Preventing frac hits and well interferences with fast marching simulation using embedded discrete fracture models constrained by poroelastic geomechanical modelling of enhanced permeability
A. Ouenes, A. Bachir, R. Smaoui, C. Hammerquist and M. Paryani
Journal name: First Break
Issue: Vol 37, No 4, April 2019 pp. 49 - 54
Info: Article, PDF ( 687.42Kb )
Investors are not happy. A recent article by a major newspaper (Olson et al., 2019) again highlighted the issue of ‘underperforming’ unconventional wells’ production targets. It notes that financial executives from the oil industry state that predicting well performance is an art rather than a science. Others involved in the management of billions of shale assets offer their opinion by noticing that ‘Geology doesn’t line up with Excel spreadsheets too well, unfortunately.’ These sentiments reflect the perceived state of unconventionals’ technology which is reduced to ‘an art and relying on Excel spreadsheets’. Such comments have dramatic consequences on all stakeholders in the unconventional business. A serious consequence came about shortly after the newspaper article was published: a law firm started an investigation targeting executives of an oil company accused of misleading their investors by providing them with false well performance forecasts. Lawyers and financiers quarreling about such highly technical matters put the burden onscientists and engineers to bring practical solutions to this complex problem. During this decade, great efforts have been made to better understand the performance of unconventional wells, but the challenges are overwhelming, and they evolve as our understanding of hydraulic fracturing progresses. Chief among these challenges, we find the issue of frac hits and well interferences. Frac hits are not a novelty and engineers started trying to understand and model these issues years ago (Lawal et al., 2013; Guindon, 2015; Ouenes et al., 2017; Paryani et al., 2017; Vargas-Silva et al., 2018). Now that these well interferences are affecting the bottom line and Permian shale players see a reduction of 30% to 50% in their child and/or parent well productions (Xu et al., 2019), even plenary sessions in conferences are devoted to this topic (Jacobs, 2019). These gatherings provide a good opportunity to reiterate the need for acquiring data to help improve our understanding of the stated problems while recognizing the need for an interdisciplinary approach to develop solutions (Jacobs, 2019). Unfortunately, the first boom in development of unconventional reservoirs created these myths that are increasingly hard to dislodge from the minds of many stakeholders who convinced themselves that we do not need to collect data, or model earth heterogeneities to improve our engineering designs, that there is a magical number of wells per section, and that it is OK to exchange debt among private equity-backed shale players who buy and sell billions of dollars of shale assets using decline curve analysis (DCA) and type curves. Unfortunately, the tools commonly used by the industry to design their hydraulic fracturing were invented in the 1980s and 1990s and lack the basic components needed to model and optimize the well spacing and hydraulic fracturing of the unconventional wells that will reduce or avoid the impact of frac hits and well interferences. New tools and technologies are needed to form the basis of the practical implementation of new science in unconventional reservoir development.