U.S. patent number 3,577,783 [Application Number 04/790,199] was granted by the patent office on 1971-05-04 for tool to take multiple fluid measurements.
This patent grant is currently assigned to Schlumberger Technology Corporation. Invention is credited to Roger Q. Fields, Frank R. Whitten.
United States Patent |
3,577,783 |
Whitten , et al. |
May 4, 1971 |
TOOL TO TAKE MULTIPLE FLUID MEASUREMENTS
Abstract
A plurality of readings with respect to fluids in formations
traversed by a well bore is obtained in a single traverse of the
well bore by a special tool. The tool includes a piston-cylinder
assembly having two pistons of differential diameter and serving as
a pressure multiplier responsive to the pressure of fluid in the
well bore for generating pressure in an operating fluid in a
branching conduit in the tool greater than the pressure of the
fluid in the well bore at the depth of the tool. Upon opening of a
valve in the conduit, the operating fluid sets a shoe against the
wall of the well bore and, by reaction, forces annular sealing
means on the tool against the wall of the well bore to seal off an
area of the wall from fluid in the well bore. After a short delay
to permit the setting and sealing, a collection chamber in the tool
in communication with the annular sealing means is expanded to
reduce the pressure therein and facilitate collection of a fluid
sample from the formation. The delay is facilitated by a choke
formed in one branch of the conduit and, in one embodiment, by a
check valve and a piston-cylinder assembly mounted in the same
branch.
Inventors: |
Whitten; Frank R. (Houston,
TX), Fields; Roger Q. (Houston, TX) |
Assignee: |
Schlumberger Technology
Corporation (Houston, TX)
|
Family
ID: |
25149929 |
Appl.
No.: |
04/790,199 |
Filed: |
January 10, 1969 |
Current U.S.
Class: |
73/152.02;
73/152.51 |
Current CPC
Class: |
E21B
47/00 (20130101); G01V 9/00 (20130101); E21B
49/10 (20130101) |
Current International
Class: |
E21B
49/00 (20060101); E21B 49/10 (20060101); E21B
47/00 (20060101); G01V 9/00 (20060101); E21b
047/06 () |
Field of
Search: |
;73/155,421,152
;166/264 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myracle; Jerry W.
Claims
We claim:
1. In apparatus for obtaining a plurality of readings with respect
to fluids in formations traversed by a well bore, said apparatus
including a housing, annular sealing means mounted on said housing
for sealing off an area of the wall of said well bore from fluid
within said well bore, formation-fluid-receiving chamber means
within said housing in communication with said sealed-off area of
said wall, gauge means operatively connected to said chamber means
for obtaining a reading with respect to formation fluid within said
chamber means, and motive means for bringing said chamber means
into cooperation with discrete samples of formation fluid collected
at spaced-apart locations in said well bore, whereby a plurality of
readings with respect to fluid in said formations is obtainable in
a single traverse of said well bore by said apparatus, the
improvement wherein said motive means comprises pressure multiplier
means within said housing responsive to the pressure of said fluid
within said well bore for boosting the pressure of an operating
fluid within said housing to a pressure greater than the pressure
of said well bore fluid at the depth of said apparatus, positioning
means mounted on said housing and movable between a retracted
position and a set position, conduit means communicating with said
pressure multiplier means, said conduit means being divided into a
fast-action branch communicating with said positioning means and a
delayed-action branch communicating with said chamber means, and
operating valve means in said conduit means which when opened
permits operating fluid flow from said pressure multiplier means to
said conduit means, whereby, upon opening of said operating valve
means to permit operating fluid flow from said pressure multiplier
means to said conduit means, said operating fluid flow is initially
effective in said fast-action branch to cause setting of said
positioning means, said positioning means when set forcing said
annular sealing means against the wall of said well bore, and is
thereafter effective in said delayed-action branch to expand said
chamber means to reduce the pressure within said chamber means and
facilitate collection of said formation fluid in said chamber
means.
