黄骅坳陷上古生界煤岩气成藏条件与勘探方向  

Accumulation conditions and exploration orientation of coal measure gas in the Upper Paleozoic in Huanghua Depression

作　　者：蒲秀刚[1] 董雄英[1] 柴公权[1] 李宏军[1] 李昊东 吕德胜[1] 于超[1] 勐睿 邵阳[1] 何川[1] Pu Xiugang;Dong Xiongying;Chai Gongquan;Li Hongjun;Li Haodong;Lv Desheng;Yu Chao;Meng Rui;Shao Yang;He Chuan(PetroChina Dagang Oilfield Company)

机构地区：[1]中国石油大港油田公司

出　　处：《中国石油勘探》2024年第4期60-70,共11页China Petroleum Exploration

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“风险勘探领域和目标研究、工程技术攻关及现场试验”(2023YQX101)。

摘　　要：黄骅坳陷上古生界太原组—山西组煤层分布广、厚度大、埋藏深,具备煤岩气勘探条件,但勘探亟待明确主力煤层分布、顶板封挡性、煤层含气性与资源规模等地质问题。文章基于坳陷内40余口煤层钻遇井钻井、测井、录井及地球化学资料,进行了煤层分布、太原组煤岩气形成条件、含气性及资源量等前期评价。研究认为:黄骅坳陷太原组—山西组煤层发育孔店—关家堡、泊头—盐山地区南北两个聚煤区,主体埋深为1500~4500m,“煤薄层多”,单层厚度为0.5~6.2m,大多为1~3m,累计厚度可达32.7m;受深埋和火山活动的热作用,太原组煤岩镜质组反射率R_(o)普遍大于0.85%,处于中等热演化阶段;研究区内煤岩与顶板岩层具有煤—泥、煤—灰、煤—砂3种储盖组合类型,其中广泛发育的煤—泥储盖类型,封挡条件较好;利用测井参数多元回归分析等方法,预测太原组Ⅳ、Ⅴ、Ⅵ组煤层含气量分布,初步计算太原组煤岩气资源量超1.1×10^(12)m^(3)。优选乌马营地区王官屯斜坡为突破方向,探索煤岩气“常非储层共生、吸附气和游离气共存”成藏模式。In Huanghua Depression,coal seams in Shanxi-Taiyuan formations have wide distribution area,great thickness,and large burial depth,showing good conditions for coal measure gas exploration.However,some geological parameters should urgently be clarified such as the main coal seam distribution,sealing capacity of cap rocks,gas bearing property,and resource amount.Based on drilling,wireline logging,mud logging and geochemical data from wells encountering coal seams in the depression,the preliminary assessment has been conducted on coal seam distribution,coal measure gas accumulation conditions,gas content,and resource amount in Taiyuan Formation.The study results indicate that two main coal accumulation areas of Shanxi-Taiyuan coal seams were developed in Kongdian-Guanjiabao and Botou-Yanshan areas in the southern and northern parts,with the main burial depth range of 1500-4500 m,multi set thin coal seams,single coal seam thickness of 0.5-6.2 m and mostly of 1-3 m,and cumulative thicknesses reaching up to 32.7 m;Due to deeply burying and volcanic heating,the vitrinite reflectance(Ro)of Taiyuan Formation coal measure rocks are generally greater than 0.85%,indicating a moderate thermal evolution stage;In the study area,there are three types of lithologic combinations between coal seam and cap rock,i.e.,coal-mudstone,coal-limestone,and coal-sandstone,among which the extensively developed coal-mudstone combination provides favorable sealing conditions;By using methods such as multivariate regression analysis of well logging parameters,gas content ofⅣ,Ⅴ,andⅥcoal groups in Taiyuan Formation has been predicted,and the preliminarily estimated coal measure gas resources of 1.1×10^(12) m^(3).In addition,Wangguantun slope in Wumaying area has optimally been selected as a favorable orientation to study the coal measure gas accumulation pattern of“coexistence of conventional and unconventional reservoirs,and cooccurrence of adsorbed and free gas”.

关 键 词：黄骅坳陷 太原组 煤岩气 勘探方向 

分 类 号：TE122.1[石油与天然气工程—油气勘探]