Study of the interrelation between the geneseses and reservoir properties of productive series deposits in Pirallahi field on the basis of oil-field geophysical data

Abstract

Petrophysical properties of reservoir rocks are also influenced by a certain relationship between the lithological-mineralogical composition of rocks and the reservoir properties. For this reason, the study of the relationship between the genesis of Productive Series deposits and reservoir properties provides a basis for predicting the regularity of distribution of sand particles throughout the field and making some judgments about the development of porous and permeability zones. This, in turn, is of more scientific and practical importance while identifying variation of reservoir properties of rocks in sedimentary cover. The paper offers a rational approach that determines the relationship between the genetic origin of sedimentary rocks and their reservoir properties and expounds on the study results. As a research area, we chose «Qirmakiustu clay», «Qirmakiustu sand», Qirmaki and Qirmakialty series of Productive Series sediments studied in sections of conventional X1, X2, X3, X4, and X5 well sections located on one profile of Pirallahifield and their sedimentation environment and facies origin have been studied in more detail. In the section of well under the study, the average value of effective porosity (Kav.p.), average thicknesses of sandy and clayey layers (Hav.cl., Hav.sand), and the relative thickness of sand bodies (Hrel.sand) were calculated for intervals at which the facies of flow, bar, and beach plain origin were identified. The curves of these parameters’ variation across the profile were drawn. At the same time, the curves of thicknesses of flow, bar, and beach plain origin facies were drawn for the interval identified for each well section. These curves were compared and analyzed separately for each facies. A study of the sedimentation environment and genesis of sedimentation and a comparative analysis of lithofacial and reservoir properties may be important for accurately evaluating oil and gas presence in the study area.