海拉尔盆地呼和湖凹陷大二段低煤阶煤层气成藏条件及有利勘探区预测  

Accumulation conditions and favorable exploration areas prediction of lowrank coalbed methane in Member K_(1)d_(2) of Huhehu Sag in Hailar Basin

作　　者：马文娟[1] MA Wenjuan(Exploration and Development Research Institute of PetroChina Daqing Oilfield Co Ltd,Daqing 163712,China)

机构地区：[1]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《大庆石油地质与开发》2022年第1期33-40,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“大型油气田及煤层气开发”(2016ZX0504);中国石油天然气股份有限公司重大科技专项“煤层气勘探开发关键技术研究与应用”(2017E-14);大庆油田有限责任公司科研项目“海拉尔盆地煤炭地下气化资源潜力及有利区优选研究”(202121KT002)。

摘　　要：海拉尔盆地呼和湖凹陷大磨拐河组煤层主要发育褐煤,是中国低阶煤层气资源重点勘探目标区。由于该区受多期构造运动控制,煤层发育条件比较复杂,煤层气成藏条件与富集机理认识不清,为下一步煤层气勘探部署增加了难度。为了研究呼和湖凹陷大二段煤层气分布规律并指导勘探部署,在煤层发育及含气特征研究的基础上,通过对HM2井大二段已发现煤层气成藏条件解剖,对呼和湖凹陷大二段煤层气成藏模式进行了研究。结果表明:呼和湖凹陷煤层大二段最为发育,最大累计厚度100 m以上,全区分布;沉积环境、构造特征及水文地质是大二段煤层气成藏的主要条件;大二段发育有局部高点和凹陷边缘斜坡带富集2种煤层气成藏模式。预测出大二段Ⅰ类煤层气成藏有利区面积251.97 km^(2)和Ⅱ类煤层气成藏有利区面积199.06 km^(2)。研究结果为指导呼和湖凹陷大二段煤层气勘探提供了理论依据,对实现海拉尔盆地煤层气资源的规模发现具有重大意义。Lignite is mainly well-developed in Damoguaihe Formation coal seams in Huhehu Sag of Hailar Basin,and is one of key exploration target of low-rank coalbed methane(CBM)resource in China.This area is controlled by multi-stage tectonic movements,coal seam development conditions are complex,and coal seam gas accumulation conditions and enrichment mechanism are not clear,bringing more challenge for next-step coal seam gas exploration deployment.In order to study distribution law of coalbed methane in Member K;d;of Huhehu Sag and guide its exploration deployment,based on studies of coal seam development and gas-bearing characteristics,with the help of characterization of discovered CBM accumulation conditions in Member K;d;of Well HM2,studies on accumulation patterns in Huhehu Sag are conducted.The results show that Member K;d;coal seam in Huhehu Sag is the most developed,with maximum cumulative thickness more than 100 m and widely distributed in the whole area.Sedimentary environments,structural characteristics and hydrogeology are main accumulation conditions for K_(1)d_(2) coalbed methane.There are 2 types of coalbed methane accumulation patterns in Member K_(1)d_(2),including enrichment in local high and marginal slope zone of sag.Predicted favorable areas of Type I and Type II coalbed methane accumulations in Member K_(1)d_(2);are 251.97 km^(2)and 199.06 km^(2)respectively.The research provides theoretical evidences presented for guiding coalbed methane exploration in Member K_(1)d_(2) of Huhehu Sag and have great significance for large-scale discovery of CBM resource in Hailar Basin.

关 键 词：呼和湖凹陷大二段 低煤阶煤层气 成藏条件 有利区预测 

分 类 号：TE122.1[石油与天然气工程—油气勘探]