U.S. patent application number 14/789899 was filed with the patent office on 2015-12-31 for environmentally friendly base fluids and methods for making and using same.
The applicant listed for this patent is Olusegun M. Falana, Sarkis R. Kakadjian, Edward C. Marshall, Frank Zamora. Invention is credited to Olusegun M. Falana, Sarkis R. Kakadjian, Edward C. Marshall, Frank Zamora.
Application Number | 20150377002 14/789899 |
Document ID | / |
Family ID | 45569779 |
Filed Date | 2015-12-31 |
United States Patent
Application |
20150377002 |
Kind Code |
A1 |
Falana; Olusegun M. ; et
al. |
December 31, 2015 |
ENVIRONMENTALLY FRIENDLY BASE FLUIDS AND METHODS FOR MAKING AND
USING SAME
Abstract
Non-toxic, biodegradable base fluids are disclosed for use in
making downhole fluids, where the base fluids include blends of
paraffins, olefins, naphthenes, esters, and oxygenates, having low
viscosities, having a pale-yellow color, having a flashpoint of
>80.degree. C. (175.degree. F.) and have a pour point of about
19.degree. F. Methods for making and using fluids include the base
fluids of this invention are also disclosed
Inventors: |
Falana; Olusegun M.;
(Houston, TX) ; Zamora; Frank; (Ft. Worth, TX)
; Marshall; Edward C.; (Houston, TX) ; Kakadjian;
Sarkis R.; (Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Falana; Olusegun M.
Zamora; Frank
Marshall; Edward C.
Kakadjian; Sarkis R. |
Houston
Ft. Worth
Houston
Houston |
TX
TX
TX
TX |
US
US
US
US |
|
|
Family ID: |
45569779 |
Appl. No.: |
14/789899 |
Filed: |
July 1, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12885128 |
Sep 17, 2010 |
9085724 |
|
|
14789899 |
|
|
|
|
Current U.S.
Class: |
166/308.2 ;
175/65 |
Current CPC
Class: |
C09K 8/64 20130101; C09K
8/34 20130101; C09K 8/703 20130101; E21B 43/26 20130101; G05B
2219/31121 20130101; G05B 2219/33192 20130101; C09K 8/38 20130101;
E21B 21/14 20130101; E21B 7/00 20130101 |
International
Class: |
E21B 43/26 20060101
E21B043/26; E21B 21/14 20060101 E21B021/14; E21B 7/00 20060101
E21B007/00; C09K 8/38 20060101 C09K008/38; C09K 8/70 20060101
C09K008/70 |
Claims
1. A method for using a downhole fluid comprising the step:
drilling an oil or gas well, fracturing a formation, completing an
oil or gas well, stimulating an oil or gas well, producing an oil
or gas well, or lifting fluid from an oil or gas well using a
downhole fluid comprising: a base fluid comprising a blend of
biodegradable, non-toxic, non-hazardous solvents including
biodegradable isoparaffins, terpenes, or mixtures and combinations
thereof, and a drilling, fracturing, completing, stimulating,
producing, or lifting additive package, where the base fluid has a
low viscosity, has a flashpoint of >80.degree. C. (175.degree.
F.), has a pour point of about 19 .degree. F. (-7.2.degree. C.), is
non-toxic, is biodegradable, and has an operating temperature range
up to about 450.degree. F.
2. The method of claim 1, wherein the drilling, completing,
producing or lifting additive package comprises at least a foaming
agent and a gas in concentrations sufficient to produce a foamed
drilling fluid having a foam height of at least 150 mL and a half
life of at least 2 minutes.
3. The method of claim 2, wherein the base fluid comprises blends
of isoparaffins and terpenes.
4. The method of claim 3, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
5. The method of claim 2, wherein the base fluid comprises blends
of isoparaffins and mixtures of terpenes.
6. The method of claim 5, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
7. The composition of claim 2, wherein the base fluid comprises
blends of isoparaffins.
8. The composition of claim 1, wherein the completing, stimulating,
producing, or lifting additive package include polymers and gelling
agents, where the gelled compositions have increased viscosity.
9. A method for drilling comprising the step: drilling an oil or
gas well with a drilling fluid comprising: a base fluid comprising
a blend of biodegradable, non-toxic, non-hazardous solvents
including biodegradable isoparaffins, terpenes, or mixtures and
combinations thereof, and a drilling fluid additive package
comprising at least a foaming agent and a gas in concentrations
sufficient to produce a foamed downhole fluid having a foam height
of at least 150 mL and a half life of at least 2 minutes, where the
additive package comprises at least a foaming agent and a gas in
concentrations sufficient to produce a foamed drilling fluid having
a foam height of at least 150 mL and a half life of at least 2
minutes, and where the base fluid has a low viscosity, has a
flashpoint of >80.degree. C. (175.degree. F.), has a pour point
of about 19.degree. F. (-7.2.degree. C.), is non-toxic, is
biodegradable, and has an operating temperature range up to about
450.degree. F.
10. The method of claim 9, wherein the base fluid comprises blends
of isoparaffins and terpenes.
11. The method of claim 10, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
12. The method of claim 10, wherein the base fluid comprises blends
of isoparaffins and mixtures of terpenes.
13. The method of claim 12, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
14. The composition of claim 10, wherein the base fluid comprises
blends of isoparaffins.
15. A method for fracturing comprising the step: fracturing an oil
or gas well with a fracturing slurry comprising: the base fluid,
and a fracturing fluid additive package comprising at least a clay,
a surfactant blend, a polymer, and a winterizing agent, where the
base fluid has a low viscosity, has a flashpoint of >80.degree.
