Effect of produced water on indicators of drilling muds

The article deals with the problems associated with the ""invasion"" of produced water into the composition of drilling muds in the process of drilling wells in anomalous conditions. It is marked that various types of complications, particularly, debris and collapses, emersion and adsorption cause very serious problems in the well construction, for the elimination of which large investments are required. For example, drilling mud influenced by produced water was used in some fields of the Republic. The electrical conductivity parameter was estimated based on the carried out research. This indicator allows evaluating the physical-chemical properties of the drilling mud before and after the treatment with formation fluid. It should be noted that the good electrical conductivity of the drilling mud is also significant for geophysical surveys. In order to preserve required properties of the drilling mud under conditions of ingress into the composition of the produced waters, the treatment of the drilling mud with salt-resistant polymeric reagents is recommended.

Poly(vinyl pyridine)s: A Versatile Polymer in Catalysis

The PVP and its derivatives have been broadly applied in polymers, organic syntheses, and catalysis processes. The crosslinked PVP is a well-known polymer support for numerous reagents and catalysts. Cross-linked PVPs are commercially available polymers and have attracted much attention over the past due to their interesting properties such as the facile functionalization, high accessibility of functional groups, being nonhygroscopic, easy to prepare, easy filtration, and swelling in many organic solvents. A brief explanation of the reported applications of PVPs in different fields followed by the discussion on the implementation of methodologies for catalytic efficiency of PVP-based reagents in the organic synthesis is included. The aim is to summarize the literature under a few catalytic categories and to present each as a short scheme involving reaction conditions. In the text, discussions on the synthesis and the structural determination of some typical polymeric reagents are presented, and the mechanisms of some organic reactions are given. Where appropriate, advantages of reagents in comparison with the previous reports are presented. This review does not include patent literature.

MAINTENANCE OF FILTRATION AND CAPACITIVE RESERVOIR PROPERTIES DURING TEMPORARY ISOLATION

The article provides the analysis of factors affecting the reservoir properties (filtration and capacity) during repair works. It is revealed that the maintenance of filtration and capacitive reservoir properties is ensured by high-quality blocking and unblocking the reservoir, as well as by prevention of clay material swelling. Solution of these problems is possible through proper selection of the bridging agents (nature, type and fractional composition) used in the blocking composition, and various functional additives (salts, polymeric reagents and surfactants). Furthermore, the reasons of clay minerals swelling and various ways to prevent this process are analyzed. It is determined the peculiarities of clay minerals structure are essential for their properties, and in particular, their ability to swell.