Production from unconventional resources is from permeability challenged reservoirs. Such reservoirs vary from conventional oil and gas trapped in ultra-tight or tight formations to the source rock plays. Tight reservoirs are an extension of the uneconomic conventional plays with the promise of economic production through hydraulic fracturing and multistage stimulation. The tight and ultra-tight reservoirs are referred to as hybrid reservoirs. The production mechanism of hybrid reservoirs is similar to that of unconventional source /shale plays but the reservoir performance differs from that of source rock plays. The success in the development and production from the tight reservoirs in the United States has been mostly through trial and error methods. During the last decade, improvement and advances in the areas of reservoir evaluation, well completion methods, hydraulic fracturing, and operational efficiencies resulted in the economic production of gas/oil from the hybrid reservoirs. This paper addresses the popular question of using a successful hybrid reservoir production as an analog for the development and production of hybrid reservoirs in other basins of the world. Two of the tight reservoirs from North American oil & gas fields are analyzed as case studies to determine the key factors in reservoir evaluation and completions that drive success for long term production. Specific learnings from the reservoir performance and production from these fields are identified and its usefulness as analog is discussed. The learnings are expected to accelerate the understanding of a new reservoir and focus not only on similarities but also to understand the differences that play into the equation. It will also address how best to analogize hybrid reservoirs and avoid the pitfalls of transferring analog mindset that may have worked for the conventional field development.
AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018