泥页岩强抑制剂支化聚醚胺PEA-1的特性及在卫456井的应用

Application of branched polyether amine PEA-1 for drilling fluid in well Wei 456

针对中原区块膏泥岩地层井壁失稳问题,自主研发泥页岩强抑制剂支化聚醚胺PEA-1产品,对PEA-1产品的配伍性能、抑制性能、抗温性能及生物毒性进行了评价,结果表明:PEA-1产品与饱和盐水钻井液配伍性好,相对抑制率大于98%,EC_(50)值为521400 mg/L,远大于排放标准30000mg/L。PEA-1产品在卫456井进行了现场应用,结果表明:PEA-1产品加入现场饱和盐水钻井液后,显著提高了钻井液的抑制防塌性能,有效解决了泥岩、膏泥岩的井壁失稳难题,可实现现场绿色、安全、高效钻进,为该产品在强水敏性泥岩、泥页岩、膏泥岩等易坍塌地层的现场应用提供了较好的技术指导。

Aiming at the wellbore instability problem of gypsum shale formation in Zhongyuan block,we independendy developed a strong shale inhibitor branched polyether amine PEA-1 product.In order to determine the characteristics of PEA-1 product,the compatibility,inhibition,temperature resistance and biological toxicity of PEA-1 product were evaluated.The results showed that PEA-1 product had good compatibility with saturated brine drilling fluid,the relative inhibition rate was more than 98%,and the EC_(50) value was 521 400 mg/L,which was far greater than the emission standard of 30 000 mg/L. PEA-1 product had been applied in well Wei456. The test results showed that PEA-1 product could significandy improve the inhibition and anti sloughing ability of drilling fluid by adding saturated brine drilling fluid,and effectively solve the wellbore instability problem of mudstone and gypsum mudstone.PEA-1 can be used to achieve green,safe and efficient drilling,which provides a good technical guidance for the field application of PEA-1 in collapsible formations such as strong water sensitive mudstone,shale and gypsum mudstone and other collapsible formations.