C. (175.degree. F.), has a pour point of about 19.degree. F.
(-7.2.degree. C.), is non-toxic, is biodegradable, and has an
operating temperature range up to about 450.degree. F.
16. The method of claim 15, wherein the fracturing slurry further
includes a foaming agent and a gas in concentrations sufficient to
produce a foamed drilling fluid having a foam height of at least
150 mL and a half life of at least 2 minutes.
17. The method of claim 15, wherein the base fluid comprises blends
of isoparaffins and terpenes.
18. The method of claim 17, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
19. The method of claim 17, wherein the base fluid comprises blends
of isoparaffins and mixtures of terpenes.
20. The method of claim 19, wherein the terpenes comprise
d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes,
orange oil, lemon oil, other citrus terpenes, other citrus oils, or
mixtures and combinations thereof.
21. The composition of claim 17, wherein the base fluid comprises
blends of isoparaffins.
Description
RELATED APPLICATIONS
[0001] This application is a continuation application and claims
the benefit of and priority to U.S. patent application Ser. No.
12/885,128 filed 09/17/2010 (17 Sep. 2010).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of this invention relate to environmentally
friendly base fluids for use in downhole fluid systems and methods
for making and using same.
[0004] More particularly, embodiments of the present invention
relate to environmentally friendly base fluids for use in downhole
fluid systems and methods for making and using same, where the
fluids include a solvent system comprising a blend of paraffins,
olefins, naphthenes, esters, and oxygenates, where the solvent
system has a low viscosity, is a pale-yellow liquid, has a
flashpoint >80.degree. C. (175.degree. F.) and has a pour point
of about 19.degree. F.
[0005] 2. Description of the Related Art
[0006] Employment of base fluids either in the formulation of
drilling fluids for various drilling operations or as carrier for
solutes is commonly practiced in the oilfield or related
industries. Increasingly, more stringent regulations to curtail use
of hazardous or toxic chemicals are being legislated across the
Globe. Consequently, use of some chemicals like diesel is
prohibitive in some regions while there are wide spread strict
regulations for handling and disposal of several others.
[0007] A number of biodegradable mineral or synthetic oil base
fluids have been disclosed in prior art. U.S. Pat, Nos. 6,455,474
and 6,096,690 disclose environmentally friendly low temperature
base oils and drilling fluids made therefrom. U.S. Pat. Nos.
5,189,012 and 4,787,990 disclose low viscosity blends of poly
alpha-olefins (PAO) as a means of reducing the cost of suitable,
but expensive and limited in supply PAOs as biodegradable oils.
[0008] While other environmentally friendly or biodegradable
solvent systems have been discribed in the prior art, there is
still an immediate and long felt need in the art for non-hazardous,
non-toxic, environmentally friendly and biodegradable solvent
systems for use as a base fluid in downhole operations or other
similar operations.
SUMMARY OF THE INVENTION
[0009] Embodiments of this invention provide base fluids for use in
downhole operations, where the base fluids comprise solvent systems
include blends of paraffins, olefins, naphthenes, esters, and
oxygenates, having low viscosities, having a pale-yellow color,
having a flashpoint of >80.degree. C. (175.degree. F.) and
having a pour point of about 19.degree. F.
[0010] Embodiments of this invention provide drilling fluids
including abase fluid of this invention.
[0011] Embodiments of this invention provide fracturing fluids
including a base fluid of this invention.
[0012] Embodiments of this invention provide fluid carriers
including a base fluid of this invention.
[0013] Embodiments of this invention provide lift fluid including a
base fluid of this invention.
[0014] Embodiments of this invention provide completion fluids
including a base fluid of this invention.
[0015] Embodiments of this invention provide stimulating fluids
including a base fluid of this invention.
[0016] Embodiments of this invention provide methods for drilling,
fracturing, completing, stimulating, lifting and/or other downhole
operations, where the fluids include a blend of paraffins, olefins,
naphthenes, esters, and oxygenates, having low viscosities, having
a pale-yellow color, having a flashpoint of >80.degree. C.
(175.degree. F.) and having a pour point of about 19.degree. F.
DEFINITIONS OF TERM USED IN THE INVENTION
[0017] The following definitions are provided in order to aid those
skilled in the art in understanding the detailed description of the
present invention.
[0018] The term "fracturing" refers to the process and methods of
breaking down a geological formation, i.e. the rock formation
around a well bore, by pumping fluid at very high pressures, in
order to increase production rates from a hydrocarbon reservoir.
The fracturing methods of this invention use otherwise conventional
techniques known in the art.
[0019] The term "surfactant" refers to a soluble, or partially
soluble compound that reduces the surface tension of liquids, or
reduces inter-facial tension between two liquids, or a liquid and a
solid by congregating and orienting itself at these interfaces.
[0020] The term "drilling fluids" refers to any fluid that is used
during oil and/or gas well drilling operations.
[0021] The term "completion fluids" refers to any fluid that is
used in oil and/or gas well completion operations.
[0022] The term "production fluids" refers to any fluid that is
used in oil and/or gas well production operations.
[0023] An under-balanced and/or managed pressure drilling fluid
means a drilling fluid having a circulating hydrostatic density
(pressure) lower or equal to a formation density (pressure). For
example, if a known formation at 10,000 ft (True Vertical
Depth--TVD) has a hydrostatic pressure of 5,000 psi or 9.6 lbm/gal,
an under-balanced drilling fluid would have a hydrostatic pressure
less than or equal to 9.6 lbm/gal. Most under-balanced and/or
managed pressure drilling fluids include at least a density
reduction additive. Other additive many include a corrosion
inhibitor, a pH modifier and a shale inhibitor.
