Sandstorm Contingency for Logging with Coiled Tubing: Coiled Tubing Cut, Site Evacuation and Safe Recovery - Success Story from Middle East Field

Abstract

Objectives/Scope: Operations in onshore fields at UAE are affected during the months of March through June by the weather, as sand storms are created and attack the area, there is always a need to plan abandonments to avoid harm to any personnel, environment and minimize damage to facilities. In March 2016, while executing a logging with coiled tubing operation on a well at one of ADCO fields with 1.75'' coiled tubing (CT), a message from the field's safety team was communicated to terminate all operations and lower all cranes due to a severe storm approaching the area. It was required to evacuate the area within two hours. A team was formed at the base communicating with the in-charge engineer onsite to safely secure the CT string at surface, which would allow for abandonment while maintaining well control (WC). Methods, Procedures, Process: During this process three options were analyzed: the first option was to add additional support to the injector head (IH) and leave the coiled tubing package rigged up; this option was rejected because it would not guarantee WC in the event that the storm takes down the crane along with IH. The second option was to secure the CT with lower Blow out Preventers (BOP), Combi type, then shear it and rig down the IH. This approach provided WC, but it created additional risk and limitations when resuming the retrieval operations after the storm. The third option was to secure the CT utilizing the upper BOP, Quad type, and keep the pipe held with the lower BOP while secured by the upper BOP. The removal of the IH would leave the section of pipe along with the logging tools held while the well is secured using the BOP provided WC. Furthermore, a cap was installed at the top of BOP and a pressure gauge was set to monitor pressure during retrieval of the pipe. Results, Observations, Conclusions: After analyzing available options, the third alternative was selected by the team; as this option addressed WC and allowed safe recovery by rigging down the top BOP, reconnecting the pipe through double end connector into the IH, and rigging up the required equipment to proceed with the pipe recovery operation. Novel/ Additive Information: Availability of two BOPs reduced the complexity of pipe recovery in addition of maintaining WC at all stages of the operation. Logging with CT is one of the most complicated rigless operations in terms of rig up and rig down, utilizing two BOPs provided the option of securing the well at any point of the operation with reduction in difficulties of pipe recovery. This paper illustrates contingency procedure for CT cut and recovery in abnormal situations through a certain rig up setup.