"Cement Packer": An Innovative Technique to Recover Reserves Above Packer Without Re-completion

Abstract

Abstract Reserves with marginal production potential are often by-passed during the early stages of reservoir development. Re-evaluations of well logging data has resulted in the discovery of potential reserves located above the production packer that were not previously considered in the initial completion strategy. Conventional completion techniques required a workover to re-complete to these potential zones. However, due to marginal reserves or the presence of production from existing zones below the proposed re-completion (ex: a dual completion where the long string is still producing while short string is shut-in), a workover is not a good economic option to recover these zones. A novel technique of cement packer has been successfully developed in Offshore West Java (OWJ) field to re-complete these zones without pulling out the existing completion. Pressure isolation of potential zones is accomplished by placing cement in the tubing-casing annulus above the production packer. This cement then acts as a new production packer further up the wellbore. Conventional or oriented perforating is then used to complete the well in the new productive intervals. The advantages of this technique are it is inexpensive (rigless), there is no need to wait for other tubing strings in the well to deplete to their economic limit before re-completing up-hole and –most importantly-access to and production from lower completion is not affected. To date, a total of 9 wells have been reactivated using this technique to recover productive zones located above the production packer. The average cost was only 20-60% of conventional workovers and savings of up to US$ 800,000 have been achieved. These successful results have brought new opportunities for reactivating many more shut-in wells with by-passed reserves that are economically marginal.