U.S. patent number 3,762,219 [Application Number 05/181,984] was granted by the patent office on 1973-10-02 for apparatus for conducting controlled well testing operations.
This patent grant is currently assigned to Halliburton Company. Invention is credited to Robert L. Jessup.
United States Patent |
3,762,219 |
Jessup |
October 2, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
APPARATUS FOR CONDUCTING CONTROLLED WELL TESTING OPERATIONS
Abstract
A well testing apparatus, and method for effecting well testing,
wherein a translatable barrier means is operable to both permit and
indicate a flow of formation fluid through a testing string portion
while continuously preventing a transmittal of fluid from a
formation being tested to a well head and/or a flow of such fluid
past the barrier means. In practicing this method and utilizing
this apparatus, an abruptly operable indicating means is operable
in response to a generation of pressure within a testing string to
provide a well head indication that such a pressure generation has
been achieved.
Inventors: |
Jessup; Robert L. (Duncan,
OK) |
Assignee: |
Halliburton Company (Duncan,
OK)
|
Family
ID: |
22666622 |
Appl.
No.: |
05/181,984 |
Filed: |
September 20, 1971 |
Current U.S.
Class: |
73/152.23;
166/330; 73/152.55; 166/317 |
Current CPC
Class: |
E21B
49/084 (20130101); E21B 34/063 (20130101); E21B
49/088 (20130101) |
Current International
Class: |
E21B
49/08 (20060101); E21B 49/00 (20060101); E21b
049/00 () |
Field of
Search: |
;73/155
;166/264,291,113,224 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myracle; Jerry W.
Claims
What is claimed is:
1. An apparatus for testing the productivity of well formations
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means to wellhead means; barrier means translatable within said
conduit means and operable to permit a flow of formation fluid
through said well formation testing means but block a transmittal
of fluid from said well formation testing means to said wellhead
means, said barrier means including,
first stop means carried by said conduit means,
second stop means carried by said conduit means, and
barrier means carried by said conduit means between said first and
second stop means,
said barrier means being operable to translate between said first
and second stop means in response to a flow of fluid from said well
formation testing means through said conduit means, while
preventing a passage of fluid from said well formation testing
means to said wellhead means;
abruptly operable means carried by said conduit means and abruptly
operable to indicate a generation of pressure within said conduit
means in response to flow of well fluid through said well formation
testing means; and
selectively operable circulating valve means operable to control
the removal of fluid from said conduit means, beneath said barrier
means, said circulating valve means being carried by said conduit
means and at least comprising,
valve means carried by said conduit means beneath said first stop
means operable to control fluid communication between the interior
and exterior of said conduit means, and
means for effecting valving operation of said valve means for
controlling the removal of fluid from said conduit means.
2. An apparatus for testing the productivity of well formations
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means to wellhead means;
barrier means translatable within said conduit means and operable
to permit a flow of formation fluid through said well formation
testing means but block a transmittal of fluid from said well
formation testing means to said wellhead means;
abruptly operable means carried by said conduit means and abruptly
operable to indicate a generation of pressure within said conduit
means in response to a flow of well fluid through said well
formation testing means said abruptly operable means including,
generally telescoping assembled first and second portions of said
conduit means,
detent means operable to secure said first and second portions of
said conduit means in a first predetermined portion,
pressure responsive means movable, in response to exposure to fluid
pressure external of said conduit means in said well bore, to
release said detent means and permit relative movement of said
first and second portions of said conduit means to a second
position, and
differential pressure operated means carried within said conduit
means and operable in response to a generation of pressure
therewithin to cause said pressure responsive means to be exposed
to the pressure of fluid external of said conduit means; and
selectively operable circulating valve means operable to control
the removal of fluid from said conduit means, beneath said barrier
means.
3. An apparatus for testing the productivity of well formations
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means to wellhead means;
barrier means translatable within said conduit means and operable
to permit a flow of formation fluid through said well formation
testing means but block a transmittal of fluid from said well
formation testing means to said well-head means;
abruptly operable means carried by said conduit means and abruptly
operable to indicate a generation of pressure within said conduit
means in response to a flow of well fluid through said well
formation testing means; and
selectively operable circulating valve means operable to control
the removal of fluid from said conduit means, beneath said barrier
means, said circulating valve means including,
first circulating valve means carried by said conduit means and
including
sleeve valve means carried by said conduit means operable to
control fluid communication between the interior and exterior of
said conduit means,
turnbuckle means, manually operable at said wellhead means, to
effect valving operation of said sleeve valve means, and
second circulating valve means carried by said conduit means and
including
rupturable means carried by said conduit means and operable when
ruptured, to provide fluid communication between the interior and
exterior of said conduit means, and
pressure relief valve means operable to limit the generation of
static pressure within the interior of said conduit means adjacent
said rupturable means;
said first and second circulating valve means being spaced
longitudinally of said conduit means.
4. An apparatus for testing well formations, said apparatus
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means, disposed in a well bore, to wellhead means, and
including
upper stop means carried by said conduit means,
lower stop means carried by said conduit means, and
barrier means carried by said conduit means between said upper and
lower stop means,
said barrier means being operable to translate between said lower
and upper stop means in response to a flow of fluid from said well
formation testing means through said conduit means, while
preventing a passage of fluid from said well formation testing
means to said wellhead means;
said barrier means being operable to provide an indication of a
flow of well fluid into said well formation testing means;
selectively operable circulating valve means operable to control
the removal of fluid from said conduit means, including at
least
valve means carried by said conduit means and positioned beneath
said upper stop means to control fluid communication between the
interior and exterior of said conduit means;
said barrier means being further operable to provide a continuously
effective barrier between said upper stop means and the interior of
said conduit means above said barrier means while fluid is being
removed from the interior of said conduit means through said valve
means beneath said upper barrier means.
5. An apparatus for testing well formations, said apparatus
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means, disposed in a well bore, to wellhead means, and
including
first stop means carried by said conduit means,
second stop means carried by said conduit means, and
barrier means carried by said conduit means between said first and
second stop means,
said barrier means being operable to translate between said first
and second stop means in response to a flow of fluid from said well
formation testing means through said conduit means, while
preventing a passage of fluid from said well formation testing
means to said wellhead means;
said barrier means bbeing being to provide an indication of a flow
of well fluid into said well formation testing means;
said barrier means being further operable to provide a continuously
effective barrier between said first and second stop means and the
interior of said conduit means above said barrier means while fluid
is being removed from the interior of said conduit means beneath
said barrier means; and
abruptly operable impact means operable to indicate the generation
of pressure within said conduit means, said abruptly operable
impact means including
generally telescoping assembled first and second portions of said
conduit means,
detent means operable to secure said first and second portions of
said conduit means in a first predetermined position,
pressure responsive sleeve means movable, in response to exposure
to fluid pressure external of said conduit means in said well bore,
to release said detent means and permit relative movement of said
first and second portions of said conduit means to a second
position, and
differential pressure operated means carried within said conduit
means and operable in response to a generation of pressure
therewithin to cause said pressure response sleeve means to be
exposed to the pressure of fluid external of said conduit
means.
6. Apparatus for testing well formations, said apparatus
comprising:
well formation testing means:
conduit means operable to extend from said well formation testing
means, disposed in a well bore, to ellhead means, and including
first stop means carried by said conduit means,
second stop means carried by said conduit means, and
barrier means carried by said conduit means between said first and
second stop means,
said barrier means being operable to translate between said first
and second stop means in response to a flow of fluid from said well
formation testing means through said conduit means, while
preventing a passage of fluid from said well formation testing
means to said wellhead means;
said barrier means being operable to provide an indication of a
flow of well fluid into said well formation testing means;
said barrier means being further operable to provide a continuously
effective barrier between said first and second stop means and the
interior of said conduit means above said barrier means while fluid
is being removed from the interior of said conduit means beneath
said barrier means;
first circulating valve means carried by said conduit means and
including
sleeve valve means carried by said conduit means operable to
control fluid communication between the interior and exterior of
said conduit means,
turnbuckle means, manually operable at said wellhead, to effect
valving operation of said sleeve valve means; and
second circulating valve means carried by said conduit means and
including
rupturable means carried by said conduit means and operable when
ruptured, to provide fluid communication between the interior and
exterior of said conduit means, and
pressure relief valve means operable to limit the generation of
static pressure within the interior of said conduit means adjacent
said rupturable means;
said first and second circulating valve means being spaced
longitudinally of said conduit means.
7. An apparatus for testing well formations, said apparatus
comprising:
well formation testing means;
conduit means operable to extend from said well formation testing
means, disposed in a well bore, to wellhead means; and
including
first stop means carried by said conduit means,
second stop means carried by said conduit means, and
barrier means carried by said conduit means between said first and
second stop means,
said barrier means being operable to translate between said first
and second stop means in response to a flow of fluid from said well
formation testing means through said conduit means, while
preventing a passage of fluid from said well formation testing
means to said wellhead means;
said barrier means being operable to provide an indication of a
flow of well fluid into said well formation testing means;
abruptly operable impact means operable to indicate the generation
of pressure within said conduit means, said abruptly operable
impact means including
generally telescopingly assembled first and second portions of said
conduit means,
detent means operable to secure said first and second portions of
said conduit means in a first predetermined decision,
pressure responsive sleeve means movable, in response to exposure
to fluid pressure external of said conduit means in said well
bore,
to release said detent means and permit relative movement of said
first and second portions of said conduit means to a second
position, and
differential pressure operated means carried within said conduit
means and operable in response to a generation of pressure
therewithin to cause said pressure responsive sleeve means to be
exposed to the pressure of fluid external of said conduit
means;
first circulating valve means carried by said conduit means and
including
sleeve valve means carried by said conduit means operable to
control fluid communication between the interior and exterior of
said conduit means,
turnbuckle means, manually operable at said wellhead, to effect
valving operation of said sleeve valve means; and
second circulating valve means carried by said conduit means and
including
rupturable means carried by said conduit means and operable when
ruptured, to provide fluid communication between the interior and
exterior of said conduit means, and
pressure relief valve mmeans operable to limit the generation of
static pressure within the interior of said conduit means adjacent
said rupturable means;
said first and second circulating valve means being spaced
longitudinally of said conduit means.
Description
GENERAL BACKGROUND, OBJECTS AND SUMMARY OF INVENTION
In connection with the evaluation of well formations, a variety of
devices and techniques have been proposed for evaluating the
pressure of well formations and obtaining a sample of fluid from
formations being tested.
In certain instances it is desirable that such testing operations
be performed without transmitting formation fluid to the wellhead
during the testing operation itself.
Such a prevention of transmission of formation fluid is desirable
where it is imperative or important to maintain secrecy in relation
to the results of the formation test.
In other instances it may be desirable to prevent the transmission
of formation fluid to a wellhead because of the potentially harmful
or noxious nature of the formation fluid itself. Thus, for example,
formation fluid having a hydrosulphide gas content is potentially
dangerous and it would be desirable to insure that such formation
fluid would not be transmitted to the wellhead during a testing
operation so as to insure the safety of personnel in the vicinity
of the wellhead.
Certain techniques have heretofore been proposed for achieving
secrecy and/or safety controls of this general nature.
For example, United States Nutter Patent No. 3,422,896, United
States Jensen Patent No. 3,412,607 and United States Raugust Patent
No. 3,356,137 each relate to techniques for effecting formation
testing under certain conditions of control.
However, in each instance, these three prior art patentees
contemplate arrangements which would permit a flow of fluid from a
formation to a wellhead or past a barrier means during a sample
recovery operation.
In the event that such a valve mechanism should be improperly
operated, the secrecy of a testing operation would be vitiated. In
the event that dangerous or noxious formation fluids were being
handled, a failure to properly operate the valve mechanism could
easily produce a potentially hazardous wellhead situation.
During testing operations it may become desirable to provide an
indication at a wellhead that a particular pressure level has been
generated within a testing string.
A prior art approach at providing such an indication is described
in the aforesaid Nutler U.S. Pat. No. 3,422,896. However, the
Nutter indicating mechanism inherently operates as a dash-pot
apparatus to provide impeded movement of components of a pressure
generation indicating mechanism.
Rather than being vulnerable to the inertia of a dash-pot type
mechanism, it would be preferable to provide an abrupt and timely
indication of the generation of a particular pressure level in a
testing string so that an operator at the wellhead would be
promptly informed of testing conditions.
Bearing these general criteria in mind, and recognizing the state
of the art as heretofore developed, it is a general object of the
invention to provide a method and apparatus for effecting formation
testing such that a flow of formation fluid into a testing
apparatus is permitted, while positively and continuously
preventing a transmission of such fluid to a wellhead and/or past a
barrier means.
It is likewise an object of the invention, in an independent sense,
to provide an abruptly operable and novel mechanism for indicating
at the wellhead that a particular pressure level has been achieved
within a testing apparatus.
It is also an object of the invention to provide an improved valve
system for effecting the controlled removal of formation from the
interior of a testing string.
