Note: Descriptions are shown in the official language in which they were submitted.
~ ~z~
PETROLFU~ EOUIP~ENT TUBULAR CONNECTION
BACKGROUND OF TH~ INVENTION
I. Field o~ the Invention
The present invention relates to an anaerobic sealant
composition and the use thereo~ to seal pipe joints
between pin and box members intended ~or downhole
~z~
tubular goods used in petroleum drilling operations.
The invention encompasses the method of application of
the sealant composition to the pipe joint structure, and
the resulting connection.
For purposes of the invention, the term "petroleum
operations" will be taken to include, but not
necessarily be limited to, operations related to the
exploration, drilling, the extraction from the earth of
oil, gas, water, and geothermal materials as well as the
disposal of nuclear and/or toxic wastes. Additionally
the term "pipe" will be used for convenience to refer to
all downhole tubular goods, whether it be tubing, drill
pipe, casing, production pipe, or the like.
The term "drilling" will be taken to include the
formation of a deep hole through which the materials are
extracted or returned beneath the surface of the earth.
It will be understood, however, that pipe having the
same characteristics of that used in petroleum
operations can also be used in the opposite sense, that
is, to return materials into the earth. Such a
procedure is involved in the return of petroleum
products to underground storage or the transfer of
nuclear wastes to underground containment fields.
.~ .
4~
The invention herein is concerned with the connection
between two lengths of pipe. The ends to be joined of
the two lengths of pipe are commonly referred to as a
"pin" and as a "box". In this context, a "pin" may be
a threaded end of pipe and a "box" may likewise be a
threaded end of pipe and a coupling connected thereto
with suitable threads for receiving a pin. However,
these terms should be read sufficiently broadly to cover
connecting mechanisms other than threads. Also, the
term "make up" and variations thereof are taXen to mean
assembly to two pin and box members, and the term
"break out" and variations thereof, are taken to means
disassembly of the pin and box members.
II. Description of the Prior Art
The problems associated with petroleum drilling
operations are many and extreme. The conditions
experienced include extremes in kemperature, not only
between polar regions and equakorial regions, but also
of the products being extracted and the high temperature
of the formations at depth. Pressures can be intense in
the depths of the earth as well as exposure to the harse
corrosiveness of such toxic materials as sulfur dioxide
and hydrogen sulfide.
~ ~ ~Z~8~7
LC-184 ~4~
Particulary grueling are the stresses impo~ed on
downhole tubular goods in the inætance of a string of
pipe which may be many thou6and~ of f eet in 1 ength.
Couplings or tubular connection~ for lengths of pipe
are of paramount importance in the drilling operation
and serve two primary functions. In the first
instance, they hold the weight of the pipe which can
amount to two million pounds or more and they serve to
seal the pipe both against incursions from its exterior
as well as loss of the products being extracted. The
customary type of pipe connections used in drilling
operations are threaded joints and the industry
standards which have been established by the American
Petroleum Institute ~API) are known as ~API 8-round~
and as ~API buttress~ threads.
Leaking pipe connection~ have represented a significant
problem to the petroleum indu~try, and the problem
continues although recent research and development
efforts by connection manufacturers and op~rators have
made significant improvements in technology. Premium
connection designs employing various combinations of
~2~Z4~
interference fit threads metal-to-metal seals, new
generation of non-metallic seal materials, higher
alloyed steels, and computer/numerical control machining
technology have been developed and are very effective.
Typical of such premium connection designs ara those
disclosed in U.S. patents to Blose No. 4,244,607 issued
January 13, 1981 and Re. 30,647 reissued June 16, 1981.
Some of these designs include "Teflon"TM brand o-rings,
or the like, as sealing aids. In this instance,
sufficient material must be removed from the pipe end in
the region of the joint to accommodate the o-ring.
Such removal necessarily weakens the joint and increases
the stresses imposad on the joint. Furthermore, the o-
ring material does not have sufficient plasticity to
satisfactorily seal the interstices of the joint.
"A,
lZ~2~
Nonetheless, failures continue to occur due in part to
greater sensitivity of many of these designs to
handling, running, and environmental factors. Single
failures of production strings have cost millions of
dollars and they continue to occur as industry continues
to push back the technology frontier. One of the most
pervasive causes of these connection failures is
leakage. Aside from design problems, many new
connections are easily damaged by a variety of common
rig and handling procedures.
As a further effort to prevent leaking connections,
sealing materials have been developed and are widely
used by the industry. Numerous such sealing materials
are available such as ShellTM high pressure thread
compound produced by Shell Oil Corporation, EXXONTM 706
thread compound produced by EXXON Corporation, and
"Liquid-O-Ring" brand thread compound manufactured by
Oil Center Research, Inc. of Lafayette, Louisiana.
These material meet API standard and are referred to as
"API modified". Typically, the components of these
sealing materials include an oil based lubricant, and
sealant components which may include, for example,
.~
., .. ~
12~2413~
LC-184 -7-
powdered graphite, lead powder, zinc dust, and copperflake. There is no chemical reaction between the
sealant componen~s and the lubricant. The composition
is merely a mixture and there is no curing step
involved in its preparation or u~e. These sealing
materials remain in a liquid form, seeking any voids
which are present between the mating threads within the
joint.
While such sealing materials have worked reaæonably
well, they are, in composition, primarily a lubricant
and only secondarily a sealant. The sealant components
of the mixture seek out the voids within the threaded
joint, but if a hole is large enough, the sealant
lS material will extrude out and the sealant will no
longer be effective for its intended purpose. It also
often occurs in the harsh envlronment in which drilling
operations take place that the li~uid component o the
sealant material bakes of~ in the extreme heat to which
it is exposed, leaving voids and the metallic sealant
components behind. These components typically have
particle sizes lying in a range o 50 to 500 microns.
This is not only undesirable during normal drilling
operations, but becomes even more of a problem during
disassembly of the pipe. Customarily, the same pipe can
be used in a number of reinstallations in the same well
or installations in successive wells. This, of course,
is desirable because of the heavy expense of the piping.
However, in the instance in which the lubricant bakes
off, the metallic particles left behind are of a gritty
consistency and, upon disassembly, sometimes causes
galling to occur on the threads of the pipe. This
causes the pipe to be more difficult to disassemble and
severely limits the reusability of the pipe.
SUMMARY OF TH~ INVENTION
It was with knowledge of the prior art and the problems
existing which gave rise to the present invention.
