鄂尔多斯盆地天环坳陷北段低生烃强度区致密气成藏富集规律及勘探目标  

Accumulation regularity and target of tight sandstone gas in low hydrocarbon generation intensity area of northern Tianhuan Depression,Ordos Basin

作　　者：赵会涛[1,2] 刘晓鹏[1,2] 贾丽[1,2] 虎建玲[1,2] 卢子兴 周国晓 ZHAO Huitao;LIU Xiaopeng;JIA Li;HU Jianling;LU Zixing;ZHOU Guoxiao(Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi'an 710018,China;National Engineering Laboratory for Low Permeability petroleum Exploration and Development,Xi'an 710018,China)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018

出　　处：《天然气地球科学》2021年第8期1190-1200,共11页Natural Gas Geoscience

基　　金：国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05047-001)资助。

摘　　要：鄂尔多斯盆地天环坳陷北段上古生界煤系烃源岩生烃强度为(10~20)×10^(8)m^(3)/km^(2),下石盒子组8段(盒8段)储层平均孔隙度为8.3%,平均渗透率为0.94×10^(-3)μm^(2),裂缝相对较发育;试气出水普遍,同时多口井获高产工业气流,气水关系复杂;天然气富集规律不明,勘探目标优选困难。针对上述问题,通过对构造、烃源岩、储层等成藏地质条件及成藏主控因素的系统分析,明确了天环坳陷北段属低生烃强度区,气藏类型为构造—岩性复合气藏,改造期浮力调整对天然气二次成藏富集起到了关键作用,相对优质储层区局部构造高部位是首选有利区带。经过对烃源岩生烃强度、地层局部构造的精细刻画和储层的综合评价,优选了有利区带,积极助推了天环坳陷北段上古生界天然气勘探取得突破。Hydrocarbon generation intensity of the Upper Paleozoic coal measure source rocks in the northern section of Tianhuan Depression,Ordos Basin,is(10-20)×10^(8) m^(3)/km^(2),average porosity of reservoir is 8.3%,average permeability is 0.94×10-3μm2,and the fractures are relatively developed.The gas test effluent is common,and many wells have obtained high-yield industrial air flow.The gas-water relationship is complex,the gas enrichment rule is unclear,and it is difficult to optimize the exploration target.Through the systematic analysis of the geological conditions and main controlling factors of the formation of the study area,it is clear that the north section of Tianhuan Depression is a low hydrocarbon generating intensity area,and the gas reservoir type is a structural-lithologic complex gas reservoir.The buoyancy adjustment during the transformation period plays a key role in the accumulation of natural gas accumulation.The favorable zone is the preferred area relative to the high structural part of the high quality reservoir area.Through the fine description of hydrocarbon generation intensity,local structure of the formation and comprehensive evaluation of reservoir,favorable zone is selected and the breakthrough in the exploration of Upper Paleozoic gas in the northern section of Tianhuan Depression is actively promoted.

关 键 词：低生烃强度区 致密气富集规律 勘探思路 有利区带 天环坳陷 

分 类 号：TE122[石油与天然气工程—油气勘探]