부산대학교 도서관

Carbonate reservoirs are typically characterized by low reservoir property values. In such conditions, economically viable oil production is achieved by carrying out stimulation activities at the wells. Under the conditions considered in this work, the most effective stimulation method is hydraulic fracturing. This work is based on the accumulated experience of hydraulic fracturing in carbonate reservoirs of the Perm Krai. To solve the tasks set, the authors comprehensively use the materials of field, well tests and geophysical (microseismic) studies. Based on the studies performed, it was found that during hydraulic fracturing of carbonate reservoirs, fractures of various geometries—simple and complex—are formed. Simple geometry is understood as a classic fracture—two symmetrical wings beginning at the intersection “reservoir—well.” Complex geometry refers to a network of fractures that breaks the rock into blocks, which is highly consistent with the Warren-Root model. It has been established that the formation of a complex geometric fracture network is due to the interaction between hydraulic fractures and natural rock fractures. Rock fractures of core samples were studied by computed microtomography and electron microscopy methods. Also, according to the well tests treated using the Warren-Root method, we have shown for the first time that the absence of the intersection of the zone of localization of microseismic events in the process of monitoring hydraulic fracturing does not imply poor-quality research. The reason for the localization of microseismic events at a distance from the well is the formation of complex geometric fractures. It also proves that the formation of a complex fracture network during hydraulic fracturing is preferable, which contributes to obtaining additional oil production. A matrix has been obtained that shows the influence of the shape of the formed hydraulic fracture on additional oil production.