# Patent

## Title
Methods using formate gels to condition a pipeline or portion thereof

## Abstract

A gelled composition for pipeline, flowline, pipeline jumper or flowline jumper dewatering or preventing ingress of seawater into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits operations is disclosed, where the composition includes a concentrated metal formate solution and a hydratable polymer. The gelled formate compositions have improved dewatering properties with 100% or 360 pipe coverage. The gelled formate compositions have can also be reused by breaking and reformulation.

## Background
RELATED APPLICATIONS
This application is a divisional claiming priority to and the benefit of U.S. patent application Ser. No. 12/167,645, filed 3 Jul. 2008 (Jul. 3, 2008), now U.S. Pat. No. 8,099,997 issued 24 Jan. 2012 (Jan. 24, 2012).


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a gelled, aqueous, metal ion formate salt composition for the prevention of seawater ingress during subsea pipeline tie-in operations and for the removal of seawater and conditioning of residual seawater film left on the pipewall during and following pipeline or flowline dewatering operations, which may involve the use of a pig or a plurality of pigs.
More particularly, the present invention relates to a method and a use of a gelled metal ion formate composition for pipeline or flowline operations. In certain embodiments, the metal ion formate starting solution is a concentrated metal ion formate solution including at least 40 wt. % of a metal ion formate or mixture thereof. The method includes the step of filling an interior or a section of a pipeline, flowline, pipeline jumper or flowline jumper with the gelled composition, where the composition includes a metal ion formate solution and an effective amount of a gelling agent sufficient to gel the solution and where the composition reduces substantially all or part of a residual water film from the interior of the pipeline, flowline, pipeline jumper or flowline jumper during a dewatering operation, or minimize or prevent the ingress of seawater into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits. The gelled metal ion formate salt composition is effective in reducing a water concentration of a residual film in a pipeline formed during a dewatering operation, where the dewatering operation may involve the use of a pig or multiple pigs. A slug of the gelled metal ion formate salt composition can be added to the dewatering pig train in order to achieve an improved result.
2. Description of the Related Art
To date fluids such as methanol and glycols including in gelled form are utilized for dewatering pipeline or flowline applications offshore and constantly exceed the acceptable limitations for both subsea and overboard discharge. A liquid product that Weatherford International, Inc. supplies made up of a concentrated metal ion formate solution including at least 40 wt. % of a metal ion formate or mixture thereof of potassium formate is a newly accepted liquid product generally utilized to provide hydrate control; however, the establishment of a potassium formate gel provides equally good performance in regards to dewatering applications or minimization or prevention of seawater ingress in addition to hydrate control, while being less hazardous, and less environmentally damaging.
Historically, methanol and glycols, both of which pose immediate safety concerns as well as being potentially hazardous, have been utilized for dewatering pipelines and flowlines offshore. Secondly, these fluids are considered to be toxic for overboard discharge.
Thus, there is a need in the art for compositions that address these safety issues as well as overboard discharge problems associated with chemicals for dewatering pipelines in addition to an increase in dewatering performance capabilities/potentials.
SUMMARY OF THE INVENTION
The present invention provides an improved system for dewatering and conditioning pipelines or flowlines, where the system includes a composition comprising a metal ion formate solution and an effective amount of a gelling agent, where the effective amount is sufficient to gel the composition and the composition is effective in reducing an amount of bulk water and/or an amount of residual water in the pipeline or flowline, reducing an amount of a residual water film in a pipeline or flowline below a desired amount, removing substantially all of the residual water in the pipeline or flowline, or effectively preventing seawater ingress into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits
The present invention also provides a method for dewatering a pipeline or flowline including the step of pumping, into a pipeline or flowline, pipeline jumper or flowline jumper, a composition comprising a metal ion formate solution and an effective amount of a gelling agent, where the effective amount is sufficient to gel the composition and the composition is effective in reducing an amount of a residual water film in the pipeline, flowline, pipeline jumper or flowline jumper, reducing an amount of the residual water film in a pipeline, flowline, pipeline jumper or flowline jumper below a desired amount, removing substantially the residual water film in the pipeline, flowline, pipeline jumper or flowline jumper or preventing ingress of seawater. into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits The method can also include the step of recovering the gelled composition, breaking the gelled composition, filtering the gelled composition and reformulating the gelled composition for reuse. Because the potassium formate compositions are considered to be environmentally benign, some or all of the composition can be pumped into a marine environment without pretreatment.
The present invention also provides a method for installing a pipeline or flowline including the step of filling a pipeline, flowline, pipeline jumper or flowline jumper with a gelled composition of this invention. After the pipeline, flowline, pipeline jumper or flowline jumper is filled, the pipeline is installed, at a subsea location. After installation the pipeline, flowline, pipeline jumper or flowline jumper on occasion may be pressurized using an external water source. After pressure testing, the pipeline is brought on production by displacing the composition and the fill medium of the pipeline, flowline, pipeline jumper or flowline jumper, with production fluids or gases to the ocean without the need for treatment. By using the composition of this invention, hydrate formation is precluded during the composition displacement operation. In certain embodiments, the pressure testing is performed at a pressure that is a percentage of the maximum allowable operating pressure or a specific percentage of the pipeline design pressure. In other embodiments, the pressure testing is performed at a pressure between about 1.25 and about 1.5 times the operating pressure. Of course, an ordinary artisan would understand that the pressure testing can be at any desired pressure.



BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be better understood with reference to the following detailed description together with the appended illustrative drawings in which like elements are numbered the same:
FIG. 1A a plot of testing of a clarified Xanthan-CMHPG gelled formate composition.
FIG. 1B a plot of the testing of FIG. 1A through the first 330 minutes.
FIG. 2 a plot of testing of a 80 ppt CMHPG dry polymer gelled formate composition.
FIG. 3 a plot of the testing of a CMHPG-Xanthan 80-20 w-w gelled formate composition.
FIG. 4 a plot of the testing of a CMHPG-130 gelled formate composition.
FIG. 5 a plot of the testing of a CMHPG-130 gelled formate composition@ 100/s.
FIG. 6 a plot of the testing of a 20 gpt WGA-5L gelled formate composition.
FIG. 7 a plot of the testing of a HPG gelled formate composition.
FIG. 8A a plot of rheological data for a gelled formate composition of this invention.
FIG. 8B a plot of rheological data for a gelled formate composition of this invention.



