Hydraulic Fracturing To Improve Production

Tech 101 - Consultant Ali Daneshy presents an overview of hydraulic fracturing. Reasons for Hydraulic Fracturing In their natural state, most oil and gas wells do not produce at their optimum level, but hydraulic fracturing can address multiple challenges to efficient production. Radial flow from the reservoir into the wellbore is not an efficient flow regime. As the fluid approaches the wellbore, it has to pass through successively smaller and smaller areas. This causes "jamming" of the fluid and reduction in flow. If one were to complete the well such that the radial flow changes to nearly linear, then the change in flow pattern will increase well productivity. A properly designed and executed hydraulic fracture can change flow from radial to nearly linear (Fig. 1). Nearwellbore permeability in most formations is reduced by drilling, cementing, and completion operations. Theoretically, one can show that this permeability reduction causes substantial reductions in production rates (Fig. 2). Hydraulic fracturing can extend the reach of the wellbore beyond the damaged area and abate its negative effect on production. Hydraulic fracturing extends the reach of the wellbore far into the formation. Production is therefore controlled by the properties of the average reservoir reached by the fracture, instead of the much smaller near-wellbore region. The net effect is a reduction in the risk of drilling into less- or nonproductive zones.