2. Apparatus according to claim 1 wherein said pressure multiplier
means comprises a mud cylinder communicating with said fluid within
said well bore, a mud piston within said mud cylinder, a
high-pressure piston rigidly connected to said mud piston, said
high-pressure piston being of smaller diameter than said mud
piston, and a high-pressure cylinder housing said high-pressure
piston, said high-pressure cylinder communicating with said conduit
means.
3. Apparatus according to claim 1 wherein said delayed-action
branch is formed with a choke to slow the flow of operating fluid
therethrough.
4. Apparatus according to claim 1 wherein said delayed-action
branch is divided into subbranches in parallel one of said
subbranches comprising a check valve preventing operating fluid
flow therethrough towards said chamber means and permitting
operating flow therethrough away from said chamber means and the
other of said subbranches comprising a delay cylinder and a delay
piston mounted in said delay cylinder, said delay piston being
normally within said delay cylinder to prevent operating fluid flow
therethrough towards said chamber means but being forced out of
said delay cylinder sufficiently to permit operating fluid flow
toward said chamber means beginning a finite time following opening
of said operating valve means, whereby, during operating fluid flow
in said fast-action branch causing setting of said positioning
means, there is initially no operating fluid flow in said
delayed-action branch between said subbranches and said chamber
means.
5. Apparatus according to claim 4 further comprising biasing means
for preventing said delay piston from being forced out of said
delay cylinder until after setting of said positioning means.
6. Apparatus according to claim 1 further comprising a dump valve
means in said conduit means and a dump chamber connected to said
conduit means, said dump valve means when open permitting dumping
of operating fluid from said conduit means into said dump
chamber.
7. Apparatus according to claim 1 wherein said gauge means is a
pressure gauge.
8. Apparatus according to claim 1 wherein said gauge means is a
temperature gauge.
9. Apparatus according to claim 1 wherein said gauge means is a
resistivity gauge.
10. Apparatus according to claim 1 wherein said gauge means is a
radioactivity gauge.
Description
CROSS-REFERENCE TO RELATED APPLICATION
The present invention is an improvement of an invention disclosed
and claimed in a copending application of Maurice P. Lebourg and
Roger Q. Fields, Ser. No. 790,321 filed Jan. 10, 1969 for "TOOL TO
TAKE MULTIPLE FORMATION FLUID PRESSURES."
BACKGROUND OF THE INVENTION
This invention relates to well surveying and, in particular, to
novel and highly effective apparatus facilitating the obtaining of
a plurality of readings with respect to fluids in formations
traversed by a well bore in a single traverse of the well bore.
The copending application identified above also discloses methods
and apparatus facilitating the obtaining of a plurality of readings
with respect to fluids in formations traversed by a well bore in a
single traverse of the well bore, and the generic invention is
claimed there.
The art of gathering information regarding earth formations is
developed to a high state, as evidenced by a U.S. Pat. to
Desbrandes et al. No. 3,011,554, U.S. Pat. to Whitten No. 3,104,712
and No. 3,261,402, and a U.S. Pat. to Voetter No. 3,329,208. There
remains a need, however, for improved means for obtaining a
plurality of readings with respect to fluids in earth
formations.
It is possible, of course, to obtain a plurality of readings with
respect to fluids in earth formations traversed by a well bore by
the expedient of lowering a conventional measuring tool or
instrument a plurality of times in the well bore, each time
obtaining information with regard to fluids in a formation at a
selected depth in the well bore. This process is time consuming and
expensive, however, because of the delay occasioned each time it is
necessary to withdraw the tool from the well bore following a given
reading, prepare the tool to take a subsequent reading, and lower
the tool into the well bore to the depth selected for the
subsequent reading.
Withdrawal of the tool between successive readings is the
conventional practice, because of the limited capacity of
conventional tools to receive fluid samples for pressure or other
measurements.
SUMMARY OF THE INVENTION
An object of the present invention is to provide improved apparatus
for obtaining a plurality of readings with respect to fluids in
formations traversed by a well bore. Another object of the
invention is to reduce the cost and time involved in the surveying
of a well. A further object of the invention is to provide rugged
and compact apparatus that is inexpensive to manufacture and repair
and that can obtain as many readings as may be desired in a single
traverse of a well bore.