DEFINITIONS USED IN THE INVENTION
The term “substantially” means that the actual value is within about 5% of the actual desired value, particularly within about 2% of the actual desired value and especially within about 1% of the actual desired value of any variable, element or limit set forth herein.
The term “residual film” means a water film left in a pipeline, flowline, pipeline jumper or flowline jumper after a pig bulk dewatering operation. For carbon steel pipelines, a water residual film of about 0.1 mm is generally left in the pipeline. The present composition is used to change the make up of the residual film coating the pipeline to a film having at least 70% w/w of the aqueous, metal ion formate salt composition of this invention and 30% w/w residual water. In certain embodiments, the residual film comprises at least 80% w/w of the aqueous, metal ion formate salt composition of this invention and 20% w/w residual water. In certain embodiments, the residual film comprises at least 90% w/w of the aqueous, metal ion formate salt composition of this invention and 10% w/w residual water. In certain embodiments, the residual film comprises at least 95% w/w of the aqueous, metal ion formate salt composition of this invention and 5% w/w residual water. In certain embodiments, the residual film comprises at least 99% w/w of the aqueous, metal ion formate salt composition of this invention and 1% w/w residual water. Of course, for other pipeline, flowline, pipeline jumper or flowline jumper materials, the film make up can vary, but generally it will be within these ranges. Of course, the final make up of the residual film coating the pipeline will depend on operating conditions and is adjusted so that the water content is below a dew point of pure water under the operating conditions.
The term “formate” means the salt of formic acid HCOO−.
The term “metal ion formate salt” means the salt of formic acid HCOOH−M+, where M+ is a metal ion.
The term “sub-freezing temperature” means a temperature below the freezing point of pure water.
The term “gpt” means gallons per thousand gallons.
The term “ppt” means pounds per thousand gallons.
The term “HPG” means hydroxypropyl guar.
The term “CMHPG” means carboxymethylhydroxypropyl guar.
DETAILED DESCRIPTION OF THE INVENTION
The inventors have found that a new gelled composition can be formulated for use in pipeline, flowline, pipeline jumper or flowline jumper dewatering, conditioning or preventing ingress of seawater. into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits and/or pressure testing operations, where the new fluid is capable of being used without environmental consideration. The new gelled composition comprises a gelled metal ion formate solution. These compositions are well suited for pipeline flowline, pipeline jumper or flowline jumper dewatering operations, pipeline flowline, pipeline jumper or flowline jumper repair operations, pipeline flowline, pipeline jumper or flowline jumper pressure testing operations, pipeline flowline, pipeline jumper or flowline jumper conditioning operations, pipeline flowline, pipeline jumper or flowline jumper hydrotesting operations or other pipeline flowline, pipeline jumper or flowline jumper operations without being concerned with collecting and disposing of the compositions as is true for competing dewatering fluids such as glycol containing fluids or alcohol containing fluids. Moreover, the gelled compositions are also recyclable, where the gel can be broken, filtered and the recovered formate solution regelled. Of course, the formate ion concentration may need adjusting.
The inventors have found that gelled compositions of metal ion formates such as potassium formate, marketed as Superdry 2000 by Weatherford International, is an alternative for many pipeline applications. The gelled formate compositions have similar conditioning properties to currently used fluids such as methanol and glycols, without the hazards associated with methanol and glycols. Non-gelled formate solutions, such as potassium formate solutions, are known to be non-toxic and suitable for discharge directly into marine environments, without further processing. The ability to discharge formate solutions directly into marine environments is of particular benefit as it avoids the handling of typically large volumes of methanol or glycol containing fluids. In a previous application, assignee's employees demonstrated that formate solutions are well suited in pipeline applications as a substitute for alcohol and glycol dewatering and testing fluids, U.S. patent application Ser. No. 11/767,384, filed Jun. 22, 2007, incorporated herein by reference, even though all references are incorporated by reference through the last paragraph before the claims.
The use of a gelled metal formate compositions for dewatering pipelines flowline, pipeline jumper or flowline jumper or preventing ingress of seawater. into open pipeline systems or components during tie-in operations of jumpers or additional pipe, valving, manifolds, subsea pipeline architecture or flow conduits proved to have an added benefit compared to fluids such as methanol and glycols due to the formation of a gel column. In addition, the gel column established is compatible with all metal alloys and elastomers. Furthermore, the gelled formate compositions can be reused by breaking the gel column, filtering the debris out of the resulting fluid, and regelling the recovered formate solution with or without the adjustment of formate concentration, pH, etc.
The gel column established using of the gelled formate compositions of this invention provides a 100% (360 degree) coverage of the pipewall, compared to only about 60% coverage with the use of fluids, thus improving the dewatering capabilities/potentials. Dewatering applications constantly are in high demand in the Gulf of Mexico and improved product performance are of extreme and immediate interest.
Chemicals such as biocides, corrosion inhitors, oxygen scavangers, dyes, polymers or surfactants can optionally be added to the composition as needed for the intended application.
Purpose
To date fluids such as methanol and glycols utilized for dewatering pipeline, flowline, pipeline jumper or flowline jumper applications offshore constantly exceed the acceptable limitations for both subsea and overboard discharge. Potassium formate solutions are generally utilized to provide hydrate control; however, more recently, formate solutions have been used in dewatering application. Such formate solutions likely will not suffer from the same regulatory restrictions as do methanol and glycol and do not suffer from other problems associated with alcohols and glycols. However, these formate solutions are not gelled and do not form gel columns. Gelled compositions have significant advantages over solutions as they are less prone to leakage, are less prone to flowing, and represent a more controlled dewatering environment especially for off shore and sub sea applications.
The purpose of this project is to develop and confirm gelled formate compositions. A gelled formate composition would effectively increase the efficiency as well as the viscosity of pipeline fluid(s), where the gel found result from gelling a formate solution having at least about 50 wt. of a metal formate or mixture of metal formates. In certain embodiments, the formate solution includes at least 60 wt. % of a metal formate or mixture of metal formates. In other embodiments, the formate solution includes at least 70 wt. % of a metal formate or mixture of metal formates. These gelled compositions are designed for, but not limited to, use in pipeline drying or cleaning processes/applications. These gelled composition are designed to maintain viscosity for several hours at temperatures between about 70° F. and about 75° F. under shear rates ranging from about 40/s to 100/s without any significant viscosity degradation.
Suitable Reagents
Suitable metal ion formate salts for use in this invention include, without limitation, a compound of the general formula (HCOO−)nMn+ and mixtures or combinations thereof, where M is a metal ion as set forth above and n is the valency of the metal ion.
Suitable metal ions for use in this invention include, without limitation, alkali metal ions, alkaline metal ions, transition metal ions, lanthanide metal ions, and mixtures or combinations thereof. The alkali metal ions are selected from the group consisting of Li+, Na+, K+, Rd+, Cs+, and mixtures or combinations thereof. The alkaline metal ions are selected from the group consisting of Mg2+, Ca2+, Sr2+, Ba2+ and mixtures or combinations thereof. In certain embodiments, the transition metal ions are selected from the group consisting of Ti4+, Zr4+, Hf4+, Zn2+ and mixtures or combinations thereof. In certain embodiments, the lanthanide metal ions are selected from the group consisting of La3+, Ce4+, Pr2+, Pr3+, Pr4+, Sm2+, Sm3+, Gd3+, Dy2+, Dy3+, and mixtures or combinations thereof.
Suitable polymers for use in the present invention to gel a formate solution includes, without limitation, hydratable polymers. Exemplary examples includes polysaccharide polymers, high-molecular weight polysaccharides composed of mannose and galactose sugars, or guar derivatives such as hydropropyl guar (HPG), hydroxypropylcellulose (HPC), carboxymethyl guar (CMG), carboxymethylhydropropyl guar (CMHPG), hydroxyethylcellulose (HEC) or hydroxypropylcellulose (HPC), carboxymethylhydroxyethylcellulose (CMHEC), Xanthan, scleroglucan, polyacrylamide, polyacrylate polymers and copolymers or mixtures thereof.
Compositional Ranges
For dewatering or the prevention of seawater ingress applications, the general concentration range of metal ion formate salt in water is between about 40% w/w and supersaturation. In certain embodiments, the concentration range of metal ion formate salt in water is between about 45% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is between about 50% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is between about 55% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is between about 60% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is between about 65% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is between about 70% w/w and supersaturation. In other embodiments, the concentration range of metal ion formate salt in water is sufficient to prepare a supersaturated solution. Of course one of ordinary art would understand that the concentration will depend on the required reduction in the amount of bulk and/or residual water left in the pipeline. In certain embodiments, the amount of metal ion formate salt in water can result in a supersaturated solution, where residual water in the pipeline will dilute the solution form supersaturated to saturated or below during the dewatering operation.
EXPERIMENTS OF THE INVENTION
Introduction
Assignee has used aqueous potassium formate solutions in pipeline drying or dewatering application and other pipeline application as set forth in U.S. patent application Ser. No. 11/767,384, filed Jun. 22, 2007. However these fluids suffer dilution over the course of pipeline dewatering resulting in loss of effective transport of water as the drying process proceeds to completion. We then set out to increase the viscosity of these formate solutions to more effectively allow the fluid to convey water or other debris through the pipeline as it is being dried or cleaned. Earlier efforts at drying with high viscosity compositions revolved around formulation using biopolymers like xanthan gum. Xanthan gum has been one of the polymers effectively use used in pipeline cleaning and drying, for example in gel pigging. Formulations including mixtures of Xanthan and other polysaccharides have higher viscosity over a broad shear rate range. Such formulations have demonstrated their cost effectiveness in other technologies. Graft copolymers of polysaccharides and polyacrylates have also proven to be effective formulations in other technologies.
Xanthan Gum Chemistry
Xanthan gum is produced by fermenting glucose or sucrose in the presence of a xanthomonas campestris bacterium. The polysaccharide backbone comprises two β-d-glucose units linked through the 1 and 4 positions. The side chain comprise two (2) mannose residues and one (1) glucuronic acid residue, so the polymer comprises repeating five (5) sugar units. The side chain is linked to every other glucose of the backbone at the 3 position. About half of the terminal mannose residues have a pyruvic acid group linked as a ketal to its 4 and 6 positions. The other mannose residue has an acetal group at the 6 positions. Two of these chains may be aligned to form a double helix, giving a rather rigid rod configuration that accounts for its high efficiency as a viscosifier of water. The molecular weight of xanthan gums varies from about one million to 50 million depending upon how it is prepared. An idealized chemical structure of xanthan polymer is shown below:




Guar Gum Chemistry

Guar Chemistry-Guar gum (also called guaran) is extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba, where it acts as a food and water store. Structurally, guar gum is a galactomannan comprising a (1→4)-linked β-d-mannopyranose backbone with branch points from their 6-positions linked to α-d-galactose (that is, 1→6-linked-α-d-galactopyranose). There are between 1.5-2 mannose residues for every galactose residue. Guar gums molecular structure is made up of non-ionic polydisperse rod-shaped polymers comprising molecules made up of about 10,000 residues. Higher galactose substitution also increases the stiffness, but reduces the overall extensibility and radius of gyration of the isolated chains. The galactose residues prevent strong chain interactions as few unsubstituted clear areas have the minimum number (about 6) required for the formation of junction zones. Of the different possible galactose substitution patterns, the extremes of block substitution and alternating substitution give rise to the stiffer, with greater radius of gyration, and most flexible conformations respectively (random substitution being intermediate). If the galactose residues were perfectly randomized, it unlikely that molecules would have more than one such area capable of acting as a junction zone, so disallowing gel formation. A block substitution pattern, for which there is some experimental evidence, would allow junction zone formation if the blocks were of sufficient length. Enzymatic hydrolysis of some of the galactose side chains is possible using legume a-galactosidase. An idealized chemical structure of a guar gum is shown below:




Derivatized guar polymer can be obtained by reaction with propylene oxide and/or chloracetic acid producing hydroxypropylguar (HPG) and carboxymethylhydroxypropylguar (CMHPG). These reaction products have enhanced hydration properties. The carboxyl functionality allows for polymer crosslinking at low pH levels less than 7. Idealized structure of HPG and CMHPG are shown below:




Guar gum is an economical thickener and stabilizer. It hydrates fairly rapidly in cold water to give highly viscous pseudo plastic solutions of generally greater low-shear viscosity when compared with other hydrocolloids and much greater than that of locust bean gum. High concentrations ( ̃1%) are very thixotropic but lower concentrations ( ̃0.3%) are far less so. Guar gum is more soluble than locust bean gum and a better emulsifier as it has more galactose branch points. Unlike locust bean gum, it does not form gels but does show good stability to freeze-thaw cycles. Guar gum shows high low-shear viscosity but is strongly shear-thinning Being non-ionic, it is not affected by ionic strength or pH but will degrade at pH extremes at temperature (for example, pH 3 at 50° C.). It shows viscosity synergy with xanthan gum. With casein, it becomes slightly thixotropic forming a biphasic system containing casein micelles. Guar gum retards ice crystal growth non-specifically by slowing mass transfer across solid/liquid interface.
General Preparation Method
We tested several formulations using a seventy (weight percent 70 wt. %) potassium formate base fluid and a polymer to form composition having significantly improved viscosity properties. Several polymers were tested along with combinations of polymers to study their properties. The polymer tested were guar, hydroxypropyl guar (HPG), carboxymethylhydroxypropyl guar (CMHPG) and “clarified” xanthan gum. We also discovered that the pH of formate solutions was generally above about pH 9. This high pH was found to inhibit polymer hydration when using certain natural polysaccharide polymers. The inventors found that by adjusting the pH of the base formate fluid to a pH between about 7 and about 7.5 using an acetic anhydride-glacial acetic acid composition improved polymer hydration and gel formation.
Polymers were then dispersed into the pH adjusted formate solution, while the formate solution was mixed. In certain embodiments, mixing was performed at 2500 rpm using an O.F.I.T.E. constant speed mixer apparatus. The mixing continued for about 5 minutes. The inventors also found polymer slurries or suspensions were more efficiently disperse into the formate solution than dry polymers. However, dry polymers can be used with additional mixing and/or shearing.
After preparation, a small aliquot of the gelled composition was taken, and the viscosity stability of the aliquot was measured versus time at about 75° F. for more than 900 minutes. Shear sweeps were made at 30 minutes intervals during the 900 minute test period. The viscosity measurements were made using an automated Grace Instrument high temperature-high pressure rotational M5500 viscometer following standard testing procedures for that apparatus. The 900 minute period was used to simulate residence time that such a composition would be expected to encounter in a typical pipeline cleaning project. The rotor-bob geometry was R1:B1. The interim shear rates were 40 and 100 reciprocal seconds (s−1) as shown in Tables 1A through 7C and graphically in FIGS. 1 through 7. Indices of n′ and k′ fluid flow and fluid consistency were calculated from shear stress measurements at varying shear rate.







TABLE 1A





Test Description


















Test Name:
TEST-5207



Fluid ID:
Hydro Gel 5L PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
0



Post-Test pH:
0



Description:
SHEAR RATE: 50/S

















TABLE 1B







Formulation and Test Conditions














Lot



Additives
Concentration
Units
Number
Conditions














70% KCOOH
1000
GPT

zero time @






temperature =






1.1 minutes


BIOCLEAR
0.05
GPT
Russia
maximum sample


200



temperature =






79.0° F.


Hydro Gel 5L
16
GPT
Batch
time at excess





K06-420
temperature = 0.0






minutes


Hydro
10
GPT

total test


Buffer 552L



duration = 935.1






minutes


Clarified
4
GPT
L0110012
initial viscosity =


Xanthan Gum



413.3 cP






cool down






viscosity = N.R.cP






cool down






temperature =






N.R.° F.
















TABLE 1C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
77
0.4045
0.0951
0.9363
0.0916
0.1077
573
332
242


35
75
0.2997
0.2618
0.9970
0.2506
0.2978
1077
567
391


65
74
0.2749
0.3130
0.9990
0.2992
0.3559
1174
604
411


95
74
0.2770
0.3212
0.9991
0.3071
0.3652
1214
626
427


125
75
0.2713
0.3322
0.9990
0.3175
0.3776
1229
631
428


155
75
0.2683
0.3379
0.9992
0.3228
0.3840
1237
632
429


185
75
0.2662
0.3410
0.9993
0.3257
0.3874
1238
632
428


215
75
0.2674
0.3389
0.9991
0.3238
0.3852
1236
632
428


245
75
0.2666
0.3398
0.9984
0.3246
0.3861
1236
631
428


275
74
0.2633
0.3460
0.9992
0.3305
0.3931
1243
633
428


305
74
0.2659
0.3415
0.9994
0.3263
0.3881
1239
632
428


335
75
0.2678
0.3380
0.9995
0.3230
0.3842
1235
631
428


365
75
0.2646
0.3427
0.9991
0.3274
0.3894
1237
631
427


395
75
0.2635
0.3435
0.9995
0.3281
0.3902
1235
629
425


425
75
0.2609
0.3482
0.9993
0.3326
0.3956
1240
630
425


455
74
0.2604
0.3488
0.9989
0.3331
0.3963
1239
629
425


485
74
0.2623
0.3485
0.9997
0.3329
0.3959
1247
635
429


515
73
0.2601
0.3510
0.9996
0.3352
0.3987
1246
632
427


545
73
0.2597
0.3538
0.9995
0.3379
0.4019
1254
636
430


575
73
0.2601
0.3547
0.9996
0.3387
0.4029
1259
639
431


605
73
0.2576
0.3581
0.9995
0.3419
0.4067
1259
638
430


635
72
0.2594
0.3583
0.9997
0.3422
0.4070
1268
643
434


665
72
0.2543
0.3649
0.9999
0.3483
0.4143
1267
640
431


695
72
0.2577
0.3606
0.9997
0.3443
0.4095
1268
642
433


725
72
0.2559
0.3630
0.9997
0.3466
0.4123
1268
641
432


755
72
0.2664
0.3506
0.9993
0.3350
0.3984
1274
650
441


785
72
0.2562
0.3641
0.9986
0.3476
0.4135
1273
644
434


815
72
0.2605
0.3596
0.9995
0.3434
0.4084
1278
649
438


845
72
0.2620
0.3575
0.9996
0.3415
0.4062
1278
650
439


875
71
0.2591
0.3614
0.9991
0.3452
0.4106
1278
648
438


905
72
0.2535
0.3685
0.9997
0.3518
0.4184
1276
644
433


935
71
0.2642
0.3552
0.9995
0.3393
0.4036
1280
652
442
















TABLE 2A





Test Description


















Test Name:
TEST-5206



Fluid ID:
CMHPG PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.55



Post-Test pH:
0



Description:
SHEAR RATE: 50/S

















TABLE 2A







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number
Conditions














70% KCOOH
1000
gpt

zero time @






temperature = 1.1






minutes


BioClear 200
0.05
gpt
Russia
maximum sample






temperature = 79.0° F.


CMHPG-
80
ppt
Batch
time at excess


130:Xanthan


#L0222098
temperature = 0.0


(80:20 w/w)



minutes


Hydro Buffer
10
gpt

total test duration =


552L



 935.1 minutes






initial viscosity =






413.3 cP






cool down viscosity =






N.R. cP






cool down






temperature =






N.R. ° F.
















TABLE 2C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
75
0.3444
0.1736
0.9653
0.1666
0.1973
842
462
326


35
74
0.2899
0.2700
0.9973
0.2583
0.3071
1071
559
383


65
75
0.2781
0.2969
0.9991
0.2839
0.3376
1127
582
397


95
75
0.2773
0.3047
0.9990
0.2912
0.3464
1153
595
405


125
74
0.2677
0.3198
0.9995
0.3055
0.3634
1168
597
405


155
75
0.2762
0.3107
0.9988
0.2970
0.3532
1171
603
411


185
75
0.2713
0.3151
0.9998
0.3011
0.3581
1166
598
406


215
74
0.2661
0.3208
0.9974
0.3065
0.3645
1164
594
403


245
73
0.2666
0.3252
0.9985
0.3107
0.3696
1183
604
409


275
73
0.2727
0.3185
0.9991
0.3044
0.3621
1185
609
414


305
74
0.2668
0.3244
0.9993
0.3100
0.3687
1181
603
409


335
74
0.2682
0.3237
0.9989
0.3093
0.3678
1184
606
411


365
73
0.2650
0.3265
0.9996
0.3119
0.3710
1180
602
408


395
74
0.2691
0.3214
0.9990
0.3071
0.3653
1180
604
410


425
74
0.2699
0.3200
0.9988
0.3058
0.3637
1178
603
410


455
74
0.2639
0.3274
0.9986
0.3127
0.3719
1178
600
406


485
73
0.2665
0.3259
0.9993
0.3114
0.3704
1185
605
410


515
73
0.2639
0.3305
0.9981
0.3157
0.3755
1190
606
410


545
73
0.2655
0.3297
0.9987
0.3150
0.3747
1194
609
413


575
72
0.2624
0.3331
0.9986
0.3182
0.3784
1193
607
410


605
72
0.2610
0.3367
0.9986
0.3216
0.3825
1199
609
412


635
72
0.2627
0.3364
0.9982
0.3213
0.3822
1206
614
415


665
72
0.2617
0.3376
0.9981
0.3224
0.3835
1205
613
414


695
72
0.2609
0.3391
0.9981
0.3239
0.3852
1207
613
414


725
72
0.2693
0.3298
0.9995
0.3152
0.3749
1212
620
421


755
72
0.2594
0.3428
0.9986
0.3274
0.3894
1214
616
416


785
72
0.2594
0.3428
0.9980
0.3274
0.3894
1213
616
416


815
72
0.2663
0.3344
0.9991
0.3195
0.3800
1215
620
420


845
72
0.2607
0.3411
0.9994
0.3258
0.3875
1214
616
416


875
72
0.2607
0.3436
0.9993
0.3282
0.3904
1222
621
419


905
72
0.2583
0.3468
0.9980
0.3311
0.3938
1222
620
418


935
71
0.2542
0.3519
0.9985
0.3360
0.3996
1222
617
415
















TABLE 3A





Test Description


















Test Name:
TEST-5206



Fluid ID:
HPG PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.55



Post-Test pH:
0



Description:
SHEAR RATE: 50/S

















TABLE 3B







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number
Conditions














70% KCOOH
1000
gpt

zero time @






temperature = 0.6






minutes


BIOCLEAR 200
0.05
gpt
Russia
maximum sample






temperature =






77.2° F.


