GB2111104A - Viscous heavy brines and method for their manufacture - Google Patents
Viscous heavy brines and method for their manufacture Download PDFInfo
- Publication number
- GB2111104A GB2111104A GB08234591A GB8234591A GB2111104A GB 2111104 A GB2111104 A GB 2111104A GB 08234591 A GB08234591 A GB 08234591A GB 8234591 A GB8234591 A GB 8234591A GB 2111104 A GB2111104 A GB 2111104A
- Authority
- GB
- United Kingdom
- Prior art keywords
- brine
- bromide
- calcium
- calcium chloride
- zinc bromide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 17
- 238000004519 manufacturing process Methods 0.000 title description 2
- VNDYJBBGRKZCSX-UHFFFAOYSA-L zinc bromide Chemical compound Br[Zn]Br VNDYJBBGRKZCSX-UHFFFAOYSA-L 0.000 claims abstract description 93
- 229940102001 zinc bromide Drugs 0.000 claims abstract description 42
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims abstract description 40
- 239000001110 calcium chloride Substances 0.000 claims abstract description 38
- 229910001628 calcium chloride Inorganic materials 0.000 claims abstract description 38
- 229920002678 cellulose Polymers 0.000 claims abstract description 37
- 229910001622 calcium bromide Inorganic materials 0.000 claims abstract description 36
- WGEFECGEFUFIQW-UHFFFAOYSA-L calcium dibromide Chemical compound [Ca+2].[Br-].[Br-] WGEFECGEFUFIQW-UHFFFAOYSA-L 0.000 claims abstract description 36
- 239000012267 brine Substances 0.000 claims abstract description 32
- 239000001913 cellulose Substances 0.000 claims abstract description 32
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims abstract description 32
- QAOWNCQODCNURD-UHFFFAOYSA-L sulfate group Chemical class S(=O)(=O)([O-])[O-] QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims abstract description 30
- 239000000203 mixture Substances 0.000 claims abstract description 5
- TWNIBLMWSKIRAT-VFUOTHLCSA-N levoglucosan Chemical group O[C@@H]1[C@@H](O)[C@H](O)[C@H]2CO[C@@H]1O2 TWNIBLMWSKIRAT-VFUOTHLCSA-N 0.000 claims description 18
- 150000003839 salts Chemical class 0.000 claims description 16
- -1 sulfate ester Chemical class 0.000 claims description 11
- 150000002148 esters Chemical class 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 6
- 150000003467 sulfuric acid derivatives Chemical class 0.000 abstract description 10
- 229920000642 polymer Polymers 0.000 abstract description 3
- 238000006467 substitution reaction Methods 0.000 abstract description 2
- 235000011148 calcium chloride Nutrition 0.000 description 27
- 239000012530 fluid Substances 0.000 description 12
- 235000002639 sodium chloride Nutrition 0.000 description 12
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 9
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 9
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 6
- 239000008186 active pharmaceutical agent Substances 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 4
- 238000000518 rheometry Methods 0.000 description 4
- 150000003751 zinc Chemical class 0.000 description 4
- 239000000084 colloidal system Substances 0.000 description 3
- 238000005553 drilling Methods 0.000 description 3
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012956 testing procedure Methods 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
- 239000000230 xanthan gum Substances 0.000 description 1
- 229920001285 xanthan gum Polymers 0.000 description 1
- 235000010493 xanthan gum Nutrition 0.000 description 1
- 229940082509 xanthan gum Drugs 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/06—Clay-free compositions
- C09K8/08—Clay-free compositions containing natural organic compounds, e.g. polysaccharides, or derivatives thereof
- C09K8/10—Cellulose or derivatives thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Paper (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
The viscosity of heavy brines containing calcium chloride, calcium bromide, zinc bromide, or mixtures thereof, can be increased by adding certain homogeneously substituted cellulose sulfate esters to the brine. Such cellulose sulfate esters are effective viscosifiers for certain heavy brines depending on the degree of substitution of sulfate groups in the polymer.
