Furmanite’s many years of experience in solving problems on site has enabled development of a specialist casing cutting service designed to provide the oil industry with a quick, safe and effective method for cutting and profiling casings on offshore/onshore wellheads. Designed for the demanding environment of the North Sea, the machines are successfully used in numerous applications worldwide.
Casing cutting (tube in tube) is a special application. The oil and gas drilling industries have experienced problems inserting the tubing carrying the oil or gas from the reservoir to the surface, due to sticking in the casing. When this occurs an emergency cut is made to achieve the correct configuration for a seal to the wellhead. A special Furmanite casing cutting machine is mounted on the wellhead, instead of the pipe outside diameter is used to cut the casing at a predetermined height, either above or below the wellhead flange.
Traditionally, casing cutting has been carried out manually by burning and grinding techniques which are not only time consuming but can also cause substantial deformation and surface damage to the casing, making subsequent sealing difficult. Furthermore, since no burning is involved in the Furmanite method, possible hazards created by the presence of oil based muds are reduced to an absolute minimum. The air powered machines are designed for safe use where the potential presence of flammable oil or gas at the wellhead prevents the use of hot cutting equipment.
The Furmanite casing cutting machines cut and profile both internal and external casings ranging from 130mm to 245mm (5.2” to 9.625”) when cutting internally and 500mm (20”) down to 125mm (5”) when cutting externally. The main sections of the machine are designed to split into two halves allowing the whole unit to be mounted quickly and simply by “wrapping” it around the casing. The machines are pneumatically powered and incorporate automatic toolpost traverse to permit a “hands free” operation. Designed to be rigid, accurate and reliable, Furmanite casing cutting activities are delivered through its global operations. The unique Furmanite design includes two simple operations. First the clamp type machine (split in two halves for easy fitting) is mounted on the face of the hub and cuts through the protruding casing to make it flush with the top of the wellhead. Then the casing is cut internally using the boring bar, which cuts through from inside and bevels the edge to ensure a smooth chamfer for the installation of the seal assembly.
Both operations produce accurate and clean results in a simple operation with greatly reduced cutting time. There is no need for rough cuts or to drain the casing prior to cutting.
In some specialist cases, customers have required casings cut which fall outside the standard machine range. Furmanite has modified existing machines to meet the individual customer demands with very little notice required. Whatever the casing cutting demands, Furmanite is able to offer a fast track solution enabling the wellhead operations to continue.