Abstract: According to a lot of theoretical studies, laboratory experi-ments and oilfield experience, It was proved that the bottom-hole flow field seriously affected the drilling efficiency, down-hole safety and bit operation life. The geometry shapes and ar-rangements of the nozzle are the key factors to determine that
the bottom-hole flow field is reasonable or not. In order to de-velop the predictable and quantitative research technology, the potential flow theory was used to simulate the bottom-hole crossflow field. Compared the results of the simulation to the experiment in the laboratory, it was shown that the result of the numerical simulation about bottom-hole crossflow field can
describe the cases of several jet interactions under the condition
of the deferent nozzle combinations, different lateral inclina-tions, different rear inclinations. It can provide a certain theory supports for the evaluation of the bottom-hole flow field and drilling efficiency.

Key words: bottom-hole crossflow field, potential flow theory, jet, digital simulation, result analysis