access device
connected in said tubing string for each of one or more production
zones, each said access device having a port that allows production
fluid to flow into in the tubing string, comprising the steps of:
(a) conveying an intervention tool to an access device associated
with a production zone from which production parameters are to be
measured; (b) positioning said intervention tool in said access
device so that production fluid passes through the intervention
tool; and (c) measuring parameters of the selected production zone
with sensors contained in said intervention tool.
2. The method of claim 1, further comprising the step of providing
data respecting said measured parameters to a computer that is
located at the earth's surface.
3. The method of claim 2, further comprising the step of using the
data respecting the measured parameters to make decisions
concerning production from the selected production zone.
4. The method of claim 2, further comprising the steps of repeating
the steps of claim 2 for at least one more production zone in the
well.
5. The method of claim 4, further comprising the step of using the
data respecting the measured parameters from the measured
production zones to make decisions concerning production from the
well.
6. The method of claim 1, further comprising the step of storing
data respecting said measured parameters in a memory device.
7. The method of claim 6, further comprising the step of providing
the data stored in the memory device to a computer.
8. The method of claim 6, further comprising the steps of repeating
the steps of claim 6 over a preselected period of time.
9. The method of claim 8, further comprising the step of providing
the data stored in the memory device to a computer.
10. The method of claim 1, wherein step (b) comprises reducing the
cross-sectional area through which production fluid from said
production zone may flow.
11. A method of production logging in a cased well having (i) a
plurality of production zones that are isolated from one another,
(ii) a tubing string for conveying production from said production
zones to the earth's surface, and (iii) at least one sliding sleeve
device connected in said tubing string for each of one or more
production zones, each said sliding sleeve having a port which
permits production fluid to flow into the tubing string, comprising
the steps of: (a) outfitting an intervention tool with one or more
sensors to measure parameters; (b) conveying said intervention tool
to a sliding sleeve device associated with a production zone from
which production parameters are to be measured; (c) positioning the
intervention tool in said sliding sleeve device so that the
production fluid entering the port of said sliding sleeve device
passes through the intervention tool; and (d) measuring parameters
of the production zone with the sensors contained in the
intervention tool.
12. The method of claim 11, further comprising the step of
providing data respecting said measured parameters to a computer
that is located at the earth's surface.
13. The method of claim 12, further comprising the step of using
the data respecting the measured parameters to make decisions
concerning production from the selected production zone.
14. The method of claim 12, further comprising the steps of
repeating the steps of claim 11 for at least one more production
zone in the well.
15. The method of claim 14, further comprising the step of using
data respecting the measured parameters from the measured
production zones to make decisions concerning production from the
well.
16. The method of claim 11, further comprising the step of storing
data respecting said measured parameters in a memory device.
17. The method of claim 16, further comprising the step of
providing the data stored in the memory device to a computer.
18. The method of claim 16, further comprising the steps of
repeating the steps of claim 15 over a preselected period of
time.
19. The method of claim 18, further comprising providing the data
stored in the memory device to a computer.
20. The method of claim 11, where step (c) comprises reducing the
cross-sectional area through which production fluid from said
production zone may flow.
21. Apparatus for use in production logging operations in a cased,
completed well having a plurality of production zones that are
isolated from one another and a tubing string for conveying the
production from said production zones to the earth's surface,
comprising: (a) a plurality of access devices connected in the
tubing where there is at least one access device for each of one or
more of said production zones; and (b) an intervention tool which:
(i) is conveyed through the tubing string from the surface of the
earth to a selected one of the access devices, (ii) is positioned
in the selected access device, and (iii) contains sensing devices
to measure parameters of the production zone corresponding to the
access device in which the intervention tool is positioned.
22. The apparatus of claim 21, wherein the sensing devices are
selected from a group of devices which measure pressure, density,
temperature, capacitance/dielectric and/or velocity.