In accomplishing at least certain of the foregoing objectives, a
method of performing well operations is presented through this
invention which initially entails the disposing of well formation
testing means in a well bore. A barrier means is translated within
this conduit means while permitting a flow of formation fluid
through the well formation testing means but continuously blocking
a transmittal of fluid from the well formation testing means to the
wellhead means and/or past the barrier means. A signal or
indicating means, carried by the conduit means, is abruptly
operable to indicate a generation of pressure within the conduit
means in response to a flow of well fluid through the well
formation testing means. Thereafter a circulating valve means is
operated to remove fluid from the conduit means beneath the
translatable barrier means.
An independently significant method aspect of the invention entails
a method of testing well formations where well formation testing
means is disposed in a well bore. Again, a conduit means is
provided which is operable to extend in the well bore from the well
formation testing means to wellhead means.
Included in this conduit means is a first stop means carried by the
conduit means and a second stop means carried by the conduit means.
A barrier means is carried by the conduit means and interposed
between the first and second stop means.
The barrier means is translated between the first and second stop
means in response to a flow of fluid from the well formation
testing means through the conduit means while continuously
preventing a passage of fluid from the well formation testing means
to the wellhead means and/or past the barrier means. In response to
this translation of the barrier means, an indication is provided at
the wellhead of a flow of well fluid into the well formation
testing means.
Other independently significant aspects of the invention relate to
various combinations of apparatus means operable to accomplish
either or both of the foregoing method aspects of the
invention.
Another independently significant apparatus facet of the invention
pertains to structure of the aforesaid signal means.
This signal means comprises generally telescopingly assembled first
and second portions of the conduit means which extends between the
wellhead means and the well formation testing means. A detent means
is included in the signal means and is operable to secure the first
and second portions of the conduit means in a first predetermined
position. A pressure responsive means, included in the signal
means, is operable to move in response to exposure to fluid
pressure external of the conduit means in the well bore to release
this detent means and permit relative movement of the first and
second portions of the conduit means to a second position. A
differential pressure operated means included in the signal means
and carried within the conduit means is operable in response to a
generation of pressure within the conduit means to cause the
pressure responsive means to be exposed to the pressure of fluid
external of the conduit means.
A unique hydraulic system for counteracting forces tending to
impede operation of the aforesaid detent means is also of
independent significance.
Another independently significant apparatus facet of the invention
relates to structure of the aforesaid circulating valve means.
This structure includes first circulating valve means carried by
the conduit means and comprising sleeve valve means and turnbuckle
means. The sleeve valve means is carried by the conduit means and
operable to control fluid communication between the interior and
exterior of the conduit means. The turnbuckle means, which is
manually operable at the wellhead means, is operable to effect
valving operations of the sleeve valve means.
A second circulating valve means included in the circulating valve
means is carried by the conduit means and includes rupturable means
and pressure relief valve means. The rupturable means is operable
when ruptured to provide fluid communication between the interior
and exterior of the conduit means. The pressure relief valve means
is operable to limit the generation of static pressure within the
interior of the conduit means adjacent the rupturable means. The
first and second circulating valve means are spaced longitudinally
of the conduit means.
Particular advantages are derived from overall combinations of the
various apparatus aspects noted above.
DRAWINGS
In describing the invention reference will be made to preferred
embodiments shown in the appended drawings.
In the drawings:
FIGS. 1a through 1f provide a schematic series of views
illustrating certain sequential manipulations involved in a well
testing operation during the practice of the present invention;
FIG. 1a illustrates a testing string disposed within a well bore at
commencement of a testing operation;
FIG. 1b illustrates the FIG. 1 apparatus near the conclusion of a
testing phase involving a flow of formation fluid;
FIG. 1c illustrates the FIG. 1a apparatus after telescoping
components have been abruptly converged to provide a wellhead
indication of the generation of a testing pressure within the
interior of the testing string;
FIG. 1d illustrates the FIG. 1a apparatus after the apparatus has
been raised at the end of a testing operation so as to dispose
manually operable circulating valve at a location at the wellhead
accessible to operating personnel;
FIG. 1e illustrates the testing string, as disposed in FIG. 1d, and
schematically indicates the manner in which fluid is pumped at the
wellhead into the interior of the conduit string so as to effect
the opening of another circulating valve, carried by the testing
string but disposed within the well bore;
FIG. 1f schematically indicates a circulating technique which may
be employed to effect the removal of formation fluid from the
interior of the testing string;
FIG. 2 provides an enlarged, longitudinally sectioned fragmentary
view of a portion of the FIG. 1a testing string, illustrating
details of a translatable barrier means and a manually operable
valve means during an intermediate phase of a formation flow;
FIG. 2a provides a view of the FIG. 2 components at the conclusion
of a flow phase of a testing operation;
FIG. 3 provides a still further enlarged view of a portion of FIG.
2, illustrating a turnbuckle operated, sleeve-type circulating
valve mechanism which is operable at a wellhead as described in
connection with FIG. 1d;
FIG. 4 provides a transverse sectional view of a spline mechanism
associated with the turnbuckle mechanism of FIG. 3, as viewed along
section line 4--4 of FIG. 3;
FIGS. 5, 6 and 7 joined respectively along juncture lines a--a,
b--b, c--c, provide an enlarged, longitudinally sectioned,
fragmentary view of a portion of the FIG. 1a apparatus illustrating
components of a pressure generating indicating or signal means,
with these components being disposed in their normal or relaxed
condition;
FIG. 8 provides a transverse, sectional view of a detent mechanism
which serves to control the telescoping movement of conduit
components of the FIG. 5-7 indicating mechanism, as viewed
generally along section line 8--8 of FIG. 6;
FIGS. 5a through 7a provide illustrations of the components of the
FIG. 5-7 mechanism, with these components being disposed as they
would be located in response to the generation of a pressure within
the interior of the conduit string sufficient to permit the FIG. 8
detent means to permit relative telescoping movement of telescope
conduit portions of the testing string;
FIG. 8a illustrates the FIG. 8 detent means in the position
operable to permit the aforesaid telescoping movement;
FIG. 9 provides an enlarged, longitudinally sectioned, fragmentary
view of the FIG. 1a assembly illustrating components of a
rupturable circulating valve mechanism associated with pressure
relief means;
FIG. 10 provides a still further enlarged view of that portion of
FIG. 9 which encompasses the aforesaid pressure relief means;
FIG. 10a provides a view of the components of the FIG. 10 relief
valve mechanism, with these components being shown in "exploded"
format; and
FIG. 11 provides an enlarged view of that portion of FIG. 9 which
is directed to a rupturable circulating valve mechanism.
