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Carbonate deposits hold the major part of resource potential of the whole world and of Rosneft Oil Company in particular. For the majority of carbonates the presence of secondary porosity presented by fractures and caverns is typical. Dividing the voids in types – is the significant stage while evaluating the reserves, choosing the schemes and parameters of developing the deposits. The article presents the analysis of the cavernosity degree of Vendian and Low-Cambrian deposits of Nepa-Botuoba anteclise within the Rosneft Oil Company license areas, according to the results of the core research. There was suggested the approach for evaluation the proportion of cavernous porosity using the well logging. For evaluation there were used: computer tomography methods, nuclear magnetic resonance method and also the difference of porosity value of different diameter samples. For cavernous porosity evaluation using well logging data the method of V.M. Dobrynin has been taken as the base, it is based on the difference of each type of the voids according to the voluminal compressibility values. The analysis of the elastic properties on the core research results and the consideration of the specifics of the deposits, in particular polymineral composition and halitisation of the voids, will allow to choose the technique parameters for the best correlation of well logging cavernous porosity and core cavernous porosity. Verification of the received results with the nuclear magnetic resonance methods and computer tomography had the good repeatability. Most likely the differences are caused by the different scales of the researches. For more detailed adjustment of the cavernous porosity evaluation technique it is necessary to define the border of the fractures, caverns, pores compressibility. References 1. Atlas karbonatnykh kollektorov mestorozhdeniy nefti i gaza Vostochno-Evropeyskoy i Sibirskoy platform (Atlas of carbonate reservoirs oil and gas fields of the East European and Siberian platforms): edited by Bagrintseva K.I., Dmitrievskiy A.N., Bochko R.A., Moscow: Nauka Publ., 2003, 264 p. 2. Ghafoori M.R., Roostaeian M., Sajjadian V.A., Secondary porosity: A key parameter controlling the hydrocarbon production in heterogeneous carbonate reservoirs, Petrophysics, 2009, February, pp. 67–78. 3. Bayuk I.O., Ryzhkov V.I., Determination of parameters of cracks and pores of carbonate reservoirs according to wave acoustic logging (In Russ.), Tekhnologiya seysmorazvedki, 2010, no. 3, pp. 32–42. 4. Dobrynin V.M., An investigation of the porosity of complex carbonate reservoirs (In Russ.), Geologia nefti i gaza, 1991, no. 5, pp. 30–34. 5. Kazatchenko E., Markov M., Mousatov A., Determination of primary and secondary porosity in carbonate formations using acoustic data, SPE-84209-MS, 2003. 6. Gadzhiev V., Solov'ev Yu., Eynaudi F., Advanced acoustic applications for the Karachaganak field, Kazakhstan (In Russ.), SPE-139778-RU, 2010. 7. Kostin D.K., Kuznetsov E.G., Vilesov A.P., Experience of TNNC LLC in core study using CT scanner (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2014, no. 3, pp. 18–21. 8. Kolesov V.A. et al., Calculation of residual water saturation of east siberian reservoirs from nuclear magnetic logging data (In Russ.), Karotazhnik, 2014, no. 8 (242), pp. 50–58. 9. Dobrynin V.M., Deformatsii i izmeneniya fizicheskikh svoystv kollektorov nefti i gaza (Deformations and changes in the physical properties of oil and gas collectors), Moscow: Nedra Publ., 1970, 239 p. |
