Recent in Advances in Hydraulic Fracturing – More than just Modeling and Simulation

ABSTRACT: This is an increasingly “mature” industry where we have an abundance of resources that justifies a moderately low recovery factor. The primary obligation then has been cost reduction – and this can trigger advances or impede them and may not optimize production. Over the last couple of decades, some of the greatest advances in understanding fracturing have come from large-scale field experiments and the deployment of new instrumentation, particularly fiber optics. Fiber optics, sealed wellbore pressure measurements, and other diagnostics now give an unprecedented view at where fractures are going and what they look like. Interference tests, downhole pressure measurements, geochemical fingerprinting, and other injection/production data allow us to infer proppant location and the shape of depletion. These have been supplemented by other notable monitoring efforts such as nanoparticulate tracers and high-frequency surface pressure evaluations. Possibly the most important trend in hydraulic fracturing over the past decade has been a movement towards high-density plug and perf fracturing with limited-entry completion. Diagnostics show that high-density fracturing creates a maximum propped fracture area and overcomes flow localization caused by stress shadowing. Designs based on uncemented liners and ‘natural fracture complexity’ and/or propped conductivity have become scarce as they have been “outcompeted on performance.” Proppant volume per ft of lateral has increased greatly over the past decade. From an equipment perspective, there has been a movement to electrified fleets. It is difficult to say whether these will become routine or an endangered species. Regardless, equipment efficiency has improved substantially, with increased reliability, control, and reduced emissions. Maintenance has been improved by electronic monitoring, service duty tracking and processing, and consequently prescribed proactive intervention and maintenance. Some commodities have remained relatively unchanged. Handling of proppant has continuously evolved, and lower quality proppant is tolerated, legitimately, at least for short-term production. Water handling has evolved and reuse rather than disposal has gained some favor. Treating fluids are slickwater or lightly viscosified with HVFR (high viscosity friction reducer dosage). Artificial intelligence and machine learning are the talk of the town – and are here to stay. Critics might argue that they are impeded by the lack of universally reliable and complete information. Proponents will say that the experiential data would not be evaluated otherwise and that we are leaving easy money on the table. The increase in computational power and client-server facilities have re-invigorated interest in studying initiation, near-wellbore mechanics, and propagation coupled with the transport and placement of proppant. As a cost-driven industry, we will see increased activity in certain plays – maybe the Utica and the Haynesville are examples. Larger-scale treatments and lower-quality proppant are and will remain common. There is continued interest in understanding proppant distribution, particularly hindered settlement. Refrac’ing, as well as secondary and tertiary recovery, have seen renewed interest, and the prospects of international low-mobility development remain strong.