Research on relationship between weight-on-bit and drilling rate during jetting drilling in sub-bottom deepwater

The mechanical drilling rate of jetting drilling in sub-bottom deepwater relates closely to formation strength, drilling bit structure, hydraulic parameters and so on, and according to practice, Weight-on-Bit（WOB）is one of the important factors impacting the mechanical drilling rate. In order to examine the relationship between WOB and mechanical drilling rate for jetting during in deepwater, simulation tests about jetting technology are carried out. The model of inter-relations between WOB and mechanical drilling rate is found, which is suitable for the Baiyun area, through analysis and processing of the data of simulation tests. The theoretical model is applied and checked by the real-test data of Baiyun 6-1-1 well. The conclusion indicates that the best WOB and the maximal mechanical drilling rate calculated by the theoretical model match the real-test data. Therefore, the research result could provide scientific basis for tripping in surface pipe by jetting in deepwater drilling.