CMHPG-
80
ppt
Batch #
time at excess


130:Xanthan


L0222098
temperature =


(80:20 w/w)



0.0 minutes


Hydro Buffer 552L
10
gpt

total test






duration =






935.1 minutes






initial viscosity =






619.7 cP






cool down






viscosity = N.R. cP






cool down






temperature =






N.R. ° F.
















TABLE 3C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
75
0.3444
0.1736
0.9653
0.1666
0.1973
842
462
326


35
74
0.2899
0.2700
0.9973
0.2583
0.3071
1071
559
383


65
75
0.2781
0.2969
0.9991
0.2839
0.3376
1127
582
397


95
75
0.2773
0.3047
0.9990
0.2912
0.3464
1153
595
405


125
74
0.2677
0.3198
0.9995
0.3055
0.3634
1168
597
405


155
75
0.2762
0.3107
0.9988
0.2970
0.3532
1171
603
411


185
75
0.2713
0.3151
0.9998
0.3011
0.3581
1166
598
406


215
74
0.2661
0.3208
0.9974
0.3065
0.3645
1164
594
403


245
73
0.2666
0.3252
0.9985
0.3107
0.3696
1183
604
409


275
73
0.2727
0.3185
0.9991
0.3044
0.3621
1185
609
414


305
74
0.2668
0.3244
0.9993
0.3100
0.3687
1181
603
409


335
74
0.2682
0.3237
0.9989
0.3093
0.3678
1184
606
411


365
73
0.2650
0.3265
0.9996
0.3119
0.3710
1180
602
408


395
74
0.2691
0.3214
0.9990
0.3071
0.3653
1180
604
410


425
74
0.2699
0.3200
0.9988
0.3058
0.3637
1178
603
410


455
74
0.2639
0.3274
0.9986
0.3127
0.3719
1178
600
406


485
73
0.2665
0.3259
0.9993
0.3114
0.3704
1185
605
410


515
73
0.2639
0.3305
0.9981
0.3157
0.3755
1190
606
410


545
73
0.2655
0.3297
0.9987
0.3150
0.3747
1194
609
413


575
72
0.2624
0.3331
0.9986
0.3182
0.3784
1193
607
410


605
72
0.2610
0.3367
0.9986
0.3216
0.3825
1199
609
412


635
72
0.2627
0.3364
0.9982
0.3213
0.3822
1206
614
415


665
72
0.2617
0.3376
0.9981
0.3224
0.3835
1205
613
414


695
72
0.2609
0.3391
0.9981
0.3239
0.3852
1207
613
414


725
72
0.2693
0.3298
0.9995
0.3152
0.3749
1212
620
421


755
72
0.2594
0.3428
0.9986
0.3274
0.3894
1214
616
416


785
72
0.2594
0.3428
0.9980
0.3274
0.3894
1213
616
416


815
72
0.2663
0.3344
0.9991
0.3195
0.3800
1215
620
420


845
72
0.2607
0.3411
0.9994
0.3258
0.3875
1214
616
416


875
72
0.2607
0.3436
0.9993
0.3282
0.3904
1222
621
419


905
72
0.2583
0.3468
0.9980
0.3311
0.3938
1222
620
418


935
71
0.2542
0.3519
0.9985
0.3360
0.3996
1222
617
415
















TABLE 4A





Test Description


















Test Name:
TEST-5192



Fluid ID:
CMHPG PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.45



Post-Test pH:
7



Description:
50/S TEST

















TABLE 4B







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number














70% KCOOH
1000
gpt

zero time @






temperature =






0.6 minutes


BioClear 200
0.05
gpt
RUSSIA
maximum sample






temperature =






76.0° F.


CMHPG-130
80
ppt
LOT: H0601-
time at excess





055-D (P176-01)
temperature =






0.0 minutes


Hydro Buffer
10
gpt

total test


552L



duration =






935.1 minutes






initial viscosity =






659.8 cP






cool down






viscosity =






N.R. cP






cool down






temperature =






N.R. ° F.
















TABLE 4C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
72
0.3156
0.2120
0.9184
0.2031
0.2411
924
494
343


35
73
0.2424
0.4562
0.9947
0.4353
0.5175
1514
756
506


65
75
0.2205
0.5265
0.9993
0.5018
0.5958
1609
788
521


95
76
0.2174
0.5407
0.9994
0.5153
0.6116
1632
797
526


125
75
0.2194
0.5428
0.9994
0.5173
0.6141
1651
808
534


155
74
0.2164
0.5537
0.9989
0.5276
0.6261
1665
812
536


185
74
0.2146
0.5581
0.9997
0.5317
0.6310
1667
812
535


215
75
0.2150
0.5553
0.9993
0.5290
0.6278
1661
809
533


245
75
0.2139
0.5574
0.9998
0.5310
0.6301
1661
808
532


275
75
0.2169
0.5532
0.9987
0.5272
0.6257
1667
813
537


305
75
0.2166
0.5554
0.9984
0.5292
0.6281
1671
815
538


335
74
0.2154
0.5578
0.9979
0.5314
0.6307
1671
814
537


365
74
0.2146
0.5600
0.9990
0.5336
0.6331
1673
815
537


395
74
0.2137
0.5583
0.9998
0.5319
0.6311
1662
808
533


425
74
0.2183
0.5493
0.9984
0.5234
0.6214
1664
813
537


455
74
0.2167
0.5518
0.9990
0.5258
0.6241
1661
811
535


485
74
0.2162
0.5531
0.9996
0.5270
0.6255
1662
811
535


515
74
0.2174
0.5516
0.9987
0.5256
0.6239
1665
813
537


545
74
0.2185
0.5493
0.9987
0.5235
0.6214
1666
814
538


575
74
0.2157
0.5540
0.9991
0.5278
0.6264
1662
810
534


605
74
0.2168
0.5526
0.9993
0.5266
0.6250
1665
812
536


635
74
0.2163
0.5519
0.9980
0.5259
0.6242
1659
809
534


665
74
0.2172
0.5508
0.9991
0.5249
0.6230
1662
811
535


695
74
0.2139
0.5583
0.9991
0.5319
0.6311
1663
809
533


725
73
0.2119
0.5613
0.9994
0.5347
0.6343
1659
806
530


755
73
0.2151
0.5574
0.9996
0.5311
0.6302
1668
812
536


785
73
0.2110
0.5651
0.9996
0.5383
0.6386
1665
808
532


815
73
0.2164
0.5556
0.9990
0.5295
0.6284
1671
815
538


845
73
0.2128
0.5628
0.9992
0.5362
0.6362
1669
811
534


875
73
0.2150
0.5591
0.9985
0.5327
0.6322
1673
815
537


905
73
0.2139
0.5609
0.9985
0.5344
0.6342
1671
813
536


935
73
0.2158
0.5561
0.9993
0.5298
0.6288
1669
813
536
















TABLE 5A





Test Description


















Test Name:
TEST-5191-



Fluid ID:
HPG PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.45



Post-Test pH:
7



Description:
100/S TEST

















TABLE 5B







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number
Conditions














70% KCOOH
1000
gpt

zero time @






temperature =






0.5 minutes


BIOCLEAR
0.05
gpt
Russia
maximum sample


200



temperature =






76.0° F.