The present invention in one aspect is directed towards
a curable sealant composition which is employed to seal
a pipe joint between pin and box members intended for use in
petroleum drilling operations. In lts preferred form,
4~7
LC-184 ~9~
the composition is a single component anaerobic
material which is applied to one or both of the
members. The members are then joined and the
composition cures into a 801 id form which bonds to the
members and fills the space between them. The
constituents of the composition can be ~electively
varied to control its lubricity which also affects the
make up torque. Additionally, the concentration of the
constituents of the sealant composition can be
~electively varied to control the break out torque of
the joint to which it is applied, and preferably make
the break out torque substantially greater than the
make up torque. Excellent seals can be obtained using
lower grade pipe, and the pin and box members can be
made up with the application of lower torque to the
a~sembly without reducing the sealing capability of the
connection. Tbe preferred composition also serves as
a rust and corrosion inhibitor for the joint.
Subsequent discussion refers primarily to this
preferred composltion. The curable sealant composltion
o~ the invention (hereinafter ~sealantn), in its
preerred form, ls a high viscosity anaerobic resin
~9;~l37
LC-184 -10-
which may be combined with powders of PTFE
(polyte~rafluoroethylene~ and/or polyethylene having
particles approximately 10 microns,in diameter for
lubrication. Having a consistency between a ~hick
liquid (e.g~ maple syrup) and a soft paste (e.g~
toothpaste), the sealant polymerizes between clo-~e
fitted metal surfaces to provide sealing and resistance
to loosening with a low break out strength. The
sealant remains liguid indefinitely while exposed to
the air~ Upon application to and make up of
connections, however, complex reactions occur in the
sealant which cause it to polymerize in the absence of
air ts form a hard, high molecular weight, material
with adhesive and sealant properties. These reactions
lS are further catalyzed by the presence of iron, copper,
nickel and o~her metal~.
The sealant has been specifically designed for use in
sealing downhole petroleum drilling pipe joints. While
such pipe joints have traditionally been of a ~hreaded
nature, the application of the sealant need not be
limited to threaded joints but can be applied with
similar results to a variety to other types of joints
.
LC-184
as well. It may u~ed on slightly oiled, cadmium and
zinc plated, black oxide, and phosphate and oil coated
parts and still obtain satisfactory results. For a
maximum benefit, parts should be wipe cleaned, but need
no~ be solvent cleaned to remove an oil coating. This
is for the reason that petroleum based oils by nature
have an iron content sufficiently high to cause the
resin or monomer in the anaerobic sealant to
polymerize.
Some of the benefits of the sealant include the fact
that it can be applied to the mating surfaces of the
pin and box members either by machine or by hand. In
the instance of threaded joints, the sealant seals
between the thread~ to prevent spiral leak paths~
Indeed, the sealant seals all voids including
microgrooves and other regions such as the metal to
metal seal areas as found in premium connections. The
sealant contains no lead (which is toxic to human
being~ non-stringy ~and therefore easy to apply),
and employs no flammable solvents ~which would be
particularly hazardous on a petroleum drilling rig)O
lZ~24B`7
LC-184 ~12-
Primary benefits of the invention, in addition to its
excellent sealing ability, reside in it9 lubricity
which improve the ability to make up and break out
pipe joints, in it~ chemical stability and in the
ability to adju~t it8 cohesive and adhesive strength
so as to achieve a de~ired predetermined value of break
out torque. As a result of some of these benef itB, the
sealant will extend the life of production strings and
will permit the upgrading of cheaper pipe for higher
pressure applications.
A particularly important feature of the invention
resides in the ability to provide a different break
out torque for different members of a pipe joint.
Specifically, it i8 common practice to use lengths of
pipe in the field which have a pin at one end and a box
at the oppo~ite end. In thi~ instance, the box portion
of the joint i8 usually assembled in a factory, then
the pipe i8 shipped to the drilling site. As noted
above, the con~tituents of the sealant composition can
be controlled to thereby control the break out torque
of the joint. According to this further embodiment of
the invention, the concentration of the resin or
~Z~Z~17
~13
monomer can be consistently different when applied to
the mutually engageable surEaces of the hox than when
applied to the pin such tha~, upon subsequent breakout,
the same end of each ensuing length ~f pipe will be a
pin and its opposed end will be a box. In this way,
handling of the pipe is facilitated to a substantially
extent. Prior art sealants customarily are not applied
until make up as the pipe is descending into the well.
However, with this embodiment of the invention, the
sealant having one concentration of the resin or monomer
would preferably be applied at the factory at the time
of assembly of the box portion of the joint. Then the
sealant having a different concentration of the resin or
monomer would be applied during make up in the field.
Various aspects of the invention are as follows:
In a pipe joint including pin and box members
having opposed surfaces and intended for use in
petroleum drilling operations, the improvement
comprising:
a curable sealant composition of the
anaerobic type applied in an uncured liquid
state directly to said pipe joint prior to
assembly and cured to a solid state following
assembly so as to prevent fluid leakage
through the joint, said sealant composition
beiny of substantially equal constant volume
both in the uncured liquid state and in the
solid state.
A method of sealing a pipe joint including pin
and box members having threaded ends with mutually
engageable helical surfaces intended for use in
petroleum drilling operations comprising the steps of:
applying a curable sealant composition of
the anaerobic type in the uncured liquid state
2~87
,~
13a
directly to at least one of the helical
surfaces;
assembling the threaded ends while the
sealant composition remains in the uncured
liquid state such that the sealant blocks all
possible leak path~ including the helical flow
path defined by the helical surfaces; and
curing the curable sealant composition
without substantial volume change from the
uncured liquid state to whereby seal the pipe
joint.
A sealed connection to two tubular members
intended for use in petroleum drilling operations
comprising:
a pin member;
a box member mechanically joined to said
pin member to therPby form a joint
therebetween; and
a cured sealant of the anaerobic type
containing no solvent within said joint to
prevent leakage through said joint, said
sealant being armed after said joirt is formed
and composed partially of a polymerizable
acrylake ester monomer the concentration of
the acrylate ester monomer so chosen that the
torque required for disassembly of said pin
member and said box member is no less than the
torque required for assembly of said pin
member and said box member.
~ me~hod of sealing a pipe joint intended for
use in petroleum drilling operations, the pipe joint
including first and second opposed threaded pipe ends
and a threaded coupling for threaded engagement with the
pipe ends, the pipe ends and the coupling having
mutually engageable helical surfaces, the method
comprising the steps of:
~f~- ~2~2~ 7
13b
applying a curable sealant composition of
the anaerobic type in the uncured state
directly to at least the helical surfaces of
the pipe ends;
assembling the pipe ends and the coupling
such that the sealant blocks all possible leak
paths including the helical flow path defined
by the helical surfaces;
curing the sealant composition; and
controlling the concentration of
ingredients in the sealant composition to
thereby determine the torque required to
disassemble the pipe joint.
