1. A power element protection circuit comprising:
a voltage detector that detects, with respect to a power element having a first electrode, a second electrode, and a control electrode, a voltage between the first and second electrodes of the power element and that then outputs a current proportional to the detected voltage;
a current detector that detects a current flowing through the power element and that then outputs a current proportional to the detected current;
a first logarithmic converter that logarithmically converts and then outputs the current outputted from the current detector;
a second logarithmic converter that logarithmically converts and then outputs the current outputted from the voltage detector;
an antilogarithmic converter that antilogarithmically converts a level derived from a sum of the outputs of the first and second logarithmic converters; and
a driving limiter that limits driving of the power element based on an output of the antilogarithmic converter.
2. A power element protection circuit as claimed in claim 1,
wherein the first logarithmic converter is a first bipolar transistor that receives as an emitter current or collector current thereof the current outputted from the current detector and that outputs a base-emitter voltage thereof,
wherein the second logarithmic converter is a second bipolar transistor that receives as an emitter current or collector current thereof the current outputted from the voltage detector and that outputs a base-emitter voltage thereof, and
wherein the antilogarithmic converter is a third bipolar transistor that receives as a base-emitter voltage thereof the level derived from the sum of the outputs of the first and second logarithmic converters and that outputs an emitter current or collector current thereof.
3. A power element protection circuit as claimed in claim 2,
wherein the current detector comprises:
a first transistor of which a second electrode and a control electrode are connected respectively to the second electrode and the control electrode of the power element;
a second transistor of which one of a first electrode or a second electrode is connected to a first electrode of the first transistor; and
an operational amplifier
of which one input terminal is connected to the first electrode of the power element,
of which another input terminal is connected to the first electrode of the first transistor, and
of which an output terminal is connected to a control electrode of the second transistor,
wherein the second transistor outputs, at another of the first and second electrodes thereof, a current signal proportional to the current flowing through the power element.
4. A power element protection circuit as claimed in claim 3,
wherein the second transistor and the operational amplifier constitute a negative feedback circuit.
5. A power element protection circuit as claimed in claim 2,
wherein the current detector comprises:
a first transistor of which a second electrode and a control electrode are connected respectively to the second electrode and the control electrode of the power element;
a second transistor of which a second electrode is connected to a first electrode of the first transistor; and
a third transistor of which a control electrode is connected to the first electrode of the power element and of which a second electrode is connected to a control electrode of the second transistor,
wherein the second transistor outputs, at a first electrode thereof, a current signal proportional to the current flowing through the power element.
6. A power element protection circuit as claimed in claim 5,
wherein a first electrode of the third transistor is connected to the second electrodes of the power element and the first transistor, and a direct-current voltage is applied through a resistor to the second electrode of the third transistor.
7. A power element protection circuit as claimed in claim 6,
wherein the second and third transistors are transistors of opposite polarities, and a potential difference appearing between the second electrode and control electrode of the second transistor is substantially equal to a potential difference appearing between the second electrode and control electrode of the third transistor.
8. A power element protection circuit as claimed in claim 7,
wherein the second transistor is a transistor of a same polarity as the first transistor.
9. A power element protection circuit as claimed in claim 8,
wherein a first electrode of the third transistor is connected to the second electrodes of the power element and the first transistor, and a direct-current voltage is applied through a resistor to the second electrode of the third transistor.
10. A semiconductor device comprising:
a power element having a first electrode, a second electrode, and a control electrode;
a driver that feeds a drive signal to the control electrode of the power element to drive the power element; and
a power element protection circuit that is connected to the power element and to the driver so as to control the driver,
wherein the power element protection circuit comprises:
a voltage detector that detects a voltage between the first and second electrodes of the power element and that then outputs a current proportional to the detected voltage;
a current detector that detects a current flowing through the power element and that then outputs a current proportional to the detected current;
a first logarithmic converter that logarithmically converts and then outputs the current outputted from the current detector;
a second logarithmic converter that logarithmically converts and then outputs the current outputted from the voltage detector;
an antilogarithmic converter that antilogarithmically converts a level derived from a sum of the outputs of the first and second logarithmic converters; and
a driving limiter that limits driving of the power element based on an output of the antilogarithmic converter.
11. A semiconductor device as claimed in claim 10,
wherein the first logarithmic converter is a first bipolar transistor that receives as an emitter current or collector current thereof the current outputted from the current detector and that outputs a base-emitter voltage thereof,
wherein the second logarithmic converter is a second bipolar transistor that receives as an emitter current or collector current thereof the current outputted from the voltage detector and that outputs a base-emitter voltage thereof, and
wherein the antilogarithmic converter is a third bipolar transistor that receives as a base-emitter voltage thereof the level derived from the sum of the outputs of the first and second logarithmic converters and that outputs an emitter current or collector current thereof.
