1. A junk catcher (2, 2\u2032), said junk catcher comprising:
the junk catcher (2, 2\u2032) being releasable connected to a retrievable bridge plug (4, 4\u2032), the retrievable bridge plug (4, 4\u2032) being connectable to a setting tool (6) for the deployment of the bridge plug (4, 4\u2032) and the junk catcher (2, 2\u2032) in a borehole (9) or a tubular in the borehole (9);
the setting tool (6) extends through a fishing neck (12), a catcher tube (14), a flanged section (16), a valve chamber (18), a closable opening (20) and a portion of a setting sleeve (22, 22\u2032) of the junk catcher (2, 2\u2032);
the valve chamber (18) comprises a valve (50) arranged to close the closable opening (20) after retrieval of the setting tool (6) from the junk catcher (2, 2\u2032);
the junk catcher (2, 2\u2032) being connected to the bridge plug (4, 4\u2032) by at least one shear bolt (27, 38), the bridge plug (4, 4\u2032) comprises a plug fishing neck (32, 32\u2032) facing the junk catcher (2, 2\u2032), and the bridge plug (4, 4\u2032) comprises an equalizing channel (71) in a mandrel (7), the equalizing channel (71) extending from a bull nose (41) of the bridge plug (4, 4\u2032);
the junk catcher (2, 2\u2032) being provided with a closing sleeve (26, 26\u2032), connected to the bridge plug (4, 4\u2032) by at least one shear bolt (38, 38\u2032), and the closing sleeve (26, 26\u2032) seals at least one equalizing port (73) in the mandrel (7) when the bridge plug (4, 4\u2032) is set.
2. The junk catcher (2) according to claim 1, wherein the closing sleeve (26) seals an equalizing hole (40) aligned with the equalizing port (73) by enclosing the plug fishing neck (32) from the outside.
3. he junk catcher (2\u2032) according to claim 1, wherein the closing sleeve (26\u2032) is positioned in an annulus (77) between the plug fishing neck (32\u2032) and the mandrel (7), and seals at least one equalizing port (73) in the mandrel (7).
4. The junk catcher (2\u2032) according to claim 3, wherein the setting sleeve (22\u2032) comprises an internal shoulder (250) positioned in an annulus (87) between the setting sleeve (22\u2032) and the plug fishing neck (32\u2032), the shoulder (250) upon axial displacement relative to the plug fishing neck (32\u2032) abuts a collar (8) projecting over the plug fishing neck (32\u2032), and the collar (8) is connected to the closing sleeve (26\u2032).
5. A The junk catcher (2\u2032) according to claim 4, wherein the internal shoulder (250) is formed by a carrier sleeve (25), the carrier sleeve (25) is connected to and forming an elongation of the setting sleeve (22\u2032).
6. The junk catcher (2, 2\u2032) according to claim 1, wherein the valve (50) has an actuating device (52).
7. The junk catcher and bridge plug assembly comprising a junk catcher (2, 2\u2032) according to claim 1 and where the bridge plug (4, 4\u2032) is provided with at least one equalizing port (73) closable by a closing sleeve (26, 26\u2032) which is retrievable together with the junk catcher (2, 2\u2032).
8. A method of operation of a junk catcher (2, 2\u2032) according to claim 1, the method includes:
connecting the junk catcher (2, 2\u2032) that has a closable opening (20) for a setting tool (6), to a retrievable bridge plug (4, 4\u2032);
connecting the setting tool (6) to the bridge plug (4, 4\u2032);
positioning the junk catcher (2, 2\u2032) and the bridge plug (4, 4\u2032) downhole;
setting the bridge plug (4, 4\u2032); and
retrieving the setting tool (6), characterized in that the method further includes:
retrieving the junk catcher (2, 2\u2032) together with a closing sleeve (26, 26\u2032) which on retrieval displaces axially along a plug fishing neck (32, 32\u2032) of the bridge plug (4, 4\u2032); and
opening at least one equalizing port (73) in a mandrel (7) by the displacement of the closing sleeve (26, 26\u2032) such that an open channel forms from a bull nose (41) and through the bridge plug (4, 4\u2032), such that pressure may equalize under and above the bridge plug (4, 4\u2032) when the junk catcher (2,2\u2032) is retrieved.
