Table 1 Parameters used in simulation process

Surface temperature, °C

15.0

Geothermal gradient, °C/km

27.8

Vertical depth of well, m

2605

Rock’s density of, kg/m³

2800

Rock’s specific heat, J/(kg·°C)

920

Rock’s thermal conductivity, W/(m·°C)

3.5

Thermal conductivity of insulation pipe, W/(m·°C)

0.2

Density of mud, kg/m³

1800

Insulation tube diameter, mm

110

Length of insulation tube, m

2600

Vertical well tube diameter, mm

339.7

Horizontal well tube diameter, mm

177.8

Thermal conductivity of graphene, W/(m·°C)

5300

Thermal conductivity of mud, W/(m·°C)

1.5

Cement’s thermal conductivity, W/(m·°C)

0.7