Eliminating Multiple Interventions Using a Single Rig-Up Coiled-Tubing Solution

Abstract

This paper describes new methods to economically improve production levels in one of the mature fields of Petroleum Development Oman. This field had been developed by infill drilling programs, which were suspended in early 2001 to review the development strategy. A reservoir management team set a challenge to effectively conduct logging operations and quickly use the data collected to identify and avail of optimization opportunities. The ensuing campaign resulted in maximizing the production of the wells whilst lowering overall costs. The optimization activity consisted of clean-out, saturation logging, perforation, and stimulation. These activities were initially carried out in two ways: 1) with coiled tubing using only conventional coiled tubing and e-line coiled tubing or 2) with the combination of coiled tubing and a hoist. Both methods involved multiple well entries. Both of these methods were successful in that they resulted in incremental net oil production but at relatively high costs.This paper presents an enhanced methodology which enables clean-out, logging, stimulation, and perforation with one coiledtubing intervention, which includes a plastic-coated "e-line" coiled tubing, coiled-tubing perforating head, and new perforation technology. All systems are in complete compliance with the most stringent safety criteria. The new method has a considerable time and cost savings impact. These results are fully illustrated in this paper with field trial case histories, in which a multi-disciplinary team effectively targeted the most suitable zones for perforation and stimulation by use of a state of the art self-diverting, nondamaging, acid system. Technical and economic comparisons are made with conventional practices. The new methodology is currently being used in this field and is potentially applicable to other fields.