The foregoing and other objects of the invention are accomplished,
in representative apparatus for obtaining a plurality of readings
with respect to fluids in formations traversed by a well bore, by
the provision of apparatus including a housing, annular sealing
means mounted on the housing for sealing off an area of the wall of
the well bore from fluid within the well bore,
formation-fluid-sample-receiving chamber means within the housing
in communication with the sealed-off area of the wall, gauge means
operatively associated with the sample chamber means for obtaining
a reading with respect to formation fluid within the chamber means,
and motive means for bringing the sample chamber means into
cooperation with discrete samples of formation fluid collected at
spaced-apart locations within the well bore, whereby a plurality of
readings with respect to fluid in the formations is obtainable in a
single traverse of the well bore by the apparatus.
In accordance with the invention, the motive means comprises
pressure means within the housing responsive to the pressure of the
fluid within the well bore for boosting the pressure of an
operating fluid within the housing to a pressure greater than the
pressure of the well bore fluid, positioning means mounted on the
housing, the positioning means when set forcing the annular sealing
means against the wall of the well bore, conduit means
communicating with the pressure means, the conduit means being
divided into a fast-action branch communicating with the
positioning means and a delayed-action branch communicating with
the sample chamber means, and operating valve means in the conduit
means which when opened permits operating fluid flow from the
pressure means to the conduit means. In this way, upon opening of
the operating valve means to permit operating fluid flow from the
pressure means to the conduit means, the operating fluid flow is
initially effective in the fast-action branch to cause setting of
the positioning means and is thereafter effective in the
delayed-action branch to expand the sample chamber means to reduce
the pressure therein and facilitate collection of a formation fluid
sample.
BRIEF DESCRIPTION OF THE DRAWINGS
An understanding of additional aspects of the invention may be
gained from a consideration of the following detailed description
of representative embodiments of apparatus constructed in
accordance with the invention and of the accompanying figures in
the drawing, in which:
FIG. 1 is a diagrammatic view of apparatus constructed in
accordance with the invention suspended in a well bore;
FIG. 2 is an elevational view, partly in section, of a first
representative embodiment of apparatus constructed in accordance
with the invention; and
FIG. 3 is a fragmentary view of a second embodiment of a portion of
the apparatus of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a tool or device 10 constructed in accordance with the
invention suspended by a cable 12 in a well bore 14 traversing
earth formations 16. The tool 10 includes a housing 18 on which are
annular sealing means 20 adapted to seal off an area 22 of a well
bore 24 and positioning means such as a shoe or pad 26 adapted to
be moved outwardly with respect to the housing 18 against the wall
24 of the well bore 14 and, by reaction, force the annular sealing
means 20 against the area 22 to be sealed off from fluid in the
well bore 14.
The cable 12 runs to means (not shown) at the head of the well bore
14 for raising and lowering the tool 10 in the well bore 14. In
accordance with the invention, the annular sealing means 20 may be
forced successively against a plurality of areas of the well bore
wall 24 for collecting a plurality of samples from the formation 16
without withdrawing the tool 10 from the well bore 14 between the
taking of successive samples.
FIG. 2 shows in detail the structure of the tool 10. A channel 28
communicates with fluid in the well bore 14 and with a mud cylinder
30 in which is mounted a mud piston 32. The mud piston 32 is
slidable within the mud cylinder 30 but includes an O-ring 34
mounted in a groove 36 extending around the periphery of the mud
piston 32 and tightly engaging the wall 38 of the mud cylinder 30
for preventing passage of fluid from one side of the mud piston 32
to the other.
A ram extension 40 extends from the mud piston 32 to a
high-pressure piston 42 within a high-pressure cylinder 44. The
high-pressure piston 42 mounts an O-ring 46 in a groove 48
extending peripherally of the high-pressure piston 42. The O-ring
46 tightly engages the wall 50 of the high-pressure cylinder 44 and
prevents leakage of fluid from one side to the other of the
high-pressure piston 42.
