# Monte Carlo simulation of neutron porosity oil well logging tools: Combining the geometry-independent fine-mesh importance map and one-dimensional diffusion model approaches

## Abstract

The generation of first estimate geometry-independent fine-mesh three-dimensional importance maps with simple one-dimensional diffusion models is demonstrated for the Monte Carlo simulation of the neutron porosity oil well logging tool response benchmark problem. By combining the approach of using simple one-dimensional steady-state diffusion models for calculating neutron adjoint flux with the geometry-independent fine-mesh-based Monte Carlo importance approach previously developed, an automated and efficient variance reduction method is obtained for this specific problem. A surprising result is that the converged figures of merit after iteration are consistently larger when the initial importance map is based on the one-dimensional diffusion model rather than that obtained from an analog Monte Carlo simulation.

- Authors:

- North Carolina State Univ., Raleigh, NC (United States)
- Computalog U.S.A., Inc., Fort Worth, TX (United States)

- Publication Date:

- Sponsoring Org.:
- Los Alamos National Lab., NM (United States)

- OSTI Identifier:
- 687544

- Resource Type:
- Journal Article

- Journal Name:
- Nuclear Science and Engineering

- Additional Journal Information:
- Journal Volume: 133; Journal Issue: 1; Other Information: PBD: Sep 1999

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; MONTE CARLO METHOD; NEUTRON LOGGING; MESH GENERATION; RESPONSE FUNCTIONS; BENCHMARKS; ADJOINT FLUX; CONVERGENCE; MAPPING; MATHEMATICAL MODELS; ONE-DIMENSIONAL CALCULATIONS

### Citation Formats

```
Gardner, R.P., and Liu, L.
```*Monte Carlo simulation of neutron porosity oil well logging tools: Combining the geometry-independent fine-mesh importance map and one-dimensional diffusion model approaches*. United States: N. p., 1999.
Web.

```
Gardner, R.P., & Liu, L.
```*Monte Carlo simulation of neutron porosity oil well logging tools: Combining the geometry-independent fine-mesh importance map and one-dimensional diffusion model approaches*. United States.

```
Gardner, R.P., and Liu, L. Wed .
"Monte Carlo simulation of neutron porosity oil well logging tools: Combining the geometry-independent fine-mesh importance map and one-dimensional diffusion model approaches". United States.
```

```
@article{osti_687544,
```

title = {Monte Carlo simulation of neutron porosity oil well logging tools: Combining the geometry-independent fine-mesh importance map and one-dimensional diffusion model approaches},

author = {Gardner, R.P. and Liu, L.},

abstractNote = {The generation of first estimate geometry-independent fine-mesh three-dimensional importance maps with simple one-dimensional diffusion models is demonstrated for the Monte Carlo simulation of the neutron porosity oil well logging tool response benchmark problem. By combining the approach of using simple one-dimensional steady-state diffusion models for calculating neutron adjoint flux with the geometry-independent fine-mesh-based Monte Carlo importance approach previously developed, an automated and efficient variance reduction method is obtained for this specific problem. A surprising result is that the converged figures of merit after iteration are consistently larger when the initial importance map is based on the one-dimensional diffusion model rather than that obtained from an analog Monte Carlo simulation.},

doi = {},

journal = {Nuclear Science and Engineering},

number = 1,

volume = 133,

place = {United States},

year = {1999},

month = {9}

}