Feasibility study of artifacts on the neutron logging curve near the boundary of layers

• Autorzy: Wiącek Urszula , Woźnicka Urszula

Identyfikatory

DOI

10.1007/s11600-019-00322-1

• Języki publikacji: EN

Abstrakty

EN

The neutron borehole probe equipped with a neutron source and a system of neutron detectors is commonly used to determine porosity of geological formations. Transport of neutrons through media relies on their interaction with atomic nuclei, mainly with the process of scattering and absorption. Curves recorded by detectors for a given geological layer bordered by a medium with other neutron properties form the so-called anomalies. The course of the anomaly mainly depends on neutron properties of the bordering media and also on the measurement geometry, borehole properties, etc. The paper focuses mainly on an influence of neutron properties of bordered rock media on the course of the anomaly curve, especially near the media boundaries. In some cases of bordering media, characterized by specific neutron properties, the course of anomalies can be significantly disturbed, forming specific artifacts. The paper explains that the presence of artifacts is closely related to the properties of bordered media for both fast and thermal neutrons, i.e., the slowing down length of fast neutrons and the absorption cross section of thermal neutrons. Artifacts can be the cause of misinterpretation of the neutron rock porosity probe measurement. All considerations presented in this paper are based on results obtained from MC calculations performed using MCNP5 code (MCNP Team in X-5 Monte Carlo Team, MCNP—a general Monte Carlo N-particle transport code version 5. Los Alamos National Laboratory LA-UR-03-1987, 2008).

Słowa kluczowe

EN

neutron logging; MCNP modeling; boundary of layers; neutron transport parameters; neutron artifacts

PL

rejestrowanie neutronów; modelowanie MCNP; granica warstw; parametry transportu neutronów; artefakt neutronowy

• Wydawca: Instytut Geofizyki PAN ; Springer
• Czasopismo: Acta Geophysica
• Rocznik: 2019
• Tom: Vol. 67, no. 6
• Strony: 1721--1729
• Opis fizyczny: Bibliogr. 7 poz.

Twórcy

autor

Wiącek Urszula

• Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31‑342 Kraków, Poland

autor

Woźnicka Urszula

• Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152, 31‑342 Kraków, Poland

Bibliografia

• 1. Czubek JA (1994) Neutron tool calibration by a scaling procedure. Nucl Geophys 8:26
• 2. Gardner RP, Xu L, Wang J (2007) Some lessons learned from MCNP usage. In: SPWLA 48th annual logging symposium, June 3–6 (2007) pap. K
• 3. MCNP Team (2008) X-5 Monte Carlo Team, MCNP—a General Monte Carlo N-Particle Transport Code Version 5. Los Alamos National Laboratory LA-UR-03-1987
• 4. Wiącek U (2018) Application of computer modeling and simulations to the development of the nuclear geophysical measurement methods using neutron well logging. IFJ PAN, pp 1–199, ISBN 978-83-63542-02-3 (in polish)
• 5. Wiącek U, Dworak D (2018) Preliminary analysis of the artifacts appearing on the NNTE probe response curves at layers boundary of the two-layer rock media. In Polish, Mat. Międzynarodowej Konf. Naukowo-Technicznej Geopetrol 2018, Development of hydrocarbon exploration and production technologies. Instytut Nafty i Gazu, Państwowy Instytut Badawczy, pp 255–263, ISBN 978-83-65649-27-0
• 6. Wiącek U, Woźnicka U (2016) Feasibility of Monte Carlo modelling for the neutron–neutron logging tool response in specific geological models. Geol Geophys Environ 42:365–383. https://doi.org/10.7494/geol.2016.42.3.365
• 7. Woźnicka U, Dworak D, Wiącek U, Zorski T (2012) Geofizyczne profilowania neutronowe w asymetrycznych formacjach cienkowarstwowych (Symulacje komputerowe na przykładzie sondy NNTE). In: IFJ PAN, Kraków, ISBN: 978-83-934248-7-0 (in polish)

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).