Systematic Coiled-Tubing-Efficiency Improvement Reduces Operational Time

Abstract

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 184779, “Consistent, Systematic Approach to Deepwater Coiled-Tubing-Efficiency Improvement Substantially Reduces Operational Time, Gulf of Mexico,” by Peter Weiland, SPE, Alexander Rudnik, SPE, and Eric Gagen, SPE, Schlumberger, prepared for the 2017 SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, Houston, 21–22 March. The paper has not been peer reviewed. Deepwater coiled-tubing (CT) well interventions can benefit from significant rig-time reduction and cost savings associated with improved efficiencies of surface processes. Efficiency improvement requires a systematic approach and detailed analysis of each part of the process. The efficiency methodology allows for systematic improvement in all areas of CT operations, specifically for surface activities. The total efficiency solution described in this paper requires no additional cost to service providers, and results can be seen immediately. Deepwater Coiled Tubing The use of CT for well intervention can provide many downhole solutions throughout the life of a well. Although there is much discussion of the financial and technical aspects of CT in the industry, less conversation is directed toward the efficiency of CT surface processes. The expansion of analysis, specifically to CT process efficiency both before and after in-hole operations, is necessary for a holistic approach to total efficiency improvement. The stages of CT operation shown in green in Fig. 1 can be identified as five distinct surface activities. Design Methodology The first stage of the efficiency solution involved analysis of past performance. Some limited performance data were collected and reviewed, primarily on CT rig up, pressure testing, and transition time between CT and wire services (wireline and slickline). The underlying strategies of several widely accepted continuous-improvement programs, such as lean principles and the define/measure/analyze/implement/control methodology, were used to provide the link between performance and improvement. Low-performance areas and areas of recurring nonproductive time (NPT) were addressed through root-cause analysis and remedial-work plans that were focused on specific tasks. Mean-while, high-performance areas were analyzed to document the best practices for efficient operational execution so that efficiency gains could be realized for the duration of the campaign. Performance is compared with both baseline and previous-operation performance data so that trends and inconsistencies could be identified easily. Equipment Mobilization/Demobilization and Lifting The first stage of any CT operation involves mobilizing the required equipment to location. A typical CT spread may require 30 to 45 individual lifts to move equipment from the workboat to the rig. This first process, termed boat work and equipment spotting, is most commonly tracked by total time required to place the entire CT spread on deck.