CMHPG-130
80
ppt
Lot: H0601-055-
time at excess





D (P176-01)
temperature =






0.0 minutes


Hydro Buffer
10
gpt

total test


552L



duration =






935.1 minutes






initial viscosity =






179.9 cP






cool down






viscosity =






N.R. cP






cool down






temperature =






N.R. ° F.
















TABLE 5C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















7
85
0.3485
0.1675
0.6514
0.1608
0.1904
824
454
321


37
72
0.2533
0.4550
0.9976
0.4344
0.5166
1574
794
534


67
75
0.2414
0.4868
0.9980
0.4644
0.5521
1610
804
537


97
76
0.2440
0.4876
0.9986
0.4653
0.5532
1629
815
546


127
75
0.2408
0.5012
0.9960
0.4782
0.5685
1654
825
552


157
74
0.2427
0.5054
0.9962
0.4822
0.5734
1680
839
562


187
74
0.2413
0.5141
0.9964
0.4905
0.5831
1700
848
567


217
75
0.2396
0.5156
0.9984
0.4918
0.5847
1694
844
564


247
75
0.2416
0.5146
0.9976
0.4909
0.5837
1704
850
569


277
75
0.2378
0.5243
0.9976
0.5002
0.5945
1711
851
568


307
75
0.2320
0.5416
0.9981
0.5165
0.6137
1729
855
569


337
74
0.2353
0.5368
0.9983
0.5120
0.6085
1735
861
574


367
73
0.2389
0.5365
0.9961
0.5118
0.6084
1758
875
584


397
73
0.2355
0.5458
0.9971
0.5206
0.6187
1765
876
584


427
73
0.2357
0.5488
0.9983
0.5234
0.6221
1777
882
588


457
73
0.2350
0.5527
0.9987
0.5271
0.6265
1784
885
590


487
72
0.2330
0.5598
0.9978
0.5339
0.6345
1794
888
591


517
73
0.2349
0.5588
0.9973
0.5330
0.6334
1803
895
596


547
72
0.2377
0.5544
0.9982
0.5288
0.6286
1808
899
600


577
72
0.2336
0.5685
0.9957
0.5422
0.6443
1826
905
602


607
72
0.2355
0.5627
0.9958
0.5367
0.6379
1820
904
602


637
73
0.2344
0.5671
0.9973
0.5409
0.6428
1827
906
603


667
73
0.2270
0.5877
0.9976
0.5603
0.6655
1841
907
602


697
73
0.2254
0.5932
0.9980
0.5655
0.6716
1847
908
602


727
73
0.2300
0.5858
0.9968
0.5586
0.6637
1856
916
609


757
73
0.2299
0.5886
0.9964
0.5613
0.6669
1864
921
612


787
73
0.2304
0.5901
0.9978
0.5627
0.6685
1872
925
615


817
73
0.2315
0.5926
0.9982
0.5651
0.6715
1888
933
621


847
73
0.2321
0.5935
0.9965
0.5660
0.6725
1895
938
624


877
73
0.2283
0.6040
0.9981
0.5759
0.6842
1901
937
622


907
73
0.2222
0.6197
0.9982
0.5906
0.7013
1905
934
618


937
73
0.2276
0.6071
0.9974
0.5788
0.6876
1906
939
623
















TABLE 6A





Test Description


















Test Name:
TEST-5175



Fluid ID:
Hydro Gel 5L PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.67



Post-Test pH:
0



Description:
SHEAR RATE: 50/S

















TABLE 6B







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number
Condition














70% KCOOH
1000
gpt

zero time @






temperature =






0.6 minutes


BIOCLEAR 200
0.05
gpt
Russia
maximum sample






temperature =






77.0° F.


Hydro Gel 5L
80
ppt
Batch K070315
time at excess






temperature =






0.0 minutes


Hydro Buffer
10
gpt

total test


552L



duration =






935.1 minutes






initial viscosity =






1420.0 cP






cool down






viscosity =






N.R. cP






cool down






temperature =






N.R. ° F.
















TABLE 6C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
73
0.1454
0.8335
0.9974
0.7919
0.9272
1897
867
551


35
74
0.1467
0.8248
0.9978
0.7836
0.9179
1888
864
549


65
74
0.1447
0.8326
0.9986
0.7910
0.9260
1890
863
548


95
74
0.1438
0.8384
0.9989
0.7965
0.9321
1896
865
549


125
73
0.1449
0.8375
0.9966
0.7956
0.9314
1902
869
552


155
73
0.1437
0.8427
0.9986
0.8006
0.9369
1906
870
552


185
73
0.1436
0.8426
0.9987
0.8005
0.9367
1904
869
551


215
73
0.1441
0.8423
0.9992
0.8002
0.9365
1908
871
553


245
73
0.1445
0.8430
0.9986
0.8008
0.9374
1912
873
555


275
73
0.1438
0.8463
0.9980
0.8040
0.9409
1914
874
555


305
73
0.1425
0.8508
0.9976
0.8082
0.9454
1914
872
553


335
73
0.1428
0.8515
0.9985
0.8089
0.9463
1918
874
555


365
73
0.1430
0.8545
0.9985
0.8117
0.9497
1927
879
558


395
74
0.1422
0.8566
0.9989
0.8137
0.9518
1925
877
556


425
74
0.1427
0.8537
0.9987
0.8110
0.9488
1922
876
556


455
74
0.1418
0.8575
0.9991
0.8146
0.9527
1924
877
556


485
74
0.1425
0.8561
0.9984
0.8132
0.9513
1926
878
557


515
74
0.1442
0.8507
0.9979
0.8082
0.9459
1928
880
559


545
74
0.1434
0.8538
0.9978
0.8111
0.9491
1928
879
558


575
74
0.1445
0.8508
0.9977
0.8083
0.9461
1930
881
560


605
74
0.1444
0.8512
0.9990
0.8087
0.9466
1930
881
560


635
74
0.1442
0.8521
0.9983
0.8095
0.9474
1930
881
560


665
74
0.1439
0.8531
0.9985
0.8104
0.9485
1931
881
559


695
74
0.1443
0.8547
0.9985
0.8120
0.9504
1937
884
562


725
74
0.1417
0.8614
0.9988
0.8182
0.9569
1932
880
558


755
74
0.1435
0.8576
0.9983
0.8147
0.9533
1937
884
561


785
74
0.1428
0.8590
0.9980
0.8161
0.9547
1935
882
560


815
75
0.1442
0.8548
0.9977
0.8121
0.9505
1937
884
561


845
75
0.1432
0.8585
0.9987
0.8156
0.9543
1937
883
561


875
76
0.1432
0.8550
0.9982
0.8122
0.9504
1930
880
559


905
77
0.1458
0.8464
0.9982
0.8041
0.9416
1930
882
561


935
75
0.1437
0.8568
0.9986
0.8140
0.9526
1937
884
561
















TABLE 7A





Test Description


















Test Name:
TEST-5162



Fluid ID:
HPG PIPELINE



Rotor Number:
R1



Bob Number:
B1



Bob Radius (cm)
1.7245



Bob Eff. Length (cm):
7.62



Pre-Test pH:
7.69



Post-Test pH:
7.68



Description:
SHEAR RATE: 50/S

















TABLE 7B







Formulation and Test Conditions












Con-

Lot



Additives
centration
Units
Number
Conditions














70% KCOOH
1000
gpt

zero time @






temperature =






0.6 minutes


BioClear 200
0.05
gpt
Russia
maximum sample






temperature =






77.0° F.


