The Chelyabinsk plant of the United Metallurgical Company OMK has developed according to the requirements of PJSC Gazprom and patented the design of heat-insulated casing pipes, thermocases, with a welded joint to prevent debris and foundation failures under a drilling rig for oil and gas production in permafrost conditions. The new products, in contrast to the standard thermal cases that the plant has been producing since 2018, are more resistant to work in aggressive conditions, have a new welded connection scheme for pipes into columns, which allows creating structures up to 70 meters long without unnecessary equipment. Another advantage: the thickness of the thermocase connection is less than typical, which allows to reduce the difference between the diameters of the inner and outer pipes. Due to this, drillers can make a smaller borehole diameter, which means they can reduce labor intensity and drilling time.
The company has manufactured and successfully tested a new type of products in the presence of the customer's representatives. In January 2021, the permanent commission of PJSC Gazprom for the acceptance of new types of pipe products approved thermal cases with threaded, flanged and welded joints. Thus, OMK acquired the right to supply heat-insulated casing pipes to Gazprom's production facilities without restrictions.
In the regions of the Far North, it is required to drill wells in the permafrost. To strengthen the wellhead, casing pipes connected into a string are used. They are placed to a depth of 20 to 70 meters, then the well is concreted. But in the process of further drilling and operation of the well, permafrost around it begins to thaw, landslide and sinkholes occur, craters are formed, which leads to equipment failure and threatens an environmental disaster. Therefore, the oil and gas industry began to use special products - thermal cases.