US4034812A
Expired / Lapsed
US
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Method for recovering viscous petroleum from unconsolidated mineral formations
Assignee: Texaco Inc
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Filing: 1975-07-28
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Granted: 1977-07-12
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Expires: 1995-07-28
Abstract
Abstract Disclosed is a method whereby viscous petroleum may be recovered from a subterranean viscous petroleum-containing formation in which the formation mineral matrix is substantially unconsolidated, such as a tar sand deposit. A hot fluid such as steam is injected into the formation and pressure maintained thereon for a period of time to heat the viscous petroleum in the immediate vicinity of the well bore, which causes the unconsolidated mineral grains to settle to the bottom of the formation with the viscous oil located on the top of the settled grains. The injection pressure maintenance phase is then terminated and petroleum is recovered from the upper portion of the formation. Numerous cycles of hot fluid injection, soak, followed by production of petroleum from the upper portion of the cavity are required to exploit a reasonable aerial extent of the formation by this method. The separation is enhanced by introducing a solvent material for the viscous petroleum which has a specific gravity substantially less than the specific gravity of petroleums, such as a low molecular weight hydrocarbon solvent, or introducing a fluid which is immiscible with petroleum and which has specific gravity substantially greater than the specific gravity of the viscous petroleum, such as a dense brine which settles to the bottom portion of the cavity and displaces petroleum upward. Both treatments may be employed simultaneously for optimum recovery.
Inventors
- 👤 Richard H. Widmyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:31
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/28; E21B43/281
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
201 words
A method of recovering viscous petroleum from a subterranean, viscous petroleum-containing permeable formation, said formation containing a mineral matrix which is granular and substantially unconsolidated, including a tar sand deposit, said formation being penetrated by at least one well, said well containing two separate communication paths, the first communication path being between the surface of the earth and a protion of the formation near the bottom thereof, and the second communication path being between the surface and portion of the formation near the top thereof, comprising: a. introducing a heated fluid into the formation via the first communication path, at a gradually increasing injection pressure to a predetermined value less than the overburden fracturing pressure; b. maintaining the heated fluid in the formation for a predetermined period of time sufficient to heat the viscous petroleum and allow the unconsolidated granular mineral matrix material to settle toward the bottom of the formation; c. recovering viscous petroleum which has accumulated above the granular, unconsolidated material which is settled toward the bottom of the formation via the second communication path; and d. repeating the above steps for a plurality of cycles to expand the zone from which petroleum is recovered adjacent the production well.
Claim 2
Independent Claim
201 words
A method of recovering viscous petroleum from a subterranean, viscous petroleum-containing permeable formation, said formation containing a mineral matrix which is granular and substantially unconsolidated, including a tar sand deposit, said formation being penetrated by at least one well, said well containing two separate communication paths, the first communication path being between the surface of the earth and a protion of the formation near the bottom thereof, and the second communication path being between the surface and portion of the formation near the top thereof, comprising: a. introducing a heated fluid into the formation via the first communication path, at a gradually increasing injection pressure to a predetermined value less than the overburden fracturing pressure; b. maintaining the heated fluid in the formation for a predetermined period of time sufficient to heat the viscous petroleum and allow the unconsolidated granular mineral matrix material to settle toward the bottom of the formation; c. recovering viscous petroleum which has accumulated above the granular, unconsolidated material which is settled toward the bottom of the formation via the second communication path; and d. repeating the above steps for a plurality of cycles to expand the zone from which petroleum is recovered adjacent the production well.
Claim 3
Dependent Claim
13 words
A method as recited in claim 1 wherein the heated fluid is steam.
Claim 4
Dependent Claim
40 words
A method as recited in claim 1 comprising the additional step of introducing a fluid into the formation which is immiscible with formation petroleum, the specific gravity of the fluid being greater than the specific gravity of the viscous petroleum.
Claim 5
Dependent Claim
14 words
A method as recited in claim 3 wherein the fluid is an aqueous brine.
Claim 6
Dependent Claim
26 words
A method as recited in claim 3 wherein the fluid which is immiscible with the formation petroleum is heated prior to injecting it into the formation.
Claim 7
Dependent Claim
30 words
A method as recited in claim 3 wherein a surface-tension reducing agent is mixed with the fluid which is immiscible with formation petroleum prior to injection thereof into the formation.
Claim 8
Dependent Claim
20 words
A method as recited in claim 6 wherein the surface-tension reducing agent is a sulfonated, ethoxylated, alkyl or alkylaryl compound.