23. Apparatus for use in production logging operations in a cased,
completed well having a plurality of production zones that are
isolated from one another and a tubing string for conveying the
production from said production zones to the earth's surface,
comprising: (a) a plurality of sliding sleeve devices connected in
the tubing string where there is at least one sliding sleeve device
for each of one or more of said production zones; and (b) an
intervention tool which: (i) is conveyed through the tubing string
from the surface of the earth to a selected one of the sliding
sleeve devices, (ii) is positioned in the selected sliding sleeve
device, and (iii) contains sensing devices to measure parameters of
the production zone corresponding to the sliding sleeve in which
the intervention tool is positioned.
24. The apparatus of claim 23, wherein the sensing devices are
selected from a group of devices which measure pressure, density,
temperature, capacitance/dielectric and/or velocity.
25. A production logging system for use in a cased, completed well
having a plurality of production zones that are isolated from one
another and a tubing string for conveying the production from said
production zones to the earth's surface, comprising: (a) a
plurality of access devices connected in the tubing string where
there is at least one access device for each of one or more of said
production zones; (b) an intervention tool which: (i) is conveyed
through the tubing string from the surface of the earth to a
selected one of the access devices, (ii) is positioned in the
selected access device, and (iii) contains sensing devices to
measure parameters of the production zone corresponding to access
device in which the intervention tool is positioned; (c) a computer
which receives data respecting the measured parameters and
processes that data; and (d) a recorder operatively coupled to the
computer for displaying information respecting the measured
parameters.
26. The system of claim 25, wherein the sensing devices are
selected from a group of devices which measure pressure, density,
temperature, capacitance/dielectric and/or velocity.
27. A production logging system for use in a cased, completed well
having a plurality of production zones that are isolated from one
another and a tubing string for conveying the production from said
production zones to the earth's surface, comprising: (a) a
plurality of sliding sleeve devices connected in the tubing string
where there is at least one sliding sleeve device for each of one
or more of said production zones; (b) an intervention tool which:
(i) is conveyed through the tubing string from the surface of the
earth to a selected one of the sliding sleeve devices via the
tubing string, (ii) is positioned in the selected sliding sleeve
device, and (iii) contains sensing devices to measure parameters of
the production zone corresponding to the sliding sleeve in which
the isolation tool is positioned; (c) a computer for receiving data
respecting the measured parameters and for processing that data;
and (d) a recorder operatively coupled to the computer for
displaying information respecting the measured parameters.
28. The apparatus of claim 27, wherein the sensing devices are
selected from a group of devices which measure pressure, density,
temperature, capacitance/dielectric and/or velocity.
29. Apparatus for use in production logging operations in a cased,
completed well having a plurality of production zones that are
isolated from one another, a tubing string for conveying the
production from said production zones to the earth's surface, and a
plurality of access devices connected in the tubing string where
there is at least one access device for each of one or more of said
production zones, comprising: an intervention tool which (i) is for
conveyance through the tubing string from the surface of the earth
to a selected one of the access devices, (ii) is for positioning in
the selected access device, and (iii) contains sensing devices to
measure parameters of the production zone corresponding to the
access device in which the intervention tool is positioned.
30. The apparatus of claim 29, wherein the access devices are
sliding sleeve devices.
31. The apparatus of claim 29, wherein the sensing devices are
selected from a group of device which measure pressure, density,
temperature, capacitance/dielectric and/or velocity.
32. A method of production logging in a cased wellbore having a
tubing string for conveying production fluid from the wellbore to
the earth's surface, said tubing string including a landing device,
comprising the steps of: outfitting an intervention tool with
sensing devices; conveying the intervention tool to the landing
device; cooperatively engaging the intervention tool with the
landing device so that production fluid flows through the
intervention tool; and measuring parameters of the production fluid
with the sensing devices in the intervention tool.
33. The method of claim 32, further comprising the step of
providing data respecting said measured parameters to a computer
that is located at the earth's surface.
34. The method of claim 33, further comprising the step of using
the data respecting the measured parameters to recommend decisions
concerning production from the selected production zone.
35. The method of claim 33, further comprising the steps of
repeating the steps of claim 31 for at least one more production
zone in the well.
36. The method of claim 35, further comprising the step of using
the data respecting the measured parameters from the measured
production zones to recommend decisions concerning production from
the well.
37. The method of claim 32, further comprising the step of storing
data respecting said measured parameters in a memory device.
38. The method of claim 37, further comprising the step of
providing the data stored in the memory device to a computer.
39. The method of claim 37, further comprising the steps of
repeating the steps of claim 35 over a preselected period of
time.
40. The method of claim 39, further comprising the step of
providing the data stored in the memory device to a computer.
41. A method of production management for a hydrocarbon producing
well having a plurality of potential production zones intersected
by a wellbore, said method comprising: casing the wellbore;
providing potential access through the casing to a plurality of
said potential production zones; running a tubing string inside of
the casing and in communication with the surface; isolating one or
more of the potential production zones; providing one or more
access devices each associated with one of the isolated potential
production zones to allow selective fluid communication from said
production zone into the tubing; engaging an intervention tool with
one of said access devices; collecting data by measuring parameters
of the isolated potential production zone associated with the
engaged access device using sensors contained in said intervention
tool; and making decisions for production management based on the
data.
42. The method of claim 41, wherein data is collected at multiple
production zones.
43. The method of claim 42, wherein the decisions for production
management comprise leaving access devices open or shut, and
treating an isolated section.
44. The method of claim 41, wherein the well is monitored over time
and production from the well is optimized on an ongoing basis in
response to changes in the well.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to method and apparatus for
production logging in a cased, multilayer wellbore.
[0003] 2. Description of the Prior Art
[0004] Well logging surveys are often made in producing oil and gas
wells to determine the volumetric concentration of the oil, gas and
unwanted water components in the production flow. These data along
with measurements of the fluid flow velocity, pressure and
temperature may be used to determine production rates and other
information from each zone of interest in the well. Such data are
essential for the improvement of oil and gas production, reducing
water production, managing the field reservoir, and optimizing
production from the well.
[0005] Obtaining reliable production information in deviated,
multilayered, multi-phased reservoirs has proven to be a difficult
task. This is due to segregation of the lower density phases, e.g.
oil and gas, migrating to the high side of the hole where they
cannot be adequately measured by centralized sensors. Such sensors
may have a very limited circumferential area of measurement and may
not read globally. Additionally, the heavier fluids, e.g. water,
suffer from a phenomena known as "water fallback" where the heavier
fluids falls back downhole, which may cause the velocity
measurement to read an incorrect flow rate. Fluid segregation and
fallback thus prevent all current technology from providing
reliable production data in the majority of deviated wellbores.
[0006] Another shortcoming of current production logging technology
is that it can only measure pressure in the borehole or production
tubing and not the actual reservoir pressure of an individual layer
in a multilayer reservoir. Capturing the actual reservoir pressure
from the individual layer is critical to well optimization and
proper understanding of reservoir support mechanisms, e.g. water
floods.
[0007] If reliable production information concerning a reservoir
can be obtained, decisions concerning the management of the
reservoir should be enhanced. For example, with reliable production
information from the production zones in a reservoir, informed
decisions may be made concerning whether to continue to produce
from a production zone, to close a production zone, or to treat a
production zone, e.g. by fracturing. This affords an opportunity to
respond to changes over time with the selection of production zones
open to the production tubing. For example, production from
hydrocarbon rich zones at relatively lower pressures may be delayed
for the pressure to drop with the passage of time from production
from higher pressure production zones. A failure to properly
balance this may cause hydrocarbons brought out of one production
zone to flow back into another zone at lower pressure, causing lost
production and perhaps damage to the latter formation. Similarly,
it can be useful to make other changes over time in managing
individual production zones, the collective total, and the combined
fluids produced based on the mixture of gas, water, and oil
constituents, temperature, or other parameters observable from the
fluid produced among each of several selected zones. Such informed
decisions will tend to increase and perhaps even maximize
production from the reservoir.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, a method of
production logging in a cased well is provided. The cased well has
a plurality of production zones that are isolated from one another
and a tubing string for conveying production from said zones to the
earth's surface. At least one access device is connected in the
tubing string for each of one or more production zones, and each
such access device has a port that allows production fluid to flow
into the tubing string.
