开发中后期煤层含气量反算技术及其在储量复算中的应用——以沁水盆地潘庄气田3号煤层为例  

Inverse calculation technique for gas content of coal seams in late stage of development and application in reserve recalculation:A case study of No.3coal seam in Panzhuang CBM field,Qinshui basin

作　　者：田永净 吕玉民 王存武 朱学申 郭广山 杜希瑶 赖文奇 TIAN Yongjing;LYU Yumin;WANG Cunwu;ZHU Xueshen;GUO Guangshan;DU Xiyao;LAI Wenqi(CNO0C Research Insitute Lid.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《中国海上油气》2022年第6期110-116,共7页China Offshore Oil and Gas

基　　金：中国海油“七年行动计划”“煤层气增储上产技术研究(编号:CNOOC-KJ135ZDXM40 ZL01)”;中国海油“十四五”重大科技项目“煤层气地质工程关键参数表征及甜点区评价技术(编号:KJGG-2022-1001)”部分研究成果。

摘　　要：煤层气田勘探阶段测试含气量的参数井较少,对区域的代表性和控制性相对较差,导致储量估算时煤层含气量预测可能存在偏差。以开发中后期的沁水盆地潘庄煤层气田为例,提出了利用开发井进行煤层含气量反算的新方法。以Langmuir等温吸附理论为基础,在充分论证兰氏体积、兰氏压力和临界解吸压力取值的基础上,根据27口煤层参数井等温吸附特征及300余口开发井动态资料,对煤层原始含气量进行了反算。结果表明,潘庄煤层气田3号煤层含气量在19~30 m^(3)/t,平均含气量23.3 m^(3)/t,相较提储时平均18 m^(3)/t提高了29.6%。结合开发中后期取心测试含气量资料,利用数值模拟法对此次含气量反算结果进行了验证,误差在7.2%以内。本文研究为老气田煤层气储量复算提供了新思路,适用于参数井较少、煤岩等温吸附测试符合兰氏方程且气井产能认识清晰,处于开发中后期的煤层气田。In the exploration stage of coalbed methane field,there are few parameter wells for testing the gas content,and the representation and control of the region are relatively poor,which may lead to the deviation of coal seam gas content prediction in the estimation of reserves.Taking Panzhuang CBM field(in the late stage of development)in Qinshui basin as an example,a new method of inverse calculation of coal seam gas content for exploitation wells is proposed.Based on Langmuir isothermal adsorption theory,the original gas content of coal seam is calculated inversely according to the isothermal adsorption characteristics of 27 CBM parameter wells and performance data of more than 300 exploitation wells.The results show that the gas content of No.3 coal seam in Panzhuang CBM field ranges from 19 m^(3)/t to 30 m^(3)/t,with an average gas content of 23.3 m^(3)/t,which is 29.6%higher than the average gas content of 18 m^(3)/t before reserves increasing.Combined with the gas content testing data through coring in the middle and late stage of development,the numerical simulation method is used to verify the gas content inverse calculation results,and the error is within 7.2%.This study provides a new idea for the recalculation of CBM reserves,which is suitable for CBM fields in the middle or late stage of development with few parameter wells,coal isothermal adsorption tests in line with Langmuir equation and clear understanding of gas well productivity.

关 键 词：潘庄煤层气田 3号煤层 含气量反算 LANGMUIR方程 储量 

分 类 号：P618.11[天文地球—矿床学]