Research on the solid contents of mineralized drilling mud for production wells in Eastern Siberia

UDK: 622.244 .4

DOI: 10.24887/0028-2448-2021-2-62-66

Key words: grain distribution, mineral composition of solid contents, drilling mud cleaning system

Authors: R.R. Akhmetzyanov (Tyumen Branch of SurgutNIPIneft, Surgutneftegas PJSC, RF, Tyumen), K.A. Kostenevich (Tyumen Branch of SurgutNIPIneft, Surgutneftegas PJSC, RF, Tyumen), V.N. Zhernakov (Tyumen Branch of SurgutNIPIneft, Surgutneftegas PJSC, RF, Tyumen), A.D. Zakharov (Tyumen Branch of SurgutNIPIneft, Surgutneftegas PJSC, RF, Tyumen)

The performance of drilling fluid depends not only on the composition and concentration of its components, but also on the results of complex physicochemical interactions between the fluid and the wellbore. Such interactions are based on the specifications of the geological section. Also, their nature and intensity are influenced by technology and drilling equipment. Our aim was the research on finely dispersed solid contents (solids) and the way they affect drilling mud. The article presents the results of detailed study of solids in the drilling fluid. Actual geological and technical factors and their influence on the mineral, grain distribution and concentration were examined. Estimation of the solid contents impact to drilling fluid functionality is given. The analysis was carried out taking into account the practical experience of drilling production wells in terrigenous productive deposits in Eastern Siberia. Solids mainly consist of carbonate rock particles. In addition, solids contain particles of quartz, anhydrite, and clay minerals. Mineral composition of solids and the way it changes during drilling generally corresponds to the accepted geological and geophysical information about the section. The relative percentage of carbonate solids in the drilling fluid while drilling in terrigenous sediments slightly decreases to the well bottom and depends on the profile of well. The content of quartz, anhydrite and clay minerals increases moderately with deepening of the well. The mineral composition of solids is influenced by the geological section, the profile of the well and the type of applied rock-cutting tool. The sizes, primarily the maximum ones, and the concentration of solids depend on the removal section equipment and the technology of preparation and application of drilling mud. It is shown in the Eastern Siberia the mineralogical composition of solids is inert to the drilling fluid. The grain distribution and quantitative content of solids can have a negative impact on the functionality of drilling fluid.