US3684012A
Expired / Lapsed
US
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Method and composition for treating high-temperature subterranean formations
Assignee: ETHAN R SCHMIDT
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Filing: 1970-06-12
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Granted: 1972-08-15
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Expires: 1990-06-12
Abstract
Abstract A water-insoluble particulate composition have controlled slow oil-solubility at elevated temperatures is disclosed. The composition is comprised of solid particles of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate, (2) a paraffin wax having a melting point between about 130* F. and 175* F., and (3) about 10 to 25 weight percent of a long chain aliphatic hydrocarbon or oxidized hydrocarbon wax melting between about 195* F. and 250* F. and exhibiting an Izod strength of less than 0.9 foot-pounds. Also disclosed is a process employing this particulate composition in drilling wells into high-temperature subterranean formations, and in fracturing and treating such formations.
Inventors
- 👤 John W Scheffel
- 👤 Paul W Fischer
- 👤 Ethan R Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:32
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/70; C09K8/50; C09K8/516; Y; Y10; Y10S; Y10S507/00; Y10S507/922
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
19 words
The method defined in claim 1 wherein said particles contain at least 55 weight percent of said paraffin wax.
Claim 2
Dependent Claim
24 words
The method defined in claim 1 wherein said ethylene-vinyl acetate copolymer exhibits a melt index of about 1 to 600 grams per 10 minutes.
Claim 3
Dependent Claim
16 words
The method defined in claim 1 wherein said ethylene-vinyl acetate copolymer is selected from Table I.
Claim 4
Dependent Claim
17 words
The method defined in claim 1 wherein said oil solubility retarding agent is selected from Table II.
Claim 5
Dependent Claim
50 words
The method defined in claim 1 wherein said ethylene-vinyl acetate copolymer contains about 17 to 19 weight percent vinyl acetate and exhibits a melt index of about 2 to 3 grams per 10 minutes, and wherein said paraffin wax has a melting point between about 160* F. and 170* F.
Claim 6
Dependent Claim
20 words
The method defined in claim 1 wherein the temperature of said formation is between about 155* F. and 180* F.
Claim 7
Dependent Claim
25 words
The method defined in claim 1 wherein said oil solubility retarding agent is selected from the group consisting of Fischer-Tropsch waxes, polyethylenes and natural waxes.
Claim 8
Dependent Claim
101 words
The method defined in claim 1 wherein said particles are a homogeneous mixture of (1) about 8 to 13 weight percent of an ethylene-vinyl acetate copolymer containing about 17 to 19 weight percent vinyl acetate and exhibiting a melt index of about 2 to 3 grams per 10 minutes, (2) at least about 60 weight percent paraffin wax having a melting point between about 160* F. and 170* F. and (3) about 17 to 23 weight percent of a Fischer-Tropsch wax having a melting point between about 210* F. and 220* F. and an Izod strength of less than 0.1 foot-pounds.
Claim 9
Independent Claim
144 words
The method of completing a well drilled into a permeable, high-temperature subterranean formation, which comprises circulating a completion fluid from the surface to a drilling zone in said formation during the drilling operation and returning to the surface at least a portion of said fluid said completion fluid comprising a liquid having suspended therein discrete slowly oil-soluble, water-insoluble solid particles comprised of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer that contains about 15 to 30 weight percent vinyl acetate, (2) a paraffin wax having a melting point between about 130* F. and 175* F., and (3) about 10 to 25 weight percent of an oil solubility retarding agent comprising long chain aliphatic hydrocarbon and oxidized hydrocarbon waxes having melting points between about 195* F. and 250* F. and Izod strengths of less than 0.9 foot-pounds.
Claim 10
Dependent Claim
19 words
The method defined in claim 10 wherein said particles contain at least 55 weight percent of said paraffin wax.
Claim 11
Dependent Claim
24 words
The method defined in claim 10 wherein said ethylene-vinyl acetate copolymer exhibits a melt index of about 1 to 600 grams per 10 minutes.
Claim 12
Dependent Claim
16 words
The method defined in claim 10 wherein said ethylene-vinyl acetate copolymer is selected from Table I.
Claim 13
Dependent Claim
17 words
The method defined in claim 10 wherein said oil solubility retarding agent is selected from Table II.
Claim 14
Dependent Claim
50 words
The method defined in claim 10 wherein said ethylene-vinyl acetate copolymer contains about 17 to 19 weight percent vinyl acetate and exhibits a melt index of about 2 to 3 grams per 10 minutes, and wherein said paraffin wax has a melting point between about 160* F. and 170* F.
Claim 15
Dependent Claim
20 words
The method defined in claim 10 wherein the temperature of said formation is between about 155* F. and 180* F.
Claim 16
Dependent Claim
25 words
The method defined in claim 10 wherein said oil solubility retarding agent is selected from the group consisting of Fischer-Tropsch waxes, polyethylenes and natural waxes.
Claim 17
Dependent Claim
102 words
The method defined in claim 10 wherein said particles are a homogeneous mixture of (1) about 8 to 13 weight percent of an ethylene-vinyl acetate copolymer containing about 17 to 19 weight percent vinyl acetate and exhibiting a melt index of about 2 to 3 grams per 10 minutes, (2) at least about 60 weight percent paraffin wax having a melting point between about 160* F. and 170* F., and (3) about 17 to 23 weight percent of a Fischer-Tropsch wax having a melting point between about 210* F. and 220* F. and an Izod strength of less than 0.1 foot pounds.
Claim 18
Independent Claim
136 words
A method of fracturing a permeable, high-temperature subterranean formation penetrated by a well, which comprises injecting a fracturing fluid into said well and into contact with said formation at a pressure and volumetric flow rate sufficient to fracture said formation, said fracturing fluid comprising a liquid having suspended therein discrete oil-soluble, water-insoluble solid particles of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate, (2) a paraffin wax having a melting point between about 130* F. and 175* F., and (3) about 10 to 25 weight percent of an oil solubility retarding agent comprising long chain aliphatic hydrocarbon and oxidized hydrocarbon waxes having melting points between about 195* F. and 250* F. and Izod strengths of less than 0.9 foot-pounds.
Claim 19
Dependent Claim
20 words
The method defined in claIm 19 wherein said particles contain at least about 55 weight percent of said paraffin wax.
Claim 20
Dependent Claim
24 words
The method defined in claim 19 wherein said ethylene-vinyl acetate copolymer exhibits a melt index of about 1 to 600 grams per 10 minutes.
Claim 21
Dependent Claim
16 words
The method defined in claim 19 wherein said ethylene-vinyl acetate copolymer is selected from Table I.
Claim 22
Dependent Claim
17 words
The method defined in claim 19 wherein said oil solubility retarding agent is selected from Table II.
Claim 23
Dependent Claim
50 words
The method defined in claim 19 wherein said ethylene-vinyl acetate copolymer contains about 17 to 19 weight percent vinyl acetate and exhibits a melt index of about 2 to 3 grams per 10 minutes, and wherein said paraffin wax has a melting point between about 160* F. and 170* F.
Claim 24
Dependent Claim
20 words
The method defined in claim 19 wherein the temperature of said formation is between about 155* F. and 180* F.
Claim 25
Dependent Claim
25 words
The method defined in claim 19 wherein said oil solubility retarding agent is selected from the groups consisting of Fischer-Tropsch waxes, polyethylenes and natural waxes.
Claim 26
Dependent Claim
101 words
The method defined in claim 19 wherein said particles are a homogeneous mixture of (1) about 8 to 13 weight percent of an ethylene-vinyl acetate copolymer containing about 17 to 19 weight percent vinyl acetate and exhibiting a melt index of about 2 to 3 grams per 10 minutes, (2) at least about 60 weight percent paraffin wax having a melting point between about 160* F. and 170* F., and (3) about 17 to 23 weight percent of a Fischer-Tropsch wax having a melting point between about 210* F. and 220* F. and an Izod strength of less than 0.1 foot-pounds.
Claim 27
Dependent Claim
88 words
A well treating composition comprising discrete solid particles of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate, (2) a paraffin wax having a melting point between about 130* F. and 175* F., and (3) about 10 to 25 weight percent of an oil solubility retarding agent comprising Fischer-Tropsch hydrocarbon and oxidized hydrocarbon waxes having melting points between about 195* F. and 250* F. and Izod strengths of less than 0.9 foot-pounds.
Claim 28
Dependent Claim
16 words
The composition defined in claim 28 containing at least 55 weight percent of said paraffin wax.
Claim 29
Dependent Claim
24 words
The composition defined in claim 28 wherein said ethylene-vinyl acetate copolymer exhibits a melt index of about 1 to 600 grams per 10 minutes.
Claim 30
Dependent Claim
94 words
A well treating composition comprising discrete solid particles of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer containing about 15 to 30 weight percent vinyl acetate selected from Table I, (2) a paraffin wax having a melting point between about 130* F. and 175* F., and (3) about 10 to 25 weight percent of an oil solubility retarding agent comprising long chain aliphatic hydrocarbon and oxidized hydrocarbon waxes having melting points between about 195* F. and 250* F. and Izod strengths of less than 0.9 foot-pounds.
Claim 31
Dependent Claim
17 words
The composition defined in claim 31 wherein said oil solubility retarding agent is selected from Table II.
Claim 32
Dependent Claim
25 words
The method defined in claim 31 wherein said oil solubility retarding agent is selected from the group consisting of Fischer-Tropsch waxes, polyethylenes and natural waxes.
Claim 33
Dependent Claim
106 words
A well treating composition comprising discrete solid particles of a homogeneous mixture of (1) about 8 to 12 weight percent of an ethylene-vinyl acetate copolymer containing about 17 to 19 weight percent vinyl Acetate and exhibiting a melt index of about 2 to 3 grams per 10 minutes, (2) at least about 60 weight percent paraffin wax having a melting point between about 160* F. and 170* F., and (3) about 17 to 23 weight percent of an oil solubility retarding agent comprising a Fischer-Tropsch wax having a melting point between about 210* F. and 220* F. and an Izod strength of less than 0.1 foot-pounds.
Claim 34
Dependent Claim
23 words
The method defined in claim 34 wherein said discrete particles have a mean diameter of between about 1 micron and about one-half inch.
Claim 35
Dependent Claim
104 words
A well treating composition comprising discrete solid particles of a homogeneous mixture of (1) about 4 to 30 weight percent of an ethylene-vinyl acetate copolymer containing about 17 to 19 weight percent vinyl acetate and exhibiting a melt index of about 2 to 3 grams per 10 minutes, (2) a paraffin wax having a melting point between about 160* F. and 170* F., and (3) about 10 to 25 weight percent of an oil solubility retarding agent comprising long chain aliphatic hydrocarbon and oxidized hydrocarbon waxes having melting points between about 195* F. and 250* F. and Izod strengths of less than 0.9 foot-pounds.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |