Predicting the Healthy Operation of Heavy Oil Well Casings in Permafrost Regions

Table 1

Soil layer division and physical and mechanical parameters.

Layer	Soil type	Depth (m)	Density (kg/m^3)	Internal friction angle (°)		Dilatancy angle (°)		Cohesive force (kPa)
					T^+	F	T	F	T
1	Gravel and sand	0∼30	1900	30	32	10	5	1000	5
2	Silt	30∼54	1800	15	20	5	5	2000	40
3	Silty sand	54∼63	1900	15	22	5	5	2000	35
4	Clay	63∼69	1750	5	10	0.1	0.1	2000	100
5	Sand	69∼81	1900	25	30	10	5	1000	35
6	Clayey silt	81∼90	1850	10	17	5	5	2000	50
7	Silty clay	90∼96	1900	5	12	0.1	0.1	2000	75
8	Silt	96∼102	1800	15	20	5	5	2000	40
9	Sand	102∼135	1950	25	30	10	5	1000	35
10	Silt	135∼147	1800	15	20	5	5	2000	40
11	Sand	147∼153	1950	25	30	10	5	1000	30
12	Clay	153∼156	1750	5	10	0.1	0.1	2000	100
13	Silty sand	156∼162	1900	15	22.5	10	5	1000	35
14	Clay	162∼171	1750	5	10	0.1	0.1	2000	100

indicates permafrost and T⁺ indicates thawed soil.