No abstract

In many Brownfield developments, toward the end of a well's life cycle, the primary production zone(s) commonly waters out or depletes, or the well sits idle with no alternative means of returning back to production. At this stage, as a normal course of action, the wells are re-evaluated for potential reserves that might have been bypassed during the original completion. For zones that do not appear promising or could be marginal in terms of delivery, the recompletion costs can be prohibitive. It is in such situations that "cement packer" completions performed rigless in offshore environments provide an economic alternative to workover operations. This technique can be cost-effective and has the potential to increase the producing life of a well. This paper describes the successful application of a "cement packer" to recover bypassed reserves located above the production packer in an offshore field in the Mediterranean Sea. The technique allows zonal isolation between the various upper zones by placing cement slurry in the production tubing and casing annulus.Conceptually, it might appear simple to perform such a job, but the planning and execution must be well formulated to ensure well integrity is maintained at all times. In this case history, the challenges of executing the job were examined from many different angles (i.e., high angle well, small platform, short weather window for operations, and multiple job sequences). The average cost was only 20 to 60% of conventional workover jobs, which is a savings of up to USD 400,000. The production results have also been encouraging. These successful results have revealed opportunities for reactivating many more shut-in wells with bypassed reserves that are currently considered economically marginal. BackgroundWell BB-1 was drilled in 1997 during the exploratory drilling phase of the Petro-Said field in the Mediterranean Sea, offshore Egypt (Fig. 1). The well was completed in 2005 in the Kafr el Sheikh Anomaly-4 (An-04) level from 1710.0 to 1755.0 m with an internal casing gravel pack to help prevent formation sand production. With time, the primary production zone (An-04) depleted and watered-out, and it remained idle for further development. There were a few limited shallower zones (An-02 and M1) higher up in the wellbore, above the production packer, that appeared worth investigating. These zones were small sands with possibly low static bottomhole pressure; otherwise, scarce information was available regarding their production capability. The upper completion string consisted of a 4.5-in. chrome tubing (Fig. 2) run to surface on a 9 5/8-in. completion packer set at 1648 m. A landing nipple was available in the string at 1645 m and a subsurface safety valve at 215 m. The lower completion included a gravel-pack packer set at 1675 m and a gravel pack screen and gravel across the perforated interval at 1710 to 1755 m.The recompletion of this well using an offshore workover rig would have entailed killing the well, isolating the lower completion, pulling the upper co...