The remaining deposits of oil and gas on land are getting exhausted every year. This encourages the search for new ways of solving energy shortages, among which is offshore drilling. Exploration and development of oil and gas fields in the sea maintains the balance of fuel resources.
Offshore drilling uses special platforms, floating or semi-submersible drilling rigs. For the first time the term “offshore drilling” was mentioned in 1869. It was then that a patent was received for an offshore project of a drilling rig in shallow water. Since then, science has made a huge step forward and today there are mobile platforms, which extract oil and gas at a depth of 300 m to 3 km.
Drilling from platforms uses machines with electric drives, which are powered by 6 – 35 kV cable lines. Most often, such lines are laid along the seafloor.
Offshore drilling rigs are operated by single motorized drives (diesel, alternative energy sources, etc.).
As a rule, floating semi-submersible drilling rigs are equipped with a diesel/electric drive of a constant/alternating current. The depth of offshore drilling and its conditions determine a number of power units, their power and the power of the drive of main and auxiliary mechanisms.
An integral part of the power system on offshore drilling rigs is a power transformer. It converts the incoming AC voltage into the required voltage. A transformer is responsible for reliability and profitability of a drill rig and an offshore drilling process as a whole.
A transformer in turn depends on transformer oil which is an important part of transformer insulation, performing the functions of cooling and isolating of active parts. When the oil performs its tasks well, the transformer also operates without failures. But during operation, an insulating oil is exposed to a number of negative factors that contribute to its oxidation and contamination. Oil contamination leads to a decrease in performance below the permissible values, which is unacceptable. Therefore, the oil is regenerated. This process maintains physico-chemical parameters of oil at the required level for a long time.
Offshore drilling rigs operation have hazardous conditions. The potential danger of an explosion exists in closed rooms of drilling and pumping, as well as in storage of drilling mud.
Therefore, equipment permanently located on offshore drilling rigs must have an explosion-proof design. This also applies to transformer oil regeneration plants.