US3570611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for freeing seized drill strings
Assignee: TRUSTUL DEFORAJ PITESTI
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Filing: 1969-02-05
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Granted: 1971-03-16
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Expires: 1989-02-05
Abstract
Abstract A device for freeing seized drill strings in which a longitudinally reciprocable valve controls up and down movement of a vibrating member imparting longitudinal shock to the drill string as controlled by the drilling fluid pressure. In addition, the longitudinally reciprocal member forms a valve in its casing to alternately block flow of drilling fluid and admit such flow to the lower part of the drill string whereby the pressure in the bore is alternately increased and decreased in the cadence of the longitudinal shock.
Inventors
- 👤 Vladimir Riziuc
- 👤 Silvestru Huelscher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:57
CPC Classifications
E; E21; E21B; E21B31/00; E21B31/107; E21B31/113; E21B31/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
225 words
A device for facilitating the extraction of a drill string from a bore, comprising: a tubular casing slidable in said drill string and formed at a lower end with a movable tubular member for passage of a drilling fluid below said device through the interior of said casing, said casing being formed with an annular valve seat at an intermediate location along its length and said member being provided with a tubular massive valVe body engageable with said seat in a lower extreme position of said member for blocking the flow of drilling fluid through said casing except for the flow through said tubular member; an abutment fixed to said casing above said valve body and engageable thereby upon elevation of said member to produce upward longitudinal shock; and a spring-biased normally open kicker valve at the lower end of said member, said casing being provided with a further valve seat cooperating with said kicker valve for obstructing the flow of fluid from said member through said casing, said member and said casing defining a throttle passage for bleeding drilling fluid past said kicker valve in a closed position thereof under the pressure of drilling fluid in said member, said member forming a differential piston in a closed condition of said kicker valve tending to drive the member upwardly under the pressure of said fluid.
Claim 2
Independent Claim
225 words
A device for facilitating the extraction of a drill string from a bore, comprising: a tubular casing slidable in said drill string and formed at a lower end with a movable tubular member for passage of a drilling fluid below said device through the interior of said casing, said casing being formed with an annular valve seat at an intermediate location along its length and said member being provided with a tubular massive valVe body engageable with said seat in a lower extreme position of said member for blocking the flow of drilling fluid through said casing except for the flow through said tubular member; an abutment fixed to said casing above said valve body and engageable thereby upon elevation of said member to produce upward longitudinal shock; and a spring-biased normally open kicker valve at the lower end of said member, said casing being provided with a further valve seat cooperating with said kicker valve for obstructing the flow of fluid from said member through said casing, said member and said casing defining a throttle passage for bleeding drilling fluid past said kicker valve in a closed position thereof under the pressure of drilling fluid in said member, said member forming a differential piston in a closed condition of said kicker valve tending to drive the member upwardly under the pressure of said fluid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-15 | 1974-09-14 | 1975-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-15 | 1978-09-14 | 1979-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-15 | 1982-09-14 | 1983-03-16 | $7700.00 | Window Closed / Lapsed |