Determination of the wellbore position by measuring of the Earth's magnetic field while long horizontal wells drilling in the Arctic

Drilling of a horizontal well from the shore of the offshore field at 8 km distance in the sea of 1500 m depth below sea bottom gives approximately 40% of savings in capital and operating costs, as compared to traditional drilling from a fixed platform. Economical effectiveness is proved by horizontal extended reach well drilling experience in the Sakhalin Island shelf. Development of the Arctic shelf of the Russian Federation, due to complexity of geographical, climatic and environmental conditions requires non-traditional innovative approaches for the field development. One of the ways for development of Arctic reserves is implementation of a drilling complex with tipping tower, developed at Ukhta State Technical University. Drilling complex of XXI century will allow for prospecting and exploration of minerals in rocks by a hemisphere with a radius of more than 15000 m, thus excluding or limiting the technologies associated with the construction of platforms, and use of floating drilling rigs. Application of the complex will provide maximum concentration of economic activity at well clusters during searching, exploration, development and transportation of hydrocarbons, which is especially important for hard-to-reach regions. Deposits of the Arctic shelf of the Russian Federation in the north-eastern shelf of the Barents Sea, shelf of the Pechora and Kara seas, offshore of the Ob and Taz Bays were classified. Their development can be carried out using horizontal extended reach wells from the shore or artificial islands. Accurate wellbore positioning is essential to locate and produce the resources in the Arctic. Unfortunately, high latitudes associated with drilling in the Arctic, pose a problem concerning standard geomagnetic surveying techniques. First of all, at high latitudes the accuracy of standard MWD survey may be inaccurate due to low values of the horizontal magnetic fields. The paper provides an extended description of this problem and the direction of development of approaches to its solution.