[0024] The term "foamable" means a composition that when mixed with
a gas forms a stable foam.
[0025] The term "gpt" means gallons per thousand gallons.
[0026] The term "ppt" means pounds per thousand gallons.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The inventors have found that new solvent systems can be
formulated as base fluids for use in making drilling fluids,
fracturing fluids, fluid carriers, completion fluids and/or related
systems, where the solvent systems include a blend of paraffins,
olefins, naphthenes, esters, and oxygenates. The solvent systems
have low viscosities, are pale-yellow liquids, have flashpoints of
>80.degree. C. (175.degree. F.) and have pour points of about
19.degree. F. The inventors have found that the solvent systems of
this invention maybe used to formulate drilling fluids, completion
fluids, fracturing fluids, fluid carriers for other applications,
or related fluid systems.
[0028] The inventors have found that the solvent systems maybe used
to formulate completely green systems. Thus, the inventors are able
to design a foamable drilling system including an eco-friendly
foamer or plurality of eco-friendly foamers, an eco-friendly
defoamer or plurality of eco-friendly defoamers and an eco-friendly
base fluid or plurality of eco-friendly base fluid. Embodiments of
the present invention also related to fracturing slurries with
outstanding properties prepared using the solvent systems of this
invention. Unlike other biodegradable synthetic oils that have been
previously disclosed, the solvent systems of this invention are
economical as base fluids having high flash points, >80.degree.
C. In other embodiments, drilling fluids may be formulated with the
base fluids of this invention having an extended operating
temperature range, a temperature range up to about 450.degree. F.
The inventors have found that the fluids of this invention are
reusable and possess superior properties compared to diesel, while
competing oil base fluids are neither foamable nor give
satisfactory foam properties. The present solvent systems do not
damage seals of downhole tools. The inventors have found that in
fracturing or frac applications, the fluids may be used to
formulate slurries that are non-settling and possess high yield
viscosity (lineal gel solution) as compared to known base fluids.
Products including the solvent systems of this invention have been
field tested successfully in an under-balanced drilling operation
in Houston, Tex. USA.
Drilling Fluids
[0029] Generally, a drilling fluid is used during the drilling of a
well. Drilling fluids can be designed for so-called over-balanced
drilling (a hydrostatic pressure of the drilling fluid is higher
than the pore pressure of the formation), under-balanced drilling
(a hydrostatic pressure of the drilling fluid is lower than the
pore pressure of the formation) or managed pressure drilling, where
the hydrostatic pressure of the drilling fluid is managed depending
on the nature of the material through which drilling is occurring.
Each type of drilling uses different types of drilling fluids. The
compositions of this invention are designed to improve dispersion
and stability of the resulting drilling fluids so that cuttings
remain suspended for longer periods of time or at temperatures up
to 450.degree. F.
[0030] Embodiments of the present invention relates to drilling
fluids including a base fluid composition of this invention, where
the base fluid composition includes blends of biodegradable,
non-toxic, non-hazardous solvent including biodegradable paraffins,
olefins, naphthenes, esters, and oxygenates having a flashpoint
.gtoreq.80.degree. C. and a pour point of about 19.degree. F. The
drilling fluids may optionally include a drilling fluid additive
package including the additives set forth herein or mixtures of the
additive set forth herein.
Completion Fluids
[0031] Embodiments of the present invention relates to completion
fluids including a solvent system of this invention as the base
fluid, where the solvent system of this invention include blends of
biodegradable, non-toxic, non-hazardous solvent including
biodegradable paraffins, olefins, naphthenes, esters, and
oxygenates having a flashpoint .gtoreq.80.degree. C. and a pour
point of about 19 .degree. F. The completion fluids may optionally
include a completion fluid additive package including the additives
set forth herein or mixtures of the additive set forth herein.
Fracturing Fluids
[0032] The present invention also relates to methods of fracturing
a subterranean formation comprising forming a fracturing fluid
including a surfactant system of this invention and pumping the gel
or coacervate down a wellbore, in the presence or absence of a
proppant and under pressure sufficient to fracture the formation.
Proppants suitable for our invention include all the generally used
or generally accepted proppant materials such as sand, shells, and
other hard particulates. The fluid may be used in the absence of
conventional brine-forming salts. Aqueous based gels used for
formation fracturing and other well treatment usually employ guar,
cellulose, or gums that depend on chemical bonding and are
shear-sensitive.
[0033] Embodiments of the present invention relates to fracturing
fluid compositions including a solvent system of this invention as
the base fluid, where the solvent system of this invention include
blends of biodegradable, non-toxic, non-hazardous solvent including
biodegradable paraffins, olefins, naphthenes, esters, and
oxygenates having a flashpoint .gtoreq.80.degree. C. and a pour
point of about 19.degree. F. The fracturing fluids may optionally
include a fracturing fluid additive package including the additives
set forth herein or mixtures of the additive set forth herein. For
additional information on fracturing fluid components that may be
used with the fracturing fluids of this invention the reader is
referred to U.S. Pat. Nos. 7,140,433, 7,517,447, 7,268,100,
7,392,847, 7,350,579, 7,712,535, and 7,565,933; and United States
Published Applications Nos. 20070032693, 20050137114, 20090250659,
20050250666, 20080039345, 20060194700, 20070173414, 20070129257,
20080257553, 20090203553, 20070173413, 20080318812, 20080287325,
20080314124, 20080269082, 20080197085, 20080257554, 20080251252,
20090151959, 20090200033, 20090200027, 20100000795, 20100012901,
20090067931, 20080283242, 20100077938, 20100122815, and
20090275488. These applications and patents are incorporated by
reference through the operation of the last paragraph of the
specification.
Stimulating Fluids
[0034] Embodiments of the present invention relates to stimulating
fluid compositions including a solvent system of this invention as
the base fluid, where the solvent system of this invention include
blends of biodegradable, non-toxic, non-hazardous solvent including
biodegradable paraffins, olefins, naphthenes, esters, and
oxygenates having a flashpoint 80.degree. C. and a pour point of
about 19.degree. F. The stimulating fluids may optionally include a
stimulating fluid additive package including the additives set
forth herein or mixtures of the additive set forth herein.
Compositional Ranges
[0035] In drilling fluid, stimulating fluid, completion fluid, and
lift fluid embodiments, the base fluid compositions of this
invention are used in a range between about 1 vol. % and about 100
vol. % (volume, v/volume, v) of the base fluid (the base fluid is
the fluid into which all other components of the final fluid are
added). In other embodiments, the base fluids are used in a range
between about 10 vol. % and about 90 vol. %. In other embodiments,
the base fluids are used in a range between about 30 and about 70
vol. %. In other embodiments, the base fluids are used in a range
between about 40 vol. % and about 60 vol. %. In other embodiments,
the base fluids make up greater than or equal to about 50 vol. % of
the base fluid. In other embodiments, the base fluids make up
greater than or equal to about 60 vol. % of the base fluid. In
other embodiments, the base fluids make up greater than or equal to
about 70 vol. % of the base fluid. In other embodiments, the base
fluids make up greater than or equal to about 80 vol. % of the base
fluid. In other embodiments, the base fluids make up greater than
or equal to about 90 vol. % of the base fluid. In other
embodiments, the base fluids make up about 100 vol. % of the base
fluid.
[0036] In fracturing slurries, the base fluid compositions of this
invention are present in a range between about 30 wt. % and about
70 wt. % based on the weight of the final slurry. In other
embodiments, the range is between about 30 wt. % and about 60 wt.
%. In other embodiments, the range is between about 30 wt. % and
about 50 wt. %. In other embodiments, the range is between about 40
wt. % and about 50 wt. %. In other embodiments, the base fluid
composition is present in an amount less than or equal to about 70
wt. %. In other embodiments, the base fluid composition is present
in an amount less than or equal to about 60 wt. %. In other
embodiments, the base fluid composition is present in an amount
less than or equal to about 50 wt. %.
Suitable Reagents
Base Fluid Compositions
[0037] Suitable base fluid compositions or solvent systems of this
invention include, without limitation, blends of biodegradable,
non-toxic, non-hazardous solvents including biodegradable
paraffins, isoparaffins, olefins, naphthenes, esters, and
oxygenates having a flashpoint .gtoreq.80.degree. C. and a pour
point of about 19.degree. F. Exemplary examples include
HF-1000.TM., ODC.RTM., LPA.RTM., terpenes and mixture of terpenes
derived from citrus plants including d-limonenes, orange terpenes,
lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other
citrus terpenes, other citrus oils, blends of HF-1000.TM.,
ODC.RTM., and/or LPA.RTM. with the terpenes and mixtures of
terpenes or mixtures and combinations thereof.
Foamers
[0038] Suitable foaming agents for use in this invention include,
without limitation, any foaming agent suitable for foaming
hydrocarbon based drilling fluids. Exemplary examples of foaming
agents include, without limitation, silicone foaming agents such as
tetra(trimethylsiloxy)silane, fluorinated oligomeric or polymeric
foams such as fluorinated methacrylic copolymer, or other similar
foaming agents capable of producing a foam in a hydrocarbon or
oil-based drilling fluid or mixtures or combinations thereof.
Exemplary examples of such foaming agents include, without
limitation, DC-1250 available from Dow Corning, Zonyl FSG available
from DuPont, APFS-16 available from Applied Polymer, A4851
available from Baker Petrolite, Superfoam available from Oilfield
Solutions, Paratene HFA available from Woodrising, DVF-880
available from Parasol Chemicals INC., JBR200, JBR300, JBR400, and
JBR500 available from Jeneil Biosurfactant Company, Paratene HFA,
Paratene HFB, Paratene MFA, Paratene MFB available from Woodrising
Resources Ltd. or mixture or combinations.
Polymers Used in Fracturing Fluids
[0039] Suitable polymers for use in this invention include, without
limitation, any polymer soluble in the hydrocarbon base fluid.
Exemplary polymers include, without limitation, a polymer
comprising units of one or more (one, two, three, four, five, . . .
, as many as desired) polymerizable mono-olefins or di-olefins.
Exemplary examples includes, without limitation, polyethylene,
polypropylene, polybutylene, or other poly-alpha-olefins,
polystyrene or othe polyaromatic olefins, polybutadiene,
polyisoprene, or other poly-diolefins, or copolymers (a polymer
including two or more mono-olefins or di-olefins) or copolymers
including minor amount of other co-polymerizable monomers such as
acrylates (acrylic acid, methyl acrylate, ethyl acrylate, etc.),
methacrylates (methacrylic acid, methyl methacrylate, ethyl
methacrylate, etc), vinylacetate, maleic anhydride, succinic
anhydride, or the like, provided of course that the resulting
polymer is soluble in the hydrocarbon base fluid.
