滇东老厂区块煤层气井峰值产气量主控地质因素分析  

Analysis on controlling geological factors for peak gas production of CBM wells inLaochang blcok,eastern Yunnan Province

作　　者：康刘旭 胡滨[2] 康永尚 曾雯婷[4] 王伟洪 顾骄杨 田博凡 KANG Liuxu;HU Bin;KANG Yongshang;ZENG Wenting;WANG Weihong;GU Jiaoyang;TIAN Bofan(Research Institute of China National Petroleum Corporation Xinjiang Oilfield Development Company,Karamay 834000,Xinjiang,China;China United Coalbed Methane Co.,Ltd.,Beijing 100011,China;State Key Laboratory of Petroleum Resources and Prospecting of China University of Petroleum(Beijing),Beijing 102249,China;PetroChina Coalbed Methane Co.,Ltd.,Beijing 100028,China;Beijing Youyuan Hengye Technology Co.,Ltd.,Beijing 102200,China;Unconventional Oil&Gas Branch,China National Offshore Oil Corporation,Beijing 100011,China)

机构地区：[1]中国石油新疆油田开发公司研究所,新疆克拉玛依834000 [2]中联煤层气有限责任公司,北京100011 [3]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [4]中石油煤层气有限责任公司,北京100028 [5]北京油源恒业科技有限公司,北京102200 [6]中海石油(中国)有限公司非常规油气分公司,北京100011

出　　处：《河南理工大学学报（自然科学版）》2022年第3期38-47,共10页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家科技重大专项项目(2016ZX05044-005)。

摘　　要：基于滇东老厂区块6口排采先导试验井的煤层气地质资料和排采动态资料,在分析产水和产气特征基础上,探讨老厂区块影响煤层气井排采效果的主控地质因素和影响机理,并提出主控地质因素的下限指标和井层选择建议。结果表明:(1)单井动用资源丰度、动用煤层的平均含气饱和度和平均渗透率是煤层气井峰值产量的3个主控地质因素,它们共同控制着煤层气井的峰值产气量;(2)动用煤层的含气饱和度通过控制见气时的井底流压降低幅度影响见气时和见气后的动态渗透率,从而对峰值产气量产生影响,较高的含气饱和度有利于在较低的井底流压降低幅度时见气,有利于保持较高的动态渗透率,从而有利于气体产出,实现较高的峰值产气量;(3)在老厂区块低渗透煤储层条件下获得较高峰值产气量(大于600 m^(3)/d)的单井动用资源丰度下限,为1×10^(8)m^(3)/km^(2),平均含气饱和度下限为70%,平均渗透率下限为0.08 mD;若平均含气饱和度达到90%以上,则平均渗透率的下限可降为0.03 mD。建议老厂区块今后在井层优选时规避断层影响,即在构造模型指导下选择远离断层的井位;在选择合层排采煤层组合时,将动用资源丰度1×10^(8)m^(3)/km^(2)作为下限,动用煤层的平均含气饱和度70%作为下限,平均渗透率0.08 mD作为下限。Based on the geological data and dynamic data of CBM from six pilot wells in the Laochang block,on the basis of the analysis of water and gas production characteristics,the main geological factors and influencing mechanism that influenced the coalbed methane drainage effect in the Laochang block were disscussed,and the lower limit index of the main geological factors and suggestions for well layer selection were put forward.The results showed that:(1)The producing resource abundance,the average gas saturation and the average permeability of the coal seam were the three main geological factors controlling the peak gas production;The three factors worked together to control the peak production of coalbed methane;(2)Gas saturation affected the dynamic permeability at and after gas breakthrough by controlling the reduction of bottom hole flow pressure at gas breakthrough,which had an impact on peak production.Higher gas saturation was conducive to gas breakthrough at lower bottom hole flow pressure reduction,and was conducive to maintaining higher dynamic permeability,which conducive to gas production and achieving higher peak gas production;(3)Under the background of low permeability coal reservoir in the Laochang block,the lower limit of production resource abundance was 1×10^(8) m^(3)/km^(2),the lower limit of gas saturation was 70%,and the lower limit of permeability was 0.08 mD.If the gas saturation reached more than 90%,the lower limit of permeability could be reduced to 0.03 mD.It was suggested that in the future,when optimizing the well layers in the old plant area,it was needed to avoid the influence of faults,and under the guidance of the structural model,to select the well positions far away from faults;When selecting the multi-seam drainage and mining coal seams,the abundance of produced resources of 1×10^(8) m^(3)/km^(2)should be taken as the lower limit,taking the average gas saturation of produced coal seams of 70%should be taken as the lower limit,and the average permeability of 0.08 mD should be ta

关 键 词：老厂区块 合层排采 峰值产气量 单井动用资源丰度 平均含气饱和度 平均渗透率 

分 类 号：TU528.2[建筑科学—建筑技术科学] O312.3[理学—一般力学与力学基础]