OVERALL DESCRIPTION OF APPARATUS
FIGS. 1a through 1f schematically illustrate the manner in which a
testing string, assembled in accordance with the present invention,
is positioned and manipulated to effect the evaluation of a
subterranean formation means.
As shown schematically in FIG. 1a, this testing string 1 may
comprise, in downwardly extending sequence, the following
components:
Components Reference Numeral Testing string conduit sections
(usually threadably interconnected) 2 Upper stop means 3 Upper
circulating valve means (manually operable) 4 Conduit section which
may comprise desired assembly of drill pipes and drill collars 5
translatable barrier means 6 Lower stop means 7 Pressure generation
indicating means 8 Lower circulating valve means 9 Hydraulic
impedance mechanism 10 Tester valve 11 Extension joint 12 Pressure
recorder 13 Jar mechanism 14 Safety joint 15 Tester packer 16
Perforate anchor pipe 17 Blanked-off pressure recorder 18
As shown schematically in FIG. 1a, tester string 1, which may be
assembled with components as heretofore described, is disposed in a
well bore 19.
Testing string 1 is located in well bore 19 such that a perforate
anchor pipe 17 is disposed in fluid communicating relation with a
subterranean formation 20, the pressure and fluid characteristics
of which are to be evaluated.
Packer 16 serves to isolate formation 20 from the portion of well
bore 19 above the formation 20 by engaging the periphery of well
bore 19 (which may or may not be cased).
Testing string 1 extends upwardly through well bore 19 to wellhead
21, generally indicated in FIG. 1a, and may be supported at its
upper end by conventional hoisting and manipulating means 22.
Novel aspects of the invention, which will be discussed in detail,
relate to structural and manipulative characteristics of the upper
and lower stop means, 3 and 7 respectively, which cooperate with
the translatable barrier means 6. Other novel aspects of the
invention, which will be discussed in detail, pertain to the
indicator or signal means 8 and the composite circulating valve
means 4 and 9.
The remaining individual components of testing string 1 may be
selected from components heretofore available.
For example, the impedance mechanism 10, which serves to effect
controlled lineal movement of components of testing string 1 during
the testing operation, may comprise an apparatus of the type
described in U.S. Schwegman Pat. No. 2,740,479.
The tester valve 11 may comprise a multiple completion, closed in
sampler valve of the type generally described in U.S. Chisholm Pat.
No. 3,358,755 and featured on page 144 of the 1968 Halliburton
Sales & Service Catalogue available from Halliburton Services,
Duncan, Oklahoma.
Extension joint 12 may comprise a telescoping joint corresponding
in general to the extensible joint 8 featured in the aforesaid
Chisholm Pat. No. 3,358,755 and/or the extension joint 15 featured
in a pending U.S. Manes et al. application Ser. No. 882,856, now
U.S. Pat. No. 3,646,995 assigned to the assignee of the present
invention, and the disclosure of which is herein incorporated by
reference.
Recorders 13 and 18, which serve to record the pressure of
formation fluid within the interior of the testing string, may
comprise a variety of formation testing recording devices,
including those described in the aforesaid 1968 Halliburton Sales
& Service catalogue in connection with well testing
apparatus.
Jar mechanism 14 preferably comprises a hydraulic jar mechanism of
the type featured for example in U.S. Barrington Patent No.
3,399,740 and/or U.S. Barrington Patent No. 3,429,389.
Safety joint 15 may comprise a mechanism for permitting selective
separation of the packer bearing, lower portion of the testing
string from the upper testing string portion. The safety joint 15
may comprise, for example, a safety joint of the type in U.S.
Barrington Patent No. 3,368,829.
Packer mechanism 16 may comprise a packer mechanism of the type
used for well testing purposes to isolate a test zone from a well
annulus 19a above the test zone. Such a packer mechanism may
comprise a locked down tester packer available from Halliburton
Service, Duncan, Oklahoma and may also comprise other testing
packer arrangements, including an RTTS tester packer described for
example on page 62 of the aforesaid 1968 Halliburton Sale &
Service Catalogue.
As will be understood, the testing string heretofore described
comprises an assembly of usually threadably interconnected and
generally cylindrical body components. The interior of these body
components provides a longitudinally extending passage which
permits formation fluid to flow into the perforate anchor pipe 17
and thence through the testing string. However, as will be
hereinafter described, this formation fluid is prevented from
passing through testing string 1 to wellhead 21 by the translatable
seal or barrier means 6.
The manner in which components 10 through 18 function is not known
and may be readily comprehended by those skilled in the testing
art. Reference to patents and publications heretofore noted will
provide specific descriptions of the mode of operation and
manipulation of these components.
Thus, the present discussion will be confined to novel aspects of
components 3 through 9.
Prior to describing the manner in which these components perform to
improve the control and safety aspects of well testing operations,
reference will be made to detailed structural aspects of these
components.
BARRIER MEANS STRUCTURE
Testing string 1 includes a barrier means structure comprising
first stop means 3, second stop means 7, and the translatable
barrier 6.
As shown generally in FIG. 2, first or upper stop means 3 may
comprise an annular shoulder 301 which extends, radially or
transversely across a central longitudinal passage 101 of testing
string 1. As shown in FIG. 2, annular shoulder 301 faces generally
downwardly.
The second or lower stop means 7 similarly comprises a radially or
transversely oriented shoulder 701 which extends across central
tool passage 101.
Barrier 6 is disposed in passage 101 between the downwardly and
upwardly facing top surfaces 301 and 701.
Barrier 6 may comprise a multiple stage, cementing shut-off plug of
the type generally described in the 1968 Halliburton Sale &
Service Catalogue. An exemplary plug is featured, for example, in
FIG. 3 of page 9 of this catalogue.
Referring again to FIG. 2, it will be noted that the plug 6 is
disposed in passage 101 so as to be movable in an upward direction
in response to the pressure of fluid acting there beneath.
At the commencement of a testing operation, and when the string 1
is initially positioned in the well bore 19, plug 6 will be
disposed in supported or abutted engagement with shoulder or stop
701. A flow of fluid upwardly through passage 101, beneath stop
means 7, will engage plug or barrier 6, and cause upward movement
of this barrier or plug toward the upper stop 301.
Upper movement of plug or barrier 6 will continue until the plug
engages shoulder 301 at which point upward movement of the plug is
arrested.
