摘要
针对大位移井和水平井储层段存在携带钻屑及起下钻困难等问题,研制了一种井眼清洁能力强的环保型PRD钻开液。该钻开液主要处理剂是极易生物降解的天然高分子聚合物。PRD钻开液的BOD5/CODCr为0.42;溶解氧(DO)衰减法评价结果表明,PF-VIS及PF-FLO两种天然高分子聚合物易生物降解;PRD钻开液生物毒性检验结果符合一级海区生物毒性允许值要求;LSRV(低剪切速率黏度)高达60000mPa·s,携带及悬浮钻屑能力很强,不会形成岩屑床,岩心渗透率恢复值在90%以上,对储层伤害很小。该钻开液用在我国渤海、东海、南海西部、南海东部及新疆等油田,油气产量有较大提高。
A kind of environmental-friendly water base drilling fluid, PRD drilling-in fluid, was developed to deal with tripping difficulty and carrying cuttings in extended reach wells and horizontal wells. PRD drilling-in fluid composes of several highly biodegradable natural high polymer additives. The BOD5/CODc, ratio of PRD system is 0.42. The dissolved oxygen decay evaluation showed that the two natural polymers, PF-VIS and PF-FLO were readily biodegradable, and PRD drilling-in fluid＇s biological toxicity test met the biological toxicity limit requirement for the first level seas. Low shear rate viscosity （LSRV） was up to 60 000 mPa -s so that the system could carry and suspend cuttings with no cuttings bed and the core return permeability was more than 90%, which caused tiny damage to reservoir. The PRD drilling-in fluid was successfully applied in Bohai Bay, East Sea, South Sea and Xinjiang Oilfield, with greater oil and gas production than other drilling fluids systems.
出处
《环境工程技术学报》
CAS
2012年第4期358-362,共5页
Journal of Environmental Engineering Technology
关键词
PRD钻开液
生物降解
生物毒性
渗透率恢复值
PRD drilling-in fluid
biodegradable
biological toxicity
return permeability