The diameter of the high-pressure piston 42 is less than that of
the low-pressure piston 32, and, as a result, the pressure within
the high-pressure cylinder 44 is greater than the pressure within
the mud cylinder 30. The pistons 32 and 42 and the cylinders 30 and
44 therefore constitute a piston-cylinder assembly functioning as a
pressure multiplier 52. The pressure multiplier 52 is a part of
motive means for bringing the annular sealing means 20 into contact
with a selected area 22 of the wall 24 of the well bore 14.
Conduit means 54 communicates through a regulator valve 56 with the
high-pressure cylinder 44. The regulator valve 56 may be similar or
identical to the valve 65 shown in U.S. Pat. to Desbrandes No.
3,011,554. These valves are typically used to prevent the hydraulic
pressure downstream thereof from being excessive where the
hydrostatic or mud pressure is particularly high. By way of
illustration, where the mud pressure is only 2,000 p.s.i. (gauge
pressure), the developed hydraulic pressure might have to be 4,000
to 5,000 p.s.i.g. to be certain that there is a sufficient pressure
differential to, for example, extend the backup shoe 26. On the
other hand, since the pressure multiplier 52 has a fixed
multiplication factor, the developed pressure could easily exceed
30,000 or 40,000 p.s.i.g. when the mud pressure is in the order of
15,000 to 20,000 p.s.i.g. Thus, the pressure regulator 56 is
provided as a safeguard to maintain the hydraulic pressure
downstream thereof at a reasonable differential above the
hydrostatic pressure once high mud pressures are encountered. The
purpose of this regulator 56 is, therefore, to keep the
differential acting across the seals (e.g., the O-rings around the
extensions 78 and 80) within reasonable limits. Thus, although
these regulator valves are typically used in field operations, they
are not necessary.
An alternative solution to the problems caused by excessively high
hydraulic pressures is to use a pressure multiplier such as shown
in a U.S. Pat. to Voetter No. 3,269,462. In accordance with this
patent, the pressure multiplier piston comprises a number of
telescoped members which can be selectively engaged or disengaged
to permit the operator to select a desired ratio of pressure
multiplication.
The conduit 54 includes a fast-action branch 58 and a
delayed-action branch 60. Flow through the conduit 54 is controlled
by an operating valve 62 provided with leads 64 extending to a
remote location such as the head of the wall for controlling the
valve 62.
When the valve 62 is opened by application of a suitable signal to
the leads 64, flow of operating fluid is permitted from the portion
of the cylinder 44 below the piston 42 through the conduit 54 and
the branches 58 and 60 of the conduit 54.
Flow through the branch 58 of the conduit 54 is relatively rapid,
inasmuch as this branch of the conduit is a low-impedance branch.
The operating fluid therefore quickly enters setting cylinders 66
and 68. A dump valve quickly enters setting cylinders 66 and 68. A
dump valve 70 controlled by leads 72 extending to a remote location
which may conveniently be at the head of the well is closed at this
point. The entry of operating fluid into the setting cylinders 66
and 68 forces to the right (as seen in FIG. 2) setting pistons 74
and 76, respectively. The pistons 74 and 76 are respectively
integral with ram extensions 78 and 80 which are in turn integral
with the setting shoe 26. In this way, the setting shoe 26 is
forced against the wall 24 of the well bore 14. By reaction, the
annular sealing means 20 is forced against a selected area 22 of
the wall 24 of the well bore 14.
Operating fluid is also permitted to flow through the branch 60 of
the conduit 54 upon opening of the valve 62. However, flow through
the branch 60 is much slower than flow through the branch 58,
because the branch 60 is formed with a choke 82 presenting a high
impedance to the flow of operating fluid therethrough.
The choke 82 delays the effect of the operating fluid in producing
an expansion of a sample collection chamber means 84 which is in
communication with the annular sealing means 20. Following the
setting action described above, however, the collection chamber 84
begins to expand because of the pressure of the operating fluid on
a piston 86 in a cylinder 88. The piston 86 is provided with an
O-ring 90 similar in function to the O-rings 46 and 34. No fluid is
able to pass from one side of the piston 86 to the other. A passage
92 communicates with the exterior of the housing 18 and permits
fluid in the well bore 14 to be evacuated from the cylinder 88 as
the operating fluid forces the piston 86 downwardly as seen in FIG.
2.
A ram extension 94 is connected to the cylinder 86 at one end and
to a cylinder 96 at its other end. The cylinder 96 is provided with
an O-ring 98 similar in function to the O-rings 90, 46 and 34.
Thus, fluid is unable to flow from one side of the piston 96 to the
other. The piston 96 is slidable within a cylinder 100 connected by
a passage 102 to the exterior of the housing 18. The piston 96 is
thus able to be moved downwardly in response to the pressure of the
operating fluid on the piston 86, fluid within the chamber 100
being expelled through the passage 102 to the exterior of the
housing 18.
Biasing means such as a compression coil spring 103 urges the
pistons 86 and 96 upwardly (as seen in FIG. 2) so that, upon
release of the pressure acting downwardly on the piston 86, the
pistons 86 and 96 are moved upwardly to the position illustrated in
FIG. 2.
A seal 104 fits tightly about the ram extension 94 to permit
leakage of fluid about the ram extension 94 from one side of the
seal 104 to the other.
The downward movement of the piston 96 described above enlarges the
chamber 84, thereby reducing the pressure within the chamber and
facilitating the withdrawal of a fluid sample from the formation 16
and the collection thereof within the chamber 84. Because of the
delay effected by the choke 82, the downward movement of the piston
96 that occurs prior to the setting of the shoe 26 and the forcing
of the annular sealing means 20 against the area 22 of the wall 24
of the well bore 14 is negligible. Thus, a negligible amount of
fluid from the well bore is drawn into the sample chamber 84, most
of the fluid within the sample chamber 84 being formation
fluid.
Gauge means such as a gauge 106 containing leads 108 extending to a
suitable remote location is provided for measuring a property of
the collected fluid. In a representative embodiment of the
invention, the measured property is the pressure of the fluid.
Other properties may, however, be measured, including, for example,
temperature, resistivity and radioactivity. The gauge may be read
at the surface or, if desired, the gauge may be any suitable type
designed to make a recording within the tool 10, and the recording
may be read after the tool 10 is recovered from the well bore
14.
After the making of the reading, the operating fluid employed in
the collection of the sample is dumped into a dump chamber 110 by
closing the valve 62 and opening the valve 70. The dump chamber 110
is of large capacity, so that a large number of samples can be
collected seriatim in the chamber 84 without withdrawing the tool
10 from the well bore 14. Clearly, the cylinders 30 and 44 are also
of large capacity for the same reason. The opening of the valve 70
exposes the portions of the conduit 54 downstream of the valve 62
to low pressure within the dump chamber 110, and fluid within the
conduit 54 downstream of the valve 62, or at least a significant
portion thereof, flows into the dump chamber 110. The compression
coil spring 103 and mud pressure acting through the lines 92 and
102 force the pistons 86 and 96 upwardly (as seen in FIG. 2),
thereby forcing operating fluid through the branch 60 and the choke
82 and into the branch 58, whence it flows through the valve 70 and
into the dump chamber 110. Similarly, the pressure of fluid in the
well bore 14 forces the pistons 74 and 76 to the left (as seen in
FIG. 2), thereby withdrawing the shoe 26 from the wall 24 of the
well bore 14. The operating fluid within the cylinders 66 and 68
likewise flows through the valve 70 and into the dump chamber 110.
The tool 10 is then moved to another selected location in the well
bore 14, and the sequence of events described above is repeated to
collect and measure the properties of another sample of fluid from
the formation 16.
FIG. 3 discloses an alternate embodiment of a portion of the
apparatus of FIG. 2. Flow of operating fluid in the conduit 54 is
controlled by the valve 62 in accordance with signals supplied to
the valve by lines 64 as in the embodiment of FIG. 2. Also as in
the embodiment of FIG. 2, the conduit 54 divides into branches 58
and 60 facilitating, respectively, setting of the shoe 26 and
enlargement of the collection chamber means 84. Finally, the branch
60 includes the choke 82, as in the embodiment of FIG. 2.
