Advanced Live-Well Deployment System Enables Successful Perforating Operations in Offshore Southeast Asia
Authors: McClean Charlie , Hillis Parry , Satti Rajani , Zuklic Stephen , Bouziane Cherif 
Published: October 2017

As development of oil and gas reserves moves into complex conditions, operators continue to explore new techniques in order to optimize well productivity and decrease operational costs. In recent years, advanced live well deployment systems have gained significant attention, whereby such systems can be utilized to perforate and complete without killing the well, avoid the use of kill-weight fluids, optimize underbalance, reduce operational risks and more importantly, be deployed in complex large interval HPHT wells. However, perforating operations in live well situations require complex safety considerations for handling both pressure and explosives at the same time. Therefore, the overall strength and reliability of these systems is of paramount importance in order to fully realize the benefits of live well deployment.

Of relevance to this study are HP/HT wells in the Maharaja Lela Jamalulalam field, situated at approximately 50km offshore from Brunei coast and in approximately 65m of water depth. Due to inherent challenges (offshore, large interval, bottom hole temperature ~ 330F, pressure ~ 15,000psi and a static underbalance of 4500psi), the operator reviewed potential deployment techniques considering safety, operating efficiency, conveyance method and well performance. The optimal solution was to leverage an advanced live-well deployment system to recover the perforating guns under live well conditions. The system was a modular live-well system (conveyed using coiled tubing) that included a dummy/drift run combined with memory logging tools to aid in correlation. The system also included a fully redundant top fire absolute pressure firing system. More importantly, an integrated testing and modeling workflow encompassing advanced laboratory testing (using API RP 19B Section-2), system stack-up tests and qualification, pre-job analysis using advanced computer modeling wasleveraged to quantify shaped charge performance, model gun shock and mitigate risk, maximize perforation cleanup and deliver an optimized perforating solution.

Following system qualification and operational planning, the system was successfully deployed on the HPHT well completions. The entire operation of deploying and retrieving the perforating guns without killing the wellswas executed as designed. As an example, the use of this system on one of the wells helped the operator realize significant cost savings, and saved 2.5 days of rig time compared to conventional wireline perforating, and allowed the operator to maximize the static and dynamic underbalance during the perforating operation. Excellent agreement (2% variance) between computed and measured compressional loads on the coil was also critical in foreseeing potential issues and ensuring a reduced risk operation. Computational modeling also aided in setting an optimized underbalance condition before running the guns.This successful field application of an advanced live well system demonstrates careful planning and execution as well as the cross-disciplined expertise involving coiled tubing, perforating and completions. Finally, the design of the physical assembly in conjunction with a scientifically engineered workflow (including laboratory testing and computational modeling) are critical to seamlessly deploy and ensure the benefits of an advanced live well deployment system.