Appliance of Rotary Wireline Coring Process in Marine Quaternary Stratum Drilling

In order to solve the problem of obtaining hard clay cores during drilling in Quaternary, the method of rotary wireline coring process and hammering wireline coring process is introduced to drilling and sampling. It can obtain cores in different lays through exchanging the coring equipment without lifting up the drilling pipes. In the survey of an offshore wind farm in South China Sea, the technology effectively solves the influence of wave heaving and high quality core samples are obtained. Taking the samples got in field into consideration, the rotary coring process has advantage of less disturbance and getting longer samples in hard mud layer. It can cover the shortage of hammering wireline coring process when drilling, which contributes to improving working efficiency.