A sealed connection of two tubular members
intended for use in petroleum drilling operations
comprising:
a box member including a first pin member
having a threaded end and a threaded coupling
member, said first pin member and said
coupling member having mutually engageable
helical surfaces, said first pin member and
said coupling member being threadedly joined;
a cured sealant having a first
concentration of ingredients applied in the
uncured state to said helical surfaces of said
box member to prevent leakage between said
first pin member and said coupling member
along a helical flow path de~ined by said
helical surfaces, said irst concentration of
ingredients resulting in a Eirst magnitude of
torque required to disassemble said first pin
member ~rom said coupling;
a second pin member having a threaded
end, said second pin member and said coupling
member having mutually engageable helical
surfaces, said second pin member and said box
member being threadedly joined;
,~ lX~9t8~
13c
said cured sealant having a second
concentration o~ ingredients applied in the
uncured state to said helical surfaces between
said second pin member and said coupling
member to prevent leakage therebetween along a
helical flow path defined by said helical
surfaces, said second concentration of
ingredients resulting in a magnitude of
torque, different from said fir~t magnitude of
torque, required to disassemble said second
pin member from said box member.
In a pipe joint including in and box members
having opposed surfaces and intended for use in
petroleum drilling operations, the improvement
comprising:
a curable sealant composition applied in
an uncured liguid state to said pipe joint
during assembly and cured to a solid state
following assembly so as to prevent fluid
leakage through the joint;
wherein, upon disassembly of said pin and
box members when said sealant composition is
in the fully cured states, said sealant
composition is pulverized into a power form
without causing galling of said opposed
sur~aces.
A method of sealing pipe joint intended for
use in petroleum drilling operations, the pipe joint
including f.irst and second opposed threaded pipe ends
and a threaded coupling for threaded engagement with the
pipe ends, the pipe ends and the coupling having
mutually engageable helical surfaces, the method
comprisiny the steps of:
applying a curable sealant composition in
the uncured state to at least the helical
surfaces of the pipe ends;
_~ IL2~?Z~;8'7
13d
assembling the pipe ends and the coupling
such that the sealant blocks all possible leak
paths including the helical flow path defined
by the helical surfaces;
curing the sealant c~mposition; and
controlling ~he concentration of
ingredients in the sealant composition to
thereby determine the tor~ue required to
disas~emblP the pipe joint;
the step of applying a curable sealant
composition including the steps of:
applving the sealant composition having a
first concentration of ingredients resulting
in a first magnitude of torque required to
disassembly the first threaded pipe end and
the coupling; and
applying the sealant composition having a
second concentration of ingredients resulting
in a second magnitude of torque, different
from said first magnitude of torque, required
to disassemble the second threaded pipe end
and the coupling.
A method of sealing a pipe joint intended for
use in petroleum drilling operations, the pipe joint
including first and second opposed threaded pipe ends
and a threaded coupling for threaded engagement with the
pipe ends, the pipe ends and the coupling having
mutually engageable helical surfaces, the method
comprising the steps of:
applying to a~ least the helical surfaces
of the pipe ends a curable sealant composition
of the anaerobic type composed of a
polymerizable acrylate ester monomer and other
inyredients in the uncured state;
choosing for application to the first
threaded pipe end the sealant composition
having a first predetermined concentration of
?2~ 7
13e
the monomer such that the torque required to
disassemble the first pipe end and the
coupling will be of a first magnitude; and
choosing for application to the second
threaded pipe end the sealant composition
having a second predetermined concentration of
the monomer such that the torque required to
disassemble the second pipe end and the
coupling will be o~ a second magnitude
different from the first magnitude;
assembling the pipe ends and the coupling
such that the sealant blocks all possible leak
paths including the helical flow path defined
by the helical surfaces;
curing the sealant composition; and
controlling the concentration of the
acrylate ester monomer in the sealant
composition to thereby determine the torque
required to disassemble the pipe joint.
A method of sealing a pipe joint having a
longitudinal axis and including adjoi~ing pin and box
members having opposed surfaces and intended for use in
petroleum drilling operations comprising the steps of:
applying a curable sealant composition of
the anaerobic type in the uncured liquid state
to at least one of the opposed surfaces to
prevent leakage after curing occurs;
while the sealant composition remains in
the uncured liquid ~tate, joining the two
members together so that the sealant
composition after curing adheres to the
opposed surfaces of both the pin and box
members and blocks the flow path in the
longitudinal direction existing between the
opposed surfaces; and
curing the sealant composition to the
solid state without substantial volume change
1~2~187
1~
from the uncured liquid state to thereby
prevent fluid leakage through the joint.
Other and further features, o~jects, advantages, and
benefits of the invention will become apparent from the
following description. However, it is to be understood
that both the foregoing general description and the
following detailed description are exemplary and
explanatory but are not restrictive of the invention.
DETAILED DESCRIPTION OF T~ PR~FERRED ~MBODIMENTS
The basic composition of the sealant used in the method
of the invention is of a generally known formulation
which has been used in a variety of other applications.
Examples of U.S. patents which have disclosed the use of
monomer compositions having anaerobic properties are No.
3,625,875 to Frauenglass et al and No. 3,969,552 to
Malofsky et al.
The monomers contemplated for use in the invention
disclosed herein are polymerizable acrylate esters. As
used herein, "acrylate esters" includes alpha-
substituted acrylate esters, such as the methacrylate,ethacrylate, and chloroacrylate esters. Monomers of
this type, when mixed with a peroxy initiator as
described below, form desirable adhesives and sealants
of the anaerobic type.
Anaerobic adhesives and sealants are those which remain
stable in the presence of air (oxygen), but which when
~"
~9~ 7
LC-184 -15-
removed from the presence of air will polymerize to
form hard, durable re~ins. This type of adhesive and
sealant is particularly adaptable to the bonding of
metal 8 and other nonporous or nonair permeable
S materials since they effectiYely exclude atmospheric
oxygen from contact with the adhesive or sealant, and
therefore the adhesive or sealant polymerizes to bond
the surfaces together. Of particular utility as
adhesiYe or sealant monomers are polymerizable di- and
other polyacrylate ester~ since, because of their
ability to form cross-linked polymers, they have more
highly desirable adhesive or sealant properties.
However, monoacrylate esters can be used, particularly
if the monacrylate portion of the ester contains a
hydroxyl or amino group, or other reactive substituent
which serves as a site ~or potential cross-linking.
