Apparatus for internally testing a plurality of interconnected pipe sections

An apparatus and method suitable for simultaneously testing the integrity of the joints and walls of a plurality of interconnected pipe sections is disclosed. Further, the present invention includes a method and apparatus for sequentially setting at different pressures the packers of such a device. A further feature of the present invention is the actuation of the pressurizing of an annular pipe section testing chamber by the setting of a packer adjacent to the chamber.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an apparatus and method for testing the 
integrity of the walls and joints of a plurality of interconnected pipe 
sections. More particularly, an apparatus, comprising an internal testing 
device constructed of a plurality of tool sections and designed to permit 
repetitive use of an essentially identical intermediate section to provide 
a tool capable of testing any desired number of interconnected pipe 
sections is disclosed. The device of the present invention simultaneously 
and independently determines the integrity of joints and pipe sections in 
a plurality of interconnected pipe sections. The device and method of the 
present invention is conveniently employed to simultaneously test two or 
three interconnected pipe sections prior to the lowering of these sections 
into a borehole. 
2. Description of the Background 
Pressure testing of tubing and pipe sections and particularly of the joints 
therebetween prior to placement of the pipe into a borehole is required in 
order to determine the presence of leaks in the pipe section walls or 
joints. Such testing may be conducted using an external testing tool or an 
internal testing tool. 
An external testing tool generally comprises a cylindrical apparatus having 
a diameter substantially greater than that of the pipe to be tested. This 
tool includes appropriately positioned packers on the inside thereof. An 
internal tool may be lowered about the pipe section and uppermost joint, 
or may be formed in multiple parts which may be placed around the pipe 
and/or joint. Testing is achieved by activating the packers and 
pressurizing the annular space between the pipe or joint and the testing 
tool with a testing fluid at a known pressure. Leaks may be easily 
determined by an observable drop in pressure. 
Various internal testing tools have also been employed. These tools 
generally include a cylindrical body having a diameter substantially less 
than that of the pipe to be tested and having packers on the exterior 
thereof. Such an internal testing tool is lowered into the interior of the 
top pipe section to test the integrity of the top pipe or first joint. 
Setting of the packers and pressurization of the annular space resulting 
between the interior of the pipe, the exterior of the tool and the packers 
provides a pressurized test chamber. Again, leaks are easily detected by 
an observable decrease in the predetermined pressure. 
These known testing methods and apparatus have suffered from the ability to 
provide test results with respect to only one pipe section or joint at a 
time. The loading of a long pipe string into a borehole, particularly in 
deep well operations, is extremely time consuming. It is necessary to be 
sure that there are no leaks in the joints or in the pipe sections 
themselves. Accordingly, it is necessary to test each and every joint and 
pipe section. The above known methods require the testing of each pipe 
section individually as it is added, and greatly increases the time 
required to make-up, test and move the string into the borehole. The 
make-up, testing and loading of the pipe string becomes very costly in 
deep well operations. Accordingly, it would be desirable to test stands of 
interconnected pipe simultaneously to decrease the time required for 
pressure testing the drill string. 
The present invention overcomes this major difficulty by providing an 
apparatus and method capable of testing simultaneously and independently 
the joints and pipe walls of a plurality of interconnected pipe sections. 
It is most convenient to test two or three sections of pipe in a single 
stand. The typical height of the derrick permits the convenient 
manipulation of two or three sections of interconnected pipe in most 
operations. The time required for testing pipe sections is typically cut 
by fifty to sixty-seven percent when employing the method and apparatus of 
the present invention. These savings in time produce significant savings 
in cost in drilling operations, and are particularly beneficial in deep 
drilling operations where the tripping of the drill string may consume 
many hours. 
SUMMARY OF THE INVENTION 
The present invention provides an apparatus and method for simultaneously 
testing the integrity of the pipe walls and joints of a plurality of 
interconnected pipe sections. The device comprises an internal pressure 
testing tool useful for simultaneously pressure testing a plurality of 
interconnected pipe sections. Conveniently, the device and method are 
preferably used to test the pipe joints and the walls of two or three 
interconnected pipe sections simultaneously. 
