Ambient-activated switch for downhole operations
AssigneeHalliburton Energy Services, Inc.
InventorsDaniel F. Dorffer, Donald L. Crawford
Life of this patent
Estimating the term…
Abstract
An apparatus includes a radiation source to output radiation after power is supplied. The apparatus also includes a power source to supply power. The apparatus includes an ambient-activated switch electrically coupled between the radiation source and the power source. The ambient-activated switch is to switch to an open position while a value for an ambient characteristic for the ambient-activated switch is at an ambient level for a surface of the Earth. The ambient-activated switch is to switch to a closed position while the value for the ambient characteristic for the ambient-activated switch is at a downhole ambient level, wherein the ambient-activated switch is to electrically couple the power source to the radiation source while in the closed position.
Claims29
An apparatus comprising:
- a neutron radiation source to output neutron radiation after power is supplied;
- a power source to supply the power;
- and
- an ambient-activated optical switch electrically coupled between the neutron radiation source and the power source, the ambient-activated optical switch being configured to switch to a decoupling condition while ambient light at the ambient-activated optical switch is at an ambient level for a surface of the Earth, the neutron radiation source being electrically decoupled from the power source while the ambient-activated optical switch is in the decoupling condition, the ambient-activated optical switch being configured to switch to a coupling condition while the ambient light at the ambient-activated optical switch is at or below a threshold level, wherein the ambient-activated optical switch is configured to electrically couple the power source to the neutron radiation source while in the coupling condition.
A system comprising:
- a drill string having a drill bit, the drill string to extend through at least part of a well bore, wherein the drill string comprises:
- a tool to emit neutrons for formation evaluation;
- a power source to supply power;
- and
- a switch electrically coupled between the tool and the power source, the switch being optically sensitive and being configured to switch to a condition in which it does not electrically couple the power source to the tool if a value of an ambient light level at the switch is at an ambient level at a surface of the Earth, the switch being configured to switch to a condition in which it electrically couples the power source to the tool if the value of the ambient light level of the switch is at or below a threshold level.
A method comprising:
- electrically coupling a radiation source to an ambient-activated switch;
- electrically coupling the ambient-activated switch to a power source, wherein the ambient-activated switch is in series or in a shunt configuration between the radiation source and the power source, the ambient-activated switch being configured to switch to a decoupling condition while an ambient light value of the ambient-activated switch is about an ambient level for a surface of the Earth, the radiation source being electrically disconnected from the power source while the ambient-activated switch is in the decoupling condition, the ambient-activated switch further being configured to switch to a coupling condition while the ambient light value of the ambient-activated switch is at or below a threshold level, the ambient-activated switch to electrically connect the power source to the radiation source while in the coupling condition;
- lowering a tool that comprises the radiation source and the ambient-activated switch down the borehole, the power source not being electrically coupled to the neutron radiation source at or adjacent the surface of the Earth;
- and
- upon reaching a depth at which an ambient light value sensed by the ambient-activated switch is at or below the threshold level, switching the ambient-activated switch to the coupling condition, to power the radiation source from the power source.
Dependencies are inferred from the claim text.