US 9,810,807 B2
Methods and systems for detecting epithermal and thermal neutrons
Grant Goodyear, Spring, TX (US)
Assigned to Halliburton Energy Services, Inc., Houston, TX (US)
Appl. No. 14/435,100
Filed by Halliburton Energy Services, Inc., Houston, TX (US)
PCT Filed Nov. 1, 2012, PCT No. PCT/US2012/063017
§ 371(c)(1), (2) Date Apr. 10, 2015,
PCT Pub. No. WO2014/070184, PCT Pub. Date May 8, 2014.
Prior Publication US 2015/0276974 A1, Oct. 1, 2015
Int. Cl. G01T 3/02 (2006.01); G01V 5/10 (2006.01)
CPC G01V 5/107 (2013.01) [G01T 3/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a tool for measuring properties of an earth formation, the tool comprising:
a tool body;
a neutron source disposed within the tool body, the neutron source to emit neutrons;
a neutron detector disposed within the tool body at a spaced apart location from the neutron source;
a first neutron shield arranged in operational relationship to the neutron detector, the first neutron shield defines an exterior surface and an interior volume, the first neutron shield to prevent neutrons having an energy below a first predetermined threshold from traveling from the exterior surface to the interior volume;
the first neutron shield movably coupled to the tool body, wherein the first neutron shield defines a non-occluded position relative to the neutron detector such that the neutron detector is at least partially outside the interior volume, and the first neutron shield defines an occluded position relative to the first neutron detector such that the first neutron detector is disposed within the interior volume.