Rubblizer™, Run History

3 May 2023

In 2017 it became apparent to Deep Casing Tools that conventional technology within the plug and abandonment and slot recovery markets could not cope with the complexities of the process. Research revealed that around 20% of all pulling operations take longer and cost more than anticipated.

As a solution to this ongoing challenge the Rubblizer™ tool was introduced to make casing recovery operations more efficient and cost-effective. Since its launch in 2019 it has built up a reputable global run history. Read on to discover more.

February 2019 – Norway

The Rubblizer™ travels to Norway for its first official run with Equinor.

The Equinor P&A team planned to permanently plug and abandon the explanatory well in the Huldra field. They needed to pull out the 9-5/8” tubular casings to complete the well abandonment.

The first attempt to pull the 9-5/8” casing failed in 2016 due to the very high loads required. A second attempt was necessary however a new method was needed to reduce the axial force to pull tubulars to surface. Deep Casing tools were given the opportunity to trial the prototype Rubblizer™ tool and in February 2019, a short top-down pass with the tool was executed from the Deepsea Bergen.

It proved to the client that it could break the bond between cement and casing successfully whilst significantly reducing the force required to pull the length of casing treated by the Rubblizer™.   

The length of 9-5/8” casing pulled prior to running the tool required 66ton/m of force to pull it free, the 3.5m length over which the Rubblizer™ was run required 35ton/m. This indicated a reduction in force of 31ton/m or 47%.

December 2021 - West Texas

The Rubblizer™ tools second run took place in West Texas for a major operator. It was used to rubblize cement round a 9-5/8” surface casing that was then cut and pulled out of hole.

The client contacted the Deep Casing Tools team requesting the deployment of the Rubblizer™ tool to aid cut and pull operations at a site in West Texas. The goal was to remove the top section of 9-5/8” casing with perfect cement quantity whilst using a mobile work-over unit with skinny 2-7/8” and a power swivel limited to 150,000lbf overpull to keep costs down.

The Rubblizer™ was deployed to break the cement bond and decrease the required overpull forces to pull the cemented casing out-of-hole. It performed a single pass through a 250ft cemented section at 2 ft/min speed, 60 RPM and 3,500 psi internal pressure. The rubblization process was followed by cut and pull operations provided by a local company. With the first 75ft being recovered, using an average force of 13ton/m.

June – October 2022 - China

In April 2022 Deep Casing Tools operating partner, PrimeStar Technologies were approached by a major Chinese operator in need of a solution to a challenging project. Deep Casing Tools Rubblizer™ was offered as a solution and was first run in June 2022 within the Chinese offshore P&A and Slot Recovery market. Due to the success on the first run it was then utilised on an additional three slot recovery projects in August, September, and October 2022.

In one of the operator’s largest fields, rig operational limits on overpull and cement located behind casing made the attempt at pulling casing difficult. If unable to recover this casing the contingency option was to pilot mill down to the required depth from surface. To avoid this the Rubblizer™ was deployed.

Across all four runs the Rubblizer™ was utilised to break the cement sheath and bond, allowing longer sections of casing to be recovered whilst reducing the force required to recover these sections of casing. Using the Rubblizer™ meant that the operational pull force limits, set by the company representative, were not exceeded during the casing recovery process, enabling casing on deck after each run.

Below we include a table that outlines sections recovered by the Rubblizer™ tool and the reduced force required to pull these sections of casing to surface:

Successful completion of all four runs saved the operator 19 days rig time, completing the operations in a total of just 4 days compared to the 23 days it would have taken conventional pilot or section milling. This helped reduce time in the red zone and multiple BHA handling requirements. Use of the Rubblizer™ also reduced emissions by 82%, when compared to pilot or section milling.    

To read more about the above projects in detail, visit our case study by clicking here.

The revolutionary Rubblizer™ tool continues to make its mark within the slot recovery and plug and abandonment markets. As word spreads of its continued successes more operators from around the globe are enquiring about the tool and the benefits it can bring to their upcoming operations. An additional 4 upcoming runs are set to take place before the end of 2023.  

If you too would like to know more about the Rubblizer™ tool and its run history contact Product Line Manager – Abandonment and Recovery Systems, Alasdair Gordon by email on Alasdair@deepcasingtools.com or by mobile +44 (0) 7480 986787.