The Innovative Design of Deep In Situ Pressure Retained Coring Based on Magnetic Field Trigger Controller

Table 1

Maximum magnetic force of the valve cover when the valve seat consists of two identical shape tile magnets in three schemes.

Distance (mm)	Maximum magnetic force (N)
	Scheme 1	Scheme 2	Scheme 3
1	259.329	354.435	161.725
5	68.370	131.817	53.001
10	19.124	49.643	18.332
15	7.851	22.130	7.991
20	4.380	10.368	3.926
25	2.817	5.049	2.077
30	1.859	2.486	1.158
35	1.179	1.229	0.661