The loss of functionality of the surface controlled subsurface safety valve (SCSSV) due to blockage of, or damage to, the hydraulic control line can present a major problem to Operators. The subsequent loss of hydraulic pressure to the valve means the valve will close resulting in loss of production and hence alternative methods for re-establishing control of the SCSSV are required. Performing a full scale work-over to replace the inoperable control line can require major expense and may not be justifiable in a mature well, while installation of a velocity or dome charged subsurface controlled safety valve may not meet well integrity or production requirements. Hence the preferred alternative is to install a System to Restore Full Safety Valve Functionality that is cost effective, restores production, and maintains well integrity requirements. The Tubing Retrievable SCSSV on well C-02 in the Sabah water of East Malaysia lost its functionality due to a leak in the control line. The SCSSV body was also found to be leaking from tubing to annulus which resulted in the failure to successfully lock open the SCSSV. Initially a major rig work-over had been anticipated to pull the tubing and replace the safety valve and control line. This operation would have required the use of a Hydraulic Work-over Unit (HWU) to perform the work which would have incurred a major expense. An alternative method was proposed that would allow replacement of the safety valve and control line, and to straddle the leak in the SCSSV body without pulling the production tubing or making changes to the wellhead configuration. This alternative method was a unique concept not previously attempted by any operator in Asia Pacific. This innovative approach would involve four elements: Installation of a Lock Mandrel and Separation Sleeve to straddle the leak in the SCSSV body & hold open the SCSSV flapper. Installation of a Wireline Retrievable Subsurface controlled safety valve with wet connector to connect to a new control line installed through the tubing (WDCL Safety Valve) which is anchored and located in the Tubing above the Tubing Retrievable SCSSV by means of a packer system. A new control line and special control line connector installed from the wellhead to the WRSCSSV through the production tubing. A new penetration in the Wellhead Lower Master Valve for the injection of hydraulic power fluid to control the WRSCSSV. These 4 elements provided a unique solution and the installation was successfully completed under a severe deadline. This was achieved by a high level of cooperation and collaboration between all parties throughout all phases of the project including and not limited to the planning, design and installation. This paper will describe in detail the system components and the decision processes and evaluations that led to the selection of this alternative solution. The collaborative efforts between the operator and two major service providers will be examined and discussed and the installation procedure described in detail. The paper will describe why the successful completion of this project marks a significant milestone in the remediation of older producing wells.
The 'S' field, located offshore East Malaysia, consists of multiple-dipping heterogeneous sandstone reservoirs with unconsolidated formation. These multi-stacked reservoirs have an overall 40m thick oil column with marginal Oil-Initial-In-Place (OIIP). A large gas cap, i.e. twice the OIIP equivalent, also exists. Scenarios of zonal gas-out leaving huge oil bypass and moderate aquifer strength with inevitable water invasion cautioned the asset team to consider intelligent zonal flow control especially in its horizontal producing wells.Two of the 14 horizontal producer wells in this marginal field have been screened to apply the modular integrated intelligent completions system (IICS) to actively control and permanently monitor zonal inflow for optimal production. Future selective production control and data surveillance enabled by the IICS are essential to fulfill the needs for delicate downhole zonal flow balance for ultimate oil incremental and recovery. It provides control against the aggressive gas cap expansion at the heels while addressing the moderate aquifer coning-up problems from the dipping toes as the field depletes. This paper highlights the successful implementation of the next generation intelligent completions system in a complicated, highly-dipping, multi-layered sandstone reservoir with commingled production. In this multi-zonal production solution, the conventional surface-controllable downhole zonal flow control valves are now integrated with data surveillance gauges, intelligent sensors and isolation packers all into one single completion joint, instead of the precedent multi-joints system (i.e. splicing required up-to 3 joints per zone conventionally). This single modulated joint system has reduced installation time substantially in comparison to conventional intelligent completions installations. The risk of surface completions make-up damage before run-in-hole is also greatly reduced with less connecting components. This robust yet compact system has made on-site completions tally adjustment easier and is enabled with LWD data update while drilling. As a result, intelligent completions design becomes more flexible and responsive to actual reservoir challenges and drilling surprises -providing an all together "intelligent" solution.This paper also discusses the screening process from simulation performed for candidate evaluation to the resulting impact on production post-installation. Future applicants of such technology with similar fields' nature and risks can benefit from the discussed lesson-learnt; best-practice workflow and seamless teamwork and coordination between the project team and service providers in delivering an advanced fit-for-purpose solution.
This paper discusses the smart Drill Stem Test (DST) string, run for a Deep Water (DW) well test operation, which enabled considerable saving of rig time, reduced risks, and provided best reservoir data quality, while performing a commingled DST in a single run. Evaluation of the zones was made without any wireline intervention runs such as Production Logging Tool (PLT) or Surface Read Out (SRO). Acoustic telemetry provided seamless access to downhole data, including production profiles from both zones, throughout the DST operations. This paper will help the well testing fraternity conduct well test operations efficiently and safely in a deep-water environment using new technology tools and innovative methods. Well testing costs and risks can be reduced significantly. The smart DST string, run in hole (RIH) for the DW well test, consisted of a combination of conventional DST tools, a new generation packer and below packer, acoustically operated tools including: Acoustically Operated Sliding Side Door (SSD) - provided access to the reservoir for Well Kill Operations after the standalone screens became plugged with unconsolidated sand and Loss Control Material (LCM) pills.Multiple Discrete Temperature Sensor Array - Eliminated the requirement of running a conventional PLT to evaluate the commingled flow of two zones, provided valuable production logs, and resulted in unexpected, additional information evident from the thermal transient data.Acoustically Activated Bottom Hole Samplers - collected bottom hole samples selectively, at different drawdowns, without wire line intervention or without applying annulus pressure.Wireless Gamma (GR) Depth Correlation Tool - Provided accurate TCP gun placement, without running a conventional wireline GR/CCL, by using a tubing conveyed Gamma Ray logging tool; results were collected wirelessly in less time than a conventional wireline run.New Generation Packer -The large size 9-5/8" Hydraulic Set Retrievable seal bore type packer was used for the first time by the company. This is a most suitable packer for DW DSTs, which eliminated the requirement for slip joints, drill collars and safety joints or the running of a permanent packer, which would have required multiple trips and restricted the gun size.
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