Examples of monomers of this type are hydroxyethyl
methacrylate, cyanoethyl acrylate, t-butylaminoethyl
methacrylate, glycidyl methacrylate, cyclohexyl
acrylate and furfuryl acrylate. Anaerobic propertiies
are imparted to the acrylate ester monomers by
combining with them a peroxy polymerization initiator
as discussed more ~ully below.
\
1~9248~
LC-184 -16-
One of the most preferable groups of polyacrylate
esters which can be used in the adhesives or sealants
disclosed herein are polyacrylate esters which have the
following qeneral formula:
[ (b`) b' ] ~
wherein Rl represents a radical selected from the group
consistiny of hydrogen, lower alkyl of from one to
about four carbon atoms, hydroxy alkyl of from one to
about four carbon atoms, and
o
-C~-O-~-C~-C~I
t
R2 is a radical selected ~rom the group consisting of
hydrogen, halogen, and lower alkyl of from one to about
four carbon atoms; ~3 is a radical selected from the
~roup consisting of hydrogen, hydroxyl, and
_o_~_a-oFI.
2~37
LC-184 -17-
m is an integer equal to a~ leas~ 1, e.g~, from 1 toabout 15 or higher, and preferably from 1 to about 8
inclusive; n is an in~eger equal to a~ lea~t 1, e.g., 1
to about 20 or more; and p is one of the following:
0, 1.
The polymerizable polyacrylate esters utilized in
accordance with the invention and corresponding to the
above general formula are exemplified by bu~ no~
restricted to the following materials: di-, tri- and
tetraethylene glycol dimethacrylate, dipropylene glycol
dimethacrylate, polyethylene glycol dimethacrylate, di
tpentamethylene glycol) dimethacrylate, tetraethylene
glycol diacrylate, tetraethylene glycol
di(chloroacrylate), diglycerol diacrylate, diglycerol
tetramethacrylate, tetramethylene dimethacrylate,
ethylene dimethacrylate, neopentyl glycol diacrylate
and trimethylol propane triacrylate. The foregoing
monomers need not be in the pure state, but may
comprise commercial grades in which inhibitors or
stabilizers, such as polyhydric phenols, quinones, etc.
are included. As used herein the term "polymerizable
polyacrylate ester monomerN includes not only the
41~7
LC-184 -18-
foregoing monomers in the pure and impure state, butalso those other compositions which contain those
monomers in amounts ~ufficient to impart to the
compositions the polymerization characteristics of
polyacrylate esters. It is also within the scope of
the present invention to obtain modified
charac~eristics for the cured composition by the
utilization of one or more monomers within the above
formula with other unsaturated monomers, such as
unsaturated hydrocarbons or unsaturated esters.
The preferred peroxy initiators for use in combination
with the polymerizable acrylate or polyacrylate esters
described above are the hydroperoxy polymerization
initiators, and most preferably the organic
hydroperoxides which have the ~ormula R400M, wherein
R4 generally is a hydrocarbon radical containing up to
about 18 carbon atoms, preferably an alkyl, aryl or
aralkyl radical containing rom one to about 12 carbon
atoms. Typical examples of such hydroperoxides are
cumene hydroperoxide, tertiary butyl hydroperoxide,
methyl ethyl ketone hydroperoxide and hydroperoxides
formed by the oxygenation of various hydrocarbons, such
4L87
LC-184 -19-
as methylbutene, cetane and cyclohexene. Other organicsubstances, such as ketones and e~ters, including the
polyacrylate esters represented by the above general
~ormula, can be oxygenated to form hydroperoxy
initiators. However, other peroxy initiators, such as
hydrogen peroxide or materials such as certain organic
peroxides or peresters which hydrolyze or decompose to
form hydroperoxides frequently can be used. In
addition, U.S. Patent No. 3,658,624 describes
peroxides having a half-life of less then 5 hours at
100C. as suitable in somewhat related anaerobic
systems.
The peroxy initiators which are used commonly comprise
less than about 20 percent by weight of the combination
of monomer and initiator since above tha~ level they
begin to affect adversely the strength of the adhesive
and sealant bonds which are Eormed. Prefera~ly the
peroxy initiator comprises from about 0.1 percent to
about 10 percent by weight of the comblnation.
Other materials can be added to the mixture of
polymerizable acrylate ester monomer and peroxy
~ ~,a~
LC-184 -20-
initiator, such a8 quinone or polyhydric phenolstabilizers, tertiary amine or imide accelerators, and
other functional material~ such as thickeners, coloring
agents, etc. These additives are used to obtain
commercially desired characteristics, i.e., sui~able
viscosity and shelf stability for extended periods
~e.g., a minimum of one month). The presence of these
additives is particularly important when peroxy
initiators other than organic hydroperoxides are used.
For a complete discussion of the anaerobic systems and
anaerobically curing compositions, reference is made to
the following U.S. Pat. Nos. 2,895,950 to Vernon K.
Rrieble, issued July 21, 1959; 3,041,322 to Vernon K.
Krieble, issued Junè 26, 1962; 3,043,820 to Robert K.
Krieble, issued Ju~y 10, 1962; 3,046,262 to Vernon K.
Krieble, issued July 24, 1962; 3,203,g41 to Vernon R.
Krieble, issued Aug. 31, 1965; 3,218,305 to Vernon~K.
Krieble, issued Nov. 16, 1965; and 3,300,547 to J.W.
Gorman et al, issued Jan. 24, 1967.
However, the aforesaid monomer compositions have
been modlfied (e.g. by adjusting the strength,
lubricity, etc.) for the purposes with which the
87
LC-l 84 -21--
present application is concerned, specifically, as a
sealant or pipe joints, and more particularly,
between pin and box members intended ~or use in
petroleum drilling operations. Indeed, monomers
S having anaerobic properties have been totally unknown
in the role disclosed herein and provide highly
desirable results of a nature previously unknownO
As noted above, the sealant is applied to mating
metallic surfaces in a liquid state. It may be applied
in any ~uitable manner as, for example, by brushing, by
means of a mechanical applicator, by a ribbon
applicator, or by sponge. So long as the parts so
coated remain exposed to the air, the sealant remains
in its liquid state. ~owever, when the parts are
joined such that the internal interengaging surfaces
are no longer exposed to the alr, then the sealant
cures to the solid state. When thi~ occurs, it forms a
physical bond to the outer surface of a metal on which
it is coated. The presence of the metal to which the
sealant is applied can also initiate and thereby
accelerate the curing process. The sealant even ~ills
the microgrooves whIch are formed in the metal
~2~2~87
22
resulting in elimination of leak paths for gases and
liquids. The sealant provides an absolute, positive
seal which works equally well with API 8-round, API
buttress, and with premium connections. ~ile the
industry has had good experience with premium
connections, the present invention provides a sound back
up seal which is far more practical and reliable than
"Teflon" brand o-rings, for example, that have come to
be widely used. Effectively, the sealant of the
invention provides a plastic seal throughout the area,
without the need to machine expensive grooves (which
weaken the pipe) as is required for the "Teflon"TM seal.