9. A method of operation of a junk catcher (2, 2\u2032) according to claim 8, where the method further comprises to inspect a the junk catcher (2, 2\u2032) for the presence of the closing sleeve (26, 26\u2032) at the surface to confirm that the at least one equalizing port (73) has been opened.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A modulated ultra wideband pulse generation system, comprising:
a pulse waveform generator circuit operable to generate an on-off pulse waveform;
a modulating circuit, operable to receive a modulating signal and to modulate the on-off pulse waveform in response to the modulating signal.
2. The modulated ultra wideband pulse generation system of claim 1, further comprising an antenna.
3. The modulated ultra wideband pulse generation system of claim 2, further comprising a capacitor placed between the antenna and the modulating circuit.
4. The modulated ultra wideband pulse generation system of claim 1, wherein the pulse waveform generator circuit generates a pseudorandom waveform.
5. The modulated ultra wideband pulse generation system of claim 1, further comprising a variable bandwidth circuit operable to change the bandwidth of the ultra wideband pulse.
6. The modulated ultra wideband pulse generation system of claim 5, wherein the variable bandwidth circuit comprises a lowpass filter.
7. The modulated ultra wideband pulse generation system of claim 6, wherein the lowpass filter comprises a resistor-capacitor circuit wherein at least one of the resistor and capacitor are variable.
8. The modulated ultra wideband pulse generation system of claim 1, wherein the modulating circuit comprises a pulse position modulator operable to selectively delay the on-off pulse waveform in response to a modulating signal.
9. The modulated ultra wideband pulse generation system of claim 8, wherein the pulse position modulator comprises a resistor-capacitor lowpass filter having a time constant that is varied in response to the modulating signal, operable to selectively delay the pulse position in response to the modulating signal.
10. The modulated ultra wideband pulse generation system of claim 1, wherein the modulating circuit comprises an on-off keying (OOK) modulation circuit that is operable to selectively pass or suppress the pulse in response to a modulating signal.
11. The modulated ultra wideband pulse generation system of claim 1, wherein the modulating circuit comprises a phase modulator operable to selectively change the phase of the waveform in response to a modulating signal.
12. The modulated ultra wideband pulse generation circuit of claim 11, wherein the phase modulator comprises an exclusive or (XOR) gate having the on-off pulse waveform as one input, a modulating signal as a second input, and a modulated signal as an output.
13. A method of producing a modulated ultra wideband pulse, comprising:
Generating an on-off pulse waveform; and
Modulating the on-off pulse waveform in response to a received modulating signal.
14. The method of claim 13, further comprising generating a modulating signal.
15. The method of claim 13, wherein the generated on off pulse waveform comprises a random or pseudorandom stream of on-off pulses.
16. The method of claim 13, further comprising changing the bandwidth of the on-off pulse waveform via a variable bandwidth circuit.
17. The method of claim 16, wherein the variable bandwidth circuit comprises a resistor-capacitor lowpass circuit wherein at least one of the resistor and capacitor are variable.
18. The method of claim 13, wherein modulating the on-off pulse waveform comprises modulating the pulse position such that the pulse position is selectively delayed in response to a modulating signal.
19. The method of claim 18, wherein the pulse position is modulated via a resistor capacitor lowpass filter having a time constant that is varied in response to the modulating signal, operable to selectively delay the pulse position in response to the modulating signal.
20. The method of claim 13, wherein modulating the on-off pulse waveform comprises on-off keying (OOK) modulation of the waveform to selectively pass or suppress the pulses in response to a modulating signal.
21. The method of claim 13, wherein modulating the on-off waveform comprises phase modulation of the waveform such that the phase of the waveform is selectively changed in response to a modulating signal.
22. The method of claim 21, wherein the phase modulation is performed via a circuit comprising an exclusive or (XOR) gate having the on-off pulse waveform as one input, a modulating signal as a second input, and a modulated signal as an output.