Spring 2020 Issue
for completion and construction methods that minimise risk and save operational expenses. Welltec's AWA system (Advanced Well Architecture) has proven itself as a solution. The system allows for the deployment of multi-zone intelligent completions in a stable environment, with the multi-zone reservoir fully isolated from the wellbore during the deployment of the upper completion – and any subsequent workovers that may be required. “Cementless” has long been an industry aim, and the recent deployment of Welltec’s Annular Isolation (WAI) metal expandable packers on the completion of Total’s Moho North field in Congo was one of the world’s first to meet the goal. The operation saved 10 days of operating time on one well and, perhaps more importantly, reduced CO2 emissions by around 400 tonnes by cutting offshore rig fuel consumption. In addition, the operation eliminated the use of cement pumps for cement placement and clean-up by an estimated 12-48 hours per well, resulting in additional CO2 emissions savings of around 10 tonnes. Other applications of the Welltec Annular Barrier (WAB) technology, from which the WAI is derived, is to manage Sustained Annular Pressure (SAP) issues. SAP is vital in preventing the harmful migration of gas to the surface. Drill sites not using this technology are allowing methane emissions into the atmosphere. The use of WAB technology can continue to cut methane emissions – which account for six to eight percent of all oilfield-related greenhouse gas. Although the WAB and WAI are recent developments, thousands of Welltec’s E-linebased interventions have replaced coiled tubing operations over the years. That means significant savings from reduced logistics and personnel at the wellsite, reduced operational time, and reduced CO2 emissions. It is hoped that E-line interventions can cut CO2 emissions almost entirely. GEOTHERMAL ENERGY Welltec has also focussed on improving efficiency and sustainability in sectors other than oil and gas. The company can help with the energy transition via geothermal energy, which has been attracting a lot of attention as an essential tool in any renewable energy options portfolio. In 2016, geothermal energy contributed to about three percent of total primary production of renewable energy in the EU, which has the fourth-largest geothermal power capacity in the world. It offers the highest-capacity factor in the renewable market, and this energy source requires a consistently high temperature fluid flow to ensure a reliable output. Here, again, Welltec’s expertise in well integrity is crucial. During the construction process of these wells, there is a requirement for high-temperature 59