Claim 9
Dependent Claim
37 words
A method as recited in claim 1 comprising the additional step of introducing a substance into the formation which is miscible with formation petroleum, having a specific gravity substantially less than the specific gravity of formation petroleum.
Claim 10
Dependent Claim
27 words
A method as recited in claim 8 wherein the fluid which is miscible with formation petroleum is an aliphatic hydrocarbon having from 4 to 10 carbon atoms.
Claim 11
Dependent Claim
26 words
A method as recited in claim 9 wherein the fluid which is miscible with formation petroleum is introduced into the formation simultaneously with the heating fluid.
Claim 12
Independent Claim
212 words
A method of recovering viscous petroleum from a subterranean, viscous petroleum-containing permeable formation, said formation containing a mineral matrix which is granular and substantially unconsolidated, including a tar sand deposit, said formation being penetrated by at least one well which is in fluid communication with at least a portion of the petroleum formation adjacent the well, comprising: a. introducing a heated fluid into the formation via the well at a gradually increasing injection pressure to a predetermined value less than the overburden fracturing pressure; b. maintaining the heated fluid in the formation for a predetermined period of time sufficient to heat the viscous petroleum and allow the unconsolidated granular mineral matrix material to settle toward the bottom of the formation; c. introducing a fluid into the formation which is immiscible with formation petroleum, the specific gravity of the fluid being greater than the specific gravity of the viscous petroleum to displace heated viscous petroleum upward; d. recovering heated viscous petroleum which has been displaced above the granular, unconsolidated material which is settled toward the bottom of the formation by the fluid having a specific gravity greater than petroleum; and e. repeating the above steps for a plurality of cycles to expand the zone from which petroleum is recovered adjacent the production well.
Claim 13
Independent Claim
212 words
A method of recovering viscous petroleum from a subterranean, viscous petroleum-containing permeable formation, said formation containing a mineral matrix which is granular and substantially unconsolidated, including a tar sand deposit, said formation being penetrated by at least one well which is in fluid communication with at least a portion of the petroleum formation adjacent the well, comprising: a. introducing a heated fluid into the formation via the well at a gradually increasing injection pressure to a predetermined value less than the overburden fracturing pressure; b. maintaining the heated fluid in the formation for a predetermined period of time sufficient to heat the viscous petroleum and allow the unconsolidated granular mineral matrix material to settle toward the bottom of the formation; c. introducing a fluid into the formation which is immiscible with formation petroleum, the specific gravity of the fluid being greater than the specific gravity of the viscous petroleum to displace heated viscous petroleum upward; d. recovering heated viscous petroleum which has been displaced above the granular, unconsolidated material which is settled toward the bottom of the formation by the fluid having a specific gravity greater than petroleum; and e. repeating the above steps for a plurality of cycles to expand the zone from which petroleum is recovered adjacent the production well.
Claim 14
Dependent Claim
13 words
A method as recited in claim 11 wherein the heated fluid is steam.
Claim 15
Dependent Claim
99 words
A method as recited in claim 11 wherein the well contains two separate communication paths between the surface of the earth and the formation, the first being in fluid communication with a portion of the formation near the bottom thereof and the second being in fluid communication with a portion of the formation near the top thereof, and wherein the heated fluid and the fluid which is immiscible with formation petroleum and greater specific gravity than petroleum are introduced into the formation via the first communication path and petroleum is recovered from the formation via the second communication path.
Claim 16
Dependent Claim
16 words
A method as recited in claim 11 wherein the fluid of (c) is an aqueous brine.
Claim 17
Dependent Claim
20 words
A method as recited in claim 14 wherein the aqueous brine is heated prior to injecting it into the formation.
Claim 18
Dependent Claim
31 words
A method as recited in claim 11 wherein a surface tension reducing agent is mixed with the fluid which is immiscible with formation petroleum prior to injection thereof into the formation.
Claim 19
Dependent Claim
21 words
A method as recited in claim 16 wherein the surface tension reducing agent is a sulfonated, ethoxylated, alkyl or alkylaryl compound.
Claim 20
Dependent Claim
37 words
A method as recited in claim 11 comprising the additional step of introducing a substance into the formation which is miscible with formation petroleum, having a specific gravity substantially less than the specific gravity of formation petroleum.
Claim 21
Dependent Claim
27 words
A method as recited in claim 18 wherein the fluid which is miscible with formation petroleum is an aliphatic hydrocarbon having from 4 to 10 carbon atoms.
Claim 22
Dependent Claim
26 words
A method as recited in claim 18 wherein the fluid which is miscible with formation petroleum is introduced into the formation simultaneously with the heated fluid.
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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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |