安塞富县组防塌泥浆研究及现场试验

安塞油田富县组泥页岩地层不稳定,塌层井径扩大,长期给钻井工作带来很大困难.为了解决这个问题,通过对富县组泥页岩成份和理化指标的分析,证实该地层不稳定是组成泥页岩的伊利石缺K~+的水敏性所致.针对这一特性,对无机盐和聚合物抑制剂进行防塌能力的试验研究,优选出适合该地层的KCl-聚合物不分散低固相泥浆的组成和配方.经现场试验,较好地解决了富县组地层不稳定问题.

Studies and Field Experiments of Anti-Cave Mud Used in Fuxian Group, Ancai Oil Field

The shale formation of Fuxian group, Ancai oil Field is unstable, The borehole diameter expands in caved in section, which brings great difficulty to drilling job. To solve this problem. this paper analyses the components and physical—chemical index and has proved that the water sensitive feature of illite (for lackof K~+) which forms shale results in the unstable feature of the formation. In view of this, studies and experiments have been made on the anti—cave in ability of morgantic salts and polymer inhibitor. KCl —polymer suitable for such formation were optimized. Such polymer does not disperse the components and formula of low solids mud. Field experiments prove that the unstable problem of Fuxian group has been fairly well solved.