[0009] A method in accordance with the present invention comprises
the steps of selecting one of the production zones from which to
measure production parameters and then conveying an intervention
tool to an access device associated with the selected production
zone. A method in accordance with the present invention further
comprises the step of positioning the intervention tool is in the
selected access device so that the production fluid passes through
the intervention tool. That step of positioning the intervention
tool in the selected access device may comprise reducing the
cross-sectional area through which production fluid from the
selected production zone may flow. A method in accordance with the
present invention further comprises measuring parameters associated
with the production zone using sensors which are contained in the
intervention tool.
[0010] The data that is generated by measuring the parameters of
the production zone may be directly provided to a computer at the
earth's surface. Alternatively, that data may first be stored in a
memory device (which may be located downhole) and then provided to
a computer. This computer may be programmed to use the data
respecting the measured parameters to make decisions concerning
future production from the well.
[0011] A method in accordance with the present invention comprises
repeating the aforesaid steps for at least one more production zone
in the well, and using the data respecting the measured parameters
from the measured production zones to make decisions concerning the
production from the well.
[0012] In accordance with the present invention apparatus is
provided for use in production logging operations in a cased well
having a plurality of production zones that are isolated from one
another and a tubing string for conveying the production from the
production zones to the earth's surface. Apparatus in accordance
with the present invention comprises a plurality of access devices,
which may be sliding sleeve devices and which are connected in the
tubing string. At least one access device is connected in the
tubing string for each of one or more production zones in the cased
well. Apparatus in accordance with the present invention further
comprises an intervention tool which is conveyed through the tubing
string from the surface of the earth to a selected one of the
access devices and is positioned in the access device that is
associated with the selected production zone. One function that the
intervention tool provides is to isolate the selected production
zone from the other production zones. Once the intervention tool is
positioned, the production flow from the isolated/selected
production zone passes through the intervention tool, and the
intervention tool contains sensors to measure parameters associated
with the production zone corresponding to the access device in
which the tubular member is positioned. The sensors may be selected
from a group including those which measure pressure, density,
temperature, capacitance/dielectric and velocity.
[0013] In accordance with the present invention, a production
logging system is provided for use in a cased well having a
plurality of production zones that are isolated from one another
and a tubing string for conveying the production from said
production zones to the earth's surface. The system comprises a
plurality of access devices connected in the tubing string where
there is at least one access device for each of one or more of said
production zones. In one embodiment the access devices are sliding
sleeve devices. A system according to the present invention
comprises an intervention tool which is conveyed from the earth's
surface to an access device associated with a selected production
zone and which is positioned in that selected device. Parameters of
the production zone corresponding to access device in which the
intervention tool is positioned are measured with sensors in the
intervention tool. A system in accordance with the present
invention further comprises a computer which receives and processes
the aforesaid data, and a recorder operatively connected to the
computer for displaying information respecting said measured
parameters.
[0014] In accordance with the present invention apparatus
comprising an intervention tool is provided for use in production
logging operations in a cased, completed well having a plurality of
production zones that are isolated from one another, a tubing
string for conveying the production from said production zones to
the earth's surface, and one or more access devices connected in
the tubing string where there is at least one access device for
each of one or more of said production zones. An intervention tool
in accordance with the present invention is for conveyance through
the tubing string and is for positioning in the selected access
device. An intervention tool according to the present invention
comprises sensing devices to measure parameters of the production
zone corresponding to the access device in which the intervention
tool is positioned.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an elevational view in partial cross-section of a
cased, completed well.
[0016] FIG. 1A is an elevational view in partial cross-section of a
cased, completed well.
[0017] FIG. 2 is a perspective view in cross-section which
illustrates a portion of a prior art sliding sleeve access device
which may be used in the well completion shown in either FIG. 1 or
FIG. 1A.
[0018] FIG. 3 is a perspective view of a prior art separation
tool.
