摘要
采用常规压裂技术对鄂尔多斯盆地东部气藏进行施工时存在试气产量低、稳产能力差和开发难度较大的问题。鉴于此,对盆地东部开发现状及储层改造技术难点进行分析,通过体积压裂增大改造体积,低黏液减轻水锁伤害、改善压后返排,纤维辅助携砂、改善裂缝铺砂剖面等技术攻关,形成了低黏液+纤维携砂压裂工艺技术。研究结果表明:高效降阻剂降阻率达到75%以上,施工排量由4.0 m^(3)/min提高到6.0 m^(3)/min,满足体积压裂施工需求;小分子防水锁剂水锁解除率大于60%、表面张力小于0.018 N/m、接触角大于60°;在低黏压裂液中加入质量分数0.20%的可降解纤维,支撑剂沉降速率降低47.85%;试验井平均试气产量2.64×10^(4)m^(3)/d,工业气流井比例达到63%;一次排通率62.5%,平均有效排液时间33.8 h,排液效率大幅提高,大大缩短了压裂液在地层中的滞留时间,进一步降低了对储层的伤害。研究结果可为鄂尔多斯盆地东部气藏开发技术的研究提供一定的借鉴。
When conventional fracturing technology is used to conduct fracturing in the gas reservoirs of eastern Ordos Basin,some problems such as low gas flow rate,poor rate maintenance capability and difficult development often occur.In view of this,this paper analyzes the current development status and reservoir stimulation technology difficulties of gas reservoirs in the east of the basin,studies the technologies such as using volume fracturing to increase the stimulated volume,using low viscosity fluid to alleviate water lock damage and improve postfracturing flowback and using fiber to assist in carrying proppant and improving fracture proppant-laying profile,and finally formed the low viscosity fluid+fiber carrying proppant fracturing technology.The research results show that the friction reducing rate of efficient friction reducer exceeds 75%,and the pumping rate is increased from 4.0 m^(3)/min to 6.0 m^(3)/min,which meets the requirements of volume fracturing;the water lock release rate of small molecule anti-water-lock agent is greater than 60%,the surface tension is less than 0.018 N/m,and the contact angle is greater than 60°;when 0.20%degradable fiber is added in the low viscosity fracturing fluid,the settlement rate of proppant is reduced by 47.85%;the average well test gas flow rate of test wells is 2.64×10^(4)m^(3)/d,and the proportion of industrial gas flow wells achieves 63%;the once clear-up rate is 62.5%,the average effective clean-up time is 33.8 h,the discharge efficiency is greatly improved,the residence time of fracturing fluid in the formation is greatly shortened,and the damage to the reservoir is further reduced.The research results provide some references for the study of development techniques of gas reservoirs in eastern Ordos Basin.
作者
胡光明
姬随波
高宇
Hu Guangming;Ji Suibo;Gao Yu(Changqing Downhole Technology Operating Company,CNPC Chuanqing Drilling Engineering Company Limited;National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Field)
出处
《石油机械》
北大核心
2021年第10期78-84,共7页
China Petroleum Machinery
基金
国家科技重大专项“大型油气田及煤层气开发”(2017ZX05023)。
关键词
浅层砂岩气
低黏液
可降解纤维
携砂
防水锁剂
压裂
shallow sandstone gas
low viscosity fluid
degradable fiber
proppant carrying
anti-water-lock agent
fracturing
