大庆油田致密油水平井强抑制防塌水基钻井液技术

针对大庆油田齐家区块致密油水平井钻井过程中存在的井塌、卡钻等问题,在聚磺水基钻井液体系基础上研制出强抑制防塌水基钻井液。室内研究表明,聚合醇和有机硅酸脂的协同抑制作用,可有效降低泥岩、泥页岩水敏性,采用铝基聚合物封堵地层微裂缝,可提高井壁稳定能力。该体系在齐家区块应用5口井,均未出现井壁坍塌和卡钻等事故,平均机械钻速14.5m/h,平均井径扩大率5%,水平段钻进摩阻30~60 k N,有效解决了大庆油田齐家区块致密油藏长水平段水平井钻井中存在的问题,为致密油储层的高效钻进提供了借鉴。

High inhibition and anti-sloughing water-based drilling lfuid technology for horizontal wells in tight oil reservoirs in Daqing Oilifeld

In view of the problems like wellbore collapse or sticking. during drilling of horizontal wells in tight oil reservoirs in Qijia Block of Daqing Oilfield, a high inhibition and anti-sloughing water-based drilling fluid was developed based on polysulfonate water-based drilling fluid system. Lab research shows that co-suppression of polyalcohol and organic silicat can effectively reduce the water sensitivity of mudstone and mud shale. Using polyaluminum plugging agent to seal the micro-fissures in the formation can also improve the wellbore stability capacity. This system was used in five wells in Qijia Block, and no accidents like wellbore collapse and lost circulation occurred. The average ROP was 14.5 m/h, the average hole size enlargement was 5% and the friction drag during drilling of horizontal section was 30kN to 60 kN. So this technology effectively addressed the problems in the drilling of horizontal well with long horizontal interval in tight oil reservoirs of Qijia Block of Daqing Oilfield, and provided reference for effective drilling in tight oil reservoirs.