塔里木泛哈拉哈塘桑塔木组硬脆性泥岩井壁失稳机理及对策  

STUDY ON INSTABILITY MECHANISM OF HARDBRITTLE MUDSTONE BOREHOLE WALL AT SANGTAMU GROUP IN HALAHATANG BLOCK OF TARIM OILFIELD AND COUNTERMEASURES

作　　者：程善平[1] 鄢家宇 曹鹏[1] 杨美纯 周彪[1] 许潇[1] 汤吉庆 邓伯龙 CHENG Shanping;YAN Jiayu;CAO Peng;YANG Meichun;ZHOU Biao;XU Xiao;TANG Jiqing;DENG Bolong(PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China)

机构地区：[1]中国石油塔里木油田公司

出　　处：《钻采工艺》2018年第5期23-24,41,132,共4页Drilling & Production Technology

摘　　要：针对塔里木油田泛哈拉哈塘区块侧钻井在奥陶系桑塔木组钻进期间的井壁失稳问题,通过实验分析发现,该区块岩性属硬脆性泥岩,层理和裂隙发育,钻井液滤液的渗入导致填充物水化分散;新井眼周围失去原有的力学平衡,形成应力坍塌;钻井液受CO_3^(2-)/HCO_3^-污染导致性能恶化。此外影响井壁失稳的因素还有:井斜角、钻井液浸泡时间和钻井液密度。针对该区块桑塔木组侧钻期间的复杂特点和影响井壁失稳的因素,从造斜点的选择、工程措施、钻井液措施和碳酸根碳酸氢根污染的处理等方面提出合理的应对措施,对在桑塔木组侧钻期间的安全钻进具有指导意义。Aiming at the borehole instability during drilling of the Ordovician Sangtamu group at Halahatang block of Tarim Oilfield,the wellbore instability mechanism is analyzed.It is found that the lithology at the block is hard and brittle mudstone,bedding and fracture developed.The infiltration of drilling fluid filtrate leads to the rock hydration and dispersion,the new well bore loses its original mechanical equilibrium and collapses under stress,and the drilling fluid is deteriorated by CO 2-3/HCO-3contamination.the factors affecting the wellbore instability are well inclination,drilling fluid soaking time and drilling fluid density.According to the complicated characteristics of Sangtamu group during sidetracking and the factors that influence the wall instability,proper measures regards KOP selection,engineering,drilling fluid and carbonate bicarbonate pollution are proposed,providing guidance on safe sidetracking through Santamu group.

关 键 词：桑塔木组 井壁失稳 机理 影响因素 应对措施 

分 类 号：TE21[石油与天然气工程—油气井工程]