Evaluation of Well Completions in the First Steam Flood Pilot Performed in an Unconsolidated Sandstone Reservoir in Kuwait

Abstract

A steam flood pilot in unconsolidated sandstone reservoir is being performed for the first time in Kuwait with inverted 5 spot configuration and pattern areas of 5 and 10 acres and a total of 26 wells. Prior to the steam flood, two cyclic steam stimulation (CSS) cycles were applied in all wells. This paper provides a detailed description of the well completions and challenges during CSS and the ongoing steam flood operations. Different designs of well completions were evaluated for injection and production wells. Injection well completion designs were evaluated by comparing actual vs. expected injection rates and review of operational issues. Production well completion designs were evaluated by comparing peak production rates, decline rates and sand issues. Two different injection well completion designs were evaluated. In the 5 acre, the steam injectors target two sand sub layers and hence initially completion were designed with downhole steam splitters but later removed due to injectivity issues. In the 10 acre, steam injectors target a single sand layer using packer less completions. Production wells were completed with 7" case hole perforated with 3.5" completion tubulars and insert sucker rod pump (ISRP). Sand screens were installed in some producers, but 50% of them were removed later due to very sharp production declines. When the screens were pulled out, screens were found completely plugged with debris. The responses from the 2 CSS cycles were very good with average peak well production rates of higher than 100 BOPD. The steam flood pilots have been running for around 6 months and the preliminary results are very encouraging. There is a clear initial response to steam flood, characterized by an overall increase in gross and oil production. The experience and the lessons learned from the CSS and evaluation of initial response of steam flood pilots are very useful in risk identification and mitigation applicable to the commercial phase.