二连盆地霍林河凹陷低煤阶煤层气储层特征  

Characteristics of low-rank CBM reservoirs,Huolinhe sag,Erlian Basin

作　　者：斯琴毕力格 宋换新 林海涛[3] 李玲 田文广 SIQIN Bilige;SONG Huanxin;LIN Haitao;LI Ling;TIAN Wenguang(College of Resources and Environment,Yangtze University,Wuhan,Hubei 430100,China;Hubei Cooperative Innovation Center of Unconventional Oil and Gas,Yangtze University,Wuhan,Hubei 430100,China;Inner Mongolia Coal Exploration Unconvention-al Energy Co.,Ltd.,Hohhot,Inner Mongolia 010000,China;Langfang Branch,PetroChina Research Institute of Petroleum Explora-tion&Development-Langfang Branch,Langfang,Hebei 065000,China)

机构地区：[1]长江大学资源与环境学院,湖北武汉430100 [2]非常规油气湖北省协同创新中心(长江大学),湖北武汉430100 [3]内蒙古煤勘非常规能源有限责任公司,内蒙古呼和浩特010000 [4]中国石油勘探开发研究院廊坊分院,河北廊坊065000

出　　处：《天然气技术与经济》2023年第4期7-13,21,共8页Natural Gas Technology and Economy

基　　金：中国石油天然气股份有限公司“十四五”前瞻性基础性重大科技项目“煤层气勘探开发技术研究”下属课题3“煤层气新区新层系新领域战略与评价技术研究”(编号:2021DJ2303);中央引导地方科技发展资金项目(编号:2022ZY0018)。

摘　　要：为了揭示二连盆地霍林河凹陷低煤阶煤层气储层特征,在对地质背景进行研究的基础上,以霍林河凹陷下白垩统大磨拐河组低阶煤为研究对象,利用低温液氮吸附实验、光学显微以及孔渗测试等方法,分析了低阶煤的孔隙结构、裂隙结构、渗透率和孔渗主控因素,明确了大磨拐河组低煤阶煤层气储层性质和主控因素。研究结果表明:①大磨拐河组低煤阶煤层气储层主要以微小孔(孔径小于100 nm)为主,占比在90%以上,孔隙形态以一端封闭的不透气孔为主,孔隙度介于11.33%~26.32%、平均值为18.62%,属于中等孔隙度;②裂隙类型以Ⅱ类为主,裂隙宽度大于5μm,长度小于10 mm;③储层渗透率介于0.067~38.550 mD、平均值为5.440 mD,一般介于0.067~1.830 mD,渗透率整体较低;④孔隙度、渗透率主要受显微组分、灰分产率和裂隙发育程度的影响。结论认为,该研究成果可以给二连盆地霍林河凹陷及其他地区的低煤阶煤层气勘探开发工作提供借鉴。Based on some investigations on geological setting of Huolinhe sag,Erlian Basin,influential factors on pore and fracture structure,permeability,as well as porosity and permeability were analyzed for the low-rank coal of the Low Creta⁃ceous Damoguaihe Formation in this sag through low-temperature nitrogen adsorption experiments,optical microscopic method,and porosity and permeability test in order to reveal characteristics of coalbed methane(CBM)reservoirs with low rank in this area.In addition,both reservoir properties and influential factors were pointed out.Results show that(i)there developed micropores(pore diameter<100 nm)predominantly in these CBM reservoirs,accounting for over 90%.Most of them are gas impermeable with one end closed.And their porosity is between 11.33%and 26.32%,18.62%on average,be⁃longing to medium porosity;(ii)there largely extended II-type fractures with the width more than 5μm and the length less than 10 mm;(iii)the permeability varies from 0.067 mD to 38.550 mD,5.440 mD on average,often in the range of 0.067-1.830 mD,staying at low level;and(iv)not only porosity but permeability are principally affected by maceral,ash content and fracture development.In conclusion,these findings may provide reference for the exploration and development of the low-rank CBM in Huolinhe sag and other areas of Erlian Basin.

关 键 词：二连盆地 霍林河凹陷 低煤阶煤层气 储层特征 主控因素 勘探开发 

分 类 号：P618.13[天文地球—矿床学]