The Results of Seismic Monitoring of Hydrofrac Operations in the Yuzhno-Russkoe Oil-and-Gas Condensate Field

The Yuzno-Russkoe oil-and-gas condensate field is located in the Krasnoselkupskiy area within Yamal-Nenets autonomous region of Tyumen province. The layer Т1–2 of Turonian stage is the target gas-bearing resevoir composed mainly of siltstones and clayey siltstones.

Sequential hydrofrac operations were performed in a sub-horizontal production well. A vertical appraisal well located in the direct vicinity of the latter allowed for hydrofrac monitoring using two seismic arrays: borehole and surface ones. Besides, additional field trials were carried out using the active seismic exploration scattered-wave method (side-view seismic locator technology) making it possible to analyze variation of fracturing in time during a month. A large data set of independent seismic information was acquired and analyzed. The uniqueness of performed investigations lies in the fact that the results of microseismic monitoring were processed by three companies using different algorithms, thus allowing for comparative analysis of the results and formulation of definite conclusions about the effectiveness of the algorithms.