US 11,906,691 B2
Method for improving neutron interpretations in subsurface formations
Paul R. Craddock, Scituate, MA (US); Laurent Mosse, Buenos Aires (AR); Jeffrey R. Miles, Arlington, MA (US); and Andrew E. Pomerantz, Lexington, MA (US)
Assigned to SCHLUMBERGER TECHNOLOGY CORPORATION, Sugar Land, TX (US)
Appl. No. 17/050,141
Filed by SCHLUMBERGER TECHNOLOGY CORPORATION, Sugar Land, TX (US)
PCT Filed Apr. 22, 2019, PCT No. PCT/US2019/028563
§ 371(c)(1), (2) Date Oct. 23, 2020,
PCT Pub. No. WO2019/209742, PCT Pub. Date Oct. 31, 2019.
Claims priority of provisional application 62/661,237, filed on Apr. 23, 2018.
Prior Publication US 2021/0231826 A1, Jul. 29, 2021
Int. Cl. G01V 5/10 (2006.01); E21B 49/00 (2006.01); G01N 21/35 (2014.01); G01N 33/24 (2006.01); G01N 21/3563 (2014.01)
CPC G01V 5/10 (2013.01) [E21B 49/00 (2013.01); G01N 21/3563 (2013.01); G01N 33/241 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for improving neutron interpretations in a subsurface formation comprising:
deploying a neutron tool directly in a borehole traversing the formation;
logging the formation using the neutron tool;
estimating mineral concentrations and kerogen concentrations at one or more depths in the subsurface formation;
estimating kerogen properties at the one or more depths in the subsurface formation;
calculating mineral properties at the one or more depths in the subsurface formation by summing a plurality of individual mineral abundances solved by infrared spectroscopy, wherein each of the plurality of individual mineral abundances is multiplied by a respective mineral property;
calculating a neutron-based log response to a rock matrix based upon, at least in part, the kerogen properties and the mineral properties at the one or more depths in the subsurface formation by subtracting a contribution from the rock matrix associated with the kerogen properties and the mineral properties from a total neutron response measured by the neutron tool when logging the formation; and
generating and delivering an output to a reservoir tool to alter operation of the reservoir tool, wherein the generated output is based at least in part on an interpretation of the neutron-based log response.