Description
SPECIFICATION
Viscous heavy brines and method for their manufacture
The present invention relates to viscous brine solutions and, more particularly, to a method of increasing the viscosity of so called heavy brines having a density greater than 1.35 g/cm3 containing two or more of the soluble salts: calcium chloride, calcium bromide, and zinc bromide In recent years, the practical operating range of clear brines for use in the oil and gas industry has been significantly extended by utilizing soluble zinc salts, particularly zinc bromide, so that the advantage of clear brines can now be obtained with fluids having densities as high as 2.30 g/cm3 at ambient temperatures and pressures.
The high density clear brines are used extensively: e.g. as completion fluids to minimize plugging of perforation tunnels, to protect formation permeability, and to minimize mechanical problems; as workover fluids, for the same reasons; as packer fluids, to allow easy movement and retrieval of the packer; for underreaming, gravel-pack and said consolidation applications; as kill fluid or ballast fluid; for wire-line work; and as drilling fluids.
Clear brines having a density of 1.70 g/cm3 or lower are generally formulated to contain sodium chloride, sodium bromide, potassium chloride, calcium chloride, calcium bromide or mixtures of these salts. Clear brines having a density up to 1.81 g/cm3 can be formulated with calcium chloride and calcium bromide; however, if the brine must have a low crystallization temperature, then clear brines in this density range are generally formulated to contain a soluble zinc salt. Zinc bromide is preferred because brines containing it are less corrosive than brines containing zinc chloride. Clear brines having a density greater than 1.81 g/cm3 are formulated to contain zinc bromide.
Viscous clear fluids are sometimes desired. Generally, hydroxyethyl cellulose (HEC) and xanthan gum polymers are compatible with the fluids which do not contain zinc salts. At higher densities, however, the hydration of the viscosifiers is significantly slower. HEC is generally considered as unsatisfactory for use in fluids containing zinc salts. However, methods of activating HEC, XC polymers, and other water soluble polymers so that they readily hydrate in heavy brines and particularly in certain brines containing zinc bromide have been disclosed in our prior British Patent Applications No. 8101828 (Publication No. 2070611 A); 8109880 (Publication No. 2075041 A); and 8131312.
There is still, however, a need for viscosifiers for heavy brines containing calcium chloride, calcium bromide, zinc bromide, and mixtures thereof, particularly such brines containing zinc bromide in admixture with calcium chloride and/or calcium bromide.
The present invention provides a method of increasing the velocity of a brine having dissolved therein any two or all three of the salts (a) calcium chloride, (b) calcium bromide, and (c) zinc bromide, which comprises mixing the brine with a homogeneously substituted cellulose sulfate ester having from 0.3 to 1.3 sulfate groups per anhydroglucose unit, but excluding (i) mixing brines containing calcium chloride and less than 9% by weight of zinc bromide with a cellulose sulfate ester having 0.3 to 0.5 sulfate groups per anhydroglucose unit, and (ii) mixing brine containing both calcium chloride and zinc bromide with a cellulose sulfate ester having 1.0 to 1.3 sulfate groups per anhydroglucose unit.
We have found that cellulose sulfate esters containing from 0.6 to 0.9 sulfate groups per anhydroglucose unit will viscosify all heavy brines containing two or more of the abovementioned soluble salts. Those esters containing 0.3 to 0.5 sulfate groups per anhydrogluclose unit will viscosify all heavy brines containing two or more of these soluble salts except those heavy brines containing calcium chloride and less than 9% by weight zinc bromide. Those esters containing 1.0 to 1.3 sulfate groups per anhydroglucose unit will viscosify all heavy brines containing calcium chloride and calcium bromide, or calcium bromide and zinc bromide.
The cellulose ester employed in accordance with this invention are preferably used in amounts from 2.5 to 15 g per 1000 cm3 of the brine.
The heavy brines for use in the present invention contain two or more soluble salts selected from calcium chloride, calcium bromide, zinc bromide, and mixtures thereof. Brines containing only calcium chloride can be formulated having a density from 1.02 to 1.40 g/cm3. Brines containing only calcium bromide can be formulated having a density from 1.02 to 1.70 g/cm3.
However, because calcium chloride is much less expensive than calcium bromide, brines in the density range from 1.35 to 1.81 g/cm3 are generally formulated to contain both calcium chloride and calcium bromide, depending on the lowest temperature at which the brine will be used. Brines heaver than 1.80 g/cm3 are genenerally formulated to contain calcium chloride, calcium bromide, and zinc bromide, or only calcium bromide and zinc bromide depending on the lowest temperature at which the brine will be used. Brines in the density range from 1.70 to
1.80 g/cm3 may be formulated to contain calcium chloride, calcium bromide, and zinc bromide if brines having a lower crystallization point are desired.
