煤层气储层压裂液添加剂的优选  

Screening and Optimizing Additives of Water Base Hydrofracturing Gelling Fluids for Coalbed Methane Reservoir

作　　者：丛连铸[1] 吴庆红[2] 赵波 

机构地区：[1]中国矿业大学资源学院,江苏徐州221008 [2]中国石油勘探开发科学研究院廊坊分院,河北廊坊065007 [3]中国石油股份公司总裁办,北京100124

出　　处：《油田化学》2004年第3期220-223,共4页Oilfield Chemistry

摘　　要：介绍了沁水盆地沁南地区无烟煤Ⅲ(3号煤)煤层气储层的物性特征:低渗中孔低压;粘土含量高,膨胀性强;水润湿吸附性差。该地区地表水符合配制压裂液要求。实验筛选了煤层气井压裂液添加剂,主要目标是减少压裂液对煤层气储层的伤害,筛选结果如下:稠化剂为羟丙基瓜尔胶GRJ和香豆胶;交联剂为硼砂;粘土稳定剂为KCl,KCl可造成测定压裂裂缝几何形状所需的高矿化度环境,但会降低压裂液粘度,其用量应适当;所选助排剂为DL 10和D 50,对助排剂的要求除界面活性高外,更重要的是在煤样表面吸附量小,吸附速率小,接触角大,不易润湿煤基质表面;配液用地表水显微酸性,当煤层地下水显碱性时应调节压裂液的pH值;使用过硫酸铵为破胶剂时,30℃下破胶时间很长,加入活化剂BT 6或TA 1使破胶时间缩短到1～2小时;对于煤层气井压裂液,当温度低,压裂液配制后存放时间短时,可不加杀菌剂(如甲醛液,TH 1)。图2表8参4。3~# coalbed seam as methane reserve of Qinnan region in Qinshui Basin is characterized by low permeability, medium porosity, and low pressure; high content of clay minerals and strong swellability; and weak wettability and adsorption. Screening and optimizing additives in water base gelling fracturing fluids (GFFs) for the coalbed methane wells in this region are performed through laboratory experiments aimed particularly on reducing the damage to the coalbed seam caused by GFFs. Following additives are selected: HPG 'GRJ' and Fenugreek gum as thickener; borax as crosslinker; KCl as clay stabilizer, which can create high salinity media needed for fractured fissure geometry measurements but reduces viscosity of the GFFs somewhat and the dosage of which should be controlled properly; DL-10 and D-50 as backflow aids, for which the most important performance property is small amount and low rate of adsorption and high contact angle on the coal surfaces, and weak wettability of these surfaces, besides of high interfacial activity; pH adjusting agent needed in cases when the coalbed water is alkalinous and the surface water taken for fluid preparing—slightly acidic; ammonium persulfate as gel breaker, with which the gel breakdown time at 30℃ is long and shortened to 1—2 hrs with activator BT-6 or TA-1 introduced additionally; bactericide formalin or TH-1, which may not be applied at lower temperatures and shorter time of standing of the GFF prepared.

关 键 词：压裂液添加剂 储层 压裂裂缝 破胶剂 助排剂 煤层气井 稠化剂 煤样 过硫酸铵 无烟煤 

分 类 号：TE357[石油与天然气工程—油气田开发工程] TE377