The specific purpose Monte Carlo code McENL for simulating the response of epithermal neutron lifetime well logging tools

Conference · Sun Aug 01 00:00:00 EDT 1993 · IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:5945972

Prettyman, T H; Gardner, R P; Verghese, K ^[1]

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1. North Carolina State Univ., Raleigh, NC (United States). Center for Engineering Applications and Radioisotopes

A new specific purpose Monte Carlo code called McENL for modeling the time response of epithermal neutron lifetime tools is described. The code was developed so that the Monte Carlo neophyte can easily use it. A minimum amount of input preparation is required and specified fixed values of the parameters used to control the code operation can be used. The weight windows technique, employing splitting and Russian Roulette, is used with an automated importance function based on the solution of an adjoint diffusion model to improve the code efficiency. Complete composition and density correlated sampling is also included in the code and can be used to study the effect on tool response of small variations in the formation, borehole, or logging tool composition and density. An illustration of the latter application is given here for the density of a thermal neutron filter. McENL was benchmarked against test-pit data for the Mobil pulsed neutron porosity (PNP) tool and found to be very accurate. Results of the experimental validation and details of code performance are presented.

• OSTI ID: 5945972
• Report Number(s): CONF-921005-; CODEN: IETNAE
• Journal Information: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States), Vol. 40:4 part 1; Conference: Institute of Electrical and Electronic Engineers (IEEE) nuclear science symposium and medical imaging conference, Orlando, FL (United States), 25-31 Oct 1992; ISSN 0018-9499
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
NEUTRON LOGGING
WELL LOGGING EQUIPMENT
M CODES
BOREHOLES
COMPUTERIZED SIMULATION
MONTE CARLO METHOD
POROSITY
RESPONSE FUNCTIONS
CALCULATION METHODS
CAVITIES
COMPUTER CODES
EQUIPMENT
FUNCTIONS
RADIOACTIVITY LOGGING
SIMULATION
WELL LOGGING
440400* - Well Logging Instrumentation