The embodiment of FIG. 3 differs from the embodiment of FIG. 2 in
that the branch 60 is further divided into subbranches 112 and 114.
The subbranch 112 includes a check valve 116 preventing flow of
operating fluid toward the piston 86 and collection chamber 84 but
permitting flow of operating fluid away from the piston 86 and
collection chamber 84. The subbranch 114 includes a delay cylinder
118 within which is slidably mounted a delay piston 120. The delay
piston 120 is formed with a groove 122 within which is mounted an
O-ring 124 tightly engaging the wall of the cylinder 118 so that,
in the position of the delay piston 120 shown in FIG. 3, no fluid
can pass from one side thereof to the other.
When the valve 62 is opened to permit operating fluid to flow from
the oil reservoir through the conduit 54, the shoe 26 is rapidly
set because flow is unimpeded through the fast action branch 58.
There is initially no flow whatever through the delayed-action
branch 60 between the subbranches 112 and 114 and the collection
chamber 84, because the check valve 116 does not permit flow of
operating fluid therethrough toward the chamber 84, and, in the
position of the delay piston 120 shown in FIG. 3, operating fluid
cannot pass from one side of that piston to the other.
When the pressure in the branch 60 reaches a value greater than the
well bore pressure plus the equivalent pressure exerted by spring
133, the delay piston 120 slowly descends in response to opening of
the valve 152 until the piston 120 is withdrawn from the delay
cylinder 118 and is within an enlarged chamber 126 having a
diameter greater than that of the delay piston 120. At this point,
operating fluid can flow around the delay piston 120 and through
the subbranch 114. The operating fluid then forces the piston 86
(FIG. 2) downwardly in the manner described above to enlarge the
chamber 84 and facilitate the collection of formation fluid. The
upward force exerted by the spring 133 on the delay piston 120 is
such that the delay piston 120 is not withdrawn from the cylinder
118 until the oil pressure to the shoe pistons 66, 68 is sufficient
to set the shoe 26 completely following the opening of the valve 62
and the annular sealing means 20 is therefore firmly pressed
against the area 22 of the wall 24 of the well bore 14, sealing off
the area 22 from fluid in the well bore 14. In accordance with the
embodiment of FIG. 3, therefore, the fluid collected in the chamber
84 consists mostly of formation fluid.
Upon the completion of the collection of the formation fluid and
the obtaining of a measurement with respect thereto by the gauge
106, the valve 62 is shut and the valve 70 (FIG. 2) is opened to
dump the operating fluid into the dump chamber 110. The pressure of
the fluid in the well bore 14 communicates with the lower side of a
piston 128 mounted within a cylinder 130. The communication is
established through a passage 132 extending to the exterior of the
housing 18. The pressure of the fluid in the well bore 14 therefore
urges the piston 128 and the piston 120 upwardly (as seen in FIG.
3). In addition, a compression coil spring 132 urges the piston 120
and 128 upwardly, so that the apparatus is restored to the position
illustrated in FIG. 3. The piston 128 is formed with a groove 134
accommodating an O-ring 136 similar in function to the O-ring 124
and preventing passage of fluid from one side to the other of the
piston 128. A ram 138 rigidly connects the pistons 120 and 128 so
that they move together.
Upon the seating of the delay piston 120 in the delay cylinder 118,
which is facilitated by a chamfer 121, no additional fluid can flow
around the piston 120 towards the dump chamber 110. However, the
check valve 116 permits free flow towards the dump chamber 110, and
the upward movement of the pistons 86 and 96 (FIG. 2) in response
to the urging of the spring 103 and the pressure of the fluid in
the well bore 14 transmitted through the lines 92 and 102 is
readily effected.
Thus there is provided in accordance with the invention novel and
highly effective apparatus facilitating the obtaining of a
plurality of readings with respect to fluid in formations traversed
by a well bore in a single traverse of the well bore. The apparatus
is inexpensive to manufacture and repair and greatly reduces the
time required to survey a well.
Many modifications of the representative embodiments of the
invention disclosed above will readily occur to those skilled in
the art. Accordingly, the invention is to be construed as including
all of the modifications thereof within the scope of the appended
claims.
* * * * *