Operators Save ~USD 3.3M in One Year with Offshore Wastewater Disposal

Overview

Major operators in Norway were planning their 2021 drilling campaign, which involved exploration wells, appraisal wells on new licenses, as well as mature fields in the North Sea, Norwegian Sea, and the Barents Sea; and sub-letting the rig to another operator for an additional well in the Barents Sea. The campaign’s primary focus was on the immediate development of three mature fields, while also prospecting new fields and licenses to increase oil reserves for planned future development. 

Challenge

Since 2018, Norway has seen a steady rise in the volume of slop sent to shore for treatment and disposal. At any given time, the capacity of treatment facilities to receive and treat waste onshore varies with location and the current activity at each location. The large slop volumes have also resulted in a significant reduction in available storage capacity along the Norwegian coastline.

Additionally, much of the increased demand has taken place in areas of Norway where the treatment capability is underdeveloped. Increased volumes combined with logistical challenges and limited treatment capacity in certain areas have put further strain on slop storage and treatment.

Solution

To address this challenge, Halliburton Baroid proposed a BaraH2O Slop Unit to treat drilling slop at the rig site. The rig contractor was originally to supply slop treatment equipment. However, after discussions with the customer, highlighting the BaraH2O unit’s inherent treatment capacity and the Baroid team’s experience from previous projects, this innovative solution was selected.

A rig survey addressed the entire rig setup, identifying opportunities for overall improvements. Vacuum lines were installed at multiple locations on the rig to collect slop for treatment. The BaraH2O Slop Unit was installed in a dedicated area, with customized pipelines to maximize efficiency. Furthermore, as the rig was to be moved between the North Sea and the Barents Sea, all pipelines and equipment were heat-traced and insulated to withstand extremely cold winter temperatures in this region.

Results

During the first year (2021), the daily treatment volumes ranged from four to 306 m3, as required. In 2021 alone, a total of 17,961 m3 (112,957 bbl) was treated, resulting in 17,679 m3 (111,187 bbl) of clean water ready for discharge, with a mere 281 m3 (1,770 bbl) of residual waste sent to shore for storage, treatment, and disposal. In summary, there was a >98% reduction in the volume sent to shore—including both operators using the rig. The cumulative net treatment cost savings for 2021 was USD 3.27M (NOK 28.6M).