Natural fractures complicate the development and production of hydrocarbon reservoirs. Such fractures can typically be smaller than seismic wavelengths and are, therefore, difficult to detect, delineate, and describe. Advances in seismic processing and visualization techniques are helping to reveal key trends concerning small-scale faulting and fracturing. This information is used to place wells inside fractured formations and better manage fractured reservoirs.
An article in the Summer 2012 issue of Oilfield Review, “Seismic Detection of Subtle Faults and Fractures,” describes successful characterization of fractured systems by applying these new seismic methods; results have played a vital role in well-placement and reservoir-management decisions. One example from Pennsylvania, USA, describes the optimal placement of wells for an underground gas storage reservoir that has shear zones controlling fracture orientation and distribution. In another example, for a North Sea fractured chalk reservoir, advanced seismic attribute analysis uncovers details of a complex fault system. Finally, in a UAE giant carbonate field, fracture network modeling helps represent fractures that are too numerous to be picked by hand but are known to affect the movement and sweep of injected fluid.
Read the full article by visiting the Oilfield Review Web site.
Aarre V, Astratti D, Al Dayyni TNA, Mahmoud SL, Clark ABS, Stellas MJ, Stringer JW, Toelle B, Vejbæk OV and White G: “Seismic Detection of Subtle Faults and Fractures,” Oilfield Review 24, no. 2 (Summer 2012): 28–43.