EVOLUTION类油基钻井液在美15x井的试验应用

Test Application of EVOLUTION Oil-based Drilling Fluids in Well Mei15x

针对福山油田流二段泥岩具有水敏性、硬脆易裂的特性,在美15x井试验应用EVOLUTION类油基钻井液。该钻井液体系具有抑制性强、润滑性和触变性好、储层保护效果佳、环保效果卓越等优点。美15x井三开采用类油基体系钻涠洲组、流沙港组一、二、三段,通过调整K+含量增强钻井液抑制性和稳定井壁的能力。实钻表明:流二段泥岩主要以物理应力垮塌为主,若钻进流二段地层之前,合理提高钻井液密度,有利于抑制垮塌,提高储层保护效果;同时类油基钻井液良好的润滑性和触变性,能够有效地降低压耗和激动压力,提高水马力利用率,增强破岩效率,提高机械钻速。

The mudstone of the second member of Liushagang formation in Fushan oilfield is of water sensitivity and is hard and brittle,and therefore the oil-based drilling fluid was used in the well Mei15 x. The drilling fluid system has many advantages, such as strong inhibition, good lubricity and thixotropy, good reservoir protection effect and excellent environmental protection effect. This type of oilbased drilling fluid was applied to the drilling of Weizhou Formation, the 1 st, 2 nd and 3 rd members of Liushagang Formation of Mei15 x,and the the inhibition and wellbore stability of the drilling fluid were strengthened by adjudging the content of K＋. The application result shows that, the mudstone of Liu 2 nd member is mainly dominated by physical stress collapse, and before drilling it, reasonably improving drilling fluid density is beneficial to restrain the wellbore collapse and improve reservoir protection effect. The good lubricity and thixotropy of the oil-based drilling fluid can effectively reduce pressure loss and exciting pressure, improve the utilization ratio of hydraulic power, enhance rock breaking efficiency and improve ROP.