Physical properties of the preferred sealant of the
invention include the following:
PHYSICAL PROPERTIES UNCURED SEALANT
Flash Point >100C (212F)
Appearance pink viscous liquid
.~.r~ "~,
~Z~ 87
LC-184 ~~3~
Pen~i~X 1.25
(~rookfield Viscometer type H~T 150-500 Pa'~
~6 Spindle, 2.5 rpm Q 23 + 2C) (150,000-500,000 cP)
Composition2-1/2 RPM 20 RPM Thixotropic Ratio
11296 75 cP 30 cP 2.5
SL21 80 cP 26 cP 3.1
SL22 67 cP 20 cP 3,4
Note: Thixotropic ratio refer~ to the gap ~illing
ability of the sealant and to its ability not
to drip when applied. The above number~
re~lect this ability of the ~ealant;
speci~ically, the greater the thixotropic
ratio is above 1.0~ the less it will drip.
Other deslrable properties of the sealant in
~2~48~
LC-184 -24-
its uncured state include: its ability to be
easily dispensed, as from a squeeze tube; $t~
stability, that i~, its long shelf life in a
package prior to being used; its low
toxicity, that is, lack of lead or other
heavy metals among its constituents; itB non-
flammability, that is, its flash point above
212F. Its lubricity is a measure of
how much tension i8 applied to a joint with a
given amount of torque.
Lub~ici~y
Ten~ion (recorded in 100'9 of pounds) at the
followiny torques:
Composition 100 200 300 400inch pounds
1129~ 1~ 25 3~ 51
SL21 15 33 49 6a
SL22 18 39 60 80
i
Z~7
LC-184 -25-
5~ E~s Inch pounds breakfprevail mea~ured on
3/8 x 16 iron nut~ and bolt~ a~ter 24
hours ~ 70F
(Un6eated) Break2revail (180)
11296 1 in. lb.1 in. lb.
10 SL21 6 in. lb.2 in. lb.
SL22 8 in. lb.3 in. lb.
Vl~1m~Q ~t~çngth: As above but after 4 hours @ 2000F
1129650 in. lb. 0 in. lb.
SL2160 in. lb. 2 in. lb.
SL2260 in. lb. 5 in. lb.
Note:Un~eated break means that the nut is ree
spinning on the bolt. Other desirable
properties of the sealant in its cured and
curing state include: its cured lubricity:
its resistance to heat: it has been
-~,
~''}~9~&~7
LC-184 ~26-
tested to 330~F in heat cycling te8t8; it~
resi~tance to chemical attack ~it i~
essentially chemically inert): and its hot
strength - since it is a thermoset plastic
composition, the sealant has a high hot
strength.
It was previously noted that the sealant may contain
PTFE and/or polyethylene additives in the form of a
lQ powder for lubricity. Each of these additives may be
provided in the range o~ 0 - 20% by weight. PTFE
increases lubricity slowly while polyethylene
increases lubricity at a rapid rate per unit amount
added.
In its liquid form, the sealant lubricates as well as
or better than existing API thread compounds.
~urthermore, becau~e the sealant contains no solvent,
there can be no "bake out~ or 1033 of volume under
temperature or with time as with known thread
compounds. ~ecause there is ~ubstantially no 10B8 of
volume when it i~ cured, it prevents leak paths from
developing. Furthermore, in its cured solid state~
~ 8
LC-184 -27-
when the pipes are di~asfiembled, the ~ealant i~pulverlzed into a powder form wi~h lubricatlng
qualities and continue~ to be a~ ef~eative a lubricant
as it wa~ previously ln it8 liquid or uncured state.
This is because molecules of the sealant penetrate and
remain in micro-burrs which exist on threads and other
~urfaces in the connection and reduce the galling
effect caused by them.
The re~ulting threads are substantially clean and
require little preparation for re-use. Thus, the
sealant of the invention serves a~ a lubricant during
both the make up and break out operations at the same
time that it i8 an e~fectiYe seal.
Another prlmary benefit i~ that the sealant permit~
sealing at lower make up torque than currently used
with non-curing sealants since the curing sealant will
plug larger gaps throughout the joint. With known
sealants, high torque i~ necessary in order to prevent
leakage, even with premium connections. It will be
appreciated that with lower tor~ue, there i~ less
deformation of the pipe and hence a higher life
z~
LC-184 -28-
expectancy to be anticipated from the thread. Thi8
would enable the use of API 8-round thread and API
buttress thread in virtually all instances, thereby
eliminating the need for the higher priced premium
connectionsO This is important when one con~iders that
a current price range for API 8-round connections is
between ten dollars and twenty dollars per coupling
whereas that for premium connection~ is between two
hundred and five hundred dollars per coupling. In some
specialized instances, the premium connections can cost
even more than five hundred dollars per coupling
Another benefit of a lower torque requirement is that
less stress is imparted to the pipe connections
assuring that the pipe will be more resistant to the
corrosive effects of ~uch highly toxic subs~ances as
hydrogen sulfide and sulfur dioxide which are common
in petroleum well environments. Such toxic substances
are known to corrode stressed regions in connections
more rapidly than unstre~sed or lesser stressed
regions.
Another significant benefit of the invention resides in
37
LC-184 -29-
the ability to control the strength of the sealant, by
adjusting the percentage of its conetituents~ When
translated into oil field terminologyA this means that
the break out torque can be controlled. Specifically,
the greater the percentage o resin or monomer, the
greater the break out torque when the sealant is
applied to a pipe joint, and vice versa. Strength may
al~o be increased by increasing the amount of mineral
fillers, although not to the extent of resin variation.
Typical mineral fillers are titanium dioxide used as a
whitening agent and mica used as a strengthening
filler.
Still another benefit of the invention is the ability
to a~sure a substantially h~gher break out torque than
make up torque in those connections where a low makeup
torque i8 desirable. This is achieved by controlling
the concentration of the ingredients in the sealan~
composition. In the preferred embodiment, the
ingredient being controlled iB the polymerizable
acrylate ester monomer. This will assure that an end
will not break out inadvertently due to low make
up torque.
