钻井液与完井液2017，Vol.34Issue(6)：35-40,6.DOI:10.3969/j.issn.1001-5620.2017.06.007
煤层气弱凝胶和微固相双效钻井液体系
Dual-effect Drilling Fluids with Weak Gel and Micro Solids for CBM Drilling
摘要
Abstract
Dual-effect drilling fluids with weak gel and micro solids have been developed to better satisfy the needs of borehole wall protection in coal bed methane (CBM) drilling,to minimize the damage to CBM pay zones by drilling fluid,and to realize safe and efficient drilling operations.Laboratory evaluation of the drilling fluids showed that they had excellent basic properties,good inhibitive capacity,temperature resistance (50 ℃),salt resistance (NaCl,CaCl2,MaCl2) and drilled cutting (coal) tolerance.A 500 mL weak-gel drilling fluid sample and a micro-solid drilling fluid sample treated respectively with 0.1 g cellulose,0.1 g neutralized a-amylase and 0.1 g compound enzyme had rates of degradation of the two drilling fluid sample were 90.9％ and 83.0％,respectively.The weak-gel drilling fluid and the micro-solid drilling fluid had friction coefficient of0.17 and 0.12,respectively,and percent permeability recovery of 91.3％ and 82.3％,respectively,exhibiting good lubricity and reservoir protection capacity.Observation under microscopy showed that contact angles of the two drilling fluids were increased,capable of protecting formations from being damaged by water block.The compound bio-enzyme used in the drilling fluids not only reduced the apparent viscosity of the drilling fluids,it also helped degrade mud cakes,thereby minimizing blocking of fractures in CBM zones,greatly mitigating the negative effects of mud cakes on CBM production.关键词
煤层气/弱凝胶钻井液/微固相钻井液/生物酶/双效Key words
Coal bed methane/Weak-gel drilling fluid/Micro-solid drilling fluid/Bio-enzyme/Duel-effect分类
能源科技引用本文复制引用
王道宽,彭斌,乌效鸣,惠增辉..煤层气弱凝胶和微固相双效钻井液体系[J].钻井液与完井液,2017,34(6):35-40,6.基金项目
国家科技重大专项“山西重点煤矿区煤层气与煤炭协调开发示范工程”(2016ZX05067)和山西省煤基重点科技攻关项目“煤层气钻井关键技术及装备研发”(MQ2014-04)资助项目. （2016ZX05067）
