When developing drilling fluid formulations, first of all, the geological situation should be assessed, the mineral composition should be determined and the properties of the rocks to be drilled should be comprehensively studied.
To study the mineral composition of the planes, along which the core of argillites is destroyed in the process of drilling, samples of different degrees of stability were selected from the section of the Exploration Formation of well 1687 of the Talnakhskoye field.
The practice of exploratory drilling within the field indicates that the overwhelming number of complications and accidents during well sinking is associated with zones of argillized ignimbrites, genetically related to ore mineralization.
Borehole penetration of mudstones of the Exploration Formation of the Talnakhskoye field is often complicated by collapse of borehole walls. The strong tectonic disturbance of the area and high rock pressure due to the great depth (2000 m) of the formation do not fully explain this phenomenon, since both emergency and accident-free wells have been recorded in equal conditions ...
Drilling operations at placer deposits are difficult due to the specific structure of placers. Incohesion, friability of sandy-pebble deposits, their water content, disorderliness, presence of boulders of different sizes complicate drilling in alluvial strata ...
Dolomitization of phosphorite ores increases the content of MqO, which worsens the quality of ores and in some cases makes them substandard, off-balance sheet. Some local areas of the deposit are subject to dolomitization. Naturally, it is desirable to identify them in the process of exploration work and exclude them from the balance reserves. ...
The lithologic-paleophytologic substantiation of the Lower Permian coal-bearing sediments of the Minusinsk basin was made on the basis of a detailed lithologic-facial and paleophytologic description of the section of the Izikhskoye field, where the productive stratum (1750 m thick) is most fully developed and where sediments in the age range from Carboniferous to Permian are traced.
At the Kayerkanskoye field, a comprehensive study was carried out of the alteration of coals in seams X and IX (Daldykan Formation, P ) at contacts with dolerite dikes in order to determine the nature of the relationship between the size of intrusions and the near‑contact zones of altered coal, as well as the characteristics of contact‑thermal metamorphism of the coal. At different distances from the contacts with dikes, changes in the values of the main coal parameters were traced: ash content, volatile matter yield, calorific value, carbon content, specific gravity, reflectance, and microhardness.
