Link for citation: Nekrasova I.L.,  Khvoshchin P.A., Kazakov D.A., Borovkova I.S., Garshina O.V.,  Predein A.A. Methodological approaches to selection of composition and properties of technological fluids used for core sampling. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2021, vol. 332, no. 11, рр. 212-222. In Rus.

The relevance. The main changes in the geochemical characteristics of rock samples at the core sampling are associated with an unjustified choice of the type and properties of the drilling fluids, at the storage stage – with the low quality of the core-insulating liquid. In order to obtain a representative core of the required quality, it is important to substantiate the composition and properties of drilling fluids and core-insulating liquids, as well as other parameters of the drilling process. The aim: to determine and propose criteria for selecting the composition and properties of drilling fluids and core-insulating fluids used for core sampling, depending on the geological conditions of application. nObjects: water-based and hydrocarbon-based drilling fluids, waterless drilling fluids, core-insulating fluids. Methods: analysis and systematization of Russian and foreign experience in theoretical and practical research of core sampling, filtration, rheological and other research methods provided for ISO 10414-1:2008 and ISO 10414-2:2011. Results. The analysis of the world experience in the use of drilling fluids and core-insulating liquids in various geological drilling conditions is presented. The most promising types of drilling fluids for core sampling and core-insulating fluids are determined from the point of view of preserving the initial properties of the rock. An algorithm is proposed for selecting the type and component composition of drilling fluids used for core sampling, depending on the purpose of the work, the category of rocks according to the difficulty of core sampling, and the types of geochemical studies.