[0019] FIG. 4 is a perspective view of an isolation tool for use as
part of an intervention tool in the present invention.
[0020] FIG. 5 is an elevation view in cross-section which
illustrates a sliding sleeve device with an intervention tool
positioned therein in accordance with the present invention.
[0021] FIG. 6 is an enlargement of that portion of the apparatus of
FIG. 5 which is contained in the box labeled 6 in FIG. 5.
DESCRIPTION OF SPECIFIC EMBODIMENTS
[0022] It will be appreciated that the present invention may take
many forms and embodiments. Some embodiments of the invention are
described so as to give an understanding of the invention. It is
intended for the embodiments of the present invention described
herein to be illustrative, and not limiting, of the invention.
[0023] In accordance with the present invention, method and
apparatus are provided for production logging in a cased, completed
wellbore. With reference first of FIG. 1, there is illustrated a
cased completed wellbore 10 having multiple production zones 12, 14
and 16. A tubing string 18 positioned in wellbore 10 intersecting
the production zones 12, 14 and 16. Access through the casing 20 to
production zones 12, 14 and 16 is provided by perforating the
casing at 12a, 14a and 16a. The wellbore 10 has a casing 20, and an
annulus 22 between the casing 20 and the tubing string 18. Inflated
packers 24,25 and 26 isolate the production zones 12, 14 and 16
from one another. While completed wellbore 10 is illustrated as a
vertical well, those skilled in the art will appreciate that the
present invention is also applicable to deviated wells.
[0024] The tubing string 18 comprises a plurality of tubular
members, i.e. pipes, which are joined together in threaded
engagement. A plurality of access devices 30 are joined in threaded
engagement to tubular members in the tubing string 18. Each
production zone 12, 14 and 16 has at least one access device 30
associated with it. While FIG. 1 illustrates an embodiment with one
access device 30 per production zone, another embodiment may
include more than one access device 30 per production zone. Access
devices 30 may be opened and closed to permit selective control of
fluid flow between each of the production zones 12, 14 and 16 and
the tubing string 18. Each access device has an axial bore (not
shown in FIG. 1) which forms a passage from one end of the access
device to the other, and when the access device is opened,
production fluids may flow into the tubing string 18 via port
29.
[0025] The tubing string 18 connects to a wellhead 21 which is
located at the earth's surface. The production fluids may be
directed from the tubing string 18 via the wellhead to a pipeline
(not shown). Wellhead 21 includes a port to permit access to the
tubing string 18 by logging apparatus.
[0026] With reference now to FIG. 1A, another configuration of a
cased, completed wellbore 100 with which the method and apparatus
of the present invention may be used is illustrated. Wellbore 100
comprises two production zones 112 and 114 and access through the
casing 20 to production zones 112 and 114 is provided by
perforating the casing 20 at 112a and 114a. A tubing string 118 is
positioned in wellbore 100 intersecting production zones 112 and
114. The wellbore 100 has a casing 20 and an annulus 22 between the
casing 20 and tubing string 118. Inflated packers 24 and 25 isolate
the production zones 112 and 114 from one another.
[0027] In the completed wellbore 100 of FIG. 1A, production zone
112 has at least one access device 30 associated with it, while
production zone 114 does not have any access device associated with
it. The completion configuration shown in FIG. 1A may, for example,
be employed when it is reasonably certain that sustained production
from production zone 114 will be realized without need for the
convenient access and shut-off capability of an access device, yet
where zone 112 requires convenient access and shut-off capability
and required, the production from zone 112 will require
monitoring.
[0028] In the completed wellbores shown in FIGS. 1 and 1A, there is
at least one access device connected in the tubing string for "each
of one or more of the production zones." In FIG. 1, there is
illustrated at least one access device 30 for each production zone
12, 14 and 16, and in FIG. 1A, there is illustrated at least one
access device 30 for production zone 112.