A device in accordance with the present invention includes an elongated 
conduit, generally of cylindrical shape and having an outer diameter 
substantially smaller than the inner diameter of the pipe sections into 
which it is to be introduced to provide a radial clearance therebetween. 
The device further includes a plurality of packers associated 
longitudinally along the elongated conduit and also normally having outer 
diameters substantially smaller than the inner diameter of the pipe 
sections to facilitate longitudinal movement of the packers and conduit 
within and relative to the pipe sections. The packers are of appropriate 
size and shape so that when expanded they provide a seal against the 
interior of the pipe section to produce a plurality of generally annular 
chambers between the testing apparatus and the pipe. Alternate annular 
chambers are appropriately sized and spaced for testing the integrity of 
the pipe joints and the pipe section walls. The packers are appropriately 
spaced in relation to the pipe to be tested for producing a plurality of 
generally annular testing chambers, some of appropriate size and location 
to provide separate annular chambers for testing the integrity of each 
pipe joint and others for testing the integrity of the major portion of 
each pipe section wall. In a preferred embodiment, the packers are 
positioned so that relatively short chambers are produced for testing the 
pipe joint areas and relatively long chambers are produced for testing the 
pipe wall sections. 
The elongated conduit includes one or more fluid passageways to provide 
passage of fluid therethrough in order to expand and set the packers and 
to provide pressurizing fluid to the generally annular testing chambers 
produced by the setting of the tool within the pipe to be tested. In a 
preferred embodiment, a single longitudinal fluid passageway with 
appropriately spaced generally radial passageways provides a fluid 
communication system for both setting the packers and testing the 
integrity of the pipe section walls. A second longitudinal fluid 
passageway with appropriate generally radial passageways provides a second 
fluid communication system for testing the integrity of the pipe joint 
areas. 
In another aspect of the present invention, the testing device and method 
include packers set at different fluid pressures. In this embodiment, low 
pressure packers are set at a first predetermined fluid pressure followed 
by the setting of high pressure packers at a second, higher predetermined 
fluid pressure. In a further refinement, pressurizing of the annular 
chambers formed adjacent certain packers is actuated by the setting of 
those packers. 
In a preferred embodiment of the present invention, the testing device 
comprises a plurality of interconnected conduit sections, including a top 
section, a bottom section and one or more identical intermediate sections. 
In this preferred embodiment, the intermediate sections each include two 
packers, one being set at a first predetermined pressure and the other 
being set at a second, higher predetermined pressure. These packers are 
arranged generally in close relation to one another so that the annular 
testing chamber formed therebetween is appropriately used to test the 
integrity of a pipe joint. These intermediate sections further include 
appropriate fluid passageways to set the packers and to conduct testing 
fluids through the sections and to the area between one packer, preferably 
the packer set at a higher pressure, and the end of the section. By using 
one or more of these essentially identical intermediate sections, together 
with a top and bottom section, the pipe joints and associated pipe walls 
of two or more interconnected pipe sections are simultaneously tested. In 
a preferred embodiment, one or two of these intermediate sections are 
employed to provide a tool capable of testing simultaneously the joints 
and pipe wall sections of two or three interconnected pipe sections. 
A tool designed to test two or three interconnected pipe sections are 
conveniently used with standard derricks and draw works. Although any 
number of intermediate sections could be used to simultaneously test the 
joints and walls of even larger numbers of interconnected pipe sections, 
such testing becomes impractical because of the height of the derrick and 
draw works which would be required. 
The present method further includes means for setting some of the packers, 
preferably the bottom packers of each pipe wall testing annular chamber, 
prior to the setting of the top packers and introduction of testing fluid 
to the annular testing chamber. This configuration ensures that pressure 
testing fluid used in testing the pipe walls does not invade the annular 
chamber used to test the pipe joints. 
The apparatus and method of the present invention briefly summarized above 
provides significant advantages over that conventionally used in the 
pressure testing of pipe sections. The present method and apparatus 
provides a means of simultaneously testing the integrity of both the pipe 
joints and the pipe walls of a plurality of interconnected pipe sections. 
This method and apparatus significantly reduces the testing time required 
to test an entire pipe string and is particularly useful in deep well 
operations. 
These and other meritorious features and advantages of the present 
invention will be more fully appreciated from the following detailed 
description and claims.

