Performance Prediction and Benchmarking Using FIRM (Forecasting Through Inferred Reservoir Modelling) for Bakken, Wolfcamp and Bone Spring Plays
Use of Arp's equation for forecasting well performance in shale and tight oil plays when production history is less than five years can result in errors in EUR estimates of 20-100%. Decline curve analysis (DCA) has worked for conventional reservoirs since the production response is primarily dependent on drive mechanism and not convoluted by the hydraulic fractures that alter the near wellbore region. However, in shale plays, production characteristics are heavily influenced by the complex hydraulic fractures. Since completions have been constantly evolving, individual wells even in geologically similar areas have significantly different flow profiles. Therefore, forecasting well production with decline parameters extracted from older wells and applying such parameters across newly drilled wells can lead to large errors. We introduce a semi-analytical technique for well performance prediction and reserve estimation called FIRM analysis (Forecasting through Inferred Reservoir Modeling). This physics based tool uses data available in the public domain to effectively infer reservoir, fluid and completion characteristics using novel reservoir flow models, exhaustive reservoir simulations and artificial neural network. Since performance forecasts are based on diagnosed rock, completion and fluid properties at a well level, FIRM yields better estimates of well performance. It also provides play-wide objective benchmarking of completion effectiveness and can also estimate the impact of spacing on EURs. Since FIRM relies only on data that can be sourced from the public domain data, it is a very powerful method that intelligently selects the representative DCA parameters based on the diagnosed reservoir, fluid and completion parameters. FIRM also considers the effects of various drawdowns and therefore accounts for operational issues such as choking very effectively. Using our analysis for the Bakken, Wolfcamp and Bone Spring plays, we compare long-term well performance, EURs, production forecasts and economics obtained from FIRM with traditional DCA. We demonstrate that FIRM yields superior estimates even when short production histories are available. This is particularly important in today's M&A market because, several large transactions in the Permian are being based on analysis of few wells with limited production histories. FIRM also allows for estimating upside from improving completions and optimize wells per section to maximize NPV.
AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017