Gelling Agents Using in Fracturing Fluids
[0040] Suitable gelling agents for use in this invention include,
without limitation, any gelling agent. Exemplary gelling agents
includes phosphate esters, ethylene-acrylic acid copolymer,
ethylene-methacrylic acid copolymers, ethylene-vinyl acetate
copolymers, ethylene-maleic anhydride copolymers,
butadiene-methacrylic acid copolymers, ethylene-methacrylic acid
copolymers, styrene-butadiene-acrylic acid copolymers,
styrene-butadiene-methacrylic acid copolymers, or other copolymer
including monomers having acid moieties or mixtures or combinations
thereof. Exemplary examples phosphate ester gelling agents include,
without limitation, WEC HGA 37, WEC HGA 70, WEC HGA 71, WEC HGA 72,
WEC HGA 702 or mixtures or combinations thereof, available from
Weatherford International. Other suitable gelling agents include,
without limitation, Geltone II available from Baroid, Ken-Gel
available from Imco or the like.
[0041] Suitable cross-linking agent for use in this invention
include, without limitation, any suitable cross-linking agent for
use with the gelling agents. Exemplary cross-linking agents
include, without limitation, di- and tri-valent metal salts such as
calcium salts, magnesium salts, barium salts, copperous salts,
cupric salts, ferric salts, aluminum salts, or mixtures or
combinations thereof. Examples cross-linking agent for use with
phosphate esters include, without limitation, WEC HGA 44, WEC HGA
48, WEC HGA 55se, WEC HGA 55s, WEC HGA 61, WEC HGA 65 or mixtures
or combinations thereof available from Weatherford
International.
Defoamers
[0042] Suitable defoaming agents for use in this invention include,
without limitation, any defoaming agent capable of reducing the
foam height of the foamed drilling fluid systems of this invention.
Exemplary examples of defoaming agents are polydimethylsiloxane
(Down Corning 200 Fluid.TM., 50 centistokes), low molecular weight
alcohols with isopropanol or isopropyl alcohol (IPA) being
preferred.
Gases
[0043] Suitable gases for foaming the foamable, ionically coupled
gel composition include, without limitation, nitrogen, carbon
dioxide, or any other gas suitable for use in formation fracturing,
or mixtures or combinations thereof.
Corrosion Inhibitors
[0044] Suitable corrosion inhibitor for use in this invention
include, without limitation: quaternary ammonium salts e.g.,
chloride, bromides, iodides, dimethylsulfates, diethylsulfates,
nitrites, bicarbonates, carbonates, hydroxides, alkoxides, or the
like, or mixtures or combinations thereof; salts of nitrogen bases;
or mixtures or combinations thereof. Exemplary quaternary ammonium
salts include, without limitation, quaternary ammonium salts from
an amine and a quaternarization agent, e.g., alkylchlorides,
alkylbromide, alkyl iodides, alkyl sulfates such as dimethyl
sulfate, diethyl sulfate, etc., dihalogenated alkanes such as
dichloroethane, dichloropropane, dichloroethyl ether,
epichlorohydrin adducts of alcohols, ethoxylates, or the like; or
mixtures or combinations thereof and an amine agent, e.g.,
alkylpyridines, especially, highly alkylated alkylpyridines, alkyl
quinolines, C.sub.6 to C.sub.24 synthetic tertiary amines, amines
derived from natural products such as coconuts, or the like,
dialkylsubstituted methyl amines, amines derived from the reaction
of fatty acids or oils and polyamines, amidoimidazolines of DETA
and fatty acids, imidazolines of ethylenediamine, imidazolines of
diaminocyclohexane, imidazolines of aminoethylethylenediamine,
pyrimidine of propane diamine and alkylated propene diamine,
oxyalkylated mono and polyamines sufficient to convert all labile
hydrogen atoms in the amines to oxygen containing groups, or the
like or mixtures or combinations thereof. Exemplary examples of
salts ofnitrogen bases, include, without limitation, salts of
nitrogen bases derived from a salt, e.g.: C.sub.1 to C.sub.8
monocarboxylic acids such as formic acid, acetic acid, propanoic
acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid,
octanoic acid, 2-ethylhexanoic acid, or the like; C.sub.2 to
C.sub.12 dicarboxylic acids, C.sub.2 to C.sub.12 unsaturated
carboxylic acids and anhydrides, or the like; polyacids such as
diglycolic acid, aspartic acid, citric acid, or the like; hydroxy
acids such as lactic acid, itaconic acid, or the like; aryl and
hydroxy aryl acids; naturally or synthetic amino acids; thioacids
such as thioglycolic acid (TGA); free acid forms of phosphoric acid
derivatives of glycol, ethoxylates, ethoxylated amine, or the like,
and aminosulfonic acids; or mixtures or combinations thereof and an
amine, e.g.: high molecular weight fatty acid amines such as
cocoamine, tallow amines, or the like; oxyalkylated fatty acid
amines; high molecular weight fatty acid polyamines (di, tri,
tetra, or higher); oxyalkylated fatty acid polyamines; amino amides
such as reaction products of carboxylic acid with polyamines where
the equivalents of carboxylic acid is less than the equivalents of
reactive amines and oxyalkylated derivatives thereof; fatty acid
pyrimidines; monoimidazolines of EDA, DETA or higher ethylene
amines, hexamethylene diamine (HMDA), tetramethylenediamine (TMDA),
and higher analogs thereof; bisimidazolines, imidazolines of mono
and polyorganic acids; oxazolines derived from monoethanol amine
and fatty acids or oils, fatty acid ether amines, mono and bis
amides of aminoethylpiperazine; GAA and TGA salts of the reaction
products of crude tall oil or distilled tall oil with diethylene
triamine; GAA and TGA salts of reaction products of dimer acids
with mixtures of poly amines such as TMDA, HMDA and
1,2-diaminocyclohexane; TGA salt of imidazoline derived from DETA
with tall oil fatty acids or soy bean oil, canola oil, or the like;
or mixtures or combinations thereof.
Other Additives
[0045] The drilling fluids of this invention can also include other
additives as well such as scale inhibitors, carbon dioxide control
additives, paraffin control additives, oxygen control additives, or
other additives.