While the invention will be described in connection with a presently 
preferred embodiment, it will be understood that it is not intended to 
limit the invention to that embodiment. On the contrary, it is intended to 
cover all alternatives, modifications and equivalents as may be included 
within the spirit of the invention as defined in the appended claims. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1, there is generally illustrated a pressure testing 
apparatus 10 in accord with the present invention. Apparatus 10 is 
illustrated having a top unit comprising packer section 12a and extension 
section 12b. The apparatus further includes a bottom unit comprising joint 
packer section 14a and bottom packer section 14b. The testing apparatus 
illustrated in FIG. 1 includes two identical intermediate units, each 
including joint packer section 16a and extension section 16b. The 
apparatus illustrated in FIG. 1 is useful in simultaneously pressure 
testing three pipe sections and three joints. Elimination of one 
intermediate unit comprising both sections 16a and 16b would result in a 
pressure testing apparatus useful in testing two pipe sections and two 
associated joints. Insertion of additional intermediate units comprising 
both sections 16a and 16b would provide an apparatus having the capability 
of pressure testing additional pipe sections and joints. 
The apparatus illustrated in FIG. 1 includes a plurality of packers 50 and 
52. In a preferred embodiment, packers 50 are expanded and set at a given 
predetermined pressure. Packers 52 are expanded and set at a second and 
higher predetermined pressure. 
Test apparatus 10 is illustrated disposed within the upper portion of a 
pipe stand including three pipe sections 20 having three connections, 
couplings, collars or the like 26. Pipe sections 20 include box ends 22 
and pin ends 24. When apparatus 10 is so disposed with packers 50 and 52 
expanded and set against the interior walls of pipe sections 20, a 
plurality of generally annular testing chambers 30, 32 and 34 are 
produced. Annular test chambers 30 are preferably relatively short and 
located about joints 26 for testing the integrity of the joint. Longer 
test chamber 32 is located along the wall portion of the first or 
uppermost pipe section 20 while a plurality of similar longer test 
chambers 34 are located along the walls of lower pipe sections. Test 
chambers 32 and 34 are useful in determining the integrity of the pipe 
walls of pipe sections 20. 
Test apparatus 10 illustrated in FIG. 1 includes conventional fluid 
pressurizing systems 36, 40 and 44 comprising an appropriate fluid source 
and pressurizing pump associated with three different fluid passageways 
within the test apparatus. In one embodiment, pressurizing system 36 
provides a liquid hydraulic fluid, e.g., water, useful in setting packers 
50 and 52 to the packer setting chambers. System 40 provides a pressure 
testing fluid, e.g., a single phase inert gas such as nitrogen, for 
pressurizing annular testing chambers 30 for testing the integrity of 
joints 26. Pressurizing system 44 provides a second pressure test fluid, 
e.g., water, for pressurizing annular test chambers 32 and 34 for testing 
the integrity of the pipe section walls. Systems 36, 40 and 44 include 
respectively visual readouts 38, 42 and 46, for providing an easily 
observed visual readout of the fluid pressure in each system. A drop in 
this pressure after pressurization indicates leakage of the pressure 
testing fluid and indicates a failure in one or more of the appropriate 
joints or pipe section walls. 
In a preferred embodiment, pressurizing system 36 is used both to set 
packers 50 and 52 and to pressurize at a known pressure annular testing 
chambers 34. System 40 provides nitrogen at a known pressure to annular 
chambers 30 for testing joints 26. System 44 simply provides a pressure 
testing fluid, preferably water, to upper chamber 32 for testing the 
integrity of the wall of upper pipe 20. 
Referring now to FIGS. 2A-2E, a more detailed description of the presently 
preferred embodiment of the present invention will be provided. FIGS. 
2A-2E illustrate pressure testing apparatus 10 disposed within the upper 
portion of a drill string including a plurality of interconnected drill 
pipe sections 20 and joints 26. Packers 50 and 52 are in the set position 
in the illustrations producing a plurality of generally annular test 
chambers 30, 32 and 34 between the test apparatus and the interior of the 
drill pipe sections. The illustration shows testing apparatus 10 arranged 
to test simultaneously the integrity of the pipe section walls and joints 
of two interconnected pipe sections. A device in accord with the present 
invention useful for testing three or more interconnected pipe sections is 
constructed by inserting the device as illustrated in FIGS. 2B and 2C the 
desired number of times between the device as illustrated in FIGS. 2C and 
2D as is discussed in more detail hereinafter. 
