RIASSUNTO
Abstract
Stuck pipe incidents are one of the major operational challenges of the E&P industry and events usually lead to significant amount of lost time and associated costs. Various industry estimates claim that stuck pipe costs may exceed several hundred million US dollars per year. In Saudi Aramco, the recent increase in drilling activity, drilling in depleted and higher-risk reservoirs have led to an increased risk of stuck pipe. In 2010 Saudi Aramco formed a task force to focus on lowering its stuck pipe costs. In its campaign to reduce this cost, the task force selected key personnel from each of the Drilling & Workover (D&WO) operating departments.
This paper summarizes the result of the Stuck Pipe Teams' findings and the best practice documents generated. For 2009, 69.5% of the total stuck pipes were due to mechanical sticking and 30.5% attributed to differential sticking. Furthermore, based on the team's findings, a customized training plan was formulated to certify key D&WO operations personnel every 2 years.
Background
The high level of drilling activity in Saudi Aramco demands efficient deployment of resources to deliver approved plans. One area adversely impacting the drilling performance is Non Productive Time (NPT). Stuck Pipe accounts for about 25 % of the NPT and this translates to the cost of about 2 rig-years every year. Management charged the drilling teams to come up with tangible measures to ensure that positive improvements to reducing stuck pipe are achieved. A review of the stuck pipe incidents identified the major causes of stuck pipe as mechanical (pack-off/bridging) and differential sticking. Subsequently, a stuck pipe avoidance team was set up to develop and produce strategies to mitigate and reduce stuck pipe incidents. It should be noted that the scope of the stuck pipe review and analysis covered all wells drilled including re-entries and side-tracks with drilling assemblies deployed in open hole.
Strategies to Reduce Stuck Pipe
Efforts to minimize stuck pipe incidents are not new to Saudi Aramco. In the past, steady efforts have been made by drilling operations to reduce stuck pipe related NPT but the impact had not been consistent. The objective of the task force was to concentrate extra focus to accelerate the reduction of Saudi Aramco's stuck pipe costs (Hopkins et al, 1995; Yarim et al, 2007).