12. A semiconductor device as claimed in claim 11,
wherein the current detector comprises:
a first transistor of which a second electrode and a control electrode are connected respectively to the second electrode and the control electrode of the power element;
a second transistor of which one of a first electrode or a second electrode is connected to a first electrode of the first transistor; and
an operational amplifier
of which one input terminal is connected to the first electrode of the power element,
of which another input terminal is connected to the first electrode of the first transistor, and
of which an output terminal is connected to a control electrode of the second transistor,
wherein the second transistor outputs, at another of the first and second electrodes thereof, a current signal proportional to the current flowing through the power element.
13. A semiconductor device as claimed in claim 12,
wherein the second transistor and the operational amplifier constitute a negative feedback circuit.
14. A semiconductor device as claimed in claim 11,
wherein the current detector comprises:
a first transistor of which a second electrode and a control electrode are connected respectively to the second electrode and the control electrode of the power element;
a second transistor of which a second electrode is connected to a first electrode of the first transistor; and
a third transistor of which a control electrode is connected to the first electrode of the power element and of which a second electrode is connected to a control electrode of the second transistor,
wherein the second transistor outputs, at a first electrode thereof, a current signal proportional to the current flowing through the power element.
15. A semiconductor device as claimed in claim 14,
wherein a first electrode of the third transistor is connected to the second electrodes of the power element and the first transistor, and a direct-current voltage is applied through a resistor to the second electrode of the third transistor.
16. A semiconductor device as claimed in claim 15,
wherein the second and third transistors are transistors of opposite polarities, and a potential difference appearing between the second electrode and control electrode of the second transistor is substantially equal to a potential difference appearing between the second electrode and control electrode of the third transistor.
17. A semiconductor device as claimed in claim 16,
wherein the second transistor is a transistor of a same polarity as the first transistor.
18. A semiconductor device as claimed in claim 17,
wherein a first electrode of the third transistor is connected to the second electrodes of the power element and the first transistor, and a direct-current voltage is applied through a resistor to the second electrode of the third transistor.
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 method of completing a well comprising:
running a first tubing into a wellbore, wherein the wellbore comprises a cased portion;
hanging the first tubing in the wellbore; and
running a second tubing into the first tubing that is hung in the wellbore to mate the first and second tubing together, wherein running the second tubing into the first tubing expands a portion of the first tubing from a first inner diameter to a larger second inner diameter accommodating an outer diameter portion of the second tubing that is larger than the first inner diameter.
2. The method of claim 1, wherein running the second tubing into the first tubing produces negative surplus expansion as the second tubing is stabbed into the first tubing.
3. The method of claim 1, wherein running the second tubing into the first tubing engages a seal disposed on an outside surface of the second tubing into sealing contact with an inside surface of the first tubing.
4. The method of claim 1, wherein running the second tubing into the first tubing engages an anchor disposed on an outside surface of the second tubing into gripping contact with an inside surface of the first tubing.
5. The method of claim 1, wherein running the second tubing into the first tubing engages a seal and an anchor disposed on an outside surface of the second tubing into respectively sealing and gripping contact with an inside surface of the first tubing.
6. A system for completing a well, comprising:
existing tubing hung in a wellbore; and
production tubing mated into the existing tubing that is hung in the wellbore independent of the production tubing being mated into the existing tubing, wherein the production tubing includes an expansion cone formed on an outer surface of the production tubing.
7. The system of claim 6, further comprising a coupling arrangement disposed on the outer surface behind the expansion cone, the coupling arrangement configured for engagement with a portion of the existing tubing that is expanded by the expansion cone.
8. The system of claim 7, wherein the coupling arrangement comprises a seal.
9. The system of claim 7, wherein the coupling arrangement comprises an anchor.
10. The system of claim 7, wherein the coupling arrangement comprises a ratchet that grips an inner diameter of the existing tubing.
11. The system of claim 7, wherein the coupling arrangement comprises a seal and an anchor.
12. The system of claim 6, further comprising a slip mechanism to hang the existing tubing in the wellbore.
13. A method of completing a well, comprising:
hanging a tubular member in a wellbore; and
running production tubing into the tubular member that is hung in the wellbore to mate the tubular member and production tubing together, wherein the running the production tubing into the tubular member expands a portion of the tubular member.
14. The method of claim 13, wherein the portion of the tubular member is expanded to form a polished bore receptacle.
15. The method of claim 13, wherein running the production tubing into the tubular member produces negative surplus expansion as the production tubing is stabbed into the tubular member.
16. The method of claim 13, further comprising flowing production fluid through the production tubing that serves as a conduit to a surface of the well.
17. The method of claim 13, wherein running the production tubing into the tubular member positions a coupling arrangement disposed on an outer surface of the production tubing in engagement with the portion of the tubular member that is expanded.
18. The method of claim 13, wherein running the production tubing into the tubular member engages a seal set disposed on an outer surface of the production tubing into sealing contact with an inside of the tubular member.
19. The method of claim 13, wherein running the production tubing into the tubular member engages a seal and an anchor disposed on an outer surface of the production tubing into respectively sealing and gripping contact with an inside of the tubular member.
20. The method of claim 13, wherein hanging the tubular member includes setting a slip mechanism independent of the production tubing being mated into the tubular member.