ISSN 2658–5782
DOI 10.21662
DOI 10.21662
Electronic Scientific Journal
Today, oil production is a complex and high-tech process that is constantly evolving and improving. One of the pressing problems in the oil industry is the decline in the flow rate of most production wells and, as a consequence, an increase in the production of hard-to-recover reserves and the need to process the bottomhole zone in order to improve its reservoir characteristics, for example, creating hydraulic fracturing (HF) cracks. These processes require studying the state of the formations and obtaining information about the fracture geometry. This paper presents one of the possible methods for studying formations and HF cracks based on the excitation of natural oscillations of a liquid column in a well and the analysis of the wave characteristics of the oscillations. Based on a theoretical model of natural oscillations of a liquid column obtained as a result of a hydraulic shock, the effect of the conductivity of a hydraulic fracturing crack on pressure disturbances in the formation and the crack itself was studied. An analysis was made of the dependence of pressure on time and changes in the amplitude of pressure oscillations at various points in the formation and HF crack.
well,
oil,
hydraulic shock,
natural oscillations of liquid,
oscillation frequency,
damping coefficient and decrement
The development and further modernization of acoustic methods for geophysical wellbore research has been a challenging yet necessary task for many years. Many researchers in both scientific and practical fields are interested in advancing such methods to obtain information about rock formations. Acoustic spectroscopy is one of the techniques that allows for the examination of the formation and provides insights into its reservoir characteristics. An acoustic wave, generated naturally or artificially, during the operation of oil and gas extraction systems, carries important indicators of both the formation and the hydraulic fracture. In this work, we assume that the fluid vibrations are generated by a hydraulic shock in the wellbore.
The primary objective of this study is to analyze the propagation of fluid vibrations in the formation and in the hydraulic fracture for varying fracture conductivity.
Key results. The study demonstrates how, over time, the pressure disturbances at specific points in the formation and fracture change with different fracture conductivity values.
When examining the vibrations in the formation, it is clearly evident that the fracture conductivity significantly alters the amplitude and the time of complete damping of the acoustic wave. It is important to note the influence of the hydraulic fracture because, as its conductivity increases, the propagation of vibrations into the formation decreases noticeably. The analysis of vibrations in the fracture also clearly shows that changes in fracture conductivity lead to observable transformations in amplitude and damping time. The study reveals that the higher the fracture conductivity, the longer the vibration damping time, and the vibrations penetrate deeper into the hydraulic fracture.
Conclusion. A brief review of acoustic methods used in the operation of oil and gas wells is provided. These methods are in high demand and widely applied in the oil extraction industry. The influence of fracture conductivity on the disturbance dynamics in both the formation and the hydraulic fracture has been analyzed. It has been established that the fracture significantly alters the propagation characteristics of vibrations, both in the formation and within the fracture itself.
