MEG在泥页岩地层的井壁稳定机理研究  

MECHANISM OF MEG FOR WELLBORE STABILITY IN SHALE FORMATIONS

作　　者：雷祖猛[1] 赵虎[1] 司西强[1] 

机构地区：[1]中国石化中原石油工程有限公司钻井工程技术研究院

出　　处：《天然气勘探与开发》2015年第2期68-71,9-10,共4页Natural Gas Exploration and Development

基　　金：中国博士后科学基金(2011M501194)"钻井液用糖苷基季铵盐的合成及其抑制机理研究";中国博士后科学基金(2012T50641)"钻井液用两性甲基葡萄糖苷的合成及其作用机理";中石化先导项目(SG12035)"水平井烷基糖苷无土相钻井液技术";中原石油勘探局科技攻关项目(2011231)"钻井液用阳离子烷基糖苷的研究"联合资助

摘　　要：为了探索甲基葡萄糖苷(MEG)在泥页岩地层的井壁稳定作用机理,对MEG降低水活度、在黏土表面的吸附性、半透膜效率以及抑制性变化规律进行了研究。结果表明,MEG在黏土表面吸附达到一定浓度后形成半透膜,MEG浓度越高半透膜越致密,可抑制黏土的水化分散,岩心回收率最高可达99%;MEG同时可显著降低水活度,最高可降低至0.85以下。对MEG的成膜规律进行了探索,MEG在泥页岩表面的膜效率同MEG浓度、浸泡时间有关系,MEG浓度越大、膜效率越高,随着浸泡时间延长,膜效率降低。MEG通过在黏土表面吸附成膜抑制黏土水化和提高膜效率维持了井壁的稳定。Methyl glucoside(MEG)plays an important role in wellbore stability, especially in shale formations. In order to make its mechanisms clear, we study some MEG performances, including water activity lowering, adsorbability on clay surface, semi-permeable membrane efficiency, and changing rule of inhibition. Results show that,when reaching to a certain concentration at clay surface, the MEG forms a semi-permeable membrane which can inhibit clay hydration dispersion, finally resulting in the recovery rate of core being up to 99%. The higher is the concentration of MEG, the denser is the membrane. The MEG can also lower significantly the water activity up to below 0.85. MEG membrane-forming rules indicate that the membrane efficiency on shale surface is correlated with its concentration and soaking time. The efficiency increases with increasing concentration, and decreases with increasing soaking time. Therefore, through inhibiting clay hydration and raising membrane efficiency, MEG may maintain this wellbore stability.

关 键 词：MEG 泥页岩 膜效率 井壁稳定 

分 类 号：TE28[石油与天然气工程—油气井工程]