An internal testing tool in accord with the present invention comprises a 
conduit means, preferably comprising a series of threadedly interconnected 
mandrels and sleeves having thereon a plurality of packers positioned so 
as to produce in cooperation with the interior of the pipe sections to be 
tested a plurality of appropriately configured annular testing chambers 
for simultaneously testing the integrity of both the pipe joints and the 
pipe wall sections of a plurality of interconnected pipe sections 20. The 
illustrated device includes upper mandrel 60 having attached thereto tool 
head 18 including bore 28 for attachment of the device to a wireline (not 
illustrated). The device is suspended from a lift cable or wireline 
attached through bore 28 of tool head 18 for lowering into and removing 
from the interconnected pipe sections. Mandrel 60 and all other mandrels, 
sleeves and the like comprising the present tool are of a diameter 
substantially smaller than the inner diameter of the pipe sections to be 
tested to provide a radial clearance therebetween. Mandrel 60 is 
threadedly connected with low pressure packer mandrel 62 about which is 
located first packer 50 of the illustrated embodiment. Packer mandrel 62 
is threadedly interconnected with a long, hollow extension sleeve 64 whose 
length is determined by the length of drill pipe sections to be tested. It 
is desirable that the packers all be located near the pipe joints and 
those skilled in the art can easily provide sleeves, mandrels and the like 
of appropriate length to accomplish this for the pipe sections to be 
tested. Sleeve 64 should be of sufficient length so that the packer 
mandrels and packers threadedly connected at either end thereof are 
located near the ends of the pipe sections. Sleeve 64 is threadedly 
connected at its opposite end with low pressure packer mandrel 66. Packer 
mandrel 66 is threadedly connected to mandrel 68 which in turn is 
threadedly connected to short hollow sleeve section 70 and mandrel 72 for 
passage through a joint 26 of the interconnected pipe sections. Mandrel 72 
is threadedly connected with high pressure packer mandrel 74, having a 
diameter somewhat greater than that of the low pressure packer mandrels, 
e.g., 62 and 66. High pressure packer mandrel 74 is threadedly connected 
at its lower end to hollow, extension sleeve 64. In the illustrated 
embodiment intermediate extension sleeve 64 is threadedly connected at its 
lower end with low pressure packer mandrel 66 located so as to be adjacent 
to the next pipe joint 26. Mandrel 66 is threadedly connected with mandrel 
68, hollow sleeve 70 and low pressure packer mandrel 76 for passage 
through final pipe joint 26. Finally, low pressure mandrel 76 is 
threadedly connected with lowermost low pressure packer mandrel 78 which 
in turn is threadedly connected with end cap 80. 
A test apparatus 10 in accordance with that illustrated in FIGS. 2A-2E and 
partially described above is useful in simultaneously pressure testing the 
integrity of the joints and pipe walls of two interconnected pipe sections 
20 attached to the top of a drill string. Each additional set of mandrels 
and sleeves 66, 68, 70, 72, 74 and 64 and their associated packers and 
internal fluid passage means located between sleeve 64 and mandrel 66 of 
FIG. 2D would permit the simultaneous testing of an additional pipe 
section. 
The conduit means includes therein one or more fluid flow passageways for 
conducting pressurizing fluid to set the packers and test fluid to 
pressurize the annular test chambers formed by the setting of the packers. 
Any number of such fluid passageways may be provided, including one such 
passageway for each test chamber and each packer. However, the space 
available and connection difficulties limit the number which are 
conveniently used. It is convenient to set all the packers from a single 
fluid passageway. Further, because there are few leaks discovered, it is 
convenient to test all of the joints with one fluid passageway system and 
all of the pipe walls with another. Accordingly, it has been found that 
satisfactory result are generally obtained with two or three fluid 
passageways. In a preferred embodiment, a first fluid passageway 82 
extends generally longitudinally through apparatus 10 and comprises a 
plurality of interconnected conduits and connecting chambers such as 
chamber 88. First fluid passageway 82 provides a means for setting all of 
the packers of tool 10 with an appropriate fluid, preferably water. In 
fact, in one embodiment, fluid passageway 82 is employed to conduct the 
pressure testing fluid to pipe wall testing annular chambers 32 and 34. In 
the presently illustrated embodiment, passageway 82 simply conducts the 
pressure testing fluid to chambers 34. A pressure testing fluid, 
preferably water, is conducted to chamber 32 via generally longitudinal 
fluid passageway 104 and generally radial exit port 106. 
