Europe

CHALLENGE

During a routine test, a major operator in the Danish North Sea determined that a Sub-surface Safety Valve (SSSV) of a well on an offshore platform would not successfully perform a routine inflow pressure test. The operator believed this was due to scale buildup in the upper completion.

Two separate interventions were attempted using conventional chemical and mechanical methods, but these failed to re-activate the SSSV. The operator had heard about electro-hydraulic stimulation (EHS), which can break up scale using shock waves and pressure pulses. The operator decided to mobilize Blue Spark’s WASP® technology, with its ability to remove scale from complex downhole completion equipment items, without risking any damage to them.

It was also decided to acquire a multi-fingered caliper log through a section of tubing to confirm the build-up of scale, then treat that scale, and lastly run the calipers again after the WASP® treatment to validate the removal of scale.

The post-treatment caliper log was then acquired, confirming that the scale was removed from the tubing (see figure at right). The scale was approximately 0.36 inches thick.

OUTCOME

• The WASP® tool is efficient to operate as it is deployed using a standard mono-conductor wireline unit. The treatment replaced either multiple slickline runs or a coiled tubing operation.
• The treatment was completed in less than 15 hours total operating time, while strictly following all normal protocols. The technology allows for the treatment of multiple intervals on the same run in the hole, further increasing efficiency.
• The technology is ideally suited for small footprint platforms and does not require an excessive amount of rig-up height or unusual lifting capability.
• The technology requires no chemicals, explosives or controlled goods, and as such is environmentally friendly and extremely safe.
• The technology was proven to be a very cost-effective solution to remove scale inside any completion equipment, including tubing, Subsurface Safety Valves, Side Pocket Mandrels, and Gas Lift Valves.

Marie Morkved, Head of Production Technology from Maersk Oil, presents a case study of a recent well intervention using coilhose technology, noting how it allows deployment with slick line equipment but still enables pumping to offer flexibility and efficiency.

This Video of the Month showcases how the application of SandVA, paired with Optis Infinity technology, helped the operator of a gas well to confirm the integrity of their asset and demonstrate compliance with regulatory requirements.
 
Sand control or sand management is estimated to be required in more than 50% of wells globally during their productive lives. The need arises in both conventional and unconventional wells with high rate gas production from unconsolidated sandstones reservoirs and flowback from hydraulically fractured wells providing common examples. In certain regions the use of slotted liners or sand screens to control sand production is widespread. In these locations production from unconsolidated sands would not be economically possible without their use.
 
A gas storage well operator in continental Europe required detailed assessment and visual confirmation of the condition of sand screens within the well. Sand control in this well is further complicated by frequently alternating periods of injection and production. Regulatory requirements entail periodically confirming the condition of sand screens and other downhole components.
 
EV’s Optis Infinity M125 tool was deployed on slickline with both downview and sideview video footage acquired over the entire well. Four screen sections with an average length of 6m (20 feet) were captured. The resulting images were subsequently visually inspected and measured to evaluate both erosion and plugging of the screens, to provide a quantitative evaluation of screen integrity and inflow performance.
 
Having demonstrated that the integrity of the screen was indeed intact, the operator satisfied the legislative requirements to continue operation of the well. The plugging of the base holes was noted, but the operator elected to take no further action at this time and would assess changes in the levels of plugging during subsequent inspections. From this time-lapse information a rate of change could be calculated to provide input for decision making on when to schedule wellbore and screen clean-up interventions. This quantified information provided by SandVA allows patterns and trends to be identified, helping diagnose the causes of problems and understand their severity. This information helps operators implement effective sand management programs, enabling them to maximize the performance and productive life of their assets.