HPG-400DG
80
ppt
Batch #
time at excess





L0222098
temperature =






0.0 minutes


Hydro Buffer
10
gpt

total test duration =


552L



935.1 minutes






initial viscosity =






279.7 cP






cool down viscosity =






N.R. cP






cool down temperature =






N.R. ° F.
















TABLE 7C







Test Data
















Time
Temp

Kv

K′
K′ Slot
Calc. cP
Calc. cP
Calc. cP


(min)
(° F.)
n′
dyne-sn′/cm2
R2
dyne-sn′/cm2
dyne-sn′/cm2
@40 (1/s)
@100 (1/s)
@170 (1/s)



















5
75
0.5424
0.0344
0.9985
0.0334
0.0382
338
222
174


35
74
0.5372
0.0356
0.9985
0.0345
0.0395
343
225
176


65
74
0.5363
0.0358
0.9984
0.0348
0.0398
345
225
176


95
73
0.5369
0.0361
0.9982
0.0351
0.0402
348
228
178


125
73
0.5335
0.0369
0.9982
0.0359
0.0411
352
230
179


155
73
0.5414
0.0362
0.9986
0.0351
0.0402
354
233
183


185
73
0.5290
0.0374
0.9965
0.0363
0.0417
351
228
178


215
73
0.5213
0.0383
0.9989
0.0372
0.0427
350
226
175


245
73
0.5373
0.0364
0.9973
0.0354
0.0405
352
230
180


275
73
0.5348
0.0369
0.9977
0.0358
0.0411
353
231
180


305
73
0.5304
0.0374
0.9971
0.0363
0.0417
353
229
179


335
73
0.5243
0.0385
0.9989
0.0373
0.0429
355
230
178


365
73
0.5242
0.0386
0.9976
0.0374
0.0430
356
230
179


395
73
0.5266
0.0382
0.9981
0.0371
0.0426
356
230
179


425
73
0.5252
0.0386
0.9977
0.0374
0.0430
357
231
180


455
73
0.5307
0.0380
0.9982
0.0369
0.0423
359
233
182


485
72
0.5272
0.0384
0.9980
0.0373
0.0428
358
232
181


515
72
0.5276
0.0384
0.9977
0.0373
0.0428
358
233
181


545
72
0.5251
0.0388
0.9983
0.0376
0.0432
359
232
181


575
72
0.5389
0.0371
0.9969
0.0360
0.0413
361
236
185


605
72
0.5484
0.0347
0.9987
0.0337
0.0385
348
230
181


635
73
0.5559
0.0338
0.9981
0.0329
0.0375
349
232
183


665
73
0.5595
0.0330
0.9982
0.0321
0.0365
345
230
182


695
73
0.5512
0.0339
0.9988
0.0330
0.0377
344
228
180


725
73
0.5607
0.0332
0.9980
0.0323
0.0367
348
233
184


755
73
0.5509
0.0344
0.9979
0.0334
0.0382
349
231
182


785
73
0.5536
0.0338
0.9989
0.0328
0.0375
346
230
181


815
73
0.5390
0.0357
0.9963
0.0347
0.0397
347
228
178


845
73
0.5513
0.0344
0.9968
0.0335
0.0382
349
232
183


875
73
0.5529
0.0344
0.9983
0.0334
0.0382
351
233
184


905
72
0.5477
0.0352
0.9986
0.0342
0.0391
353
233
183


935
73
0.5532
0.0343
0.9981
0.0333
0.0380
350
233
183









Additional rheological properties are shown in Tables 8A&B and graphically in FIGS. 8A&B.







TABLE 8A







Rheology @ 200° F. (93° C.)











time

K′
μa @ 100/s



minute
n′
lbf · sn′/ft2
cP














0


618
521


15
0.390
0.2233
590
493


30
0.380
0.2209
565
471


45
0.374
0.2195
544
452


60
0.370
0.2185
527
438


75
0.367
0.2177
512
427


90
0.365
0.2171
501
420


105
0.363
0.2165
492
415


120
0.361
0.2160
486
412


135
0.359
0.2156
481
411


150
0.358
0.2153
479
412


165
0.356
0.2149
479
414


180
0.355
0.2146
481
417


195
0.354
0.2143
484
420


210
0.353
0.2141
488
423


225
0.352
0.2138
494
425


240
0.351
0.2136
500
427


255
0.350
0.2134
507
427


270
0.349
0.2132
515
426


285
0.349
0.2130
522
422


300
0.348
0.2128
530
416
















TABLE 8B





Rheological Conditions and Results

















R = less10% gel



Q = 30# gel



μa = −1E−05 * t3 + 0.0087 * t2 − 2.0024 * t + 617.83



μa = −2E−05 * t3 + 0.0115 * t2 − 1.9994 * t + 520.93










Table 9 tabulates a summary of pre and post test conditions, test values, components used, etc. set forth in Table 1A-8B above.







TABLE 9







Testing Results of Gelled Compositions of This Invention










Gellant Loading Variance
KCl Loading Variance


Additive or measurement
gallon/1,000 gallon
gallon/1,000 gallon


















Test Number
(1) 
(4) 
(5) 
(6) 
(7) 
(1) 
(2) 
(3) 


variable parameter %
0%
10% 
−10% 
20% 
−20% 
2%
4%
7%









water
Sparkletts Distilled Water
Sparkletts Distilled Water















Bio-Clear ® 200
 0.05




 0.05













KCl [% (lbm)]
  2 (167)
2 (167)
4 (334)
7 (583)















WNE-342LN‡
1.0




1.0




WPA-556L‡
 0.25




 0.25


WGA-11L‡
71⁄2
81⁄4
63⁄4
9 
6 
 71⁄2


hydration pH
 4.78
 4.75
 4.72
 4.72
 4.76
 4.78
 4.75
 4.87


base gel viscosity (cP)
32.1 
33.4 
25.6 
41.0 
19.5 
32.1 
29.7 
29.1 


WGA-160L‡
1.5




1.5


WPB-584L‡
2.0




2.0


buffer pH
11.58
11.60
11.63
11.72
11.56
11.58
11.58
11.87


WXL-101L‡
1.0




1.0


crosslink pH
11.54




11.54









test temperature [° F. (° C.)]
200 (93)
200 (93)















post test pH
11.04




11.04





‡These products are available from Clearwater International, LLC of Elmendorf, Texas






Field Mixing

The gelled composition can be prepared in the field using dry polymer, but using dry polymer required high shear to active a desired gelled composition. In certain embodiments, the dry polymer is encapsulated in a gel membrane to assist in hydration as the encapsulate erodes. In other embodiments, polymer slurries or suspensions are readily dispersed with little shear. In other embodiments, field mixing of the formulations is accomplished using an “on the fly” or “continuous mix” process. In this type of process, all additives are metered concomitantly at strategic points as the formate solution is injected into the pipeline. A detailed field mixing procedure as shown in attachment 1 is recommended for delivery of these formulations.
Xanthan—CMHPG Formulation
This example illustrates a pipeline fluid mixing procedure for preparing a gelled potassium formate composition of this invention.
Chemicals
The following chemical were used in the preparation of the composition:
70% w/w potassium formate (KCOOH)
Hydro Buffer 552L (hydration buffer)
Hydro Gel 5L (mineral oil base gelling agent)
Clarified xanthan gum slurry (mineral oil base)
Equipment
The following pieces of equipment were used in the preparation of the composition:
Positive displacement injection (metering) pumps or peristaltic pumps
Multi-stage Centrifugal Pump
Static Mixers (In line static mixers)
Additive micro-motion flow meters
Mass flow meter
Potassium Formate Storage Tank(s)
The composition was prepared in a “continuous mix” process, where all components are be injected concomitantly into the formate solution at a volume ratio base on formate injection rate.
The injection points for all components to be metered into the process flow line are disposed after the single stage centrifugal pump and before the centrifugal pump. Static mixers were installed between each centrifugal pump and downstream of each chemical additive injection point to facilitate mixing and to assure additive dispersion while the fluid stream is transiting to the pipeline.
Meter the 70 wt. % potassium formate base solution (first component) from the storage tank using a single stage centrifugal pump into the pipeline at the predetermined rate using a multistage centrifugal pump (FIG. 5).
Inject hydration buffer Hydro Buffer 552L (second component) at 10 gallons per thousand gallons (gpt) or 10 liters per cubic meter (10 L/m3) into the potassium formate solution. The total or combined rate of the chemical(s) being injected is maintained equal to the initial potassium formate rate, requiring the potassium formate rate to be decreased by the volume of hydration buffer being injected into the stream. Delivering the additives in this manner ensures a constant delivery of the final blended formulation. In certain embodiments, micromotion flow meters are used to maintain accurate injection rates of additive being deliver to the pipeline process flow stream.
Inject the gelling agent Hydro Gel 5L (third component) to the formulation downstream of the hydration buffer Hydro Buffer 552L and a first static mixer at a rate of 16 gpt (16 L/m3). Reduce the rate of the formate solution as described in step three of this procedure.
Inject the clarified xanthan gum slurry (forth and final component) of the formulation downstream of gelling agent Hydro Gel 5L and a second static mixer at a rate of 4 gpt (4 L/m3). Reduce the rate of the formate solution as described in step three of this procedure.
Meter the final composition through the multistage centrifugal pump to ensure rapid hydration of the gelling agent and the polymer slurry and fast fluid viscosity development of the final composition without the need for a hydration holding tank.
Inject this final hydrated mixture into the pipeline for drying.
CONCLUSION
Adjusting the pH of the potassium formate solutions to pH between about pH 7 and pH 7.5 permits effective and efficient hydration of guar and/or guar derivative polymers.
Highest viscosity stability at 935 minutes and at 70° F. to 75° F. was demonstrated with carboxymethylhydroxypropylguar and carboxymethylhydroxypropylguar xanthan polymer blends.
Generally, the polymer or polymer blend is added to the format solution in an amount of at least 40 pounds of polymer per thousand gallons of total solution (ppt). In other embodiments, the polymer or polymer blend is added to the format solution in an amount of at least 50 ppt. In other embodiments, the polymer or polymer blend is added to the format solution in an amount of at least 60 ppt. In other embodiments, the polymer or polymer blend is added to the format solution in an amount of at least 70 ppt. In other embodiments, the polymer or polymer blend is added to the format solution in an amount of at least 80 ppt.
In certain embodiments, a dry polymer or dry polymer blend is used, generally accompanied by high shear mixing with or without a holding tank to ensure complete gellation. In other embodiments, polymer suspensions in an oil such as mineral oil or a glycol is used to disperse the polymer or polymer blend into the formate solution.
All references cited herein are incorporated by reference. Although the invention has been disclosed with reference to its preferred embodiments, from reading this description those of skill in the art may appreciate changes and modification that may be made which do not depart from the scope and spirit of the invention as described above and claimed hereafter.

## Claims

1. A method for conditioning pipelines comprising the steps of:
filling a pipeline or portion thereof with an aqueous composition including a metal ion formate salt and an effective amount of a gelling agent, where the effective amount is sufficient to form a gelled composition having increased viscosity and where the gelled composition provides a 100% (360 degree) coverage of the pipe wall, and
pressurizing the pipeline or portion thereof filled with the gelled composition to a desired test pressure, where the formate salt in the gelled composition reduces gas hydrate formation in the pipeline or portion thereof during the pressurizing step.

2. The method of claim 1, wherein the gas hydrate comprises methane hydrate.

3. The method of claim 1, wherein the metal ion formate salt is a compound of the formula (HCOO−)nMn+ and mixtures thereof, where M is a metal ion and n is the valency of the metal ion.

4. The method of claim 3, wherein the metal ion is selected from the group consisting of an alkali metal ion, an alkaline metal ion, a transition metal ion, a lanthanide metal ion, and mixtures thereof.

5. The method of claim 4, wherein the alkali metal ion is selected from the group consisting of Li+, Na+, K+, Rb+, Cs+, and mixtures thereof.

6. The method of claim 5, wherein the alkali metal ion is K+.

7. The method of claim 4, the alkaline metal ion is selected from the group consisting of Mg2+, Ca2+, Sr2+, Ba2+ and mixtures thereof.

8. The method of claim 4, wherein the transition metal ion is selected from the group consisting of Ti4+, Zr4+, Hf4+, Zn2+ and mixtures thereof.

9. The method of claim 4, wherein the lanthanide metal ion is selected from the group consisting of La3+, Ce4+, Nd3+, Pr2+, Pr3+, Pr4+, Sm2+, Sm3+, Gd3+, Dy2+, Dy3+, and mixtures thereof.

10. The method of claim 1, further comprising:
recovering the gelled composition,
breaking the gelled composition,
filtering the gelled composition, and
reformulating the gelled composition for reuse.

11. The method of claim 1, further comprising:
flushing the gelled composition from the pipeline or portion thereof.

12. The method of claim 1, wherein the effective amount is between about 5% w/w of metal ion formate salt to water and a saturated or supersaturated solution of the metal ion formate salt in water.

13. The method of claim 1, wherein the effective amount is between about 25% w/w of metal ion formate salt to water and a saturated or supersaturated solution of the metal ion formate salt in water.

14. The method of claim 1, wherein the effective amount is between about 45% w/w of metal ion formate salt to water and a saturated or supersaturated solution of the metal ion formate salt in water.

15. The method of claim 1, wherein the effective amount is between about 65% w/w of metal ion formate salt to water and a saturated or supersaturated solution of the metal ion formate salt in water.

16. The method of claim 1, wherein the gelling agent comprises a hydratable polymer.

17. The method of claim 16, wherein the hydratable polymer is selected from the group consisting of polysaccharide polymers, high-molecular weight polysaccharides composed of mannose and galactose sugars, hydropropyl guar (HPG), hydroxypropylcellulose (HPC), carboxymethyl guar (CMG), carboxymethylhydropropyl guar (CMHPG), hydroxyethylcellulose (HEC) or hydroxypropylcellulose (HPC), carboxymethylhydroxyethylcellulose (CMHEC), xanthan, scleroglucan, polyacrylamide, polyacrylate polymers and copolymers and mixtures thereof.