埕岛油田埕北CB30A-1井钻井液技术

Drilling Fluid Technology Used in CB30A-1 Well of Chengdao Oilfield

CB30A - 1井是胜利油田胜利五号钻井平台在 2 0 0 0年埕岛海域CB30井组基础上所钻探的一口定向井。完钻井深 430 3.88m ,钻探目的为开发CB30区域古生界、太古界潜山油藏。针对所钻地层上部造浆性强、井壁坍塌严重 ,下部易发生井喷、井漏的特点 ,介绍了该井不同井段钻井液的配方 :上部地层选用聚合物钻井液体系 ,下部地层选用无固相聚合醇钻井液体系 ,利用欠平衡钻井技术钻至42 2 0 .44m ,发生井漏 ,漏失速度为 48m3/h ,随后采用无封堵、保护储层钻井液顺利完钻。现场应用结果表明 :聚合物钻井液体系抑制能力强、携岩和井眼稳定等性能满足现场施工要求 ;无固相聚合醇钻井液体系具有较好抗高温、润滑、防塌性能 ,且性能稳定 ,在保护油气层等方面具有独特作用。同时 ,无封堵、保护储层钻井液为开发该区同类地层积累了丰富经验。

CB30A-1 well is a direction well based on the area of CB30, with bottom depth at 4303.88m. It aims at exploring buried hill reservoir. Different drilling fluid system were selected in relation to different formation characteristic. In the upper formation, polymer drilling fluid is used, and the lower, no-solids polyalcohol drilling fluid is used. Lost circulation was encountered when reached at 4220.44m, losing rate is 48m 3/h. Subsequence, no-plugging and protecting reservation drilling technology was applied to achieve the fourth drilling. Results reveal polymer drilling fluid has strong shale inhibition, cutting transportation, hole stabilization abilities. No-solids polyalcohol drilling fluid has better high-temperature resistance and lubricity, sloughing prevention and formation damage prevention.