水包油钻井液在BZ28-1油田潜山地层的研究和应用

Researches on Oil—in—water Drilling Fluid and the Application Thereof in Buried Hill Formations in Block BZ28-1.

N8和S3井是为开发BZ28-1油田剩余储量而钻的2口调整井。因为该油田油藏压力系数已降至1左右,而且已完钻的开发井在钻遇潜山地层时均出现了严重漏失,决定用低密度水包油钻井液配合压力控制钻井技术钻N8和S3井φ152.4 mm井段的潜山储层。对水包油钻井液配方进行了优选并评价了钻井液性能。研究与现场应用结果表明,水包油钻井液总体性能稳定,其良好的流变性、抑制性、降滤失性和携砂性满足了潜山地层近平衡条件下的压力控制钻井要求,储层保护效果好,2口井不仅顺利钻穿漏失严重的潜山储层,且都获得了较高的油气产量。该技术为今后渤海油田潜山地层的勘探开发提供了一条新的模式。

Well N8 and Well S3 are two wells drilled in Block BZ28-1 for producing the remaining reserves,Low density oil-in-water drilling fluid,combined with pressure control technology,was selected to drill the buried hill formations in wells N8 and S3(both in 152.4mm sections)because of the low pressure gradients(less than 1.0) and mud losses.Laboratory studies were done on the selection of the oil-in-water drilling fluids.Filed application showed that the mud had good rheology,inhibition,filtration control and cutting-carrying capacity,the buried hill formations in the two wells,in which mud losses had been very severe,were successfully drilled,and high oil and gas production was obtained.