Scale Control
[0046] Suitable additives for Scale Control and useful in the
compositions of this invention include, without limitation:
Chelating agents, e.g., Na.sup.+, K.sup.- or NH.sub.4.sup.+,
K.sup.+ or NH.sub.4.sup.- salts of NTA; Na.sup.+, K.sup.+ or
NH.sub.4.sup.+ salts of Erythorbic acid; Na.sup.30 , K.sup.+ or
NH.sub.4.sup.+ salts of thioglycolic acid (TGA); Na.sup.+, K.sup.+
or NH.sub.4.sup.+ salts of Hydroxy acetic acid; Na.sup.+, K.sup.+
or NH.sub.4.sup.+ salts of Citric acid; Na.sup.+, K.sup.+ or
NH.sub.4.sup.+ salts of Tartaric acid or other similar salts or
mixtures or combinations thereof. Suitable additives that work on
threshold effects, sequestrants, include, without limitation:
Phosphates, e.g., sodium hexamethylphosphate, linear phosphate
salts, salts of polyphosphoric acid, Phosphonates, e.g., nonionic
such as HEDP (hydroxyethylidene diphosphoric acid), PBTC
(phosphoisobutane, tricarboxylic acid), Amino phosphonates of: MEA
(monoethanolamine), NH.sub.3, EDA (ethylene diamine),
Bishydroxyethylene diamine, Bisaminoethylether, DETA
(diethylenetriamine), HMDA (hexamethylene diamine), Hyper
homologues and isomers of HMDA, Polyamines of EDA and DETA,
Diglycolamine and homologues, or similar polyamines or mixtures or
combinations thereof; Phosphate esters, e.g., polyphosphoric acid
esters or phosphorus pentoxide (P.sub.2O.sub.5) esters of: alkanol
amines such as MEA, DEA, triethanol amine (TEA),
Bishydroxyethylethylene diamine; ethoxylated alcohols, glycerin,
glycols such as EG (ethylene glycol), propylene glycol, butylene
glycol, hexylene glycol, trimethylol propane, pentaerythritol,
neopentyl glycol or the like; Tris & Tetra hydroxy amines;
ethoxylated alkyl phenols (limited use due to toxicity problems),
Ethoxylated amines such as monoamines such as MDEA and higher
amines from 2 to 24 carbons atoms, diamines 2 to 24 carbons carbon
atoms, or the like; Polymers, e.g., homopolymers of aspartic acid,
soluble homopolymers of acrylic acid, copolymers of acrylic acid
and methacrylic acid, terpolymers of acylates, AMPS, etc.,
hydrolyzed polyacrylamides, poly malic anhydride (PMA); or the
like; or mixtures or combinations thereof.
Carbon Dioxide Neutralization
[0047] Suitable additives for CO.sub.2 neutralization and for use
in the compositions of this invention include, without limitation,
MEA, DEA, isopropylamine, cyclohexylamine, morpholine, diamines,
dimethylaminopropylamine (DMAPA), ethylene diamine, methoxy
propylamine (MOPA), dimethylethanol amine, methyldiethanolamine
(MDEA) & oligomers, imidazolines of EDA and homologues and
higher adducts, imidazolines of aminoethylethanolamine (AEEA),
aminoethylpiperazine, aminoethylethanol amine, di-isopropanol
amine, DOW AMP-90.TM., Angus AMP-95, dialkylamines (of methyl,
ethyl, isopropyl), mono alkylamines (methyl, ethyl, isopropyl),
trialkyl amines (methyl, ethyl, isopropyl), bishydroxyethylethylene
diamine (THEED), or the like or mixtures or combinations
thereof.
Paraffin Control
[0048] Suitable additives for Paraffin Removal, Dispersion, and/or
paraffin Crystal Distribution include, without limitation:
Cellosolves available from DOW Chemicals Company; Cellosolve
acetates; Ketones; Acetate and Formate salts and esters;
surfactants composed of ethoxylated or propoxylated alcohols, alkyl
phenols, and/or amines; methylesters such as coconate, laurate,
soyate or other naturally occurring methylesters of fatty acids;
sulfonated methylesters such as sulfonated coconate, sulfonated
laurate, sulfonated soyate or other sulfonated naturally occurring
methylesters of fatty acids; low molecular weight quaternary
ammonium chlorides of coconut oils soy oils or C.sub.10 to C.sub.24
amines or monohalogenated alkyl and aryl chlorides; quanternary
ammonium salts composed of disubstituted (e.g., dicoco, etc.) and
lower molecular weight halogenated alkyl and/or aryl chlorides;
gemini quaternary salts of dialkyl (methyl, ethyl, propyl, mixed,
etc.) tertiary amines and dihalogenated ethanes, propanes, etc. or
dihalogenated ethers such as dichloroethyl ether (DCEE), or the
like; gemini quaternary salts of alkyl amines or amidopropyl
amines, such as cocoamidopropyldimethyl, bis quaternary ammonium
salts of DCEE; or mixtures or combinations thereof. Suitable
alcohols used in preparation of the surfactants include, without
limitation, linear or branched alcohols, specially mixtures of
alcohols reacted with ethylene oxide, propylene oxide or higher
alkyleneoxide, where the resulting surfactants have a range of
HLBs. Suitable alkylphenols used in preparation of the surfactants
include, without limitation, nonylphenol, decylphenol,
dodecylphenol or other alkylphenols where the alkyl group has
between about 4 and about 30 carbon atoms. Suitable amines used in
preparation of the surfactants include, without limitation,
ethylene diamine (EDA), diethylenetriamine (DETA), or other
polyamines. Exemplary examples include Quadrols, Tetrols, Pentrols
available from BASF. Suitable alkanolamines include, without
limitation, monoethanolamine (MEA), diethanolamine (DEA), reactions
products of MEA and/or DEA with coconut oils and acids.
