Flow Field Characteristic Study of Horizontal Section PDC Bit in the Southeast of Chong Qing Wu Feng – Long Ma Xi Shale Reservoir

Abstract:

The Southeast of Chong Qing Wu Feng – Long Ma Xi group is a national shale gas exploration and development key formation. Shale contains high clay minerals,It makes serious borehole instability and large of cuttings transport.The segment length of the horizontal well, is easy to form cuttings bed.Strong shale plastic makes ROP low. In this paper, It calculates the closed N-S equation based on the k-ε two-equation model by using numerical simulation method,studys the Φ 215.9 mm PDC bit´s nozzle diameters. When the center nozzle diameter is 12.70mm in a long horizontal section shale reservoir,It reachs the diameter of external nozzle is 8.74mm ~ 11.13mm optimal for PDC bit downhole flow field.The center and peripheral nozzle diameter of PDC bit should have a certain class difference, 2 ~ 5 grades is optimal. When the peripheral nozzle diameter is 11.13mm, the center of the nozzle diameter should be greater than or equal to 11.13mm for PDC bit flow field.The center nozzle diameter can not be smaller than the external diameter of the nozzle. The study can guide the shale reservoir horizontal section PDC bit design,improve ROP and cleaning rock,reduce the probability of cuttings settlement in the horizontal section.

• Periodical: Applied Mechanics and Materials (Volumes 316-317)
• Pages: 807-814
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.316-317.807
• Online since: April 2013
• Authors: Pei He, Li Jun Cheng, Ming Gong, Ke Xiong Song, Yu Zhu
• Keywords: Assisted Breaking Rock, Cuttings, Flow Field Characteristics, Horizontal Section, Nozzle Diameter, PDC Bit, Shale Reservoir, Southeast of Chong Qing Wu Feng – Long Ma Xi Group

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