Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

Table 1

Comparison of average mechanical drilling speeds of Luo69 and Luo68 within same well intervals.

Formation	Well interval/m	⁢Avg. mechanical drill speed/(m⋅h^−1)		Relative speedup rate, %
		Luo68	Luo69
Dongying	2200~2510	8.86	20.91	136
Sha-1	2510~2750	8.90	10.60	19
Sha-2	2750~2830	5.02	6.52	30
Sha-3	2830~2850	3.57	5.96	70
Sha-4	2850~2910	1.92	6.78	254
Whole test interval	2200~2910	6.19	11.49	85.8