O. Menshov1, Cand. Sci. (Geol.), Postdoctoral Student, E-mail: firstname.lastname@example.org,
O. Karpenko1, Dr. Sci. (Geol.), Prof., E-mail: email@example.com
MAGNETIC METHODS IN UNCONVENTIONAL HYDROCARBON EXPLORATION: SETTING THE OBJECTIVES
1Institute of Geology, Taras Schevchenko National University of Kyiv, 90 Vasylkivska Str., Kyiv, 03022 Ukraine
This paper deals with unconventional hydrocarbons exploration and production. Unconventional gas and oil include hydrocarbons in tight rocks, coal bed methane, shale gas and oil. The focus is on magnetic methods in geological exploration and geophysical research on unconventional oil and gas deposits. Oil and gas genesis has no direct bearing on the use of magnetic methods, with the latter being applied directly in hydrocarbon prospecting. On the other hand, an anomalous magnetic signal from soils is comparable in its intensity and amplitude with magnetic signals from hydrocarbon deposits. We have assessed the prospects of developing a direct method of oil and gas exploration based on the assumption that hydrocarbon migration brings about changes in magnetic minerals within the lithological formations of a hydrocarbon halo along the entire oil travel path from the lower geological layers up to the near surface geological section and soils. A correlation has been found between hydrocarbon deposits and changes in magnetic mineralogy caused by hydrocarbon fluid migration. The main magnetic attributes under study include magnetic susceptibility, frequency dependence magnetic susceptibility, isothermal remanent magnetization, saturation magnetization, and the parameters of thermomagnetic analysis. Hydraulic fracturing, which is commonly used to extract hydrocarbons from unconventional reservoirs, often results in emitting environmental pollutants, such as toxic chemical reagents, petroleum derivatives and sand fraction. Furthermore, hydrocarbon handling entails the risk of accidental release of pollutants and contaminating the subsurface, geologic sections, groundwater and soil. It has been shown that environmental pollution caused by hydraulic fracturing and hydrocarbon handling is associated with formation and introduction of secondary magnetic minerals. Magnetic methods used to detect autogenic magnetic substances are rapid, highly efficient and economically sound.
Keywords: magnetic methods, hydrocarbons, shale gas, oil, soil magnetism, magnetic susceptibility.
Aifa T., Zerrouki A., Baddari K., Geraud Y., (2014). Magnetic susceptibility and its relation with fractures and petrophysical parameters in the tight sand oil reservoir of Hamra quartzites, southwest of the Hassi Messaoud oil field, Algeria. Journal of Petroleum Science and Engineering, 123, 120-137.
Civan F., Rai C.S., Sondergeld C.H., (2011). Shale-Gas and Transport Mechanisms Permeability and Diffusivity Inferred by Improved Formulation of Relevant Retention. Transp Porous Med, 925–944.
Goldhaber M.B., Reynolds R.L., (1991). Relations among hydrocarbon reservoirs, epigenetic sulfidization, and rock magnetization: examples from the South Texas Coastal Plain. Geophysics, 56, 748-757.
Gonzalez F., Aldana M., Constanzo-Alvarez V., Diaz M., Romero I., (2002). An integrated rock magnetic and EPR study in soil samples from a hydrocarbon prospective area. Physics and Chemistry of the Earth, 27, 1311-1317.
Holditch S.A., Morse, R.A. Large, (1971). Fracture Treatments May Unlock Tight Reservoirs. Oil and Gas Journal, 29 March and 5 April.
Jeleńska M., Hasso-Agopsowicz A., Kopcewicz B., Sukhorada A., Tyamina K., Kądziałko-Hofmokl M., Matviishina Z., (2004). Magnetic properties of the profiles of polluted and non-polluted soils. A case study from Ukraine. Geophys. J. Int., 159, 104-116.
Liu Q., Liu Q., Chan L., Yang T., Xia X., Cheng T., (2006). Magnetic enhancement caused by hydrocarbon migration in the Mawangmiao Oil Field, Jianghan Basin China. Journal of Petroleum Science and Engineering, 53, 25-33.
Menshov O., Sukhorada A., (2010). Magnetic Properties of Ukraine Soils and Their Informational Content. 72th EAGE Conference & Exhibition, http://www.earthdoc.org/detail.php?pubid=39881.
Rijal M.L., Appel E., Petrovsky E., Blaha U., (2009). Change of magnetic properties due to fluctuation of hydrocarbon contaminated groundwater in unconsolidated sediments. Environmental Pollution, 1-7.
Settari A., Bachman R.C., (2009). Reservoir and fracturing engineering challenges in tight gas development. First break, 27, 59-64.
Shao G., Liang Z., Wang Z., Liu G., Wang W., (2005). Surface Loess Susceptibility Anomalies Directly Indicating Oil and Gas Reservoirs. Applied Geophysics, 1-2, 4, 197-203.
12. Arhipova T.O., Menshov O.I., Sukhorada A.V., (2006). Pro perspectyvy zastosuvanna priamyh metodiv poshukiv vuglevodniv. Materialy Vseukrainskoi naukivoi konferencii "Monitorinh nebezpechnyh geologichnyh procesiv ta ekologichnogo stanu seredovisha, 229-230 (In Ukrainian).
13. Bogdanovich N.M., (2013). Oglad umov rozrobki argyllitopodibnyh kolektoriv gazonaftovih rodovish v Rosii ta za kordonom. Geoinformatika 2013, Kyiv, Disk CD (In Ukrainian).
14. Menshov O., Sukhorada A., Kruglov O., Homenko R., (2009). Gruntoviy pokryv viyskovih aerodromiv Ukrainy ta ih mojliva ekologichna sanacia (na prikladi aerodromu v m. Priluki). Visnyk KNU Tarasa Shevchenka: Geologia, 47, 36-38 (In Ukrainian).
15. Ognianyk N.S., Paramonova N.K., Briks A.L., Pashkovskiy I.S., Konnov D.V., (2006). Osnovy izuchenia zagraznenia geologicheskoy sredy legkimi nefteproduktami. Monogr. I-t geolog. Nauk NAN Ukrainy, 278 p (In Russian).