4~3
LC-184 -30-
~he foregoing benef~t of controlling break ou'c torque
by adjusting the concen~ration of the resin or monomer
in the sealant composition leads to still another
benefit of the invention~ Specifically, it is
desirable from a materials handling standpoint to know
which end of a reusable pipe being withdrawn from a
well will be a pin and which end will be a box so that
the pipe can be uniformly stacked pending further use.
This object can be achieved by applying sealant having
one concentration of monomer to the box when it is
assembled (most likely at the factory~, then applying
sealant having a different concentration of monomer to
the pin at the drill site. The concentration of the
monomer would be known in each instance such tha~ the
torque for break out of each portion of the joint would
likewise be known. By maintaining the concentration of
the monomer uniform in each instance, as the pipe is
withdrawn from the well ~or subseqllent use, the same
end of each subsequent length of pipe will be a pin and
its opposite end will be a box. Heretofore, there was
no way of knowing whether an end o pipe would be a box
or a pin upon break out. This created difficulty with
87
LC-1~4 -31-
sub~equent operations which would be alleviated by the
invention.
In addition to adjusting the percentage of the resin or
monomer in the sealant compo~ition to adjust break out
torque, by making further adjustments to the
formulation, it can be be made certain that the
prevailing strength is less than the break out
strength. Prevalling strength i8 defined as the torque
used to unscrew a pin from a box after the pin has been
rotated through an arbitrary arc, for example, 180. If
prevailing strength is not maintained to a value less
than the break out strength, the torque may increase
with continued un~crewing of the pin from the box wlth
the result that the disassembly of the pin and the box
will become extremely difficult.
In current practice, relatively high torques are used
for make up and ~omething less than the make up torque
is required for break out. This latter ~ituation i8 not
desirable, but is a characteristic of a joint to which
known sealants have been applied. The higher torques
; are required to ensure sealing in the connections. The
2~ 7
~C-184 -32-
following is an extract from Test Summary 4 below o~this disclosure~ It clearly shows how the connection
wa~ made up to lower torques when the sealant was
applied without compromising it8 sealing capabilities.
~ke-~~ IQ~9Ç~ =hk~ UUL~ ~5~
~1 2,500 Leak at 1,500
35,000 Leak at 8,000
10Sealant 2,500 ~eld at 8,000
Typically, using known sealant materials, break out
torque is less than make up torque. However, by reason
of the invention, break out torque can be made greater
than make up torque by controlling the properties,
specifically, the percentage of resin or monomer in the
cured polymer. For example, in the above test, the
cbnnectlon broke out at a torque somewhat less than
make up torque when made up with API compound. When
the sealant wa~ used, an~ the connection made up
to 2,500 Ft-Lbs, the break-out torque was 14,000
Ft-Lbs.
. ~2~29L~37
LC-184 -33-
Still another significant benefit of the invention i8
the chemical ~tability of the sealant. Specifically,
its compo~ition is such that it i8 inert to the
chemicals normally encountered in petroleum drilling
operations. Furthermore, the sealant composition is
non-toxic when properly used and will not pollute the
environment as will the known sealants, which contain
heavy metals such as lead, nickel and the like.
Substantial experimentation has indicated no adverse
effects with expo~ure to chem~cals encountered in oil
field use~ including hydrogen sulfide and sulfur
dioxide.
Another significant feature of the invention i5 the
self cleaning ability of the ~ealant. Speciically,
upon break out, the solid polymeric material pulverizes
and leaves a fine coating on the thread~. This fine
coating doe~ not inter~ere with subsequent make up, but
has been found to effectively prevent oxidation to an
extent better than most known corrosion resistant
protective coatings.
Exten~ive testing has been performed regarding the
~ Zf~7
LC-184 -34-
sealant, and the following reflect some of the moresignificant tests which have been performed to date
using both the anaerobic sealant composition of the
invention and previously known compositions in a
5 variety of applications
IQ~ mm~LY L
In thi~ group of tests, the connections used were
standard ~VAM" single metal-to-metal seal connections
with buttress thread~. ~VAM~ is a trademark of
Vallourec, a corporation with headquarters in Paris,
France, and one of the leading manufacturers of premium
connections Leaks were created on the test sides of
the connections by grooves filed into the seals. The
connections were then tested to insure that they leaked
readily when made up with API ~American Petroleum
Institute) modified premium thread compounds, and then
they were tested as followss
~a) 2-7/8 inch tubing. Pressure: 10,000 psi
nitrogen. Heat cycling: ambient to 320F.
-
12~Z~B7
LC-184 -35-
Tension: 200,000 lbs.
tb) 3-1~2 inch casing. Pressure: 10l000 psi
hydrostatic
~c) 7-5/8 inch casing. Pre~sure: 9,000 psi nitrogenO
Heat cycling: ambient to 300F.
In all instances, the connections sealed when the
anaerobic sealing composition was applied to the
crippled ~ide o~ the connection. The break out torques
averaged approximately 150% of make up torques. There
was no evidence of galling.
Pipe Size: 7-5/8 inch
Connection types: "VAM~ premium connections with
metal-to-metal seals and buttress
threads.
Two pup ~oints and two end plugs were assembled with
three couplings respectively interposed between the~pup
2~8~
LC-184 -3~
joints and the end plug~ One of the end plugs would
not hold pressure above 4000 psi, preventing the
testing of tha complete assembly. This connection was
further crippled by notches filed into the seal to
cause it to leak. The anaerobic sealant composition of
the invention wa~ then applied to the thread area, and
the connection was made up again and the entire
assembly was subjected to heat and pressure cycling for
several days. The connection held pressure through the
threads ~or the entire test period, while leaks
occurred in several o~ the healthy connections in the
assembly. The maximum pressure was 9000 psi of
nitrogen, and the temperature was cycled from ambient
to approximately 300F.
Thi~ test u6ed 2~7/8 inch 8-round thread tubing and was
designed to compare the anaerobic sealant composition
o~ the invention with an ~PI modified high pressure
thread compound manufactured by Shell Oil Corporation:
The sample comprised two threaded pins and a single
-
1~32fl~B~7
LC-184 ~37~
coupling. One pin contained a machined groove to
simulate a field defect. 5he groove waæ cut to the
root of ~he thread for the entire length of the thread.
~he groove was cut 0.060 inches wide at the nose of
the pin and ~apered ~o 0.020 inche~ wide at the end of
the thread.
The sample was made up to 2,300 ft-lbs. o torque using
a light application of API Modified pipe dope
manufactured by Shell Oil Corporation. The sample was
pressure tested with nitrogen gas and a leak was noted
immediately on the grooved end. It was disassembled
and additional API Modified was applied to the grooved
end to simulate ~ield conditions. The samp~e was
remade to 1,900 ft-lbs. of torque using the same amount
of turns used during the initial make up. Internal gas
pressure was then applied and at 3,500 psiy pipe dope
was noted extruding at the machined groove. A leak
developed and the internal pressure bled down to zero
psig.
