Pump injected reverse circulation drilling is a new drilling method. It has lots of advantages (such as cleaned hole and high ROP) compared with previous method, which can be used in drilling complex structural well. As we all know, cyclic pressure loss is one of the most important topics in drilling. The laws of cyclic pressure loss in different nozzles or mud parameters are studied experimentally in lab. The paper analyses the major factors affected cyclic pressure loss, according to results of the simulated experiment. It comes to the conclusions that the area of the bit nozzles should be a half of the drilling stem. And the edge of the bit is the best position to place the bit nozzles. At the same time, the cyclic pressure loss can be higher while the density of drilling fluid increases. However, the density doesn’t seem to affect the best arrangement of bit nozzles. Theoretical basis is provided for optimized design of pump injected reverse drilling bit nozzles.

layout-grid-mode: both, page-break-after: auto, page-break-before: auto, direction: ltr, text-align: justify, margin: 0pt, text-justify: inter-ideograph, line-height: normal, text-autospace: ideograph-numeric, text-indent: 0pt, mso-pagination: none, mso-outline-level: body-text, mso-hyphenate: auto, mso-layout-grid-align: auto, punctuation-trim: none, punctuation-wrap: hanging, mso-line-break-override: none, mso-vertical-align-alt: auto">font-family: Calibri, font-variant: normal, vertical-align: baseline, text-transform: none, color: windowtext, mso-ascii-font-family: Calibri, mso-fareast-font-family: 宋体">Pumpfont-family: Calibri, font-variant: normal, vertical-align: baseline, text-transform: none, color: windowtext, mso-ascii-font-family: Calibri, mso-fareast-font-family: 宋体"> font-family: Calibri, font-variant: normal, vertical-align: baseline, text-transform: none, color: windowtext, mso-ascii-font-family: Calibri, mso-fareast-font-family: 宋体">injected reverse circulation drilling, Cyclic pressure loss, Bit hydraulic parameters, Experiment, Optimization