钻井液密度对盐膏层蠕变影响的三维分析

THREE-DIMENSIONAL ANALYSIS ON HOW MUD WEIGHT AFFECTS THE GYPSUM-SALT BED CREEP

曾义金

Zeng Yijin

中石化石油勘探开发研究院钻井研究所, 山东德州 253005

Drilling Dept. of Petroleum Exploration and Development Research Inst., SINOPEC

井内钻井液密度设计和盐膏层蠕动变形规律的分析是成功地进行盐膏层钻井的关键。在研究盐岩力学特性基础上,对盐膏层特别是深部盐膏层钻井后因井内钻井液密度对地层蠕动造成井眼失稳进行了分析,并提出了盐膏层蠕动压力的计算模型。针对新疆塔里木盆地北部沙24井的盐膏岩蠕动压力进行了计算分析,结果表明,研究成果与实际观察到的现象相吻合。

The design of proper drilling fluid density in the hole, combining with the analysis on the creep tendency of salt bed is the key for successful drilling in the gypsum-salt formation. Based on the study of salt bed mechanics, the phenomena of hole instability in the gypsum-salt bed, especially in the deeper formation caused by unsuitable mud density is investigated, and a gypsum-salt bed creeping-pressure calculating model is proposed therefore. Well Sha-24 in North Tarim Basin is taken as an example, and the gypsum-salt creeping pressure in this well is analyzed. The result shows that this model coincides with the real condition in the well.

10.3969/j.issn.1000-7393.2001.06.001