Development and Testing an Electrical Drill-Stem Test Tool Conveyed by Coiled Tubing with a Real Time Control and Acquisition System

Abstract

Some exploration well testing operations are executed by performing multiple runs in hole using slick line and Coiled Tubing (CT). A new technology has been developed that combines many of these operations, including contingency stimulation activities into one run. The Electrical Drill-Stem test (e-DST) Tool is an intelligent, surface-controlled tool designed to be run on coiled tubing that allows exploration well testing operations, including stimulation to be performed in one run. Existing operations involve rigging up slick line and coiled tubing in varying sequences depending on well conditions, such that the requirement for nitrogen lifting and acid stimulation through coiled tubing as well as gauge setting and retrieving by slick line can be established. In addition to saving substantial time, the new system is designed to optimize test quality through the display of real time bottom hole production logging data at surface, allowing the early ending of poor tests or the extension of interesting ones. Selective stimulation of zones through repositioning of the e-DST tool on coiled tubing eliminates costly trips into the well and the requirement for pre-planning of flow test durations is removed. The innovative tool includes: Cable head Connector, Upper Flow Port, Packer Element, Slips Anchor, Shut-In valve and real time instrumentation and control with monitoring from surface. The paper will introduce the major system components and review challenges associated with design, manufacture and testing. A summary of the first trial test results, conclusions and lessons learned will also be presented.