Patent US4691774A successfully refreshed from Google Patents.
US4691774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel ferrofluids for use in cementing wells
Assignee: Schlumberger Technology Corp
•
Filing: 1985-11-15
•
Granted: 1987-09-08
•
Expires: 2005-11-15
Abstract
Abstract Novel cementitious and non-cementitious ferrofluids are disclosed which have properties making them suitable for use in cementing wells. The cementitious fluids comprise: (a) a hydraulic cement, (b) finely divided magnetic particles, (c) a bonding agent or a surfactant, and (d) a liquid medium. The binding agent or surfactant is present in the compositions in an amount sufficient to render the compositions stable in a magnetic field. When used in cementing wells, the cementitious ferrofluids are implaced in the annulus separating a casing from the formation in a wellbore by conventional techniques and the slurry is subsequently subjected to an activating magnetic field that causes movement of the magnetic particles in the slurry. The non-cementitious ferrofluids comprise: (a) finely divided magnetic particles, (b) stabilizing agent, and (c) a liquid medium. The movement of the magnetic particles results in a "scrubbing" action against the surface of the casing and the formation and a mixing of the slurry which helps displace any residual drilling mud. The net result is better bonding of the cement.
Inventors
- 👤 Erik B. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:28
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; B; B01; B01F; B01F33/00; B01F33/45; B01F33/451; C; C04; C04B; C04B14/00; C04B14/02; C04B14/30; C04B14/34; C04B28/00; C04B28/02; C04B40/00; C04B40/02; C04B40/0204; C04B40/0209; C09; C09K; C09K8/00; C09K8/42; C09K8/46; B01F2101/00; B01F2101/49
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
A method of preparing a well for cementing comprising: (a) injecting into the annulus separating a casing and the formation a stable ferrofluid comprising an aqueous spacer or wash containing finely divided magnetic particles, and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and (b) applying a magnetic field to cause a mechanical response of said ferrofluid in the annulus.
Claim 2
Independent Claim
70 words
A method of preparing a well for cementing comprising: (a) injecting into the annulus separating a casing and the formation a stable ferrofluid comprising an aqueous spacer or wash containing finely divided magnetic particles, and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and (b) applying a magnetic field to cause a mechanical response of said ferrofluid in the annulus.
Claim 3
Independent Claim
86 words
A method of cementing a well comprising the steps of: (a) injecting a stable ferrofluid into the annulus separating a casing and a subterranean formation wherein said ferrofluid comprises an aqueous spacer or wash containing finely divided magnetic particles, and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and (b) applying a magnetic field to cause a mechanical response of said stable ferrofluid in the annulus, and (c) displacing said ferrofluid with an aqueous hydraulic cement.
Claim 4
Independent Claim
86 words
A method of cementing a well comprising the steps of: (a) injecting a stable ferrofluid into the annulus separating a casing and a subterranean formation wherein said ferrofluid comprises an aqueous spacer or wash containing finely divided magnetic particles, and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and (b) applying a magnetic field to cause a mechanical response of said stable ferrofluid in the annulus, and (c) displacing said ferrofluid with an aqueous hydraulic cement.
Claim 5
Independent Claim
129 words
A method of cementing a well comprising the steps of: (a) injecting a stable ferrofluid into the annulus separating a casing and a subterranean formation wherein said ferrofluid comprises an aqueous spacer or wash containing finely divided magnetic particles and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and, (b) applying a magnetic field to cause a mechanical response of said stable ferrofluid in the annulus, and (c) displacing said stable ferrofluid with a stable cementitious ferrofluid comprising: (i) a hydraulic cement, (ii) finely divided magnetic particles, (iii) a binding agent or a surfactant, and (iv) a liquid medium, said binding agent or surfactant being present in an amount sufficient to render the composition stable in a magnetic field.
Claim 6
Independent Claim
129 words
A method of cementing a well comprising the steps of: (a) injecting a stable ferrofluid into the annulus separating a casing and a subterranean formation wherein said ferrofluid comprises an aqueous spacer or wash containing finely divided magnetic particles and a binding agent or surfactant in an amount sufficient to render the composition stable in a magnetic field, and, (b) applying a magnetic field to cause a mechanical response of said stable ferrofluid in the annulus, and (c) displacing said stable ferrofluid with a stable cementitious ferrofluid comprising: (i) a hydraulic cement, (ii) finely divided magnetic particles, (iii) a binding agent or a surfactant, and (iv) a liquid medium, said binding agent or surfactant being present in an amount sufficient to render the composition stable in a magnetic field.
References Cited (Backward Citations)
SU294928A1
Cited
US1834898A
Cited
US2292838A
Cited
US4093028A
Cited
SU641074A1
Cited
GB2027421A
Cited
US4356098A
Cited
US4537918A
Cited
US4579173A
Cited
SU1121394A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-07 | 1991-03-09 | 1991-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-07 | 1995-03-09 | 1995-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-07 | 1999-03-09 | 1999-09-08 | $7700.00 | Window Closed / Lapsed |