The most difficult brines to viscosify contain zinc bromide, and these brines are preferred for use in the present invention. As indicated, such brines will have a density from 1.70 to 2.30 g/cm3.
Generally, brines of any density within the ranges disclosed are prepared by mixing together various standard, commercially available brines, as follows: calcium chloride brines having a density in the range from 1.32 to 1.39 g/cm3; calcium bromide brine having a density of 1.70 g/cm3 and a calcium bromide/zinc bromide brine having a density of 2.30 g/cm3 containing about 20% calcium bromide and about 57% zinc bromide. Solid anhydrous calcium chloride and solid calcium bromide are also used in conjunction with these brines to prepare heavy brines for use in this invention. Standard brine mixing tables are available from the various manufacturers of these brines.
The viscosifiers for use in the present invention are homogeneously substituted cellulose sulfate esters. Such cellulose esters can be prepared according to U.S. Patents No. 4,035,569 and 4,138,535. An article by Richard G. Schweiger which was published in Carbohydrate
Research, Vol. 70, pp. 185-198 (1979) entitled "New Cellulose Sulfate Derivatives and
Applications" describes these homogeneously substituted cellulose sulfate esters and their properties. This article discloses their potential use in drilling fluids and indicates that solutions containing these esters can be saturated with such salts as sodium or calcium chlorides.
Cellulose contains three hydroxyl groups per anhydroglucose unit at which reactions can occur to form cellulose derivatives. The average number of sulfate groups introduced into the anhydrogluclose unit may, therefore, vary from slightiy above 0 to 3, when all the hydroxyl groups in each anhydroglucose group have been substituted. The average number of sulfate groups introduced into each anhydroglucose unit is referred to as the degree of substitution (DS).
The homogeneously substituted cellulose sulfate esters which are useful in this invention have a DS from 0.3 to 1.3. However, all such cellulose esters are not efficient viscosifiers in all heavy brines containing two or more salts selected from calcium chloride, calcium bromide and zinc bromide. In accordance with this invention, we have found that only homogeneously substituted cellulose sulfate esters having a DS from 0.6 to 0.9 will efficiently increase the viscosity, as evidenced by a significant increase in the yield point, of all heavy brines containing two or more of these salts.Homogeneously substituted cellulose sulfate esters having a DS from 0.3 to 0.5 efficiently increase the viscosity of all heavy brines containing calcium chloride and calcium bromide, calcium bromide and zinc bromide, or all three of these salts, provided that the concentration of zinc bromide is greater than 9% by weight. Homogeneously substituted cellulose sulfate esters having a DS from 1 .0 to 1.3 efficiently increase the viscosity of all heavy brines except those containing both calcium chloride and zinc bromide.
To illustrate the present invention more fully, the following non-limiting examples are presented. Unless otherwise indicated, all physical property measurements were made in accordance with testing procedures set forth in STANDARD PROCEDURE FOR TESTING
DRILLING FLUID, API RP 13B, Seventh Edition, April, 1 978. The physical property parameters referred to in the examples are in units expressed as follows:
AV = Apparent Viscosity, centipoise
PV = Plastic Viscosity, centipoise
YP = Yield Point, Bars 10-Sec Gel = 10 Second Gel Strength, Bars.
Example 1
A commercially available homogeneously substituted cellulose sulfate having a DS from 0.3 to 0.5 (Colloid XHO, Stauffer Chemical Co.) was evaluated as a viscosifier in various brines containing calcium chloride, calcium bromide, and zinc bromide. The cellulose sulfate was added to the brines at a concentration of 2.86 9/1000 cm3 and mixed on a Multimixer for 1 5 minutes. Thereafter, the brines were rolled for 16 hours at 65.5"C, cooled to room temperature, and the API RP 1 3B rheology obtained. The data obtained are given in Table 1.
Example 2
A commercially available homogeneously substituted cellulose sulfate having a DS in the range from 0.6 to 0.9 (Colloid XHI, Stauffer Chemical Co.) was evaluated as a viscosifier as in
Example 1. The data obtained are given in Table 2.
