Many gas reservoirs in the central Adriatic Sea, offshore Italy, are formed of laminated, low-permeability, dirty sandstones, with as much as 50% clay content. Initially, wells were completed with gravel packs, but the nature of the formations caused productivity to decrease in some gas fields because fines plugged the gravel packs. In the past few years fracpacks have been used to alleviate the fines migration problem. However, there are many gravel-packed wells which are either sanded up and shut in or underperforming because fines have plugged the gravel-pack screens. These wells do not currently justify the expense of an immediate full rig workover.
A candidate zone was selected to evaluate the viability of a screenless completion technique for competent sand control. We placed a highly conductive tip-screenout fracture in the zone, using recent innovations in fracturing fluid technology and proppant flowback control additives, to eliminate sand production. Successful implementation of this technique was confirmed by posttreatment production more than 2.5 times the normalized rate of the initial gravel-pack completion. No formation sand or proppant was produced back to surface during production. The screenless completion technique provided a cost-effective and reliable rigless rehabilitation technique.