Enhancing the Understanding of Hydraulically Fractured Well Performance in Gas Fields Using Production-History Matching-Case Studies

Abstract

In most cases several folds of increase in production after a fracturing treatment is sufficient testimony to the success of the technology and its application in the particular well or field. A cursory look at a post-frac, pressure transient analysis (PTA) will show a stimulated well condition and validate the achievement. For a proper assessment of well potential this approach may be inadequate. The fracture geometry, conductivity, phase flow through the reservoir, reservoir quality, completion practices and pressure behavior under the boundary conditions all contribute to a well's performance. With all these factors considered, the post frac production results may be significantly different from expectations. To encompass this, the preferred methodology would be to benchmark the production from different fractured wells to have a valid comparison and then optimize the methods. Production-history matching through reservoir simulation is a very effective tool in meeting this challenge. Many subtle features of the reservoir get highlighted in relation to hydraulic fracturing with the dominant component being the fracture itself. This paper examines several successful wells, which unexpectedly fell below the benchmark. The study investigates whether the hydraulic fracture underperformed or the post-frac activities contributed to low well deliverability. Conventional hydraulic fracturing and the newer technique of channel fracturing were part of this analysis. The post-frac flowback procedures had a significant impact on the productivity of the wells. The presence of condensate brought its own set of challenges. In the long term, it was also interesting to note how the wells recovered after these damages. This paper will provide an insight into this investigation.