Stabilizing wellbores in unconsolidated formations for fracture stimulation

A wellbore stabilization system incorporating fracture stimulation has been developed and modeled in the laboratory for unconsolidated and dilatant fo rmations. The profile of resin leakoff and penetration depth into the forma tion is relatively dependent on the pattern of perforations. Use of soluble particulates as a fluid-loss control agent proved to be effective in diver ting resin, resulting in a uniform distribution of resin over the highly va rying permeability interval. A significant drop in permeability of the near -wellbore area occurred after the resin treatment, but high productivity wa s re-established by connecting the wellbore with the untreated formation th rough highly conductive fractures. During companion testing of the resin-co nsolidation technique, the unconsolidated sandpack became a competent forma tion with compressive strength in excess of 2,000 psi. This competent mater ial will be affected less by high drawdown pressures and stress cycling dur ing production/shut-in cycles. The injection pressure required to fracture the consolidated wellbore showed an increase when compared to that of the u ntreated wellbore. Stress levels existing in the formation were shown to co ntrol the number and direction of generated fractures by passing the consol idated zone.