Example 3
A commercially available homogeneously substituted cellulose sulfate having a DS from 1.0 to 1.3 (Colloid XH2, Stauffer Chemical Co.) was evaluated as a viscosifier as in Example 1. The data obtained are given in Table 3.
Comparative Example 4
A commercially available hydroxyethyl cellulose (NATROSOL 250 HHR) was evaluated as a viscosifier as in Example 1. The data obtained are given in Table 4.
TABLE 1
Evaluation of Cellulose Sulfate, D.S. = 0.3-0.5,
in Various High Density Solutions
API Pvheology Density % % % 10-Sec.
g/cm3 ZnBr2 CaBr2 Caul2 AV PV YP Gel
1.39 0 0 37.6 49 33 1.56 0.15
1.70 0 53.0 0 57.5 34 2.29 0.29
1.50 0 24.9 18.4 4i 28 1.56 0.15
1.80 0 43.2 16.3 145 97 4.69 1.07
1.81 1.7 42.5 15.8 69 53 1.56 0.15
1.83 5.0 41.1 14.8 52.5 50 0.15 0.02
1.86 8.4 39.8 13.9 61 62 0.39 0.15
1.87 10.0 39.1 13.4 70 52 1.76 0.20
1.89 13.2 37.8 12.5 87.5 67 2.29 0.15
1.92 16.3 36.6 11.6 111 85 2.54
1.74 4.5 50.4 0 51.5 34 2.20 0.29
1.80 11.7 46.2 0 58.5 35 2.29
1.86 18.4 42.4 0 60 37 2.25
TABLE 2
Evaluation of Cellulose Sulfate, D.S. = 0.6-0.9,
in Various High Density Solutions
API Rheology
Density % % % 10-Sec.
g/cm3 ZnBr2 Cabin Caul2 AV PV YP Gel
1.39 0 0 37.6 36.5 29 0.73 0.07
1.68 0 50.0 2.0 40.5 30 1.03
1.70 0 53.0 0 46 33 1.27 0.12
1.50 0 24.9 18.4 32 25 0.68 0.05
1.50 0 13.8 30.8 48 36 1.17 0.15
1.52 0 28.6 16.0 33 26 0.68 0.05
1.56 0 33.9 12.5 35.5 25 0.93 0.05
1.56 0 20.6 27.4 57.5 40.5 1.66 0.15
1.59 0 39.0 9.2 37.5 28 0.93 0.10
1.62 0 26.8 24.4 62 43 1.86 0.15
1.64 0 45.4 5.0 41 31 0.98 0.10
1.68 0 32.6 21.6 97 65 3.12 0.24
1.74 0 38.0 19.0 126 85 4.00 0.39
1.80 0 43.2 16.3 137 92 4.39 0.49
1.81 1.7 42.5 15.8 122 84 3.71 0.39
1.83 5.0 41.1 14.8 113.5 81 3.17 0.29
1.86 8.4 39.8 13.9 117.5 80 3.66 0.34
1.92 16.3 36.6 11.6 111.5 76 3.47
1.74 4.5 50.4 0 44 32 1.17 0.10
1.80 11.7 46.2 0 46.5 33 1.32
1.86 18.4 42.4 0 42 31 1.07
1.92 24.6 38.6 0 53 39 1.39
2.04 36.0 32.1 0 61 42.5 1.78
TABLE 3
Evaluation of Cellulose Sulfate, D.S. = 1.0-1.3, in Various High Density Solutions
API Rheology Density % % % 10-Sec.
g/cm3 ZnBr2 CaBr CaCl2 AV PV YP Gel
1.39 0 0 37.6 38.5 28 1.03 0.07
1.70 0 53.0 0 40 28 1.17 0.10
1.80 0 43.2 16.3 86 64 2.15 0.15
1.81 1.7 42.5 15.8 52.5 52.5 0 0.10
1.83 5.0 41.1 14.8 42.5 42 0.05 0.02
1.86 8.4 39.8 13.9 47.5 43 0 0.05
1.92 16.3 36.6 11.6 42.5 38 0.44
1.74 4.5 50.4 0 40.5 28 1.22 0.15
1.80 11.7 46.2 0 41 29 1.17 0.15 1.86 18.4 42.4 0 40.5 29 1.12 0.15
TABLE 4
Evaluation of HEC in Various High Density Solutions #PI Rheology Density % % % 10-Sec.
g/cm3 ZnBr Cabin CaCl2 AV PV YP Gel
1.39 0 0 37.6 47 31 1.51
1.70 0 53.0 0 51 31 1.95 0.24
1.80 0 43.2 16.3 127 86 4.00
1.81 1.7 42.5 15.8 34 34 0 0
1.83 5.0 41.1 14.8 35.5 36 0 0
1.86 8.4 39.8 13.9 31.5 31.5 0 0
1.92 16.3 36.6 11.6 28 28 0 0
1.74 4.5 50.4 0 7.5 7.5 0 0
1.80 11.7 46.2 0 8.5 8.5 0 0
1.86 18.4 42.4 0 13.5 13.5 0 0
The data obtained indicate that HEC is not an effective viscosifier in these heavy brines containing zinc bromide. The homogeneously substituted cellulose sulfate having a DS from 0.3 to 0.5 was an effective viscosifier in all of the heavy brines, except the brines containing less than 9% zinc bromide when calcium chloride was also present in the brine. The homogeneously substituted cellulose sulfate having a DS from 0.6 to 0.9 was an effective viscosifier in all of these heavy brines, and especially in the brines which are so difficult to viscosify containing low concentrations of zinc bromide in the presence of calcium chloride. The homogeneously substituted cellulose sulfate having a DS in the range from 1.0 to 1.3 was an effective viscosifier in all of the brines except all the brines containing both zinc bromide and calcium chloride. In the latter brines it performed similarly to HEC.
Claims (21)
1. In a method for increasing the viscosity of a brine having a density of at least 14.2 Ib/gal and containing at least two salts selected from calcium chloride, calcium bromide and zinc bromide, the improvement characterized by mixing with said brine a viscosifyng homogeneously substituted cellulose sulfate ester selected from those esters containing from 0.3 to 1.3 sulfate groups per anhydroglucose unit.
2. In the method of Claim 1 wherein said salts are calcium chloride and calcium bromide, the improvement further characterized by said ester containing from 0.3 to 1.3 sulfate groups per anhydroglucose unit.
3. In the method of Claim 1 wherein said salts are calcium bromide and zinc bromide, the improvement further characterized by said ester containing from 0.3 to 1.3 sulfate groups per anhydroglucose unit.
4. In the method of Claim 1 wherein said brine contains a mixture of at least two salts selected from calcium chloride, calcium bromide and zinc bromide, the improvement further characterized by said ester containing from 0.6 to 0.9 sulfate groups per anhydroglucoose unit.
5. In the method of Claim 1 wherein said brine contains at least 9% by weight zinc bromide, calcium chloride and, alternatively, calcium bromide, the improvement further characterized by said ester containing from 0.3 to 0.5 sulfate groups per anhydroglucose unit.
6. A viscosified brine manufactured according to the method of any of Claims 1 to 5.
7. A method as claimed in claim 6 wherein the brine contains all three salts.
8. A method as claimed in claim 7 wherein the brine has a density greater than about 1.80 g/cm3.
9. A method as claimed in any of claims 1 to 3 wherein the brine contains calcium chloride, calcium bromide, and zinc bromide, the concentration of zinc bromide exceeding 9% by weight, and the cellulose sulfate ester contains from 0.3 to 0.5 sulfate groups per anhydroglucose unit.
10. A method as claimed in claim 9 wherein the density of the brine is greater than 1.86 g/cm3.
11. A method as claimed in any preceding claim which comprises adding 2.5 to 1 5 grams of cellulose ester per 1000 cm3 of brine.
1 2. A method as claimed in claim 1 and substantially as hereinbefore described.
1 3. A brine having dissolved therein (1) any two or all three of the salts (a) calcium chloride, (b) calcium bromide, and (c) zinc bromide, and (2) a homogeneously substituted cellulose sulfate ester having from 0.3 to 1.3 sulfate groups per anhydroglucose unit, but excluding (i) brines containing calcium chloride and less than 9% by weight of zinc bromide when the cellulose sulfate ester has 0.3 to 0.5 sulfate groups per anhydroglucose unit, and (ii) brines containing both calcium chloride and zinc bromide when the cellulose sulfate ester has 1.0 to 1.3 sulfate groups per anhydroglucose unit.