The sample was dlsassembled, cleaned, and inspected.
The sealant o the invention was applied to the
;~ ?~8~
LC-184 -38-
grooved end; while API Modified was applied to theother pin endO The sample was made up to 1,700 ft-
lbs. and allowed to cure at ambient temperature
~approximately 95F) for five hours. Internal gas
pre~sure of 7,~00 psig was applied and held for two
hour~. No leakage was observed.
Subsequently, the sample was subjected to 235F
temperature for one hour. Internal gas pressure of
5,500 p~ig was applied for one hour while maintaining
the elevated temperature and no leakage was observed,
The sample was allowed to cool to ambient temperature
while maintaining the 5,500 psig internal gas pressure.
No leakage was observed.
The sample was then disassembled, cleaned and
inspected. Torque o 5,772 ft-lb~. was required to
break out the pin with the machined groove and 5,382
~t-lb~, of torque was required to break out the ~PI
Modified pin end, The grooved pin broke out ~moothly
and without problems. No galling was obsexved on
either pin end.
LC-184 -39~
~Q~ ~mm~L~ 4
Thread DeRign: 7-5/8 inch wedge
ta)This test was de~igned to test a
~Teflon~ ring as a back-up seal in a known
leaker. At 2,500 ft-lbs. of make up torque
it leaked at 1,500 psi. At 35,000 ft-lbs. it
leaked at 8,000 p8i. The inventive
composition was applied and the connection
was made up to 2,500 ft lbs. It held 8,000
; psi. The break out torque was 14,000 ft-
lbs.
IQ~ L This connection was made up to 35,000
ft-lbs. with API Modified dope and was
; sub~ected to a combined tension and
internal pressure load o~ 588,000 lbs. It
leaked at 10,000 psi7 The inventive
composition was applied and under the same
lZ~48~7
LC-l 84 - 4 0-
conditions9 the connection held 13,000 p~i.
This connection was made up wikh API
dope to 40fOOO ft-lbs. It leaked at S,000
psi. In an effort to test performance of ~he
inventive composition under adver~e
conditl ons, the box end of the connection was
completely filled with 16 lb drilling mudr
and the joint was ~tabbed into the mud. It
sealed to 13,000 psi with no adverse effects
from the presence of the drilling mud,.
~L~f'3Z~
LC-184 41-
Test Summary 5
Thxeads/Mat'~ Test/~ot~ BeSults
(a) Using preferred composition
of invention:
pipe: 3-1/2 inch diameter
12.7~/ft-SM2550
Threads from a previous Made up connection to ~ No leaks
test, but still in good approx. 4,000 ft-lbs
condition. Pins were (whereas usual min-
dry-honed with Moly Kote. imum torque for conn-
Couplings phosphated. ection is 5,220 ft-lbs).
The torque shoulder and Made up connection
s 30 seal area were allowed to cure for 2
crippled to thereby hours. Hydrostatic
create a leak path. test Q lOk psi for 2
hrs. Connection broken
apart:
~ 11 @ 5,~00 ft-lbs.
~ 12 @ 6,200 ft-lbs.
87
LC-184 -42-
Test Summary 5 ~Cont.)
Threads/~t'l Test/Notes ~ Resul~~
Same as above Another made up conn- No Test
ection to check break
out torque after short
cure time: 1 hour. Conn-
ection broken apart:
# 11 Q 4,500 ft-lbs.
lo $ 12 Q 4,500 ft-lbs. r
Using API modified compound:
Same as above Same as above ~long $ 11 leaked
cure time) except: @ 3,000 psi
Connection broken ~ 12 leaked
apart: @ 5,000 psi
# 11 Q 3,600 ft-lbs.
~ 12 @.3,750 ft-lbs,
8t7
LC-134 ~3-
Threads/~at'l $~5~c~ B~
~b) Using preferred composition of in~ention:
same as ~a) Made up connection toNo leaks
approx. 4,000 ft-lbs.
Allowed to cure for 5
hours~ Hydrostatic test
to lOk psi overnight.
Connection broken apart:
lA @ 6,000 ft-lbs.
~ 5B Q 6,300 ft-lbs.
same as ~a) Another made up connec-No test
tion to check break ou~
torque after short cure
time: 30 min~ Connection
broken apart:
~ lA e 4,750 ft-lbs.
# 5B @ 4,750 ft-lbs.
gL137
LC-184 -44-
Using API modified compound:
same as above Same as above ~long After 15 min.
cure time) except: ~ lA leaked
No information re. @ 5,100 psi;
connection broken then, ~ 5B
apart. leaked when
repressured to
7,000 psi
~c) Using preferred composition of invention:
same as ~a) Made up connection to No leaks
~15 except only approx. 4,000 Et-lbs.
pin # lB was Allowed to cure for
crippled 20 hour~. Gas ~N2)
test ~ 7,500 psi for
1 hour.
Then, pressure No leaks
removed and connection
heated to 300F;
LC-l84 -45-
~ Su~ma~y S ~o~t.)_
Th~eads~Mat'l Test/~oteS Results
Gas ~N2) test Q
lO,000 psi for l/2
hourO
Connections broken apart:
lB @ 5,700 ft-lbs.
~ 3B Q 6,300 ft-lbs.
Using API modified compound:
same as above Made up connection to No leaks
approx. 4,000 ft~lbs. Q 5,000 psi
Allowed to cure for ~ lB leaked
20 hours. Hydrostatic @ lOrOOO psi
test to lO,000 psi
LC-184 -46-
~ Threads/Mat'l TesttNotes , Results
(d) Using Composition of Made up connection to ~o ~eak
invention: Pi~e: 2 7l8 approx. 3,000 ft-lbs.
inch diameter.7.7 lbs/ft.; (Optimum torque) gas
~80 Treated same as (a) (nitrogen) test at
above, only one side 3,600 psi overnight
crippled
Gas pressure increased Slight leak;
to 6,500 psi. External small steady
10 ~ tenslle ioad added for stream of
total tensile load of bubbles coming
- approx. 200K lbs. No in through
temperature increase water in which
yet assembly immersed.
. .
Assembly heated to 300F. ~eak appeared to
(w/hot glycol); pressure stop; no more
increased to 8,600 psi; bubbles visible
,hot cycle maintained
approx. 2 hours.
