US4649996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double walled screen-filter with perforated joints
Assignee: Individual
•
Filing: 1985-10-23
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Granted: 1987-03-17
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Expires: 2005-10-23
Abstract
Abstract A well screen-filter includes a pair of substantially spaced concentric screens defining an annular filtrating space therebetween, connected with perforated joint(s) closing the lower end of the filtrating space. The annular space is filled with filtrating materials (gravel or synthetic balls) as a pack and an upper joint acts as a cover cap of the annular filtrating space to seal the pack. The lower perforated joint includes holes for passage of fine particles to a sedimentation tube, preventing clogging of the pack and enabling proper functioning of the double walled screen-filter.
Inventors
- 👤 Bozidar Kojicic, deceased
- 👤 legal representative by Djurdjina Kojicic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:24
CPC Classifications
B; B01; B01D; B01D24/00; B01D24/007; B01D24/02; B01D24/04; B01D24/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
A filter adapted to be installed in a hole formed in fluid bearing formations to prevent sanding and silting-in during production, comprising: (a) a pair of spaced, substantially concentric and cylindrical screen members positioned to define an annular filter space therebetween; (b) filter means substantially filling the annular filter space for filtering particulate materials from the fluid flowing through said material, the particulate materials having a tendency to pass into a well; and (c) means connecting the inner and outer screens together for centering the inner screen within the outer screen and for supporting and maintaining said filtering material within said filtering space, said connecting means including a bottom perforated plate including passages for enabling passage of particulate materials from the filtering space.
Claim 2
Dependent Claim
123 words
A filter adapted to be installed in a hole formed in fluid bearing formations to prevent sanding and silting-in during production, comprising: (a) a pair of spaced, substantially concentric and cylindrical screen members positioned to define an annular filter space therebetween; (b) filter means substantially filling the annular filter space for filtering particulate materials from the fluid flowing through said material, the particulate materials having a tendency to pass into a well; and (c) means connecting the inner and outer screens together for centering the inner screen within the outer screen and for supporting and maintaining said filtering material within said filtering space, said connecting means including a bottom perforated plate including passages for enabling passage of particulate materials from the filtering space.
References Cited (Backward Citations)
US1004528A
Cited
US1839044A
Cited
US1874035A
Cited
US2207184A
Cited
US2257344A
Cited
US2525897A
Cited
US2665644A
Cited
US2978033A
Cited
US2973814A
Cited
US3312349A
Cited
US3618771A
Cited
US3965981A
Cited
NL7712759A
Cited
US4526230A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |