US4160483A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating a well using fluoboric acid to clean a propped fracture
Assignee: Schlumberger Technology Corp
•
Filing: 1978-07-21
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Granted: 1979-07-10
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Expires: 1998-07-21
Abstract
Abstract The permeability of the prop pack in a subterranean fracture containing a propping agent is improved by contacting the propping agent with fluoboric acid. The fluoboric acid slowly forms hydrolysis products, including hydrofluoric acid and hydroxyfluoboric acid, which react with and stabilize clays and other fines in the prop pack, thereby improving its permeability. Because the fluoboric acid hydrolyzes slowly, it can be injected deep into the fracture extremities before significant spending of the acid occurs.
Inventors
- 👤 Ronnie L. Thomas
- 👤 Frederick A. Suhy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:57
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/25; E21B43/26; E21B43/267; C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; Y; Y10; Y10S; Y10S507/00; Y10S507/933
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
A method for increasing the conductivity of a fracture in a subterranean formation penetrated by a borehole wherein at at least some point in time prior to the partial hydrolysis of an effective amount of the fluoboric acid which is injected into the borehole in carrying out the method, the fracture contains a propping agent having siliceous fines or clays dispersed therein, comprising injecting fluoboric acid into the borehole and thereafter permitting the fluoboric acid to at least partially hydrolyze so that at least part of the propping agent pack is contacted with hydrofluoric acid and hydroxyfluoboric acid generated from said fluoboric acid.
Claim 2
Independent Claim
103 words
A method for increasing the conductivity of a fracture in a subterranean formation penetrated by a borehole wherein at at least some point in time prior to the partial hydrolysis of an effective amount of the fluoboric acid which is injected into the borehole in carrying out the method, the fracture contains a propping agent having siliceous fines or clays dispersed therein, comprising injecting fluoboric acid into the borehole and thereafter permitting the fluoboric acid to at least partially hydrolyze so that at least part of the propping agent pack is contacted with hydrofluoric acid and hydroxyfluoboric acid generated from said fluoboric acid.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein the fracture contains a proppant at the time the fluoboric acid is injected into the borehole, and wherein the fluoboric acid is injected into said fracture.
Claim 4
Dependent Claim
50 words
The method of claim 2 wherein the fluoboric acid is injected into the propped fracture and the well is thereafter shut in for a period of time to permit the fluoboric acid to hydrolyze and thereby react with and stabilize the fines and clay platelets in said propping agent pack.
Claim 5
Dependent Claim
82 words
The method of claim 3 wherein following displacement of the fluoboric acid into the formation, the well is shut in for a period of time at least about as long as the following times, depending on the bottom hole static temperature of the well: ______________________________________
Temperature, ° F.
Minimum Shut-in Time, Hours
______________________________________
100 and less 24
110 19
120 13
130 9
140 6
150 4
160 3
170 2
180 1
190 0.75
200-225 0.5
226-250 0.25
251-300 0.2
______________________________________
Claim 6
Dependent Claim
58 words
The method of claim 4 wherein the shut in time is at least about as long as the following times: ______________________________________
Temperature, ° F.
Minimum Shut-in Time, Hours
______________________________________
100 and less 96
110 76
120 52
130 35
140 24
150 16
160 11
170 8
180 5
190 3
200-225 2
226-250 1
251-300 0.5
______________________________________
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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) | 1982-07-09 | 1983-01-08 | 1983-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-09 | 1987-01-08 | 1987-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-09 | 1991-01-08 | 1991-07-10 | $7700.00 | Window Closed / Lapsed |