摘要
为了明确准噶尔盆地环东道海子凹陷侏罗系煤层气勘探方向,开展了煤层连井对比、井-震标定和地震资料解释以及煤层测、录井资料分析。研究结果表明:①准噶尔盆地侏罗系西山窑组和八道湾组煤层发育,厚度较大,分布稳定,其中西山窑组发育2~3层煤层,累计最大厚度为20 m,八道湾组发育2~4层煤层,累计最大厚度为29 m。煤岩含气性好,录井气测异常明显。②环东道海子凹陷内中下侏罗统煤系烃源岩为中等—好烃源岩,Ro为0.6%~0.8%,处于低成熟—成熟阶段,具有较好的生气能力;天然气碳同位素分析结果显示,煤层气亦可来源于深部高成熟腐殖型有机质。③研究区西山窑组煤岩为中—低孔、低渗储层,孔隙度为7.0%~20.8%,渗透率为0.32~8.67 mD;八道湾组煤岩为低孔、中—低渗储层,孔隙度为5.6%~7.8%,渗透率为2.30~13.83 mD;煤层夹于泥岩之间且煤层之上区域性泥岩盖层分布广泛,封盖保存条件好。④研究区存在凹陷区源内煤层气富集成藏和凸起区深部外源气富集成藏等2种模式。环东道海子凹陷煤层气勘探潜力较大,特别是凹陷北东方向斜坡区和凹陷北部斜坡—滴南凸起区。
A series of studies,such as coal seam connecting well profiles,logging-seismic calibration,seismic profile interpretation,analysis of coal seam logging data,have been carried out to clarify the exploration direction of coalbed methane in the area of Encircling Dongdaohaizi sag.The results show that:(1)The Jurassic Xishanyao Formation and Badaowan Formation in this area developed coal seams with thick,widely distribution.Xishanyao Formation develops 2-3 layers of coal seams,with a cumulative maximum thickness of 20 m,Badaowan Formation develops 2-4 layers of coal seams,with a cumulative maximum thickness of 29 m.Analysis of coal rock gas content and abnormal logging gas shows that good gas bearing property.(2)The analysis of the main controlling factors for coalbed methane reservoir formation indicates that the middle and lower Jurassic coal measure source rocks in the sag good,reaching a medium to good e source rock level,with Ro value ranging from 0.6%to 0.8%.It has good ability to generate hydrocarbon gas.In addition,based on the analysis results of natural gas carbon isotopes,coalbed methane also can come from deep highly mature humic source rock.(3)Xishanyao Formation coal rock is a medium-low porosity and low permeability reservoir,with value of porosity range from 7.0%to 20.8%,value of permeability range from 0.32 mD to 8.67 mD.Badaowan Formation coal rock is a low porosity and medium-low permeability reservoir,with value of porosity range from 5.6%to 7.8%,value of permeability range from 2.3 mD to13.83 mD.The coal seam is sandwiched between mudstones,and the regional mudstone cover is widely distributed above the coal seam,due to a good sealing conditions in this area.(4)There are two modes of coalbed methane enrichment and accumulation in this area:The model of coalbed methane enrichment and accumulation in the source area of the sag and a model of enriched external gas accumulation in the deep bulge area.It is considered that there are greater exploration potential of encircling Dongdaohaizi sag,especially,exploration in slope area of Dongdaohaizi sag northeastern direction and Dongdaohaizi sag northern slope to Dinan uplift.
作者
余琪祥
罗宇
段铁军
李勇
宋在超
韦庆亮
YU Qixiang;LUO Yu;DUAN Tiejun;LI Yong;SONG Zaichao;WEI Qingliang(Wuxi Petroleum Geology Institute,Research Institute of Petroleum Exploration and Development,SINOPEC,Wuxi 214126,Jiangsu,China;Key Laboratory of Petroleum Accumulation Mechanisms,SINOPEC,Wuxi 214126,Jiangsu,China;College of Geoscience and Surveying Engineering,China University of Mining and Technology,Beijing 100083,China)
出处
《岩性油气藏》
CAS
CSCD
北大核心
2024年第6期45-55,共11页
Lithologic Reservoirs
基金
中国石化科技部项目“中国石化煤层气勘探战略选区研究”(编号:P21086-5)和“油气勘查区块分类分级评价与矿权策略研究”(编号:P24235)联合资助。
关键词
煤层气
源内成藏
外源富集
斜坡区
低孔低渗
区域性泥岩盖层
西山窑组
八道湾组
侏罗系
环东道海子凹陷
准噶尔盆地
coalbed methane
accumulation in the source
accumulation out-of-source
slope area
lower porosity and low permeability
regional mudstone cap
Xishanyao Formation
Badaowan Formation
Jurassic
encircling Dongdaohaizi sag
Junggar Basin
作者简介
第一作者:余琪祥(1967-),男,高级工程师,主要从事油气矿权评价和石油地质综合研究。地址:(214126)江苏省无锡市滨湖区蠡湖大道2060号。Email:yuqx.syky@sinopec.com。
