Selection of the Optimal Technology of Re-Fracturing on Horizontal Wells with Multi-Stage Fracturing at the Field M

In order to achieve economical profitability from hydrocarbon production from formations a lot of horizontal wells are stimulated by means of multi-stage hydraulic fracturing operations. However, as analysis of production data shows duration of effect after this kind of stimulation is not long, average duration is about 9-10 months. This decline in well productivities leafs to necessity of re-fracturing. Despite the causes of productivity decline, whether it is failures during primary stimulation or natural reservoir depletion, re-fracturing operation allows to restore productivity indexes and attract new recoverable reserves. Basically, two ways to perform re-fracturing are suggested, they are: 1) re-fracturing in existing perforation intervals., 2) re-fracturing by establishing additional fractures between existing ones. Based on the achieved analysis results, a set of recommendations can be made: 1. Using more aggressive design for re-fracturing operation gives higher increase in well’s productivities relative to design of primary stimulation 2. Re-fracturing in existing perforation intervals is not effective with comparison to establishing additional fractures 3. Influence of interference between additional and existing fractures should be taken into account prior to selection quantity of new fractures at re-fracturing operations