[0029] In one embodiment, each access device 30 in FIGS. 1 and 1A
is a DuraSleeve brand sliding sleeve device that is available from
Halliburton. With reference now to FIG. 2, each such a sliding
sleeve device comprises a sliding sleeve 40 having openings 42
formed therein. The exterior of each sliding sleeve device also has
a plurality of openings 44 formed therein. Using well known
techniques, the sleeve 40 in each sliding sleeve device may be
moved to an open position as shown in FIG. 2 where the openings 42
in sleeve 40 are aligned with the openings 44 in the exterior of
the sliding sleeve or to a closed position where the openings 42 in
the sliding sleeve 40 are not aligned with the openings 44. In the
closed position, seals 46 and 48 prevent production flow from a
production zone from entering the bore of the sliding sleeve device
and hence from entering the tubing string 18.
[0030] Referring now to FIG. 5, apparatus in accordance with the
present invention comprises an intervention tool which is
positioned in a sliding sleeve device. The intervention tool
comprises an isolation tool 51 and a dart 52. In FIG. 5, the
isolation tool 51 and the dart 52 are shown positioned in a
downhole sliding sleeve device.
[0031] With reference to FIGS. 3, 4, and 5 the isolation tool 51
(FIGS. 4 and 5) is formed by modifying separation tool 53 (FIG. 3).
Separation tool 53 is a product that is manufactured by
Halliburton. Separation tool 53 has been modified as follows to
make isolation tool 51: (a) The equalizing sub 54 has been moved
near the bottom of the tool as shown in FIG. 4; (b) ports 55 have
been formed into tubular number 56; and (c) the lower end of 57 of
the separation tool has been closed off.
[0032] With reference to FIGS. 4, 5 and 6, when isolation tool 51
is positioned in access device 30, the ports 55 in isolation tool
51 are fluidly coupled with (and may be adjacent to) the ports 42
in access device 30, and all production fluid is directed through
ports 55, because of seals 49 and 50 in isolation tool 51.
Similarly, when dart 52 is positioned in isolation tool 51 as shown
in FIGS. 5 and 6, ports 75 in dart 52 are fluidly coupled with (and
may be adjacent to) the ports 55 and the ports 42 in access device
30 and all production fluid (schematically shown with the arrow 76
in FIGS. 5 and 6) is directed through dart 52, because of the seals
52A in dart 52. Those skilled in the art who have the benefit of
the present disclosure, will appreciate that dart 52 need not be
positioned in isolation tool 51 as shown in FIG. 5, but may be
positioned above isolation tool 51, so long as substantially all
the production fluid from the production zone being monitored
passes through dart 52.
[0033] Dart 52 contains a plurality of sensors in its bore, which
may, for example, include devices to measure pressure, density,
temperature, capacitance/dielectric and/or velocity at the selected
zone. In particular, the sensors may include: (a) in-line spinner
65 to measure velocity; and (b) fluid identification sensors,
density sensors (nuclear or vibration method) and
capacitance/dielectric sensors located at 63 between baffle plates
64. Baffle plates 64 are employed to force fluid into the fluid
identification sensors to ensure accurate recording. The bore of
dart 52 may also contain a sealing device 66 which may, for
example, be a door 66 that is remotely controlled by a timer (not
shown) that is powered by battery 69. When the sealing device 66 is
closed as shown in FIG. 5, actual reservoir pressure and
temperature data may be recorded for a preselected period of time
(e.g., up to 48 hours) from the pressure and temperature sensors
located at 68. After that preselected period of time as elapsed,
sealing device 66 maybe opened to allow production fluid to flow
through the upper sensors at 63.
[0034] Dart 52 may also include ports 70 to allow fluid from below
to enter the base of dart 52. In the event of a pressure
differential between the fluid in the bore of dart 52 and the fluid
below dart 52, there will be fluid movement toward equilibrium, and
this fluid movement may be measured by spinner 67.
[0035] When it is desired to measure parameters of a selected
production zone, the isolation tool 51 is conveyed through the
tubing string 18 from the earth's surface to a sliding sleeve
device 30 corresponding to the selected production zone by
wireline, slickline, coiled tubing or other conveyance techniques.
