An innovative completion technique is being used in wells that require sand control to help eliminate high skins and increase pay, or effective kh, and thus improve well productivity. The success of this technique lies in concentrating high conductivity proppants m the near-wellbore region. This is accomplished by creating and propping a properly designed, length limited, hydraulically-induced fracture in conjunction with an annular water gravel pack. The result is a highly conductive flow path from virgin formation, through the near-wellbore damaged zone, and into the wellbore that also controls formation sand.
The limited fracture is designed with the intent of preserving the integrity of the near well gravel pack since this aspect is critical to realizing the full benefits of the fracture. Industry data indicates that optimum gravel packing is achieved with a brine proppant carrier. In some cases, the entire operation (limited fracture and gravel pack) may be completed with brine. However, in other cases, as discussed here, the high leak-off associated with brine is reduced by a product developed to overcome the excessive fluid leak-off. Brine following this material provides the carrier medium for proppant placement in the fracture and for the gravel pack.
The process is described and examples of field applications and results will be presented.
The combination of a hydraulically-induced fracture with a gravel-pack completion has been termed a "frac-pac" The primary purpose of a frac-pac completion is to help eliminate the high skins often associated with cased-hole gravel packs by providing a highly conductive flow path through the near-wellbore formation damaged zone.