In the presently preferred embodiment, the integrity of joints 26 is 
determined using a single phase inert gas, preferably nitrogen, provided 
through generally longitudinal passageway 100 and generally radial ports 
102. 
Setting of the low pressure packers 50 is conveniently discussed with 
reference to FIG. 2A. Fluid under pressure enters testing apparatus 10 
through passageway 82. This fluid passes through generally radial passage 
84 into setting chamber 86 of packer 50. Setting chamber 86 is formed 
between slidable sleeve 90 and low pressure packer mandrel 62. As the 
fluid pressure increases, the size of chamber 86 increases, moving sleeve 
90 outwardly from shoulder 89. Packer 50 further comprises packer rings 
94, 92, resilient packer elements 94 of a resilient material such as 
rubber, neoprene or other material impervious to well bore fluids and stop 
ring 96. As cylindrical packer sleeve 90 moves away from shoulder 89, 
resilient packer rings 94 are compressed and forced outwardly into 
engagement with the inner wall of pipe sections 20. In the presently 
illustrated embodiment, all similar packers 50 are engaged simultaneously 
at a single predetermined pressure, such as 1200 psi. 
In the presently preferred embodiment, a second group of high pressure 
packers 52 are engaged and set at a second, higher predetermined pressure 
such as 2000 psi. As illustrated, high pressure packer mandrel 74 is of a 
significantly greater diameter than that of the various low pressure 
packer mandrels 62, 66, 76 and 78. FIGS. 5 and 2C illustrate the high 
pressure packer unit of the present invention in the retracted and set 
positions, respectively. The high pressure packer mandrel includes 
generally radial setting port 184 to conduct the setting fluid from fluid 
passageway 82 into setting chamber 186. As setting chamber 186 fills with 
fluid, cylindrical sleeve 190 moves away from shoulder 189 moving 
therewith packer rings 192 and compressing resilient packer elements 194 
between packer rings 192 and stop ring 196. 
In the presently preferred embodiment, the movement of cylindrical sleeve 
190 and the setting of packers 52 results in the opening of generally 
radial passage 180 having restriction 182 through which fluid passage 82 
is brought into fluid communication with the resulting annular chamber 34. 
Accordingly, annular chamber 34 is pressurized only after the setting of 
all of packers 50 and 52. Cylindrical sleeve 190 further includes a small 
passageway 198 near the end thereof for relieving the pressure from 
passageway 180 as the pressure is reduced and sleeve 190 moves toward 
shoulder 188. Without such a pressure relief vent O-ring 178 is likely to 
be displaced from its associated groove by the end of sleeve 190. 
The foregoing description of the invention has been directed primarily to a 
particular preferred embodiment in accordance with the requirements of the 
patent statutes and for purposes of explanation and illustration. It will 
be apparent, however, to those skilled in the art, that many modifications 
and changes in the specifically described and illustrated apparatus and 
method may be made without departing from the scope and spirit of the 
invention. For example, while the disclosure of the present method and 
apparatus has been described primarily with regard to the preferred 
embodiment and illustrated in connection with an apparatus for 
simultaneously testing two or three interconnected pipe sections, it will 
be appreciated that a testing apparatus of any length for testing of a 
plurality of interconnected pipe sections may be constructed by employing 
a plurality of intermediate sections 16 together with top section 12 and 
bottom section 14. Further, those skilled in the art will be able to 
provide various combinations of fluid passageways as desired. Therefore, 
the invention is not restricted to the particular form of construction 
illustrated and described, but covers all modifications which may fall 
within the scope of the following claims. 
It is Applicant's intention in the following claims to cover such 
modifications and variations as fall within the true spirit and scope of 
the invention.