When Control Line Fails, What is the Alternative?: West Malaysia Experience

Abstract

Angsi X06L was a firm candidate for a workover targeted to be re-completed in April 2010. This well was diagnosed with a severe downhole control line leak, causing the well to be shut in and led to Angsi field deferment of 800 barrels oil per day. PETRONAS Carigali Sdn Bhd (PCSB) had already attempted to rectify this problem by injecting pressure activated sealant a few times but failed in its efforts. Based on the diagnostic done, the leak rate was more than 1.5L/min, way beyond the selected activated sealant capability. The next possible option was to install a storm choke or ambient valve but unfortunately this method was prohibited by PETRONAS. Late April 2009, PCSB embarked on a technical feasibility study using high strength duplex alloy to permanently replace current surface control sub-surface safety valve's (SCSSV) control line. A complex operation that involves multiple services was designed and executed which comprised permanent abandonment of the old hydraulic control line, SCSSV flapper locked open and many more multifarious steps. With the use of this new innovative application, savings of about USD 7 million from the procurement cost of well completion, rig, barge and associated services was realized. This paper will discuss project background, technical feasibility study, work designs, jobs execution and lessons learnt for such an operation in West Malaysia.