Upward movement of plug or barrier 6, as heretofore described, will
upwardly displace fluid which may be present in passage 101 above
the plug or barrier 6. This displacement of fluid will be
transmitted to the portion of the testing string 1 disposed at the
wellhead and may be observable in the form of a flow or "blow" of
fluid emanating from open passage means of the string 1 at the
wellhead 21.
The fluid thus displaced in the passage 101 above the plug 6 may
comprise gas such as air and/or may comprise liquid such as water
or weighted fluid.
As will be appreciated, the nature of plug 6 is such that it
cooperates with the cylindrical wall 102 of passage 101, between
the stop means 301 and 701, to provide a translatable seal. This
translatable or piston type seal prevents a transmission of fluid
from the tester means 11 to the wellheads means 21 but does permit
a flow of fluid into the perforate tail pipe portion 17 of the
tester string and into and through the tester valve means 11.
Thus, solid plug means 6 is imperforate, i.e. non-valved, and
provides a translatable, but continuously effective, barrier or
seal which permits flow tests in relation to a subterranean
formation to be performed, and provides a surface indication of
formation flow. This barrier prevents a transmission of formation
fluid through the testing string to the wellhead and/or a flow of
fluid past the barrier during sample recovery operations.
In this manner secrecy of a testing operation is preserved and a
flow of dangerous or noxious well fluid to the surface is
prevented.
With the structure and basic mode of operation of the barrier means
having been described, attention will now be directed to the
indicator or signal means 8.
INDICATOR (SIGNAL) MEANS STRUCTURE
Structural details of the indicator or signal means 8 are set forth
in FIGS. 5 through 8 as well as in FIGS. 5a through 8a.
FIGS. 5 through 8 illustrate components of the indicator means 8 as
they are disposed, at the commencement of a testing operation, in a
normal or neutral condition.
FIGS. 5a through 8a illustrate a disposition of indicator means
components operable to provide an indication or signal at the
wellhead, responding to a generation of pressure within the passage
101. Such a generation of pressure would result when the plug or
barrier 6 was seated on the stop 301 and the pressure of formation
fluid was being transmitted to the interior of passage 101, thereby
causing a pressure buildup in response to formation pressure in
this testing string passage zone.
Indicator or signal means 8, which functions to generate an impact
or weight increase signal (detectable at the wellhead by observing
the "weight" of the testing string 1 effectively supported by
support means 22), comprises generally telescopingly assembled
first and second body portions 801 and 802.
Body portion 801 may comprise threadably interconnected, generally
cylindrical components 803 and 804. A second body means 802 may
comprise threadably interconnected components of a generally
cylindrical nature including components 805, 806, 807 and 808.
A detent means 809, generally depicted in FIGS. 5 and 8, is
operable to secure the first and second body portions 801 in a
first, predetermined, telescopingly extended position generally
depicted in FIGS. 5 through 7.
Detent means 809 may comprise a series of circumferentially spaced,
detent segments 810 carried in radially extending aperture portions
811 of body portion 805. Detent means segments 810, when biased or
disposed in a radially outward position as shown in FIG. 5, extend
or project into an annular and inwardly facing recess 812 carried
by body portion 804. This disposition of the detent segments 810 in
recess 812 effectively interlocks body portions 801 and 802 in a
first, telescopingly extended position and thereby substantially
prevents telescoping or relative lineal movement of these conduit
body portions.
Detents 810 are secured in the FIG. 5 position by a pressure
responsive sleeve means 813.
As shown in FIGS. 5 and 6, pressure responsive sleeve means
includes an outwardly facing, cylindrical surface 814 which is
operable to engage the inner surfaces of segments 810, and thus
secure these segments in locking cooperation with recess 812.
Pressure responsive sleeve means 813 includes an outwardly
extending, annular piston means 815. As shown in FIG. 6, piston 815
is telescopingly mounted in an annular recess 816 of body portion
806. To facilitate upward movement of sleeve 813, recess 816, above
piston 815 disposed in its FIG. 6 position, may be evacuated. In
any event, area 816 above piston 815 will be either occupied by a
vacuum or by a readily compressible medium or be vented.
Fluid acting on the underside of piston 817 of piston 815 will be
operable to cause the sleeve 813 to move upwardly. Such upward
movement of sleeve 813 will serve to bring an outwardly facing,
annular recess 818 into radial alignment with the segment 810. When
this occurs, the segments 810 will be operable, because of their
generally radially sliding mounting in apertures 811, to move
radially inwardly, out of locking cooperation with recess 812.
Thus, upward movement of sleeve 813, in response to pressure acting
on piston 815, will effect the releasing of the detent means 809 so
as to permit relative converging or telescoping movement of conduit
portions 801 and 802.
As will be appreciated, this telescoping movement will be
relatively abrupt so as to provide an abrupt increase in the
apparent weight of the testing string 1 supported by the means 22.
It is contemplated that this converging movement may be such as to
permit mutually facing, annular abutment means 819 and 820, carried
respectively by the first and second conduit portions 801 and 802,
to be brought into abrupt impacting cooperation so as to provide an
impact signal readily detectable at the wellhead, reflecting
converging or telescoping movements of the body portions 801 and
802.
The aforesaid upward movement of sleeve 813 may be effected by
transmitting fluid from well bore 19, externally of testing string
1, through passage means in body portion 802 to the underside of
piston 815, i.e. to surface 817.
Such passage means may comprise longitudinally extending passage
means 821 formed in body portion 807 and communicating directly
with the underside surface 817 of pisotn 815. As shown in FIG. 7,
passage means 821, at its lower end, communicates with radially
extending or transversely extending passage means 822 also carried
by body component 807. Passage means 822 extends radially inwardly
and terminates on an inner face 823 of component 807.
Another radially or transversely extending passage means 824,
carried by component 807, provides communication with the exterior
of well bore 19, surrounding testing string 1. When passage means
824 is placed in fluid communication with passage 821, well fluid
will flow from the exterior of the testing string 1, through
passage 824, upwardly into passage means 822, and from passage
means 822 through passage mmeans 821 to piston 815; i.e., to
surface 817.
The pressure of fluid in the well annulus 19a may be selectively
controlled from the well head, if necessary, to insure that the
pressure of fluid thus transmitted to piston 815 will be sufficient
to induce upward movement of the sleeve 813 and permit the
aforesaid releasing action of the detent means 809. Ordinarily
annulus pressurizing is not necessary.
In effecting sleeve movement in this manner, an operator places
reliance upon the controllable pressure of fluid in the well
annulus and does not depend upon the uncertain pressure conditions
of formation fluid which may occupy the interior passage 101.
Control over the passage of annulus fluid between passage means 824
and 822 is effected by a differential pressure operated sleeve
means 825.