Assembly cooled by flush- ~eak reappeared;
ing with cold water to small steady stream
- approx. 120F; pressure of bubbles visible
dropped to approx. 6,500 through water.
ps
Another hot cycle No leak visible
Another hot cycle Leak visible again
LC-18~ ~~7
~7
.
Threads/Mat'l Test/~otes Results
(e~ Using Composition o~
Invention:
Pipe: 2-7/8 inch diameter ~ade up connection t~ No ~eaks
i 7.7 lbs/ft; N80 approx. 4,000 ft-lbs.
VAM premium connec- External tensile load:
tion;Treated same as apprOx 170,000 lbs;
above: only one side gas preSsure (nitrogen)
crippled to 9, 500 psi
Temperature raised to No Leak visible
approx. 300F (hot
glycol); short time
cycles at hot and cold
Assembly cooled with Leak appeared; '
cold water flush s~all steady
stream of bubbles
Temp increased for No Leak visible
second hot cycle
Assembly'cooled for Leak visible again;
second cold cycle small steady stream
Temp increased for No leak visible
third hot cycle
Assembly cooled for Lcak visible again;
third cold cycle small steady stream
Two more hot and cold Small pa~tern of
cycles leaking
,
lZ~2~137
LC-184 -48~
For ~hese tes~s, the connections used were VAM-PTS
2-7/8 inch N80 premium connections. ~o galling was
evident in the connection or on the pin throughout the
test. In order ~o understand the terminology, col. (1)
represents the time of day; col. ~2) is tensile load
created by the internal applied gas pre~sure
(nitrogen); col. (3) is load applied by pulling frame;
col. (4) is combined load o cols~ (2) and (3); col.
~5) reflects heat cycling; and, with respect to col.
~6), leaks were recorded in estimated bubbl2s per
: minute e~caping from a leaking connection and ed into
a jar of water throu~h a ~mall diameter tube.
EiF~5 .Thermocycle: ~8~ somL~si5lQn ~2Q
~1) (2) (3) (4) (5) ~6)
time int.press tensile load comb.load temp. remarks
: 20 (LBS) (LBS) (LBS) (F)
10:05 373S3 162900. 200253 76 no leak
10:18 37737 164100 201837 301 no leak
lZ~;~4~37
LC-184 -49- ,
10:41 37900 162900200800 101 no leak
11:02 37980 163900201880 299 no leak
llol9 38069 16399020205~ 101 120 ~.P.M.
11:27 38061 163800201861 306 no leak
11:57 38100 163200201300 108 leak &
end of test
Results:
No leak on first 2 complete cycles
Small leak on 3rd cold cycle
Leak sealed on 3rd hot cycle
~Q~2 ~E~QÇ~-~ ~ ~OMPOSTTIO~
~ 2) (33 ~4) (5) ~6)
Time Int.pres~ tensile load comb.load temp. remarks
~LBS) ~LBS)(LBS) (OF)
16:53 13787 1501391~3926 80 0
17:13 433~2 15~126198468 312 0
17:35 45278 159272204550 288 . 0
17:~1 45270 159597204867 281 0
17:47 38402 152183 190585 96 160
~ 8
LC-184 -50-
17:53 35329165291 200620 92 1~0
17:58 40500165157 205657 324 5
18:02 43491165443 208~34 307 5
~8:11 369~5165539 202494 93 160
18:14 35661166036 201697 96 160
18:1~ 40683165997 2~6~0 323 0
18:20 43402156521 199923 310 0
18:26 37874156845 19~719 95 180
18:2~ 3651276235 112747 96 180
18:31 3586~3400 39265 97 180
18:33 3519770159 105356 98 180
18:35 34478169513 203991 99 180
Results:
No leak on initial cycle
Leak on cold cycles
Leak reduced or stopped during hot cycle
Z~37
LC-184 -51-
2~ ~3) (~) ~5) ~6)
time int.pres~ tensload comb.load temp. remarks
S ~r~Bs) ~LBS) ~LEIS)
10:16 1323 134625 135948 297 No Leaks
10:18 13604 134281 147885295 through-out
10523 18873 134376 153249 291 t~st
1010:26188~0 134109 152949290
10:30 19162 13~223 153385330
10:31 19169 134051 153220304
10 :37 17180 134223 151403103
10:40 19021 134242 153263105
1510:4520337 134281 15461~ 306
10 :48 211~7 133994 155181 312
10:54 19680 133765 153445 99
03 18079 133~60 151939 102
11 :24 17557 134739 152296 100
2011:2718830 134090 152920 266
11:31 ~01~6 1341~7 154333 286
11 :38 18927 ~33879 152806 92
11:42 18124 133994 15~118 ~7
:~Z~L87
LC-184 -52-
11:4~ 2~465133~79156344 294
11:53 23~30133841157071 2g7
11:59 2146413391~ 15~82 99
12:~4 203351339561542~1 104
12.05 200û0180690 ~00770 103
12:14 19350180289199639 99
12:18 21302179850201152 276
12 :20 219851800602~2045 2O7
12:26 20622180213200835 98
12:30 196781~0060199738 100
12:31 1968014190~161584 99
12:32 195~61~8663148249 99
12:32 1960078470 98070 98
12:34 19487785~6 98053 98
12:36 1936778699 98066 97
12:36 1939848435 67833 97
12:37 19452 2770 22222 97
RESULTS: Seal held throughout test.
~Z~Z~7
LC-184 -53-
API compound was applied to the test connections
and it leaked profusely at low pressureO
A test downhole was run on an actual well on
July 6, 1986. This comprised a string of
7-5/8 inch w~dge connec~ion, 1,200 ft in length
in the form of a liner at the bottom of a 12,800
ft. well. The pipe made up very smoothly
with no problems. The pipe stuck in the hole
during the lowering of the string~ which
neceRsitated the pulling of the string. This
re~ulted in the unusual opportunity to break
the pipe out after more than a week o exposure
to down hole conditions. The connection broke
out very smoothly, with a minimum of
cleaning required as compared to normal conditions
using API pipe dopes. The average make up torque
was 20,000 ft.lbs, and the average break out
~92~7
LC-184 -54~
torque was 30,000 ft~/lbso There was no
evidence of galling. The test can be summarized
as having been completely success~ul.
The well is located about 10 miles ~outhwest of
Lafayette, Louisiana.
Drilling rig - Glasscock 73
Operation - DaYis Oil
Connection manufacturer - Tubular Corporation of
America~ Rou~ton~ Texas
While the preferred embodiments of the invention
have been disclosed in detail, it should be
understood by tho6e skilled in the art that various
lS modifications may be made to those embodimen~s
disclosed without departing from the scope thereof a~
described in the specification and deined in the
appended claims.
