哈拉哈塘油田硬脆性泥页岩井壁失稳机理及对策  

Mechanism and Strategy to Deal with Borehole Instability of Hard and Brittle Shales in Halahatang Oilfield

作　　者：刘锋报[1] 邵海波 周志世[1] 张欢庆[1] 陈永衡[1] 

机构地区：[1]中国石油塔里木油田公司 [2]中国石油集团渤海钻探泥浆技术服务公司

出　　处：《钻井液与完井液》2015年第1期38-41,100,共4页Drilling Fluid & Completion Fluid

摘　　要：针对哈拉哈塘油田三叠系和志留系硬脆性泥页岩井壁失稳问题,分别从地层力学和地层物理化学2方面进行失稳机理及对策研究。研究结果表明,油田地层3大主应力分布规律为σZ>σH>σh,三叠系比志留系容易发生力学失稳;三叠系硬脆性泥页岩阳离子交换容量、蒙脱石率、胶体率和膨胀率分别为25.4 mmol/100 g、36.3%、76.4%和23.2%,表面水化能力较强,易发生物理化学失稳;志留系硬脆性泥页岩阳离子交换容量、蒙脱石率、胶体率和膨胀率都较低,分别为8 mmol/100 g、11.4%、25.1%和9.7%,水化膨胀能力较弱,但由于地层裂缝发育,易发生裂缝性失稳。通过提高钻井液在三叠系的密度、抑制性和在志留系的封堵性,在现场Ⅰ井和Ⅱ井试验均取得了较好的效果。Mechanism and strategy to deal with borehole instability of the Triassic System and Silurian System hard and brittle shale in Halahatang Oilfield were studied both from mechanics and physic-chemistry.The study shows that for the formations drilled,the magnitudes of the three principal stresses are in the following order:σ_Z>σ_H>σ_h,and shales in the Triassic System are more easily becoming mechanically instable than those in the Silurian System.Shales in the Triassic System have ion exchange capacity,montmorillonite content,colloidal content and percent rate of swelling of 25.4 mmol/100 g,36.3%,76.4%and 23.2%,respectively,meaning that the shales have great surface hydration capacity and are easy to become physicochemically instable.In field operations of Well Ⅰ and Well Ⅱ,by increasing mud density and enhancing the inhibitive capacity of mud in the Triassic System,and by improving the plugging capacity of mud in the Silurian System,borehole instability was almost eliminated.

关 键 词：井壁失稳 硬脆性泥页岩 抑制性 封堵性 哈拉哈塘油田 

分 类 号：TE282[石油与天然气工程—油气井工程] TE254.3