As shown in FIG. 7, sleeve means 825 is carried by body portion 802
and is disposed in telescoping cooperation with component 807
Sleeve 825 includes a longitudinally and circumferentially
extending and radially outwardly facing recess 826. When sleeve 825
is disposed in its lower position, as shown in FIG. 7, recess 826
is displaced from passage 822. However, when sleeve 825 is
elevated, the recess 826 is brought into communication with each of
the passage means 822 and 824 so as to permit a transfer of annulus
fluid from the zone 19a external of the testing string,
consecutively through passage means 824, recess 826, passage means
822, and the passage 821 for transmittal to piston 815.
Transmission of annulus fluid into the interior passage 101 may be
prevented by conventional O-type, seal ring means 827.
Differential pressure operated sleeve 825 is biased to the lower or
neutral position shown in FIG. 7 by a conventional, compression
type, coil spring 828. Coil spring 828 encircles the outer
periphery of the lower portion of sleeve 825 and engages, at its
lower end, an upwardly facing shoulder 829 carried on the outer
periphery of sleeve 825. The upper end of spring 828 engages, and
is thus secured by, a generally radially extending and downwardly
facing edge or shoulder 830 of body component 807.
Lower portion 831 of sleeve 825 has an outer surface 832 having a
diameter which somewhat exceeds the diameter of external wall
portion 833 of upper sleeve portion 824. This difference in
diameters of upper and lower sleeve portions, coupled with the
constant diameter internal surface 835 of sleeve 825, provides a
differential piston which yields a differential area or pressure
effect. With this differential pressure effect, a pressure of fluid
within passage 101 in the vicinity of sleeve 825 will provide a
differential pressure acting upwardly on sleeve 825. When this
pressure differential acting upwardly is sufficient to overcome the
downward bias force of spring 828, the sleeve 825 will shift
upwardly so as to bring the passage portions 824 and 822 into
mutually communicating relation via recess 826.
Thus, during a flow phase of a well testing operation, when the
barrier or plug 6 has engaged the stop 301, a pressure buildup will
occur in passage 101 beneath plug 6 and adjacent sleeve 825,
resulting from formation pressure being transmitted to fluid in the
passage 101. When this pressure buildup reaches a predetermined
level, as determined by the differential pressure necessary to
overcome the biasing influence of Spring 828, sleeve 825 will shift
upwardly and allow the pressure of annulus fluid external of
passage 824 to be transmitted to piston 815. This transmission of
pressure will cause sleeve 813 to shift upwardly and free the
detent segments 810. This sleeve shift, in turn, will permit
relative converging movement of body portions of 801 and 802 and
generate a surface detectable signal.
The disposition of the components of signal or indicating means 8,
after the aforesaid telescoping movement of conduit body portions
801 and 802 has occurred, is illustrated in FIGS. 5a through
8a.
Thus, FIG. 7a illustrates the differential pressure operated sleeve
825 disposed in an elevated position such that fluid pressure from
the well bore annulus is transmitted through passage means 824,
recess 826 and passage means 822 and 821 to piston 15.
As shown in FIG. 6a this transmission of pressure to piston 815 has
caused the piston and its sleeve 813 to elevate so as to permit the
detent segments 810 to collapse radially inwardly into the sleeve
recess 818. This collapse or radial inward movement of segments 810
out of recess 812 permits the body portion 801 to move downwardly
relative to body portion 802, as generally depicted in FIG. 6a.
As shown in FIG. 6a this relative convergence may be sufficient to
bring the body portion surfaces 819 and 820 into abutting impact so
as to insure the generation of a readily detectable, abrupt signal
at the wellhead.
Even without the presence of the abutment means 819 and 820, the
relative converging movements of body portions 801 and 802 would
provide a change in indication of apparent weight of the testing
string so that an operator could readily determine that abrupt to
telescoping movement of the components 801 and 802 had occurred.
This abrupt movement indicates, in a prompt manner, that level has
been obtained within the interior of passage 101 beneath the plug
means 6.
The relative converging movements of the component 801 and 802,
heretofore discussed is facilitated by providing venting means in
the telescoping joint area between these body portions.
Thus, as shown in FIG. 5, body component 804 may be provided with a
vent passage 835 which communicates with an upper zone 836 between
components 804 and 805 to the exterior of the testing string.
Another passage 837, carried by body component 805, communicates a
lower zone 838 between components 804 and 805 with the interior
passage 101.
The arrangement of passage 835 and area 836 permits annulus fluid
to act downwardly on a piston on shoulder 839 carried by lower body
portion 802 and thus offset any "buoyant" force acting on this body
portion due to the head of annulus fluid acting on the closed,
lower end of the testing string. This pressure equalizing effect
minimizes the imposition of vertical forces on detents 810 caused
by converging movement of elements 804 and 805 of body means 801
and 802, which forces might otherwise impede retracting movement of
these detents.
This "buoyant" force may be offset, for example, by the presence of
a water cushion in passage 101. Passage 837 and cavity 838 enables
this offsetting force, acting downwardly on body means 802 and
tending to separate body means 801 and 802, to itself be
substantially compensated. The pressure of fluid in passage 101, in
being transmitted via passage 837 and cavity 838, would exert a
lifting force on the underside of piston 839, tending to offset the
aforesaid downwardly directed force.
As will be understood, this downwardly directed force, by itself
and to the extent not offset, would cause body element 805 to act
downwardly on detents 810 and impede their movement.
In the manner heretofore described, both downwardly and upwardly
directed hydraulic forces acting on body means 802, and tending to
separate or converge body means 802 and 801 so as to impede
movement of detent means 810, are at least in part offset or
compensated so as to facilitate smooth retracting operations of
detent means 810. In this manner, abrupt, timely operation of
signal means is facilitated.
It will be noted that axial separation of components 801 and 802 is
prevented, even in the absence of the action of detent means 810,
by the radially extending and outwardly projecting shoulder means
839. This shoulder means is carried by body component 805 between
shoulder means 840 and 841 of body portion 801.
Relative rotation between body portions 801 and 802 is prevented by
spline means 842, depicted for example in FIG. 5.
In connection with the venting action inherently provided by
passage means 837 and 835, it will be noted that this venting is
accomplished without inducing any substantial impedance to
telescoping movements, thereby avoiding the restrictive passage
arrangement illustrated in the aforesaid Nutter U.S. Pat. No.
3,422,896. The Nutter arrangement, as disclosed, would inherently
produce a substantial throttling or dash-pot action.
In summary, the present invention contemplates an invention such
that, with the detent segments 810 released from the recess 812,
abrupt converging movement of the body portions 801 and 802 may
occur as to promptly generate a signal indicative of the generation
of a particular pressure within tool body portion 101. The
attainment of this pressure level, as indicated at the wellhead,
will advise an operator at the wellhead that the fluid recovery
operation has attained a prescribed pressure buildup level within
the recovery chamber (i.e., the chamber above component 10 and
beneath the barrier 6 when barrier 6 is disposed in its upper
position in engagement with stop 301.
Having described the manner in which the barrier means, including
plug 6, functions to 1) permit a flow of formation fluid into the
testing string, 2) prevent a transmission of this flow to the
wellhead, and 3) indicate the beginning and termination of the flow
in response to the beginning and termination of a wellhead "blow"
correlated with movement of the plug 6, and having described the
manner in which the attainment of predetermined pressure buildup
within the sample retaining cavity of the testing string is
effected to respond to operation of indicator or signal means 8, it
becomes appropriate to now consider the operation of the
circulating valve means including the upper circulating valve 4 and
the lower circulating valve 9. These circulating valves provide a
cooperation arrangement permitting controlled removal of the sample
of formation fluid from the tool cavity beneath the barrier means
6.
As will be understood, the circulating valve means 4 and 9 will be
operated only after an operator has closed tester and/or sampler
valve means 11 in response to detection of the signal indication
provided by indicator or signal means 8. In promptly responding to
this signal or indication, an operator can close valve means 11 so
as to isolate a formation fluid sample (below valve means 11 or in
a chamber thereof) under optimum and/or desired gas/oil ratio
conditions, etc.
CIRCULATING VALVE MEANS STRUCTURE
The circulating valve arrangement of the present invention is such
that valve means 4 and 9, when open, enabled a displacing fluid to
be passed into the passage 101 beneath the plug 6 and displace
formation fluid which has passed into this area of the testing
string during a flow phase of the testing operation.
The upper or first circulating valve means is manually operable and
includes components shown in FIGS. 2, 2a, 3 and 4.
As there shown, circulating valve 4 includes a valve opening or
port means 401 formed in a cylindrical wall 402 of the testing
string. A valve sleeve 403 is telescopingly mounted over opening
401 and includes a sample removal fitment 404.
Removal fitment 404 may comprise a threaded socket 405 operable to
receive either a plug 406 or conduit means connection 407
(generally depicted in FIG. 2a).
Plug 406 may be apertured so as to provide fluid passage means, as
shown in FIG. 3 or may comprise an imperforate sealing plug.
With sleeve 403 disposed as shown in FIG. 3, valve opening 401 is
closed. This closing action is facilitated by various conventional
O-type, seal rings 408.
Sleeve 403 is connected or telescopingly mounted on body means 402
by way of spline connection means 409. As shown in FIGS. 3 and 4,
spline connection means may comprise a plug 410 threadably secured
to the valve body 402 and projecting into a longitudinal slot 411.
Slot 411 is formed on the interior of a lower portion of sleeve
403.
Longitudinal valving movement of sleeve 403 is manually effected by
turnbuckle means 412.
Turnbuckle means 412 comprises a threaded sleeve 413 which is
threadably engaged with a threaded lower portion 414 of valve
sleeve 403. The lower end 415 of turnbuckle sleeve 413 is journaled
on body portion 402 and is rotatably secured between flange 416 and
a radial shoulder 417. Shoulder 417 may be provided by the upper
end of a conduit section of conduit string 1 which is connected to
the lower end of conduit or string portion 402.
With this arrangement, manually induced rotation of the turnbuckle
sleeve 413 will cause or induce longitudinal valve movement of
sleeve 403.
When this valving movement is such as to cause the sleeve 403 to
move downwardly, the sleeve aperture or recess 405 will be brought
into alignment with the opening 401.
If a fitting or connection 407 is connected with the socket 405,
when the components are disposed in the FIG. 3 relationship, i.e.
the closed valve relationship, downward movement of the sleeve 403
will bring the passage 401 into alignment with the fitting 407 so
as to enable fluid from the formation sample cavity 101 to flow out
of or into this cavity 101 via the alignment of openings 401 and
the fitting 407.
The second or lower circulating valve means 9 is generally
illustrated in FIGS. 9 through 11.
As shown in these figures, circulating valve means 9 may be
supported on body component 808 of indicating means 8.
Circulating valve means may comprise a generally cylindrical body
portion 901.
Body portion 901 may itself support rupturable passage means 902
and pressure relief valve means 903.
The rupturable means 902, as shown in FIGS. 9 and 11, may comprise
a threaded fitting 904, threaded into body portion 901. A
rupturable disc or disphragm 905 is secured against a shoulder
portion 906 of fitting 904 by a threaded ring 907.
With this arrangement, the attainment of a particular pressure
level in passage portion 101 adjacent diaphragm or disc 905 will
effect the rupturing of this disc so as to permit a flow of fluid
through a central passage 908 of fitting 904. With the disc 905
ruptured, fluid communication is thus provided between the interior
and exterior of the conduit means portion 901 of the overall
testing string.
The pressure relief valve means 903, as shown in FIG. 9 and in
greater enlarged detail in FIGS. 10 and 10a, includes a plug-like
fitting 909 threadably secured within body 901.
Fitment 909 includes a restricted passage or orifice 910 which is
operable to provide fluid communication between cavity or passage
101 and the exterior of the testing string.
A valve 911 is mounted in an interior passage 912 of fitment 909
and is operable to engage a generally frustoconical valve seat 913.
Valve 911 is biased against valve seat 913 by a conventional,
compression spring 914.
The inner end of compression spring 914 engages valve body 911
while the outer end is anchored by or secured to a bracket means
915. Bracket means 915, as shown in expanded view in FIG. 10a and
in assembled view in FIG. 10, comprises an anchor ring 916
including circumferentially spaced flow passage means 917. A snap
ring 918 serves to secure flange 916 in the FIG. 10 disposition and
prevent its outward movement.
Pressure relief valve means 903 is operable, during the time a
testing string is being raised at the conclusion of a testing
operation, to vent the portion of passage 101 containing a sample
of formation fluid when [in the event] the pressure in the interior
of the tool exceeds the pressure in the exterior. The venting
pressure differential will be determined by the strength of spring
914.
Thus, during static conditions when the string is being raised with
the space 101 occupied by formation fluid, the increase in pressure
differential will serve to automatically open vent valve 903 when
the pressure differential exceeds a limit deemed acceptable for
safety purposes. Were this arrangement not provided, the pressure
differential might be such as to induce premature rupturing of the
disc 905. Such premature rupturing could cause the entire formation
sample to be lost during the raising of the testing string, and
thus defeat the overall ample recovery operation.
As will be appreciated, the restrictive nature of orifice 910 is
such that, under flow conditions, where fluid is flowing from the
interior space 101 outwardly through the open valve 903, a pressure
buildup may be achieved within the cavity 101 adjacent disc 905
sufficient to induce rupturing of this disc.
Thus, by pressurizing the interior space 101 adjacent disc 905 to
an extent such that valve 903, when open, does not possess
sufficient flow capacity to adequately relieve the pressure
buildup, rupturing of the disc 905 may be effected.
With the overall components of the apparatus having been described,
it now becomes appropriate to consider the manner in which a
testing operation may be performed, particularly with reference to
operation of the components 3, 4, 5, 6, 7, 8 and 9.
The operation of these components will now be described with
reference to FIGS. 1a through 1f.
MODE OF OPERATION
As shown in FIG. 1, testing is initiated by disposing the testing
string 1 in the well bore 19.
Through operation of tester string components and manipulation of
the tester string, in manners now well understood, the packer 16
may be expanded so as to isolate the formation 20 from the annulus
zone 19a above the set packer 16. In this manner, the interior 101
of the testing string beneath the barrier plug 6 is placed in fluid
communicating relation with the fluid of formation means 20.
When the testing operation is initiated, the plug 6 will be
disposed in its lower position, supported on stop means 7.
Once testing commences, as generally shown in FIG. 1b, the flow of
fluid into the interior 101 of the testing string, as permitted by
the opening of valve means 11, will induce upward movement of the
plug 6. This upward movement of the plug 6 continues until plug 6
comes to rest against the upper stop means 3.
The initiation of this movement of the plug 6 will initiate a
"blow" or flow of fluid at the well head, out of passage means in
the upper end of the testing string 1. This initiation of flow at
the well head or "bow" will advise the operator of the initiation
of flow of formation fluid into the passage portion 101 beneath the
barrier or plug 6.
When plug 6 comes to rest against the stop means 3, this "blow" or
flow at the well head will cease and an operator will thus be
advised of the seating of the plug 6 and termination of flow.
With plug 6 seated, pressure will rise in cavity 101 beneath the
seated plug 6 until the detent means 809 of indicator means 8 is
released. This releasing action will permit the convergence of body
portions 801 and 802 generally depicted in FIG. 1c. This
convergence or collapsing of the telescoping means 801 and 802,
resulting from downward movement of body means 801, will provide a
well head indication that a pressure level has been obtained in
cavity 101 sufficient to induce the tripping action of indicator
means 8. This tripping action will be abrupt and prompt so that an
operator will be promptly advised that a predetermined pressure
level has been achieved.
In being thus promptly informed of the predetermined pressure
level, the testing string can be promptly manipulated so as to
close the valve 11 and prevent the generation of an excessive
pressure in the cavity 101 in the sample entrapping chamber portion
of passage 101, extending above valve 11 and beneath the set plug.
This insures a more representative gas-oil ratio in the sampler
(comprising valve 11 and/or sample chamber) then would otherwise be
obtained if too little or too much time had elapsed.
With the operator being advised of the attainment of a desired
pressure buildup in tool cavity 101, and with the testing operation
having been concluded by the closing of valve means 11, an operator
may then manipulate support means 22 so as to effect the raising of
the testing string to the position generally shown in FIG. 1d.
As shown in FIG. 1d, the testing string has been raised so as to
bring valve means 4 to the vicinity of well head 21.
As generally shown in FIG. 1d, a conduit fitting 407 has been
connected with sleeve 403 of valve means 4 and turn buckle 413 has
been operated so as to place the interior 101 of the testing string
(beneath plug 6) in fluid communication with the interior of the
conduit extending away from fitting 407.
In this connection it will be appreciated, by reference to FIG. 1,
that plug 6, when engaged with seat 301, serves to position valve
passage or opening 401 and fitting 407 beneath this plug.
As schematically depicted in FIG. 1e, pressurized fluid may be
transmitted from pump means to fitment 407 so as to intensely
pressurize the interior 101 of the testing string and induce the
rupturing of disc 905 in the manner heretofore indicated.
With disc 405 thus ruptured, conventional annulus pressurizing pump
means may be operated so as to reverse circulate annulus fluid into
passage 908. This will displace the recovered sample from cavity
101, out of passage 401 and into a conduit means extending from
valve means 4 for sample recovery purposes.
Conventional valve mechanisms associated with the conduit extending
from valve means 4 and associated with the pump system for
pressurizing the annulus may be employed to rapidly switch flow
conditions from the pressurizing and disc rupturing arrangement
shown in FIG. 1e to the sample recovery arrangement shown in FIG.
1f where fluid is flowing from valve means 4 to a sample recovery
zone 23.
As will be apparent, other circulation techniques might be employed
under certain circumstances to effect the removal of sample fluid
from the cavity 101. It is conceivable, for example, that the disc
905 might be ruptured by internal pressure so as to permit the
sample fluid to be displaced into the annulus in response to
downward movement or by passing of plug 6 before starting out of
the hole.
SUMMARY OF MAJOR ADVANTAGES AND SCOPE OF INVENTION
A particularly significant advantage of the invention is
attributable to the manner in which the barrier mechanism
positively and continuously insures that formation fluid will not
be transmitted to a well head during a sample gathering and
pressuring testing operation and will not flow past the barrier
mechanism during sample removal.
Significantly, this control and/or safety aspect is achieved
without impairing the efficiency of a testing operation.
Furthermore, the possibility of human or mechanical error
permitting an inadvertent flow of fluid to the well head or past
the barrier mechanism is avoided.
The manner in which the indicating or signaling mechanism provides
a prompt indication at the well head of the generation of a
particular pressure level in the sample recovery zone of the
testing string provides prompt and timely information to an
operator. This prompt and timely information enables an operator to
terminate a testing operation at the optimum time to obtain a
representative sample and without producing an excessive buildup
within the interior of a testing string.
The overall circulating valve system provides an improved and
simplified arrangement for removing a sample from a testing string,
in conjunction with maximum secrecy operation or conditions.
These advantages, either individually or in a combination sense,
afford a significant improvement in relation to controlled
formation evaluation operations.
Those skilled in the testing art and familiar with this disclosure
may recognize additions, deletions, substitutions or other
modifications which would fall within the purview of the invention
as set forth in the appended claims.
* * * * *