14. A brine as claimed in claim 1 3 having a density of at least 1.70 g/cm3.
15. A brine as claimed in claim 13 or 14 which comprises from 2.5 to 15 grams per liter of the cellulose ester.
1 6. A brine as claimed in any of claims 1 3 to 1 5 which comprises calcium chloride and calcium bromide or calcium bromide and zinc bromide.
1 7. A brine as claimed in any of claims 1 3 to 1 5 which contains calcium chloride, calcium bromide, and zinc bromide, and the cellulose sulfate ester has from 0.6 to 0.9 sulfate groups per anhydroglucose unit.
1 8. A brine as claimed in claim 1 7 having a density greater than 1.80 g/cm3.
1 9. A brine as claimed in any of claims 1 3 to 1 5 which contains calcium chloride, calcium bromide, and zinc bromide, the concentration of zinc bromide being greater than 9% by weight, and the cellulose sulfate ester having from 0.3 to 0.5 sulfate groups per anhydroglucose unit.
20. A brine as claimed in claim 1 9 having a density greater than 1.86 g/cm3.
21. A brine as claimed in claim 13 and substantially as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US33076581A | 1981-12-14 | 1981-12-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2111104A true GB2111104A (en) | 1983-06-29 |
| GB2111104B GB2111104B (en) | 1985-08-14 |
Family
ID=23291228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08234591A Expired GB2111104B (en) | 1981-12-14 | 1982-12-03 | Viscous heavy brines and method for their manufacture |
Country Status (9)
| Country | Link |
|---|---|
| AU (1) | AU553448B2 (en) |
| BR (1) | BR8207175A (en) |
| CA (1) | CA1196775A (en) |
| DE (1) | DE3246280A1 (en) |
| FR (1) | FR2518110B1 (en) |
| GB (1) | GB2111104B (en) |
| NL (1) | NL8204745A (en) |
| NO (1) | NO823511L (en) |
| SG (1) | SG31686G (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2167079A (en) * | 1984-11-09 | 1986-05-21 | Shell Int Research | Process for the degradation of a viscous microbial polysaccharide formulation, a process for preparing an acid degradable polysaccharide formulation, and a polysaccharide formulation thereby obtained |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2614979A (en) * | 1947-08-18 | 1952-10-21 | Phillips Petroleum Co | Drilling fluid |
-
1982
- 1982-09-30 AU AU88914/82A patent/AU553448B2/en not_active Ceased
- 1982-09-30 CA CA000412551A patent/CA1196775A/en not_active Expired
- 1982-10-21 NO NO823511A patent/NO823511L/en unknown
- 1982-12-03 GB GB08234591A patent/GB2111104B/en not_active Expired
- 1982-12-08 NL NL8204745A patent/NL8204745A/en not_active Application Discontinuation
- 1982-12-10 BR BR8207175A patent/BR8207175A/en unknown
- 1982-12-14 DE DE19823246280 patent/DE3246280A1/en not_active Withdrawn
- 1982-12-14 FR FR8220977A patent/FR2518110B1/en not_active Expired
-
1986
- 1986-04-04 SG SG316/86A patent/SG31686G/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2167079A (en) * | 1984-11-09 | 1986-05-21 | Shell Int Research | Process for the degradation of a viscous microbial polysaccharide formulation, a process for preparing an acid degradable polysaccharide formulation, and a polysaccharide formulation thereby obtained |
| US4754809A (en) * | 1984-11-09 | 1988-07-05 | Shell Oil Company | Degradation of a viscous microbial polysaccharide formulation |
Also Published As
| Publication number | Publication date |
|---|---|
| SG31686G (en) | 1987-03-27 |
| FR2518110B1 (en) | 1986-01-10 |
| CA1196775A (en) | 1985-11-19 |
| BR8207175A (en) | 1983-10-11 |
| FR2518110A1 (en) | 1983-06-17 |
| GB2111104B (en) | 1985-08-14 |
| NL8204745A (en) | 1983-07-01 |
| NO823511L (en) | 1983-06-15 |
| AU8891482A (en) | 1983-06-23 |
| DE3246280A1 (en) | 1983-06-23 |
| AU553448B2 (en) | 1986-07-17 |
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