安岳地区上三叠统须二上亚段致密砂岩气藏气井产能控制因素  

Controlling factors of gas well deliverability in the tight sand gas reservoirs of the upper submember of the second member of the upper Triassic Xujiahe Formation in the Anyue area,Sichuan Basin

作　　者：黄小琼[1] 张连进[1] 郑伟[1] 向小辉[2] 王刚[1] 

机构地区：[1]中国石油西南油气田公司勘探开发研究院 [2]中国石油西南油气田公司重庆气矿

出　　处：《天然气工业》2012年第3期65-69,129,共5页Natural Gas Industry

基　　金：国家科技重大专项课题"大型油气田及煤层气开发"(编号:2008ZX05001-005)部分研究成果

摘　　要：四川盆地安岳地区上三叠统须二上亚段气藏是近年来四川盆地发现的储量规模最大的上三叠统须家河组气藏,但试采过程中暴露出气井测试产量与投产后产量差异大的问题。为此,系统分析了单井产能与储层地质特征、加砂压裂工艺、产液量等的关系,认为气井产能控制的主要因素为:属于水下分支河道和河口坝微相、并在雷口坡组古残丘或高带古地貌上沉积形成的粗结构砂体是有利储层分布区;单井裂缝发育或处于裂缝发育区带是气井高产的关键因素,所统计的80%微气井都处于裂缝不发育区;高产井所在的储层在压裂时具有最低泵压低、日排液量大的特点,排液量百分比多在75%以上;气水关系复杂,产水量大小不受构造控制,不产水气井的产气量和地层压力均较稳定,但含水井提高天然气产量会导致水侵加剧、产气量和地层压力均快速下降。The gas reservoir of the upper submember of the second member of the upper Triassic Xujiahe Formation in the Anyue area was recently discovered with the largest reserves in the Sichuan Basin.However,from the trial test and recovery of gas wells after being put into production,a big difference was shown between the tested and the actual well productivity.In view of this,the relationships between single-well productivity and the factors such as geological characteristic,sand fracturing,and liquid producing capacity are analyzed systematically.In conclusion,dominant factors influencing the single-well productivity are as follows.First,the depositional microfacies in underwater branch channels and river mouth bars,as well as the coarse sand bodies are favorable plays formed from paleo-hammock or palaeo-geomorphology in the Leikoupo Formation.Second,high single-well productivity is due to numerous fractures or being at the fracture-developed zones,as shown by the fact that 80percent of the ultra-low deliverability wells are located in the region where fractures are not well developed.Third,during the fracturing treatment of high-productivity wells,the minimum pumping pressure needed is much lower than low or ultra-low productivity wells,and with a high daily flowing back rate of more than 75%.Forth,the relationship between gas and water is complex and the volume of water produced is not controlled by the structure.As for the well which does not produce water,its productivity and downhole pressure are consistent;while as for a water-cut gas well,the increase of its productivity will result in severe water invasion and sharp decline of its productivity and downhole pressure.

关 键 词：四川盆地 安岳气田 晚三叠世 致密砂岩 开发 生产能力 压裂(岩石) 控制因素 气水关系 

分 类 号：P618.13[天文地球—矿床学]