Preferably, such conveyance is carried out using conventional
wireline techniques. The isolation tool 51 is positioned in the
sliding sleeve device using the same techniques that are used to
position a separation tool in a sliding sleeve device. The sliding
sleeve device may be an "X" landing nipple profile and isolation
tool 51 would therefore have locking keys 58 which match that
nipple profile. Any nipple profile assembly or other "landing
device" for cooperatively engaging a tool within the bore of
another tool may, be used, so long as it is adequate to install the
isolation tool 51. The ports 55 that were formed in tubular member
56 become fluidly coupled with and may be adjacent to the ports 44
in the sliding sleeve device 30 when the isolation tool 51 is
positioned in the sliding sleeve. Once the isolation tool is
positioned, the wireline is retrieved, and dart 52 is then lowered
and is positioned within isolation tool 51, as illustrated in FIG.
5. Dart 52 has seals 52A which engage the inner surface of
isolation tool 51 so that production flow is directed through dart
52, when dart 52 is positioned as in FIG. 5.
[0036] In one embodiment of the present invention, the intervention
procedure is thus a two "trip" process--one trip to position the
isolation tool 51 in the sliding sleeve device and a second trip to
position the dart 52 in the isolation tool 51. Similarly, the
intervention tool in this embodiment comprises apparatus composed
of two component pieces. Those skilled in the art, having the
benefit of the present disclosure, will appreciate that the
intervention procedure may be carried out in a single trip and that
the isolation tool 51 and dart 52 may be formed as an integral
piece of apparatus. The appended method claims are intended to
cover multiple or single trip procedures to position the
intervention tool and the appended apparatus/system claims are
intended to cover an intervention tool which is formed as a single
unit or in two or more component pieces.
[0037] With reference to FIGS. 5 and 6, the cross-sectional area
through which production fluid flows is reduced by the positioning
of isolation tool 51 and dart 52 in the sliding sleeve
corresponding to the selected production zone. Because of this
reduced cross-sectional area, it is believed that the production
flow will have increased homogeneity, which should result in
increased accuracy of measurements being made by the sensors 60 in
dart 52. By having a more homogeneous flow, fluid segregation and
fallback should be reduced, often minimized, and potentially fully
avoided.
[0038] Referring to FIGS. 1, 2 and 5 as the sensors measure
parameters of the selected production zone, data respecting such
measurements may be stored in a memory device 61 which is located
in dart 52 and then such data may be provided to computer 31 which
may be located at the earth's surface. Alternatively, data
respecting said measurements may be transmitted to computer 31 via
a logging cable 32 or by well-known wireless communication
techniques. Computer 31 processes the data and the processed data
may be displayed on a computer monitor, provided to recorder 33 for
printing on a recording medium 34, or otherwise provided in a
useful form to the well operator.
[0039] By using the method and apparatus of the present invention,
the well operator has more accurate and meaningful data concerning
the production zone than has heretofore been available. In
particular, the operator is able by using the present invention to
measure actual reservoir pressure at each production zone of
interest, which by itself should enhance well optimization
endeavors. Without this information, production decisions may be
based on more difficult to interpret data, for example, data in
which information about an individual production zones may be
interfered with by parameters such as the hydrostatic head and/or
the net flowing pressure of other production zones.
[0040] Using the apparatus of the present invention, an operator
has the ability to operate the apparatus in a long term memory mode
in order to accumulate data over a preselected period of time, e.g.
between one and thirty days. By accumulating information over such
period of time, the operator is able to provide a more accurate
information concerning the zone of interest. For example, as wells
mature, water production generally increases which can cause the
well to slug, and this effect is amplified with well deviation. The
occurrence of the slug may, however, be difficult to predict.
Therefore, by sampling the well over an extended period of time, it
is believed that the effects of slugging can be averaged to provide
a more consistent interpretation of results than are currently
available.
[0041] Once measurements have been completed at one production
zone, the intervention tool comprising the isolation tool 51 and
dart 52 may me relocated to another production zone, and the
above-described process may be repeated.
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