摘要
鄂尔多斯盆地东缘韩城区块煤层气资源丰富,受构造地质条件影响,不同构造分区的煤层气单井产能差异较大。为明确该区块煤层气高产井地质主控因素,基于构造、煤储层特征及煤层气富集控制因素,结合气田生产数据,对煤层气高产井的地质主控因素进行了剖析。研究结果表明:(1)煤层气井产能受“构造条件、水动力条件、煤体结构”三大因素控制,其中构造条件控制煤层气富集成藏,水动力条件影响煤层气保存,煤体结构影响煤储层渗透率;(2)区块内的煤层气高产井主要分布于次级构造发育区,地层水矿化度介于(2~11)×10^(3)mg/L,原生—碎裂煤平均厚度为4.4m,单井日产气量大于1000m^(3);(3)小断层或者微构造改善了煤储层的渗透性,尤其是次级构造高部位产生的裂隙,有利于煤层气解吸渗流,有利于煤层气高产;(4)在构造活动较剧烈的条件下,大断层附近易于形成煤层气逸散通道,不利于煤层气的保存。结论认为,鄂尔多斯盆地东缘韩城区块构造运动不但造就了各种构造形态,而且使煤体结构发生了变化,不同构造形态下的水动力条件也不同,因此构造运动对韩城区块煤层气井高产起到了极为重要的控制作用;该研究成果对韩城区块的煤层气开发调整具有一定的指导意义,对地质条件类似的煤层气区块具有借鉴意义。
Coalbed methane(CBM) resources are abundant in the Hancheng block at the eastern edge of the Ordos Basin,where the structural zones are significantly different in single-well productivity,due to geological conditions.The main geological factors controlling high productivity of CBM wells in the block are identified on the basis of the characteristics of structures and coal reservoirs,controlling factors of CBM enrichment,as well as field production data.The findings are obtained in three aspects.First,CBM well productivity is mainly controlled by three factors,i.e.structural conditions,hydrodynamic conditions,and coal structures.Structural conditions control the enrichment and accumulation of CBM,hydrodynamic conditions dominate the preservation of CBM,and coal structures determine the permeability of coal reservoirs.Second,high-yield CBM wells are mainly distributed in areas with positive microstructures,high formation water salinity,and primary-fragmented coals.In the Hancheng block,such wells are found in areas with secondary structures,formation water salinity of(2-11)×10^(3) mg/L,and primary-fragmented coals having an average thickness of 4.4 m,showing a daily production of over 1 000 m^(3) per well.Third,small faults or microstructures improve the permeability of coal reservoirs.Especially,fractures created in the high parts of positive microstructures are conducive to the desorption and seepage of CBM and thus the high production of CBM.Fourth,Under conditions of intense tectonic activity,gas escape channels may easily form near major faults,which is not conducive to the preservation of CBM.Tectonic movements create various structural forms and also change the coal structures.Moreover,hydrodynamic conditions are variable under different structural forms.Therefore,tectonic movements play a critical role in controlling the high productivity of CBM wells in the Hancheng block.This has a certain guiding significance for the adjustment of CBM development in the block and is also useful for CBM blocks with simil
作者
熊先钺
季亮
张正朝
闫霞
伊伟
杨宏涛
邢雪杰
刘清
XIONG Xianyue;JI Liang;ZHANG Zhengchao;YAN Xia;YI Wei;YANG Hongtao;XING Xuejie;LIU Qing(PetroChina Coalbed Methane Company Limited,Beijing 100028,China;China United Coalbed Methane National Engineering Research Center Co.,Ltd.,Beijing 100095,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2024年第3期64-71,共8页
Natural Gas Industry
基金
中国石油天然气股份有限公司科学研究与技术开发项目“深地煤岩气成藏理论与效益开发技术研究”(编号:2023ZZ1804)
中石油煤层气有限责任公司科技项目“鄂东煤层气田气藏精细描述与二次开发技术研究与应用”(编号:2022-KJ-18)。
关键词
鄂尔多斯盆地
韩城区块
煤层气
高产井
构造条件
富集规律
地质主控因素
Ordos Basin
Hancheng block
CBM
High-productivity wells
Structural conditions
Enrichment pattern
Geological factor
