Demonstration of a downhole electrolytic cell to reduce the environmental footprint during Plugging & Abandonment of oil & gas wells.

With millions of oil and gas wells requiring to be plugged and abandoned (P&A) worldwide, and thousands in Norway alone, there is an urgent need to develop technology to reduce the environmental footprint and cost of these plugging operations. The standards for well integrity require that for permanently abandoning a well, the barriers shall extend across the full cross section of the well. The purpose of the cross-sectional plug is to guarantee the isolation of permeable formations, reservoirs and other sources of inflow that could contaminate water reservoirs or leak hydrocarbons to the surface. To provide full access to the cross section of the well, a window in the present metal tubing has to be cut, milled or in some cases entirely pulled out of the well. This operation is traditionally performed with a drilling rig and all the environmental footprint associated with it. Fortunately, there is considerable industry focus on developing new technology that will enable the many operations involved in P&A to be performed without the use of a rig. Upcoming rig-less P&A technology such as the dSolve project, would complement each other and, together, enable a rig-less P&A operation, substantially reducing the CO2 missions. dSolve uses an electrolytic cell to accelerate the corrosion of the casing in order to open cross-sectional windows in tubing without using a rig. The technology is based on over 6 years of research performed together with SINTEF. During this research it was demonstrated in near real environment that the window could be opened competitively and in a variety of casing string designs. The objective of this project is to engineer, manufacture and demonstrate in relevant environment, a downhole wireline tool that comprises an electrolytic cell. This electrolytic cell is to be used for dissolving entire sections of metal tubing for P&A applications in the most reliable and efficient manner.

It is estimated that the Norwegian Oil and Gas Industry will have to plug and abandon over 2 300 wells within the next 40 years. The standard for well integrity requires that for permanently abandoning a well, barriers shall extend across the full cross section of the well. The purpose of the cross-sectional plug is to guarantee the isolation of reservoirs and other sources of inflow that could, among others, contaminate water reservoirs or leak hydrocarbons to the surface. To provide full access to the cross section of the well, a window in the present metal tubing has to be cut, milled or in some cases the metal tubing would have to be entirely pulled out of the well. Most of the technology currently available to open this window requires the use of a drilling rig and all the environmental footprint associated with it. It is estimated that the emission related to plugging these wells may exceed 260KTons of CO2 per year or 10M Tons over the next 40 years. Fortunately, there is considerable industry focus on developing new technology that will enable the many operations involved in P&A to be performed without the use of a rig. Upcoming rig-less P&A technology such as dSolve, would complement each other and, together, enable a rig-less P&A operation, substantially reducing the CO2 emissions. The dSolve technology uses an electrolytic cell to accelerate the corrosion of metal casing in order to open cross-sectional windows in metal tubing, without using a rig or coil tubing. After over 6 years of R&D performed by SINTEF and Innovation Energy, the dSolve technology has been validated in relevant environment, showing to be competitive in a variety of casing string designs while producing environmentally friendly by-products. The next challenge towards commercialization and main objective of the project is to demonstrate the technology in a downhole environment.