Rigless Recompletion Using Cement Packer – EROTON E & P Experience

Abstract

With global Oil prices still recovering from the down cycle and coupled with high cost of drilling new wells, EROTON E & P has devised strategies to manage declining oil production, increase oil production from her existing assets and add new reserves through team integration and improved subsurface data management by using fit-for-purpose technology (cement packer) and other collaborative tools. Cement packer technology is a relatively fast-to-deploy and cost-effective rig-less intervention technique that allows easy access to hydrocarbon reserves behind pipe which are located above and between production packers in wells where the existing completion intervals have reached their economic limit. This technology can be used to separate a new zone earmarked for completion from other intervals including non-hydrocarbon zones. The cement plug is pumped into the allocated space to serve as an effective production packer. This becomes viable and economic option when the interval is above an existing parker. Cement packer activity can be carried out using a rigless unit with the benefit of significant cost savings while achieving seamless isolation of the production intervals. One example from the strings of successful cement parker operation, among a few others, is the CAAK-040 well in CAAK field. The well was drilled in 1988 and completed on X3050B and Y4050B reservoirs. Both intervals quit in 2001 at BSW above 80%. After the integrated subsurface evaluation using all available data including CO logging acquired across the existing and proposed completion intervals, CAAK-040 was proposed for a zone change. A rigless workover intervention of the well was executed and the production interval switched from Y4050B to C8000B reservoir on the new short string using cement packer technology to isolate Y4050B completion and recomplete in the new target sand. CAAK-040 did not flow after the cement packer and perforation operations were successfully executed and the well had to be lifted to production using a temporary gaslift system. Currently, the well is performing above the planned potential of 1500bopd from C8000B reservoir. This paper will discuss the lessons learnt and best practices from the cement packer and re-perforation of CAAK-040 using a rigless workover unit. There is continuous monitoring to ensure all approved company procedures and minimum standards are strictly adhered to. To date, we have a total of five (5) wells that have been recompleted and reserve added using cement packer. This activity has accelerated the production system unlocking of short-term oil generation (STOG) production of over 5,000 b/d of oil in one-year target. The average total cost of this operation is about 20-30% of a conventional workover. Thereby saving the company over $20m with added rewards of reactivating shut-in wells and producing reserves that were previously sub-economical and inaccessible.