Numerical Simulation of Response Characteristic of Neutron Porosity Logging While Drilling
Yuan Chao
Li Chaoliu
Zhou Cancan
Zhang Feng
Abstract：Neutron porosity logging while drilling (LWD)plays an important role in formation evaluation under LWD environ-ment,so it has a great significance to study the logging response characteristic.Monte Carlo method is employed to build for-mation modeling under LWD conditions,and the response characteristic is simulated.The results reveal that the changing trend of porosity response of neutron logging while drilling is similar to that of wireline under the same conditions,the sensitivity of porosity curve in LWD to porosity is higher than wireline,but the neutron porosity logging response of LWD is affected severe-ly by the drilling collar.The depth of investigation is related to formation porosity,and the depth of investigation and vertical resolution under the conditions in this paper is 28 cm and 1 9 cm,respectively.In high angle and horizontal wells,the effect of measurement azimuth on neutron porosity curve is slight.When the relative dipα is low,the midpoint of transition area of neu-tron porosity curve is close to the boundary surface.Ifα is less than 60°,the effect of the adjacent formation on porosity curve can be ignored.
Keywords：logging while drillingneutron porosityresponse characteristicnumerical simulation
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 1896-1902 )