Oxygen Control
[0049] The introduction of water downhole often is accompanied by
an increase in the oxygen content of downhole fluids due to oxygen
dissolved in the introduced water. Thus, the materials introduced
downhole must work in oxygen environments or must work sufficiently
well until the oxygen content has been depleted by natural
reactions. For system that cannot tolerate oxygen, then oxygen must
be removed or controlled in any material introduced downhole. The
problem is exacerbated during the winter when the injected
materials include winterizers such as water, alcohols, glycols,
Cellosolves, formates, acetates, or the like and because oxygen
solubility is higher to a range of about 14-15 ppm in very cold
water. Oxygen can also increase corrosion and scaling. In CCT
(capillary coiled tubing) applications using dilute solutions, the
injected solutions result in injecting an oxidizing environment
(O.sub.2) into a reducing environment (CO.sub.2, H.sub.2S, organic
acids, etc.).
[0050] Options for controlling oxygen content includes: (1)
de-aeration of the fluid prior to downhole injection, (2) addition
of normal sulfides to product sulfur oxides, but such sulfur oxides
can accelerate acid attack on metal surfaces, (3) addition of
erythorbates, ascorbates, diethylhydroxyamine or other oxygen
reactive compounds that are added to the fluid prior to downhole
injection; and (4) addition of corrosion inhibitors or metal
passivation agents such as potassium (alkali) salts of esters of
glycols, polyhydric alcohol ethyloxylates or other similar
corrosion inhibitors. Exemplary examples of oxygen and corrosion
inhibiting agents include mixtures of tetramethylene diamines,
hexamethylene diamines, 1,2-diaminecyclohexane, amine heads, or
reaction products of such amines with partial molar equivalents of
aldehydes. Other oxygen control agents include salicylic and
benzoic amides of polyamines, used especially in alkaline
conditions, short chain acetylene diols or similar compounds,
phosphate esters, borate glycerols, urea and thiourea salts
ofbisoxalidines or other compound that either absorb oxygen, react
with oxygen or otherwise reduce or eliminate oxygen.
Salt Inhibitors
[0051] Suitable salt inhibitors for use in the fluids of this
invention include, without limitation, Na Minus Nitrilotriacetamide
available from Clearwater International, LLC of Houston, Tex.
Foam Characteristics
[0052] Generally, the foamable hydrocarbon drilling fluid systems
of this invention from an initial fluid amount of 100 mL, will
produce a foam having a foam height of at least 150 mL and a half
life of at least 2 minutes. In particular, the produced foam will
have a foam height between about least 150 mL and about 500 mL and
a half life between about 2 minutes and 15 minutes depending on the
application and the exact formulation of the hydrocarbon fluid of
this invention. The stability or half life and foam height of the
produced foam is controlled by the amount and type of the
viscosifying agents in the composition, by the amount and type of
the foaming agents in the composition, by the amount of gas and
type of gas in the composition, by the temperature of the
composition and by the pressure of the composition. Generally,
increasing the amount of the viscosifying agents and/or foaming
agents leads to increased foam height and foam stability.
Generally, the viscosifying agents increase the stability more than
the foam height, while the foaming agents increase the foam height.
Of course, the foam height is also directly proportional to the
amount and type of gas dissolved or absorbed in the fluid.
EXPERIMENTS OF THE INVENTION
Introduction
[0053] The inventors designed the present solvent systems to be
eco-friendly and biodegradable and at the same time be capable of
maintaining shale integrity to insure that the fluids do not result
in adverse shale swelling problems producing shale instability.
Indeed, the inventors developed oil-based foam systems using the
solvent systems of this invention to actualize the benefits of
oil-based fluids for use in drilling through active formations. The
solvent systems of this invention provide a low cost base fluid for
preparing oil-based foam systems. The solvent systems of this
invention are capable of achieving savings of over a million
dollars in casing operations alone. The inventors have studied the
solvent systems of this invention in foamed drilling fluid
formulations and in fracturing slurry formulations.
Conclusions
[0054] The present solvent systems are suitable base fluids for
oil-based foamed drilling fluids and for fracturing slurries. The
inventors have successfully prepared foamed drilling fluid systems
using the solvent systems of this invention as base fluids in
drilling operation. The solvent systems of this invention are
suitable in the preparation of high flash point, environmentally
benign fluids that are non-settling And Have High Yield Viscosities
In Fracturing Slurry Systems.
Result & Discussion
[0055] Foamed drilling systems based on the solvent systems of this
invention were formulated, where the solvents systems of this
invention form a continuous phase. The foamed drilling systems had
desirable foam properties and were successfully field tested. The
foamed drilling systems are not only highly thermally stable due to
the thermal stability of the base fluid comprising a solvent system
of this invention, they are also recyclable in a foam-defoam-foam
process. In fracturing applications, the solvent systems of this
invention can be used to prepare biodegradable, high flash point,
fracturing slurries, which are non-settling and possess high
viscosities.
Formulations
[0056] a. Foam Systems
[0057] Often, foamers are employed in drilling operations in liquid
state; say for ease of handing, for reducing column weight or for
forming light weight drilling fluids. While the main surface active
chemicals of these systems may not be toxic (e.g., saccharide
surfactants), use of non-environmentally benign solvents like
alcohols, xylenes, toluene and ethers are common. Because of the
negative effects of such chemicals on the ecosystem, it is always
desirable to use non-toxic, biodegradable solvent systems or makeup
fluids based on non-toxic, biodegradable solvent systems. The
solvent systems of this invention were employed to formulate
surfactant systems to prepare downhole foamed fluid systems that
are non-toxic, biodegradable and non-settling. The downhole fluid
systems include non-toxic, biodegradable drilling fluids,
completion fluids, fracturing fluids, stimulating fluids, lift
fluids, enhancing fluids, production fluids, or other similar
fluids.
