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I. B. Petrov et al.
and so on. These facilities include deposits on the Arctic shelf. Most of hydrocarbon
deposits are concentrated in the Arctic zone.
Artificial ice islands are used for mining of oil and gas in the Arctic. They represent
a cheap and environmentally friendly alternative to conventional drilling platforms,
making them well suited for exploratory drilling in offshore areas. Often this is a
single way to produce the explorative drilling in shelf of northern sees, where due
to severe ice conditions there is no possibility to deliver the usual platform. Such
approach has already been successfully realized in Canada [1]. An actual problem for
the safety of structures and personnel on the surface of the ice island, as noted in [2],
is its destruction due to drilling and seismic activity. Wave processes resulting from
drilling and earthquakes also affect the response to exploration seismology. Because
of the limited possibility of conducting experimental studies in realistic conditions,
the direction of numerical simulation is promising.
In this chapter, we consider a numerical simulation of the propagation of elastic
waves in an ice island during exploration seismology and seismic activity. In modern
computational software, the finite element method is used to study the stability of
structures like ice islands [3, 4]. For seismic wave propagation modeling, researchers
usually use the finite difference method [5], method of spectral elements [6], discontinuous Galerkin method [7, 8], and grid-characteristic method [9–12]. This work
was made using the grid-characteristic method with interpolation on regular rectangular grids (in 2D case) and parallelepiped (in 3D case), as well as the unstructured
triangular (in 2D case) and tetrahedral (in 3D case) meshes. This method is actively
used also for seismic problems, for example, in [13]. It was chosen, since it allows
one to set the correct boundary and contact conditions.
In Sect. 13.2, the considered problem formulations are described in detail.
Section 13.3 is devoted to the mathematical model used and the numerical method.
Section 13.4 presents the results of mathematical modeling of problems in the above
formulations. Section 13.5 concludes the chapter.
13.2 Problem Formulation
The wave propagation simulation area is an ice island with length of 300 m, height of
10 m, surrounded by 8 m deep seawater, and resting on solid ground (Fig. 13.1). Ice,
water, and soil are considered homogeneous. Elastic characteristics (longitudinal
and transverse velocity of sound propagation and density of media) are given in
Table 13.1.
The thickness of the seafloor is 10 m, and the thickness of the sedimentary rock
is 600 m. A gas reservoir is located under the sedimentary rock, which is simulated
by the boundary condition of the free boundary to simplify the task.
The following types of loads on the ice island are modeled:
I. B. Petrov et al.
and so on. These facilities include deposits on the Arctic shelf. Most of hydrocarbon
deposits are concentrated in the Arctic zone.
Artificial ice islands are used for mining of oil and gas in the Arctic. They represent
a cheap and environmentally friendly alternative to conventional drilling platforms,
making them well suited for exploratory drilling in offshore areas. Often this is a
single way to produce the explorative drilling in shelf of northern sees, where due
to severe ice conditions there is no possibility to deliver the usual platform. Such
approach has already been successfully realized in Canada [1]. An actual problem for
the safety of structures and personnel on the surface of the ice island, as noted in [2],
is its destruction due to drilling and seismic activity. Wave processes resulting from
drilling and earthquakes also affect the response to exploration seismology. Because
of the limited possibility of conducting experimental studies in realistic conditions,
the direction of numerical simulation is promising.
In this chapter, we consider a numerical simulation of the propagation of elastic
waves in an ice island during exploration seismology and seismic activity. In modern
computational software, the finite element method is used to study the stability of
structures like ice islands [3, 4]. For seismic wave propagation modeling, researchers
usually use the finite difference method [5], method of spectral elements [6], discontinuous Galerkin method [7, 8], and grid-characteristic method [9–12]. This work
was made using the grid-characteristic method with interpolation on regular rectangular grids (in 2D case) and parallelepiped (in 3D case), as well as the unstructured
triangular (in 2D case) and tetrahedral (in 3D case) meshes. This method is actively
used also for seismic problems, for example, in [13]. It was chosen, since it allows
one to set the correct boundary and contact conditions.
In Sect. 13.2, the considered problem formulations are described in detail.
Section 13.3 is devoted to the mathematical model used and the numerical method.
Section 13.4 presents the results of mathematical modeling of problems in the above
formulations. Section 13.5 concludes the chapter.
13.2 Problem Formulation
The wave propagation simulation area is an ice island with length of 300 m, height of
10 m, surrounded by 8 m deep seawater, and resting on solid ground (Fig. 13.1). Ice,
water, and soil are considered homogeneous. Elastic characteristics (longitudinal
and transverse velocity of sound propagation and density of media) are given in
Table 13.1.
The thickness of the seafloor is 10 m, and the thickness of the sedimentary rock
is 600 m. A gas reservoir is located under the sedimentary rock, which is simulated
by the boundary condition of the free boundary to simplify the task.
The following types of loads on the ice island are modeled: