摘要
疏松地层松散,岩心难以成形,取心难度大。为进一步提高疏松地层取心收获率,针对疏松砂岩地层孔隙度较高、岩性脆等特点,采用滤失量低的取心钻井液,低钻压、低转速和小排量的取心参数,及切削型取心钻头和全封闭岩心爪,形成了老油区疏松地层取心关键技术。该技术在现场应用14口井,取心进尺311.36m,平均岩心收获率达到85.40%。应用结果表明,该技术有利于保护岩心、提高岩心收获率,能够满足浅层疏松砂岩地层取心的需要。
Core is difficult to take in unconsolidated formation,which features high porosity and brittleness.In order to improve the core recovery in this kind of formations,many measures had been taken,as the analysis of the characteristics of the unconsolidated formation,the low water loss of coring drilling fluid,lower WOB,low rotary speed and flow rate,aggressive core head and full closure core catcher,which formed a key technology for coring in unconsolidated formation in old oilfield.Field tests were conducted in 14 wells with coring footage of 311.36 m and average core recovery of 85.40%.The test proved that it is a safe and reliable technique for core protection and improvement of core recovery,and it can meet the need of coring in shallow unconsolidated sand formation.
出处
《石油钻探技术》
CAS
北大核心
2012年第5期26-29,共4页
Petroleum Drilling Techniques
关键词
疏松地层
取心
岩心收获率
取心钻头
岩心爪
unconsolidated formation
coring
core recovery
coring bit
core catcher
