Thawing of Permafrost During the Operation of Wells of North-Mukerkamyl Oil and Gas Field

Thawing of ice-saturated rocks due to climate change or various technological impacts will be accompanied by subsidence of the earth’s surface and development of dangerous permafrost geological processes called thermokarst, leading to accidents, which may destruct the wells. Currently, the investment programs of the development of new northern oil and gas fields are restricted. In this regard, reducing the cost of developing the oil and gas fields is an urgent problem. For example, diminishing the area of well pads and maintaining efficiency in the northern oil and gas fields can significantly reduce the costs, in particular, during the design stage. A model of unsteady thermal fields propagation in frozen soil from new well construction for the North Mukerkamyl oil and gas field is developed, taking into account the construction features, the annulus, and the complex lithology of the soil surrounding the well. It is planned to take into account climatic and technological factors, in particular, an annual rest period of well operation, which held from several hours to two weeks. The paper discusses the computational features of the thermal fields calculating in frozen ground from wells and explores the influence of various parameters, which in the computations may lead to a significant increasing of thawing area in the well pads