The evolution of the fracture stimulation in the Novogodnee Field in Western Siberia is detailed in this paper. The target interval is the JV1 interval of the Jurassic formation. This is a highly productive interval producing at a typical pre-stimulation rate of approximately 70 ton/day (500 bbl/day) with a high volume of gas. Significant increases in the production rate can be achieved by the successful application of fracture stimulation. Unfortunately, this was not the initial case in the field because most of the fracture treatments screened-out early in the fracturing process.
Even though the initial fracture treatments did not achieve the designs results, they did yield important information. First, there were increases in production resulting from the fracture treatments, indicating there is significant potential of higher production from successfully performing fracture stimulation. Also diagnostic injections were performed prior to the main fracture treatment to measure the critical fracture parameters.
Therefore a project was initiated to perform a detailed analysis of these fracture treatments to understand the cause of the early screenouts. As a result of this study the fracture treatments were redesigned leading to successful completion of the fracture treatments. The proppant volumes successfully placed have been as high as 213 tons (470,000 lb) of proppant. This is a significant increase over the initial treatments that screened-out with an average proppant volume of 36 tons (80,000 lb).
The resulting production increase from the successful treatments has been significant. The folds of increase in productivity have increased from 1.9 on the fracture treatments with the early screen-outs to an average on 3.0 folds of increase on the recent wells. The highest productivity increase was 3-fold. These folds of increased productivity have resulted are the equivalent post-stimulation production rates increasing from 130 tons/day (950 bbl/day) to 220 tons/day (1,600 bbl/day). Well J is an injection well as part of the pressure maintenance program. Following the fracture treatment the injection rate of fluid volume is equivalent to 1,000 tons/day (7,300 bbl/day). If the interval had not been fracture stimulated the rate would have been significantly less.
Author(s): N. Kazykhanova, A. Gayfullin, and D. Senchenko, Sibneft-NNG, B.M. Davidson; Carbo Ceramics, I. Faizullin
Paper Number: SPE 102393