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Abstract This paper will outline the snubbing operations conducted to carry out a complex reabandonment in a remote jungle location. The abandonment called for the fullbore removal of the existing cement plugs with suspected poor integrity and with uncertain pressures below. The challenge was compounded by a restricted ID in the surface equipment which was installed due to unforeseen bubbles in the 13-3/8″ casing after wellhead removal during the original abandonment. The pressures observed required the use of live well intervention techniques and equipment Several vendors for the supply of the snubbing unit were considered with focus on their stand alone capability and the availability of suitable interlock safety systems. Due to the nature/condition of the well a number of concepts were considered to initially mill a pilot hole through the surface plug to establish communication with any pressure below the plug. As the intervention was considered urgent the primary plan was to utilise coiled tubing for this (available in country), however due to the cement plugs being inside the 13-3/8″ casing it was decided to hang off a 3-1/2″ conduit string from a slip ram assembly down to the surface plug to contain any CT “walk”. Following the milling of a pilot hole, a new cement plug was to be set to act as a barrier to allow surface equipment reconfiguration to a 13-5/8″ snubbing stack. Prior to the CT being mobilised to location and whilst the snubbing unit was in transit from The Netherlands the pressure trend changed from a building trend to a stabilised pressure. As such a judgement call based on the safest and greatest chance of success was made to use the snubbing unit for all operations upon its arrival. The snubbing unit was mobilised and rigged up on to the tree to perform the initial phase of the operation of re-establishing communication to the well through a pilot hole thus allowing reconfiguration of the surface equipment. Following the reconfiguration of the surface equipment the snubbing unit was re-rigged in fullbore 13-5/8″ snubbing stack mode, whereupon the reabandonment operations were conducted based on an assured programme which was amended through management of change during operations due to the wells behaviour. The remoteness of the location required that all downhole scenarios had to be planned and equipment for all had to be prepared, tested and shipped to location. Meticulous planning was essential for this. Post job it is evident that utilising the latest interlock systems and modular tower paid dividends in providing a safe conclusion to an uncomfortable situation.
- North America > United States (0.28)
- Europe > Netherlands (0.24)
Abstract With the current government environmental directives in the Gulf of Mexico (GoM), operators are challenged to ensure that idle iron wells are correctly handled to meet regulatory requirements in the full abandonment of the wells and their platform structures. With this, there is a need to remove existing production tubulars and set the required abandonment barriers before removing the offshore structure. Because of the current operational climate, there are many challenges that operators face in the GoM with regards to their ability to secure rig set equipment and personnel to effectively perform these operations in an economic manner. This paper details an operational challenge of preparing for the temporary abandonment of an operator's GoM compliant tower structure, where an existing wellbore had been shut in with an annulus containing sustained casing pressure up to 3,000 psi. To facilitate the operational work scope, a hydraulic workover (HWO) rig was selected to be installed to the compliant tower structure, which allowed for the successful removal of the completion and preparation for the impending platform abandonment process, all while simultaneously working under the operational constraints of a producing facility. This publication shows that through the application of detailed engineering and operational programming, the challenges of adapting existing equipment, restrictions on available space, reduced deck load capacity, along with crane limitations, all before HWO operations in an offshore environment with the potential for severe weather on a compliant tower, were safely overcome while performing the operations.
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
Strategic Rigless Approach in Identifying and Curing Complex and Multiple Completion Leaks in Malaysia
Syed Mohd Shahril, S. A (PETRONAS Carigali Sdn Bhd) | Ariff Shazwan, M.. (PETRONAS Carigali Sdn Bhd) | Mohd Zulkifli, O.. (PETRONAS Carigali Sdn Bhd) | Nussbaum, C.. (Archer) | Sathish Kumar, B.. (Archer)
Abstract Integrity diagnostic has become one of the key prerequisite criteria when dealing with uncertainties in the well completion of mature assets. This is particularly true in Malaysia, where most of the tubing and casing in production wells has aged more than 30 years, and yet some of these wells are still producing beyond their original design life expectancy. Locating the source of integrity issues relies on being able to identify leaks and/or flow behind casing. Typically, conventional technologies have been used for anomaly detection, including spinners and temperature logs, downhole cameras, calipers and noise logs. In general these lack accuracy, with smaller leaks being particularly difficult to identify. Development studies pioneered in the well logging industry have led to a new diagnostic approach utilising high definition ultrasound technology. This has created a fast, accurate and reliable technique which can be used to identify leaks as small as 0.02 litres per minute inside the completion tubing. Field D and Field BN fields are two of PETRONAS Carigali Sdn. Bhd. (PCSB) mature fields where ultrasound technology has been implemented aggressively in order to mitigate complex completion problems involving tubing and annulus leaks. PCSB has successfully implemented this technology since 2008; to date the company has resolved more than 100 wells uncertainties using the method to determine multiple completion leaks and flow channelling behind casing. The ultrasound-based leak detection case histories demonstrate the practicality of the technique in many cased-hole applications. The related ultrasound-based flow-behind-pipe survey detects liquid or gas flow behind casing with a measurement from within the tubing. This unwanted flow can have a variety of negative outcomes, including poor well performance, ground water or reservoir contamination and/or more catastrophic uncontrolled fluid escape at surface. The diagnostic is sensitive to the ultrasound energy created by turbulent liquid or gas flow through small restrictions in annuli. From within the tubing, it can detect and locate undesirable flow behind pipe with great accuracy - even through multiple casing strings. This paper shares some experiences and best practices developed while implementing the technology in Field D and Field BN fields.
- Asia > Malaysia (1.00)
- North America > United States > Texas (0.28)