[0058] The inventors have found that the solvent systems of this
invention are capable of forming foamed drilling fluids including
various concentrations of active foaming agents such as
fluoroaliphatic polymeric esters foaming agents, silicon foaming
agents, or mixtures and combinations thereof. The resulting
formulations are then useable in downhole operations such as
drilling, fracturing, stimulating, lifting, stimulating, enhancing,
or other similar downhole operations, where the fluids are benign
or substantially benign (having little adverse affect on the
environment). Of great environmental appeal is suitability of the
solvent systems of this invention as a substitute for diesel or
other commonly used continuous phase solvents in downhole
operations including drilling operations using oil-based drilling
fluids, where the other drilling fluid systems might be
non-economic, toxic and/or non-biodegradable. The inventors have
demonstrated that highly stable drilling fluid systems may be
formulated using the solvent systems of this invention as the base
fluid for the drilling fluid systems.
EXAMPLE 1
[0059] The present example illustrates the use of HF-1000.TM. as
anon-toxic, biodegradable solvent system designated SS to prepare
foamed drilling fluids. The SS based drilling fluids are compared
to drilling fluids prepared with Red Diesel.
[0060] Table 1 tabulates the foam properties of drilling fluids
prepare using SS and Red Diesel.
TABLE-US-00001 TABLE 1 Comparison of Diesel and SS as Base Fluids
in Foam Systems Sea Heat Foam Base Water KCl Stability Height Half
Life Ave Fan 35A Fluid Conc. (3.5%) (3.0%) Condensate Crude Oil (24
hr) (mL) (min:sec) Recycle (Pv, Yp) Red 1.0% F1.sup.a 170 4:00
200/4:15 11, 2 Diesel 10% 170 4:00 20% 170 4:00 30% 170 4:00 5% 160
4:00 10% 160 4:00 20% 160 4:00 5% 160 4:00 10% 170 4:00 20% 180
4:00 10% 160 4:00 20% 160 4:00 450.degree. F. 160 4:00 SS 1%
F1.sup.a 170 4:00 200/4:15 5, 2 10% 170 2:45 20% 160 2:40 30% 160
2:30 5% 170 3:00 10% 160 2:45 20% 160 2:30 5% 170 3:00 10% 160 2:40
20% 160 2:30 10% 180 3:00 20% 190 3:00 450.degree. F. 160 3:40
.sup.aF1 is OleoFoam .TM.C and OleoVis .TM.HT both available from
Weatherford.
[0061] The foam properties of the foamed drilling fluid systems
shown in Table 1 for Red Diesel and SS are quite comparable and are
sufficient for foamed drilling applications. Thus, SS is a robust
and versatile solvent system for use as a base fluid for foamed
drilling fluid system.
b. Slurry Systems
[0062] Embodiments of this invention relate to slurries
compositions or formulations prepared using SS as the base solvent
system, where the compositions decrease settling of particulate
materials in the slurries and increase hydration properties of
hydratable particulate materials in the slurries. In slurry system
development, two recurring concerns are biodegradability and
flammability of the base fluid. The solvent systems of this
invention were found to satisfactorily and sufficiently address
both of these concerns.
EXAMPLE 2
[0063] Two slurry formulations were prepared using SS and Conosol
145 (a commercially available base oil from Calumet Specialty
Partners, USA) formulated independently as base fluid according to
the formulations tabulated in Table 2.
TABLE-US-00002 TABLE 2 Slurry Composition Component Concentration
(%) Base oil (g) 47.91 Winterizing Agent (Arlacel 83) 0.48 Clay
(Bentone 150) 2.00 Surfactant Blend (Suspend Aid) 0.98 Polymer (WGA
15) 48.63 Total 100.00
[0064] The slurries were tested and the test results are tabulated
in Table 3.
TABLE-US-00003 TABLE 3 SS and Conosol 145 Based Slurries Conosol
Slurry Property 145 Based Slurry SS Based Slurry Specific Gravity
(25.degree. C.) 1.048-1.062 1.059 Flashpoint (.degree. F.) >152
>212 Pour point (.degree. F.) 0 44 Dynamic Settling.sup.a 2%
<1% Static Settling.sup.b 1% <1% Hydration Yield (72.degree.
F., cP) 42 46 Slurry Viscosity (72.degree. F., cP) 320-520 .sup.
854.sup.c .sup.a%, 72.degree. F., 72 hr .sup.b%, 105.degree. F., 72
hr .sup.c(R1:B1 @ 511/s)
[0065] The data of Table 3 show physical properties of the slurries
prepared using SS and Conosol 145. The data in Table 3 exemplify
desirable and superior properties of slurries based on SS as
compared to slurries based on Conosol 145. The data show that the
SS based slurry has reduced settling (<1%) for WGA 15 polymers
(WGA 15 is available from Weatherford) in the SS based slurry as
compared to the Conosol 145 base slurry (2.0%) for WGA 15 polymers
in the Conosol 145 base slurry. In certain embodiments, the SS
slurries of this invention may be formulated having a flash point
temperature higher than 212.degree. F. In other embodiments, higher
yield viscosity slurries of the lineal gel solution are obtainable
with SS than with Conosol 145.
[0066] 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.
* * * * *