MATHEMATICAL MODELING OF ROCK CRUSHING AND MULTIPHASE FLOW OF DRILLING FLUID IN WELL DRILLING

The aim of the work is a mathematical modeling of the rock crushing during drilling and removal of the drilling cuttings (sludge) to the surface by drilling fluid. The process of rock destruction is described using the mathematical theory of fragmentation. The distribution of sludge particles in size and mass depends on such factors as the properties of the drilled rock, the rate of penetration, the type of bit, and the output power. After the formation of sludge, the process of its removal to the surface is modeled. The drilling fluid together with the rock particles is considered as a heterogeneous multiphase medium in which the carrier phase – the drilling fluid – is a non-Newtonian fluid. The flow of such a medium is described using a mixture model in the framework of the multi-fluid approach. This results in a system of nonlinear partial differential equations, for which a new closure relation is derived. To solve the system, the SIMPLE algorithm is used. As a result, the flow properties are studied with the inclusion of particles of various sizes. In particular, for particles of small size due to the action of plastic stresses in a non-Newtonian drilling fluid, an equilibrium mode arises in which the particles move with the drilling fluid without slipping. This is the fastest mode of delivery of sludge to the surface. The specific dimensions of such particles depend on the parameters of the drilling process. In particular, the appropriate size range can be adjusted by changing the parameters of the drilling fluid

Development of the Nanotechnology for Wellness Products “NatureSuperFood” Fruit and Vegetable Ice­cream Sorbets with a Record Content of Biologically Active Substances

This paper reports the newly proposed and devised technique and nanotechnology for the wellness products “NatureSuperFood” ‒ fruit and vegetable ice cream – sorbets ‒ that make it possible to obtain a product with unique features. The new types of sorbets are in the nano­dimensional form and are distinguished by a high content of natural biologically­active substances from fruits and vegetables (β­carotene, chlorophyll, phenolic compounds, anthocyanins, ascorbic acid, etc.). In addition, there are characterized by the high content of soluble pectic substances, which act in the sorbets as natural thickeners and stabilizers. That provides for a possibility to eliminate the need to use synthetic additives.Nanotechnologies of the wellness products “NatureSuperFood” ‒ fruit and vegetable ice cream ‒ are based on the application of the cryogenic “shock” freezing and the finely­ground fruits and vegetables as an innovative method for structure formation and obtaining sorbets with a record content of BAS. A combined effect of the specified factors leads to the activation and extraction of hidden BAS from fruits and vegetables into free form, as well as the transformation of pectin from the inactive form to the active form. A special feature of the sorbet production technologies is the use of natural ingredients only (fruits, berries, vegetables), as well as the absence of artificial food additives (stabilizers, thickeners, emulsifiers, synthetic dyes, etc.). The technologies make it possible to not only retain vitamins and other BAS from original raw materials in sorbets, but to extract from raw materials the hidden, inactive, bound with biopolymers and minerals in nanocomplexes, forms of BAS into the free, easily digestible nanoform. Mass fraction of BAS in sorbets is 2.5…3.5 times larger than that in fresh fruits and vegetables. In addition, the technologies make it possible to more efficiently (by 3.0...5.0 times larger than in fresh raw materials) extract and transform into a soluble form (by 70 %) those pectin substances that are in the inactive hidden form in fruits and vegetables.The developed nanotechnologies and formulations of wellness products “NatureSuperFood” include 3 types of sorbets made from chlorophyll­containing, carotene­containing, and anthocyanin­containing fruits, berries, and vegetables. Natural raw materials act as a “five­in­one” in the manufacture of sorbets: a source of BAS, a thickener, a structure­forming agent, coloring, and flavoring. The new types of sorbets are in the nano­dimensional form; they outperform known analogs in terms of BAS content. The technological production modes of ice­cream­sorbets were tested at the bench semi­industrial equipmen