Estimation of drill mud composition impact to porosity and permeability of terrigenous reservoir rocks (on example of Northern-Yugyd oil-gas-condensate field)
Last years, the highly mineralized polymeric drilling muds (DM) have been used for initial drilling of productive layers in the wells. Positive reaction of reservoir rock properties to muds with polymeric additives is explained by minimal penetration of DM’s filtrate into a reservoir (due to poor water return in case of highly mineralized polymeric DMs), and low mudding of a near-well zone (due to light status of a solid phase in a DM).Analysis of previous research information on DM parameters shows that when drilling changes over to highly- mineralized polymeric muds, there are challenges related to information capacity of well logging, and authenticity of values calculated using these logs. Besides, it is widely thought that some chemical agents of the polymeric DMs can affect the physical properties of core including rock wettability, capillary measurements, etc.The manner of DMs with different foreign and domestic chemical agents affecting the values of the quantitative parameters being calculated using core measurements and well logs was estimated. Following the results of еру laboratory tests the influence of different DMs to wettability, residual water saturation, and electric resistivity of a reservoir. On the basis of experimental research it is concluded that DMs with domestic components can be applied in field conditions within the framework of import substitution.